• TABLE OF CONTENTS
HIDE
 Title Page
 Table of Contents
 Acknowledgement
 Introduction
 Systematics
 Biogeography
 Natural history
 The sponge fishery of Florida
 Sponge culture potential
 Conclusions and recommendation...
 Bibliography






Group Title: Technical paper - Florida Sea Grant Program ;, no. 8
Title: The biology and utilization of Florida's commercial sponges
CITATION PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00072259/00001
 Material Information
Title: The biology and utilization of Florida's commercial sponges
Series Title: Technical paper - Florida Sea Grant College Program no. 8
Physical Description: 45 p. : ill. ; 28 cm.
Language: English
Creator: Stevely, John
Thompson, Jerome C. ( joint author )
Warner, Richard E ( joint author )
Publisher: State University System of Florida Sea Grant College Program
Place of Publication: Gainesville
Publication Date: 1978
 Subjects
Subject: Sponges -- Florida   ( lcsh )
Sponges -- Classification   ( lcsh )
Sponge fisheries -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 40-45.
Statement of Responsibility: by John M. Stevely, Jerome C. Thompson and Richard E. Warner.
General Note: "October 1978."
Funding: Technical paper (Florida Sea Grant College) ;
 Record Information
Bibliographic ID: UF00072259
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: aleph - 000990238
oclc - 04741041
notis - AEW7150

Table of Contents
    Title Page
        Title Page 1
        Title Page 2
    Table of Contents
        Table of Contents
    Acknowledgement
        Acknowledgement
    Introduction
        Page 1
    Systematics
        Page 1
        Classification of sponges
            Page 2
        Sheepswool or wool sponge
            Page 3
        Yellow sponge
            Page 3
        Keys grass and gulf grass sponge
            Page 3
            Page 4
    Biogeography
        Page 5
    Natural history
        Page 6
        Structure
            Page 6
        Physiology
            Page 7
            Page 8
        Reproduction
            Page 9
            Page 10
            Page 11
            Page 12
        Growth of commercial sponges
            Page 13
            Page 14
        Environmental factors affecting sponges
            Page 15
            Page 16
    The sponge fishery of Florida
        Page 17
        Methodology involved in sponge industry
            Page 17
            Page 18
            Page 19
            Page 20
        History and pattern of exploitation
            Page 21
            Page 22
        Present status of the sponge fishery in Florida
            Page 23
            Page 24
            Page 25
            Page 26
            Page 27
            Page 28
        Present market outlook
            Page 29
            Page 30
    Sponge culture potential
        Page 31
        History of sponge culture
            Page 31
            Page 32
            Page 33
            Page 34
        Present day practicality of sponge culture
            Page 35
        A sponge farm model
            Page 36
            Page 37
    Conclusions and recommendations
        Page 38
        Page 39
    Bibliography
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
Full Text


f'
1i
-Iz 2-


THE BIOLOGY AND UTILIZATION OF FLORIDA'S
COMMERCIAL SPONGES

by
John M. Stevely
Jerome C. Thompson
and Richard E. Warner


TECHNICAL PAPER NO. 8
October 1978


Florida Sea Grant


















THE BIOLOGY AND UTILIZATION OF FLORIDA'S
COMMERCIAL SPONGES

by

John M. Stevely
Jerome C. Thompson
and Richard E. Warner

TECHNICAL PAPER NO. 8
October 1978








The information contained in this paper was
developed under the auspices of the Monroe County
Marine Resource Inventory, and funded by the
Comprehensive Employment Training Act. This
document is a Technical Paper of the State
University System of Florida Sea Grant College
Program, 2001 McCarty Hall, University of Florida,
Gainesville, FL 32611. Technical Papers are
duplicated in limited quantities for specialized
audiences requiring rapid access to information,
which may be unedited.


Policy conclusions or recommendations herein
are not necessarily those of the Florida Sea Grant
College or the State University System of Florida.












TABLE OF CONTENTS


Page

1. INTRODUCTION............................................... 1

2. SYSTEMATICS ..................... .......................... 1

2.1. Classification of Sponges............................ 2
2.2. Sheepswool or Wool Sponge............................. 3
2.3. Yellow Sponge........................................ 3
2.4. Keys Grass and Gulf Grass Sponge...................... 3

3. BIOGEOGRAPHY.............................................. 3

4. NATURAL HISTORY.......................................... 6

4.1. Structure............................................ 6
4.2. Physiology........................................... 7
4.3. Reproduction......................................... 9
4.4. Growth of Commercial Sponges......................... 13
4.5. Environmental Factors Affecting Sponges............... 15

5. THE SPONGE FISHERY OF FLORIDA............................. 17

5.1. Methodology Involved in Sponge Industry.............. 17T
5.2. History and Pattern of Exploitation.................. 211
5.3. Present Status of the Sponge Fishery in Florida...... 23
5.4. Present Market Outlook............................... 29,

6. SPONGE CULTURE POTENTIAL.................................. 31,

6.1. History of Sponge Culture............................ 31!
6.2. Present Day Practicality of Sponge Culture........... 35
6.3. A Sponge Farm Model .................................. 36

7. CONCLUSIONS AND RECOMMENDATIONS ........................... 38'

8. BIBLIOGRAPHY .............................................. 40O

8.1. Literature Cited.................................... 40
8.2. Additional References................................ 42














ACKNOWLEDGEMENTS



Many people have made invaluable contributions towards the comple-
tion of the present paper. Collection of important information would
not have been possible without the assistance of: Mr. Elmer Allen, Mr.
Julio Arellano, Mr. Peter Bartholi, Ms. Julia Josiek, Ms. Robbin Kuhlik,
Ms. Shirley Pomponi, Ms. Deborah Shaw, Dr. F. G. Walton Smith, Simon and
Mimi Stafford, and Mr. Tom Weyant.

Of equal importance was the assistance of our scientific colleagues
in the critical review of the manuscript and in providing valuable consul-
tation in its preparation. A heartfelt note of thanks is extended to:
Ms. Terrie Bert, Dr. James Cato, Mr. Chris Combs, Mr. Douglas Gregory,
Mr. Thomas Murray, Ms. Leigh Taylor, Dr. Harold Humm, Dr. F. G. Walton
Smith, and Mr. Jim Tilmant for their constructive criticism of the man-
uscript.

Ms. Nancy Brewer, Ms. Charlotte Howard, and Mrs. Mary Sasnett, were
responsible for preparing the manuscript, for which sincere thanks are
tendered. Many thanks are due to Mr. H. Samuel Gamble III, who assisted
in the preparation of the figures.

Financial support for this undertaking was provided by the Monroe
County Board of Commissioners, which made available Comprehensive Em-
ployment Training Act Funds for the Marine Resource Inventory. Their
continuing sympathetic and interested support, and that of the Monroe
County Manpower Planning Subcouncil, is gratefully acknowledged. A
heartfelt thanks is extended to the Florida Cooperative Extension Ser-
vice Marine Advisory Program for direction and guidance in completion
of this project.







1. INTRODUCTION


Since the time of the Ancient Greeks man has recognized the use-
fulness of the natural sponge. Because of their ability to absorb large
amounts of water, compressable nature, and durability, sponges have been
used for a wide variety of tasks ranging from washing dishes to packing
instrument panels in rockets. Up until the 1940's the sponge fishery
was one of the most valuable fisheries in Florida; However, a combination
of disease, heavy harvesting pressure, and the introduction of synthetic
sponges has resulted in reduction of the industry to a small fraction
of its former importance. Production in the Tarpon Springs area, the tra-
ditional center for sponging in Florida, has declined to extremely low
levels of harvesting activity. Dade County has emerged as the center of
the existing sponge industry. Persistance of low level sponging activit-
ies in Florida for the last 30 years indicates that the sponge industry,
as it is currently structured, will probably not return to former prod-
uction levels without specific kinds of help.

This paper reviews the sponge fishery from several points of view,
utilizing data from scientific literature, state and federal fishery stat-
istics, commercial fishermen, and sponge processors. It is written for
several audiences, including the commercial fishing industry, marine re-
searchers, management agencies, conservation interests, interested students,
and laymen.

The purpose has been to: 1) describe the extent of available biolog-
ical information; 2) define the present status of the resource; and 3)
identify future potentials. It is hoped that this information can be used
in providing for optimun utilization of this resource.


2. SYSTEMATICS


Sponges (phylum Porifera) are members of an ancient group of animals
whose origin dates back hundreds of millions of years ago to the first
appearance of multicellular animals in the fossil record. Sponges are
considered to be primitive in relation to other animal groups because of
their simple structure and the fact that apparently no other group of ani-
mals has evolved from them. The low level of cellular specialization
(sponges lack distinct organs and tissues) and interdependence (sponges
closely resemble colonies of independent single cell organisms) are primi-
tive characteristics. A body structure based upon a water canal system
and lacking distinct anterior and posterior ends is found in no group of
animals other than sponges. All these features would suggest that sponges
are remotely related to other animals. Due to these characteristics, an-
cient naturalists thought they were plants, and it was not until 1765, when
internal water currents were observed, that the animal nature of sponges
became clearly established.

The phylum Porifera is divided into three classes based primarily on
the composition and structure of the animals' skeletal framework. The
skeleton may be composed of calcareous spicules, siliceous spicules,







1. INTRODUCTION


Since the time of the Ancient Greeks man has recognized the use-
fulness of the natural sponge. Because of their ability to absorb large
amounts of water, compressable nature, and durability, sponges have been
used for a wide variety of tasks ranging from washing dishes to packing
instrument panels in rockets. Up until the 1940's the sponge fishery
was one of the most valuable fisheries in Florida; However, a combination
of disease, heavy harvesting pressure, and the introduction of synthetic
sponges has resulted in reduction of the industry to a small fraction
of its former importance. Production in the Tarpon Springs area, the tra-
ditional center for sponging in Florida, has declined to extremely low
levels of harvesting activity. Dade County has emerged as the center of
the existing sponge industry. Persistance of low level sponging activit-
ies in Florida for the last 30 years indicates that the sponge industry,
as it is currently structured, will probably not return to former prod-
uction levels without specific kinds of help.

This paper reviews the sponge fishery from several points of view,
utilizing data from scientific literature, state and federal fishery stat-
istics, commercial fishermen, and sponge processors. It is written for
several audiences, including the commercial fishing industry, marine re-
searchers, management agencies, conservation interests, interested students,
and laymen.

The purpose has been to: 1) describe the extent of available biolog-
ical information; 2) define the present status of the resource; and 3)
identify future potentials. It is hoped that this information can be used
in providing for optimun utilization of this resource.


2. SYSTEMATICS


Sponges (phylum Porifera) are members of an ancient group of animals
whose origin dates back hundreds of millions of years ago to the first
appearance of multicellular animals in the fossil record. Sponges are
considered to be primitive in relation to other animal groups because of
their simple structure and the fact that apparently no other group of ani-
mals has evolved from them. The low level of cellular specialization
(sponges lack distinct organs and tissues) and interdependence (sponges
closely resemble colonies of independent single cell organisms) are primi-
tive characteristics. A body structure based upon a water canal system
and lacking distinct anterior and posterior ends is found in no group of
animals other than sponges. All these features would suggest that sponges
are remotely related to other animals. Due to these characteristics, an-
cient naturalists thought they were plants, and it was not until 1765, when
internal water currents were observed, that the animal nature of sponges
became clearly established.

The phylum Porifera is divided into three classes based primarily on
the composition and structure of the animals' skeletal framework. The
skeleton may be composed of calcareous spicules, siliceous spicules,








protein spongin fiber, or a combination of the last two. These spicules
are minute bodies of calcium carbonate (shell-like) or silicon dioxide
(glass-like). The commercial sponges all come from one group, those having
their skeleton made of spongin fibers only. This substance (spongin) is
related by general chemical and physical properties to silk, horn, and
chitin, the foundation of the shells of insects and crabs. The arrange-
ment of spongin into a fibrous network is responsible for the commercial
sponges properties of compressibility, resiliency and ability to absorb
large quantities of water. However, the usable sponge form is attained
only after the living material embedded in the skeleton has been removed.
Other sponge groups are commercially unsuitable because of the inclusion
of lime or silica spicules. The following is a brief synopsis of the
taxonomic relationships of commercial sponges to other sponges in general.

2.1 Classification of Sponges (Storr, 1964).

Phylum Porifera (Pore-bearing)

Class Calcispongiae or Calcarea (chalk sponges): Members of this
class have spicules composed of calcium carbonate. They are of no eco-
nomic importance and are generally restricted to relatively shallow coast-
al waters.

Class Hyalospongiae or Hexactinellida (glass sponges): Members of
this class are distinguished by siliceous, six-pointed spicules. They
are generally found only at great depths (greater than 500 m; 1640 ft),
and are of little economic importance.

Class Demospongiae (horny sponges): This class contains all of
the commercially important species and in general contains the greatest
number of sponge species. These sponges exhibit a wide variety of skele-
ton types, ranging from no skeleton to siliceous spicules, spongin fibers,
or a combination of the latter two.

Order Keratose or Keratosida: This classification grouping con-
tains the commercially important species of Florida, and is distinctive
in that the skeleton is composed of spongin fibers only.

Genus Hippiospongia

Species Hippiospongia lachne (sheepswool sponge)

Genus Spongia

Species Spongia barbara (yellow sponge)
Spongia graminea (key grass sponge)
Spongia graminea tampa (gulf grass sponge)

At one time, there were as many as 8 or 9 species of sponges taken
commercially in Florida. Currently the sponges listed above are the
only ones of commercial importance. The finger sponge (Axinella poly-
capella), glove sponge (Spongia cheiris), and wire sponge (Spongia sterea)
were once of minor importance but are no longer collected, although some-
times glove sponges are sold for ornamental purposes. The reef sponge
(Spongia obliqua) and the velvet sponge (Hippiospongia gossypina)









were once of considerable importance, but none have been found since a
sponge disease in 1939 apparently destroyed them.

2.2. Sheepswool or Wool Sponge

The sheepswool sponge (Figure 1) is considered to be the highest
quality commercial sponge found in the western Atlantic. It is the
most valuable species, representing 75% of the dollar value of sponges
collected in Florida and 87.9% in Monroe County during 1976. When alive,
the sponge is black, the color changing to a light grey at the base.
Usually this spcnge displays a rounded, cake-shaped form with a diameter
to height ratio of 2:1 to 1:1. However, there is considerable variation
in quality and shape depending on environmental influences. The surface
of this sponge is usually covered with blunt points, and the sides of
the sponges have a number of small inhalent openings. There are larger
exhalent openings (oscules) on the top of the sponge varying from 1.25
cm 3.0 cm (0.5 1.25 in) in diameter. Commonly the oscules are sur-
mounted by thin-walled chimneys up to 5 cm (2 in) in height, with the
oscules normally larger in shallow water sponges;

2.3 Yellow Sponge

The yellow sponge (Figure 2) is extremely elastic and resilient
but is harder than the sheepswool, harsher to the touch, less absorbent,
less retentive of water, and less durable. Yellow sponges accounted
for 14.7% of the dollar value of sponges collected in Florida and 6.3%
in Monroe County in 1976. The price per pound paid to the fishermen
is usually less than half that of the sheepswool. When alive, the
sponge is black, dark brown, or creamy tan in color depending on the
area and depth from which it is taken. The smooth rounded shape is
much like that of the wool sponge. However, the oscules are never
surmounted by chimneys as is common in the sheepswool sponges. When
cleaned, the color is yellow or yellowish brown, the surface is devoid
of the long'fibrous filamenhs characteri:sti-1 of 'the sheepswool, and-is
covered with a nap of short bristles of uniform length.

2.4. Keys Grass Sponge and The Gulf Grass Sponge

Grass sponges collected off the west coast of Florida differ con-
siderably from those taken in the Keys. The best are the Anclote grass
sponges from the west coast of Florida which grow in vase-shape, except
under optimal conditions when the inside of the base is almost completely
filled in. Sponges of this latter form have a fine texture and good
market value. However, during 1976, only 18 lbs. were reported to have
been harvested.

The grass sponges of the Florida Keys (Figure 3), Bahamas Islands,
and Cuba vary in form and general appearance, and are entirely differ-
ent from those just described. They grow in a rounded, more compact
form with a flat or concave top that is perforated by a number of oscules
up to 0.65 cm (1/4 in) in diameter. When cleaned, the edges of the os-
cules are quite thin and feathery and, in most cases, form chimneys 2.5 cm
(1 in) or so in height. These sponges are soft and absorbent but have









were once of considerable importance, but none have been found since a
sponge disease in 1939 apparently destroyed them.

2.2. Sheepswool or Wool Sponge

The sheepswool sponge (Figure 1) is considered to be the highest
quality commercial sponge found in the western Atlantic. It is the
most valuable species, representing 75% of the dollar value of sponges
collected in Florida and 87.9% in Monroe County during 1976. When alive,
the sponge is black, the color changing to a light grey at the base.
Usually this spcnge displays a rounded, cake-shaped form with a diameter
to height ratio of 2:1 to 1:1. However, there is considerable variation
in quality and shape depending on environmental influences. The surface
of this sponge is usually covered with blunt points, and the sides of
the sponges have a number of small inhalent openings. There are larger
exhalent openings (oscules) on the top of the sponge varying from 1.25
cm 3.0 cm (0.5 1.25 in) in diameter. Commonly the oscules are sur-
mounted by thin-walled chimneys up to 5 cm (2 in) in height, with the
oscules normally larger in shallow water sponges;

2.3 Yellow Sponge

The yellow sponge (Figure 2) is extremely elastic and resilient
but is harder than the sheepswool, harsher to the touch, less absorbent,
less retentive of water, and less durable. Yellow sponges accounted
for 14.7% of the dollar value of sponges collected in Florida and 6.3%
in Monroe County in 1976. The price per pound paid to the fishermen
is usually less than half that of the sheepswool. When alive, the
sponge is black, dark brown, or creamy tan in color depending on the
area and depth from which it is taken. The smooth rounded shape is
much like that of the wool sponge. However, the oscules are never
surmounted by chimneys as is common in the sheepswool sponges. When
cleaned, the color is yellow or yellowish brown, the surface is devoid
of the long'fibrous filamenhs characteri:sti-1 of 'the sheepswool, and-is
covered with a nap of short bristles of uniform length.

2.4. Keys Grass Sponge and The Gulf Grass Sponge

Grass sponges collected off the west coast of Florida differ con-
siderably from those taken in the Keys. The best are the Anclote grass
sponges from the west coast of Florida which grow in vase-shape, except
under optimal conditions when the inside of the base is almost completely
filled in. Sponges of this latter form have a fine texture and good
market value. However, during 1976, only 18 lbs. were reported to have
been harvested.

The grass sponges of the Florida Keys (Figure 3), Bahamas Islands,
and Cuba vary in form and general appearance, and are entirely differ-
ent from those just described. They grow in a rounded, more compact
form with a flat or concave top that is perforated by a number of oscules
up to 0.65 cm (1/4 in) in diameter. When cleaned, the edges of the os-
cules are quite thin and feathery and, in most cases, form chimneys 2.5 cm
(1 in) or so in height. These sponges are soft and absorbent but have









were once of considerable importance, but none have been found since a
sponge disease in 1939 apparently destroyed them.

2.2. Sheepswool or Wool Sponge

The sheepswool sponge (Figure 1) is considered to be the highest
quality commercial sponge found in the western Atlantic. It is the
most valuable species, representing 75% of the dollar value of sponges
collected in Florida and 87.9% in Monroe County during 1976. When alive,
the sponge is black, the color changing to a light grey at the base.
Usually this spcnge displays a rounded, cake-shaped form with a diameter
to height ratio of 2:1 to 1:1. However, there is considerable variation
in quality and shape depending on environmental influences. The surface
of this sponge is usually covered with blunt points, and the sides of
the sponges have a number of small inhalent openings. There are larger
exhalent openings (oscules) on the top of the sponge varying from 1.25
cm 3.0 cm (0.5 1.25 in) in diameter. Commonly the oscules are sur-
mounted by thin-walled chimneys up to 5 cm (2 in) in height, with the
oscules normally larger in shallow water sponges;

2.3 Yellow Sponge

The yellow sponge (Figure 2) is extremely elastic and resilient
but is harder than the sheepswool, harsher to the touch, less absorbent,
less retentive of water, and less durable. Yellow sponges accounted
for 14.7% of the dollar value of sponges collected in Florida and 6.3%
in Monroe County in 1976. The price per pound paid to the fishermen
is usually less than half that of the sheepswool. When alive, the
sponge is black, dark brown, or creamy tan in color depending on the
area and depth from which it is taken. The smooth rounded shape is
much like that of the wool sponge. However, the oscules are never
surmounted by chimneys as is common in the sheepswool sponges. When
cleaned, the color is yellow or yellowish brown, the surface is devoid
of the long'fibrous filamenhs characteri:sti-1 of 'the sheepswool, and-is
covered with a nap of short bristles of uniform length.

2.4. Keys Grass Sponge and The Gulf Grass Sponge

Grass sponges collected off the west coast of Florida differ con-
siderably from those taken in the Keys. The best are the Anclote grass
sponges from the west coast of Florida which grow in vase-shape, except
under optimal conditions when the inside of the base is almost completely
filled in. Sponges of this latter form have a fine texture and good
market value. However, during 1976, only 18 lbs. were reported to have
been harvested.

The grass sponges of the Florida Keys (Figure 3), Bahamas Islands,
and Cuba vary in form and general appearance, and are entirely differ-
ent from those just described. They grow in a rounded, more compact
form with a flat or concave top that is perforated by a number of oscules
up to 0.65 cm (1/4 in) in diameter. When cleaned, the edges of the os-
cules are quite thin and feathery and, in most cases, form chimneys 2.5 cm
(1 in) or so in height. These sponges are soft and absorbent but have










Sheepswool Sponge '(Hippiospongia lachne).


Yellow Sponge (Spongia barbara)


Figure 1.


Figure 2.








little durability. Large numbers of these sponges are presently collect-
ed in Biscayne Bay, but the market value of these sponges is the lowest
of all the commercial sponges representing 9.5% in Monroe County.


Figure 3- Key Grass Sponge (Spongia graminea)


3. BIOGEOGRAPHY


Sponges are exclusively marine except for a single family of fresh
water species. They are found in all seas, wherever there is suitable
substrate. A few species live on soft sand or mud bottom. Some sponges
are able to bore into calcareous structures, such as coral and mollusc
shells. Worldwide, more than 3,000 species of sponges have been de-
scribed, and in Florida's waters, over 100 species have been collected.

Commercial sponges are found in warm ocean waters only, principally
in the Mediterranean Sea, off the coast of Florida and Central America,
in the Gulf of Mexico, and throughout parts of the West Indies and the
Bahamas. To a lesser extent, similar types of commercial sponges are
found in the western parts of the Pacific. The commercial sponge species
found in Monroe County occur throughout the West Indies (which includes
the Bermudas), the eastern Gulf of Mexico including the coasts of Cuba,
the Antilles, the Bahamas, and as far north as Cape Hatteras (de Lauben-
fels, 1953).

Sponge grounds in Florida's coastal waters are divided into two








separated areas: 1) the "Bay Grounds" includes approximately 8,704 sq
km (3,400 sq mi) in the open waters of the Gulf of Mexico, adjacent to
Florida's west coast from about Johns' Pass to St. Marks, and 2) Keys
grounds" includes approximately 2,432 sq km (950 sq mi) stretching along
and among the reefs and Keys from Cape Florida to Boca Grande Key (west
of Key West, FL.).


4. NATURAL HISTORY

The living sponge in nature is quite different in appearance to
the sponge of commercial use. Alive, it is a solid, rather slimy-feel-
ing, fleshy mass, varying in color from light greyish-yellow through a
wide range of browns to black. Through numerous inhalent canals water
ic drawn into the sponge to provide sustaining food and oxygen and to
flush waste products out larger exhalent canals. The following discuss-
ion will attempt to summarize the available information obtained by
researchers on the physical make-up and mode of existence of sponges.

4.1. Structure

Sponges vary greatly in size. They may range from the size of a
bean to more than a meter (several feet) in diameter. Some are radially
symmetrical (similar parts of the animal symmetrically arranged around
a central axis), but the vast majority are irregular and exhibit massive,
erect, encrusting, or branching patterns (Figure 4). The type-of growth
pattern displayed is influenced by bottom type, current velocity and
wave action.

Figure 4. Some Common Non-Commercial Sponge Shapes. A: Two samples of
ramose shape. B: Flabellate. C: Vasiform. D: Tubular. Others
exist and can have extremely bizarre and symmetrically grotedi
shapes (de Laubenfels, 1953).









I-



A B C D

The body wall is relatively simple in structure. The outer surface
is covered by an epidermis (skin) of flattened polygonal cells, called
the pinococytes. The surface of the wall is perforated by many small
openings, called ostia, or incurrent pores, which allow water to flow








separated areas: 1) the "Bay Grounds" includes approximately 8,704 sq
km (3,400 sq mi) in the open waters of the Gulf of Mexico, adjacent to
Florida's west coast from about Johns' Pass to St. Marks, and 2) Keys
grounds" includes approximately 2,432 sq km (950 sq mi) stretching along
and among the reefs and Keys from Cape Florida to Boca Grande Key (west
of Key West, FL.).


4. NATURAL HISTORY

The living sponge in nature is quite different in appearance to
the sponge of commercial use. Alive, it is a solid, rather slimy-feel-
ing, fleshy mass, varying in color from light greyish-yellow through a
wide range of browns to black. Through numerous inhalent canals water
ic drawn into the sponge to provide sustaining food and oxygen and to
flush waste products out larger exhalent canals. The following discuss-
ion will attempt to summarize the available information obtained by
researchers on the physical make-up and mode of existence of sponges.

4.1. Structure

Sponges vary greatly in size. They may range from the size of a
bean to more than a meter (several feet) in diameter. Some are radially
symmetrical (similar parts of the animal symmetrically arranged around
a central axis), but the vast majority are irregular and exhibit massive,
erect, encrusting, or branching patterns (Figure 4). The type-of growth
pattern displayed is influenced by bottom type, current velocity and
wave action.

Figure 4. Some Common Non-Commercial Sponge Shapes. A: Two samples of
ramose shape. B: Flabellate. C: Vasiform. D: Tubular. Others
exist and can have extremely bizarre and symmetrically grotedi
shapes (de Laubenfels, 1953).









I-



A B C D

The body wall is relatively simple in structure. The outer surface
is covered by an epidermis (skin) of flattened polygonal cells, called
the pinococytes. The surface of the wall is perforated by many small
openings, called ostia, or incurrent pores, which allow water to flow








into an interior cavity. This internal cavity may be a single large
chamber (spongocoel) which opens to the outside through the osculum,
a large opening at the top. However, nearly all sponges are more com-
plex. In order to increase water flow through the sponge, there has
been an evolutionary trend toward reducing volume of the spongocoel, and
increasing the surface area of the body wall. This has been accomplished
by the folding of the body wall to form hundreds, thousands, or up to
millions of very small chambers. The folding of the body wall has result-
ed in the formation of branching incurrent channels, which open into
flagellated chambers. The spongocoel, in many species, has disappeared
except for water channels leading to the osculum (Figure 5). This struct-
ure, characteristic of the commercial sponges, is responsible for the
sponge's porous nature.

Beneath the epidermis lies a layer of mesenchyme unspecializedd
connective tissue), which consists of a gelatinous protein matrix con-
taining skeletal material and wandering amoebocytes (cells capable of
independent motion). The skeleton is relatively complex and provides a
supporting framework for the living cells of the animal. The skeleton
may be composed of calcareous or siliceous spicules (Figure 5-D), protein
spongin fibers (Figure 5-C), or a combination of the last two. The
spicules exist in a variety of forms and are used in the identification
and classification of sponges. The amoebocytic cells in the gelatinous
matrix are responsible for skeletal formation.

On the inner side of the mesenchyme, and lining the wall of each
chamber, is a layer of cells, the choanocytes. The choanocytes are more
commonly referred to as collar cells, due to the presence of a distinctive
collar (Figure 5-E). Collar cells bear a flagellum (whip-like hair) sur-
rounded by a basal contractile collar. The beating of the choanocytes'
flagella is responsible for the movement of water through the sponge.


4.2 Physiology

The physiology of the sponge is largely dependent on the current of
water flowing through the body. The beating of the whip-like hairs is
capable of generating an exhalent current of 8 cm/sec (about 2 mph)
and transporting large quantities of water. A commercial sponge 6 inches
in diameter may pump over 100 gallons of water in an hour (Galstoff, 1969).

The exact nature of the food particles utilized in the sponge's
nutrition has still not been properly defined. Laboratory and ecologi-
cal information gathered to date indicate that sponges probably feed on
fine detritus particles (decaying organic matter) and small planktonic
organisms, such as protozoans, diatoms, and bacteria brought in by
water currents.

Pearse and Williams (1951) suggested that sponges of the reefs of
the Carolinas may strain plankton from the water. Smith (1954) mention-
ed that commercial sponges are usually found attached on rocks only in
areas where there are muddy sediments nearby. These calcar ous mud
sediments were found to contain 160 million bacteria per cm (Crawshay,








Structure Of A Sponge. A: Diagram of the canal system of a
sponge. B: Larva of the Sheepswool Sponge (magnified about
1,500 times). C: Fiber-skeleton of the Sheepswool Sponge
(magnified about 2,500 times). D: Types of spicules found
in the non-commercial sponges (magnified about 2,500 times).
E: Collar cell found in the pumping chamber of the Wool
Sponge (magnified about 2,500 times). (from Storr, 1957)


Figure 5.








1939). Crawshay and Smith both suggest that certain bacteria form the
main food source of the sponges. It is also possible that sponges filter
out minute particles of detritus or directly absorb dissolved oxygen
nutrients (Smith, 1954). Reiswig (1973) demonstrated that Haliclona
permollis ( a non-commercial sponge) removes 83% of the bacteria circu-
lating through the sponge over a wide range of bacterial concentrations.
Bacterial uptake was judged sufficient to meet the nutritional require-
ments of the sponge.

Food particles are apparently selected largely on the basis of
size and are screened in the course of their passage into the.flagellated
chambers. Jorgensen (1966) suggested that food particles adhere to the
surface of the collars of the choanocytes and are engulfed by the cell
body. Digestion occurs within the collar cell or after transfer to
an ameobocyte.

Waste products leave the body in water being expelled through the
oscules. Gaseous exchange occurs by simple diffusion between the
flowing water and the cells in the sponge along the course of water
flow (Barnes, 1968).

Adult sponges are incapable of any locomotion, although some species
can contact or alter the body shape to some degree. There is probably
no nervous system in the sponge, and reactions are local and independent
(Barnes, 1968).


4.3. Reproduction

Sponges may reproduce by either sexual or asexual means. Asexual
reproduction is accomplished by budding or by a variety of processes
that involve formation and release of an aggregate of essential cells,
particularly amoebocytes. Sponges display remarkable powers of regen-
eration. Pieces cut from a sponge will grow to produce a viable indi-
vidual. This phenomenon will be discussed in greater detail in the
section dealing with sponge culture.

Sponges are known to produce eggs and sperm, hence to exhibit
sexual reproduction. Commercial sponges are known to be monoecious
(same individual produces both eggs and sperm). The sperm and eggs
develop from either collar cells or from amoebocytes. Sperm leave the
sponge by means of water currents and enter other sponges in the same
manner. After a sperm has reached a flagellated chamber, it enters a
collar cell or an amoebocyte. These cells act as carriers and transport
the sperm to eggs. After the carrier cell with its sperm has reached
the egg, the carrier fuses with the egg and transfers the sperm to it.
Fertilization thus occurs within the sponge. After fertilization, the
sponge egg remains within the body of the sponge for its first stages
of development. The final stage of development of the larval form is
the growth of a crown of cilia at one end (Figure 5-B). At this point,
it is released into the nearest excurrent canal where it is carried
out of the sponge by the outgoing water currents. The crown of cilia
allows for some motion (primarily in a vertical direction), but the
larva is essentially at the mercy of water currents. If the larva
lives through its 1-2 day planktonic stage and is able to find clean
hard bottom, it will attach and rapidly change into the typical sponge
form.








4,3.1., Factors Influencing Reproduction
in the Sheepswool Sponge

Reproduction in the commercial sponge has been most closely examined
in the sheepswool sponge. In field studies of living sponges, Storr (1964)
found evidence to suggest that several factors effect reproduction in the
sheepswool sponge.

1) Influence of sponge concentration on larval production. Reproduced
below are the data collected by Storr (Table 1) on concentration and
larval content of sponges examined in his study. He was able to draw
several tentative conclusions from these data:

a) There may be a critical density of sponges required for optimum
production of larvae. Areas with high concentration of large
sponges, those greater than 14 cm (5 in) in diameter, exhibited
a higher percentage of sponges containing larvae than did areas
of low sponge concentration. In addition, the density of larvae
in reproductive sponges was much higher in the areas of high
concentration (500 larvae per cubic inch compared to 50 larvae
per cubic inch). Storr attributed this to a direct relationship
between numbers of embryos produced and concentration of sperm
in the water surrounding the egg-producing sponges.

b) Sheepswool sponges may not be capable of self-fertilization.
Sponges in areas of low concentration would be expected to have as
many larvae as those in areas of high concentration if the sheeps-
wool sponge was capable of self-fertilization. Storr found that
sponges from-areas of extremely low concentration did not contain
developing larvae.

c) In the study area, sponges less than 14 cm (5 in ) in diameter
may not be sperm producing sponges. Further, sponges in high
concentrations but less than 14 cm (51 in) in diameter had no
relationship to the percentage of mature sponges that were
producing larvae.

d) In evaluating all the information gathered, Storr indicated
that perhaps only one out of every two hundred thousand larvae
survives to settle on the bottom and grow to maturity.

2) Influence of sponge size on potential larval production. Storr (1964)
presented information on the relationship of larval production to volumetric
increases in sponges of increasing diameter (Table II). These calcula-
tions show that as the diameter of the sponge increases, there is an
extremely rapid increase in the reproductive capacity of the sponge.
This data indicates that it is the volume of reproducing sponge in an
area, and not the number alone, which must be considered in evaluating
the reproductive potential in that area.

3) Influence of temperature on sponge reproduction. Data collected on
the reproduction of the sheepswool sponge from different areas of its
geographic range (Figure 6 ) was used by Storr to determine the effects of









Optimum Temperature For Sponge Egg Production In Various
Areas. In the upper portion the temperature graphs for year
and a half periods for three areas are drawn, with the prob-
able optimum temperature range indicated as being between
730 and 840 F. In the.lower portion the approximate monthly
percentage of Wool Sponges carrying developing eggs (larvae)
for the same season is shown (from Storr, 1964).


JANIFEB MA IAPR IMAY IJUN IJUL IUG ISP ocr INOVI DEC I JAN IFEBIMAR IAP M4Y JIW






S/ \ British Honduras,/

80 \ v hm..(

\f Bahamas
H -
_, .. E- \ .


S- Cedar Keys


I I I i I 1, I *. I I I


% JAN FEB'NA' APR MAY 'JUNU UL IAUO'SEP'OCT' NOV DEG 1JAN 'FEB'MAR APR 'MAY IJu.
British Honduras

H 0
S~Bahamas
QC * ** ** * ** *

O ::::::::~:r:::":~::: :::


Figure 6.


I I -1







temperature on the reproductive cycle. Based on this data, the optimal
temperature for larval production lies between 22.50 C and 28.60 C
(730 F and 840 F). Apparently above and below this temperature range,
reproductive activity ceases.


Table I. Concentration of Sheepswool Sponges Collected in July, 1956 for
Determination of Larval Content (from Storr, 1964).



Station Total Sponges Under 5" 5" Diameter Total Sponges
No. Taken per Acre Diameter and Over with Larvae
Number Number Number Number
XVII 11 0 11 9
XVIII 1 0 1 0
XXIII 2 2 0 0
XXIV A 14 11 3 3
B 15 8 7 6
C 5 0 5 4
D 4 0 4 4
XXV 4 1 3 2
XXVI A 25 24 1 1*
B 5 0 5 4
XXVII 2 0 2 2
XXVIII 20 18 2 2*
XXIX 9 6 3 0
XXX 7 6 2 0
XXXII 5 0 5 4
XXXIII A 4 1 3 1*
B 3 2 1 0
XXXIV 1 0 1 0
Very few larvae in any one sponge;


Table II. Potential Larval Production Related to Volume (From Storr, 1964).

Ratio of Larvae 2
Diameter Produced from Potential Larvae Being Yearly Production
6" Sponge Developed of Larvae

Inches Number Number
6 1 : 1 60,000 200,000
7 1.6 : 1 96,000 320,000
8 2.4 : 1 144,000 480,000
9 3.5 : 1 210,000 700,000
10 4.7 : 1 282,000 940,000
11 6.2 : 1 372,000 1,240,000


1With the observed number of larvae in a 6 inch sponge being taken as unity.

2Based on length of larval production season and length of time for maturation
of one larva (4 weeks).







Storr also presented data indicating the wool sponge reaches sexual
maturity at a smaller size in the warmer portions of its geographic
range (Figure 7). Because sexual maturity is reached at a smaller size
and the reproductive season is longer, Storr concluded that sheepswool
sponge egg production is greatest in the warmer parts of its geographic
distribution.



Figure 7. Effects of Temperature on Size and Maturation in Wool Sponges
in Various Areas (From Storr, 1964).


5

) Pa)

1E o
a 3


oa

01


1 2 3 4 5 6 7 8 9 10
Number of Months Temperature Above 26.60 C (80 F)

Area A: Northernmost portion of sponging grounds off west coast of
Florida.
Area B: Southern portion of sponging grounds off west coast of Florida.
Area C: Florida Keys sponging grounds.


Storr also made another ecological observation. He postulated that
size at maturation affected by variation of temperature with geographical
location might also be affected by variation of temperature with depth
of water. If this is true, it seems reasonable to suggest that dispersion
of sheepswool sponges, especially in northern regions, to deep water areas
in the Gulf may be retarded by the effects of temperature on the repro-
ductive period and the sexual maturation of the sponges.

4.4. Growth of Commercial Sponges

Several researchers have made observations on the growth rate of
commercial sponges in different areas of their geographic ranges. Growth
may be expressed in terms of increase in diameter, or, as has been most
commonly expressed in past studies, in terms of a growth factor (the
number of times a sponge increases in volume during a 1-year period).
Table III presents data obtained on the average growth factor, for com-
parable growth periods, by a number of investigators working in


&Area A

Area B
SBahamas


SArea C








different locations. The information gathered shows wide variation.


Table III. Growth Rates of Commercial Sponges in Different
Geographic Areas


Species Location
sheeDswool..........Sugarloaf Key, FL. (Moore, 1910a).....
sheepswool..........Anclote Key, FL. (Moore, 1910a).......
sheepswool..........Piney Point, FL. (Storr, 1964)........
sheepswool...........Bahamas (Crawshay, 1939).............
sheepswool..........British Honduras (Crawshay, 1939).....
grass...............Card Sound, FL. (Smith, 1973).........


Growth Factor
....1.86
....1.91
....2.27
....2.34
....2.94
....0.77


Crawshay (1939), working with sponge cuttings in the
duras, suggested that a growth factor of 2.0 was adequate
good. He also considered a growth factor of 3 or more as
that a high accumulation of waste matter accompanying the
of food necessary for such growth might prove detrimental
in disease.


British Hon-
and 2.5 was
high, and
high intake
and result


Based on a growth factor of 2.3, Storr (1964) calculated that a
sponge in the northern Gulf of Mexico would require 3 years to reach
a size of 12.7 cm (5 in) and 4 years to reach 15.2 cm (6 in) in di-
ameter. Information gathered on growth rates of wool sponges in the
Keys by Moore would indicate an even longer peroid of time until sponges
attain market size. The slower growth rate in the warmer waters of
Sugarloaf Sound (compared to Anclote Key and Piney Point, Florida) is
surprising. Sponges in the warm waters of the Bahamas and British
Honduras exhibit the most rapid growth. Smith (1973) found that when
temperatures fell below 270 C (80.60 F) water temperatures were positive-
ly correlated with sponge growth. Moore felt that the slow growth
rates that he observed might have been attributable to an absence of
strong currents or by the character of the seed sponges. Apparently,
the seed sponges used in that area were all small specimens despite the
fact that the area had, in the past, produced many large sponges. Moore
indicated that in these shallow waters the spongers might be able to
rigidly select out all the marketable sponges, a process which would
logically tend to eliminate those which grew rapidly and had an inher-
ited tendency to reach larger dimensions. Also, it is worthy of note
that growth rates from within an area can be extremely variable.
Smith (1973) obtained growth factors for the grass sponge (Spongia
graminea) in Card Sound, Florida that ranged from 0.24 to 1.31. Storr,
(1964) made the observation that there was considerable variation in
growth rates of sponges even when they were located on the same rock
outcropping.

Many investigators have noted that sponge growth is affected by
water currents in the surrounding area. Cotte (1908) noted that a
moderate current seemed most suitable for sponge growth. Crawshay,








(1939) states that the most favorable conditions for sponges are
usually found in or near areas subject to regular tidal interchange.
Storr (1964) observed unusually rapid growth of sponges in a current
of two knots or more. However, these sponges had heavy overgrowths of
tunicates and algae which distorted their shape. Smith (1973) attribu-
ted a dramatic increase in the growth rate of sponges in his study area
to an increase in water currents.

4.5 Environmental Factors Affecting Sponges

4.5.1. Physical Factors

The commercial sponges apparently cannot tolerate salinities much
below oceanic levels. Moore (1910a) considered salinities of 27.5
parts per thousand (ppt) as detrimental and salinities below 26 ppt as
lethal. In the Bahamas, W. Smith (Storr, 1964) reported that salinities
of less than 32 ppt are harmful to sponges. Sponge kills, caused by
an increase in fresh water run-off reducing salinities have been re-
ported by many investigators (Rathbun, 1887; Moore, 1910; Crawshay,
1939; Storr, 1964).

Temperature has been shown to be an important factor affecting
sponges. Commercial sponges appear to have a tolerance range from 100 C
to 35 C (500 F to 90 F,'Smith, cited in Storr, 1964). The effects
of temperature on reproduction and growth have been discussed in the
preceding sections dealing with these topics.

Sponges due to their sessile nature, are dependent upon water
currents to bring food, dissolved oxygen, disperse larvae, and to carry
away wastes. Bidder (1923) demonstrated that despite the relatively
impressive water currents generated by the sponge's flagellated cells,
sponges can remove wastes no further than a few meters, and the excur-
rent water is soon:recirculated unless there is a current to carry it
away. Japanese researchers working in the South Pacific found that slug-
gish turbid waters were unsuitable for sponges (Cahn, 1948). The effect
of water currents on growth was discussed in the section dealing with
sponge growth (see section 4.4).

The availability of clean, hard substrate for the sponge larvae
to settle upon is extremely important. Larvae are easily smothered by
sediments (Moore, 1910a). Only a small percentage of the large areas
defined as the Florida sponge grounds actually support sponge pop-
ulations due to the scarcity of rock outcroppings. Many times the
structure on which a sponge is growing breaks off and the sponge cont-
inues to live as it is rolled along the bottom by water currents. Such
sponges are termed "rollers" and are distinguished by new growth over the
area of former attachment.

4.5.2. Biological Factors Affecting Sponges

During 1938-1939, populations of commercial sponges throughout
the western Atlantic were decimated by disease. Mortality was similar
to Brice's (1898) description of heavy losses of sponges in the Knight








Key to Cape Sable region of Florida, when the sponges "rotted internally".
The disease first appeared in the Bahama Islands and rapidly spread
throughout the West Indies and the Gulf of Mexico (Galstoff, 1940).
The progress of the mortality was recorded in a detailed manner and trans-
mission of the disease attributed to water currents (Smith, 1941).
Galstoff (1940) estimated that from 60% to 90% of the adult population
of the commercial sponges of the Bahama Islands were killed by the
disease. He also indicated that the disease was somewhat milder in Florida
waters and suggested that sponges in this area might have been more
resistant.

Examination of diseased sponges led Galstoff (1940) to conclude
that a fungus was the probable cause of the disease. His conclusion
was primarily based on a number of observations: 1) filaments of a
fungus were always present in the affected parts of diseased sponges;
2) only a few filaments were found attached to skeleton fibers of the
dead portion of the body; and 3) no filaments were found outside of the
diseased layer in healthy tissues. Further evidence supporting the con-
tention that a fungus was the causitive agent was obtained by Galstoff
in a number of experiments dealing with transmission of the disease. He
found that when a diseased sponge was placed in contact with a healthy
sponge, the destruction of sponge tissue spreads from the affected sponge
to the healthy sponge and that the progress of the disease was accompan-
ied by the spread of fungal infection.

Carter (1878; cited in Galstoff, 1940) had observed the presence
of a fungus-like organism in the tissues of sponges which he named
Spongiophaga communis. Carter describes the fungus as destroying the
entire body of the sponge, leaving only an outside crust (this was similar
to Galstoff'-s description of the sponge disease of the Bahamas and Florida).
Galstoff tentatively placed the fungus he observed in Carter's genus
Spongiophaga.

Investigation of the disease was hampered by the researchers' in-
ability to culture the fungus in the laboratory. In British Honduras,
Spongiophaga was observed growing on the surface of turtle grass,
Thalassia, with no apparent ill effect (Storr, 1964).

If the-observations of Carter, Brice and Galstoff deal with the
same pathogen, it would appear that outbreaks of the disease are quite
infrequent. A sponger in the Key West area reports that he continually
finds a small number of sponges affected by the blight. Exactly why
the blight has not triggered mass mortalities, as it has been reported
to do in the past, is not understood.

During 1947-1948, a disease affecting the commercial sponges along
the west coast of Florida was reported. Investigation of this phenomenon
by members of the Marine Laboratory, University of Miami, did not reveal
the cause of this sponge mortality. No evidence of fungal disease was
found (Storr, 1964).

Mortality of sponges due to the outbreak of red tide (tremendous
accumulations of planktonic organisms that sometimes have a deleterious
affect on marine organisms) has been noted. Rathbun (1887), and Smith







(1976) have reported sponge mortality associated with outbreaks of
red tide.

Sponge fishermen have reported that sponges in shallow water are
occasionally killed off by a phenomenon they'call malleee". This malleee"
is a heavy growth of fine algae that usually breaks loose, smothering
sponges.

There is a wide assortment of organisms living in association with
sponges (Pearse, 1934; Storr, 1964). Numerous animals and plants live
within the mass of the sponge, in the internal canals, or on the surface.
However, no animal or plant, with the exception of the fungus disease,
can be said to be parasitic exclusively on commercial sponges (Storr, 1964).

The commercial value of a sponge can be-greatly reduced by deform-
ities caused by algae or other fouling organisms growing on the sponge
surface or by the sponge crab, Pilumnus sayi. This crab often occupies
a hole at the base of the sponge. The hole may not affect the sponge
as a living animal but destroys the commercial value of the sponge.


5. THE SPONGE FISHERY OF FLORIDA

5.1. Methodology Involved in Sponge Industry

5.1.1. Harvesting

The methods used for harvesting commercial sponges have essentially
remained the same since they were first introduced to sponging activities
in Florida. There are two methods by which sponges are harvested in
Florida: hooking and diving.

1) Hooking. In the hooking method, a heavy, four-pronged iron rake
attached to the end of a 5.5 to 7.3 m (18 to 24 ft) pole is utilized
to bring the sponges to the surface. The hooker works from a small skiff,
checking the bottom for sponges by looking through a glass-bottomed
bucket. When a sponge is seen, the hook is lowered quickly to the bot-
tom and the size of the sponge is estimated by the width of the hook.
If the sponge is legal size, 12.8 cm (5 in) minimum diameter, the hooker
sets the hook into the base of the sponge and tears it loose. If a
small fraction of the sponge is left attached to the base, a new sponge
will regenerate. By lashing rakes together, sponges may be collected in
this manner from water up to 12.2 m (45 ft) deep. However, the majority
of sponges collected by this method are taken from water less than 3 m
(10 ft) in depth.

In Tarpon Springs, sponge fishermen work in pairs, one man rowing
and the other hooking. In the past, hooking methods in the Florida Keys
differed from those used in Tarpon Springs. In the Keys, the dinghy is
usually operated by one man. Instead of using oars for propulsion, the
hooker uses a pole. Sometimes a small quantity of oil is poured over
the water to smooth surface chop for better vision. The pole is used
mainly to keep the hooker in the center of the oil slick which moves







(1976) have reported sponge mortality associated with outbreaks of
red tide.

Sponge fishermen have reported that sponges in shallow water are
occasionally killed off by a phenomenon they'call malleee". This malleee"
is a heavy growth of fine algae that usually breaks loose, smothering
sponges.

There is a wide assortment of organisms living in association with
sponges (Pearse, 1934; Storr, 1964). Numerous animals and plants live
within the mass of the sponge, in the internal canals, or on the surface.
However, no animal or plant, with the exception of the fungus disease,
can be said to be parasitic exclusively on commercial sponges (Storr, 1964).

The commercial value of a sponge can be-greatly reduced by deform-
ities caused by algae or other fouling organisms growing on the sponge
surface or by the sponge crab, Pilumnus sayi. This crab often occupies
a hole at the base of the sponge. The hole may not affect the sponge
as a living animal but destroys the commercial value of the sponge.


5. THE SPONGE FISHERY OF FLORIDA

5.1. Methodology Involved in Sponge Industry

5.1.1. Harvesting

The methods used for harvesting commercial sponges have essentially
remained the same since they were first introduced to sponging activities
in Florida. There are two methods by which sponges are harvested in
Florida: hooking and diving.

1) Hooking. In the hooking method, a heavy, four-pronged iron rake
attached to the end of a 5.5 to 7.3 m (18 to 24 ft) pole is utilized
to bring the sponges to the surface. The hooker works from a small skiff,
checking the bottom for sponges by looking through a glass-bottomed
bucket. When a sponge is seen, the hook is lowered quickly to the bot-
tom and the size of the sponge is estimated by the width of the hook.
If the sponge is legal size, 12.8 cm (5 in) minimum diameter, the hooker
sets the hook into the base of the sponge and tears it loose. If a
small fraction of the sponge is left attached to the base, a new sponge
will regenerate. By lashing rakes together, sponges may be collected in
this manner from water up to 12.2 m (45 ft) deep. However, the majority
of sponges collected by this method are taken from water less than 3 m
(10 ft) in depth.

In Tarpon Springs, sponge fishermen work in pairs, one man rowing
and the other hooking. In the past, hooking methods in the Florida Keys
differed from those used in Tarpon Springs. In the Keys, the dinghy is
usually operated by one man. Instead of using oars for propulsion, the
hooker uses a pole. Sometimes a small quantity of oil is poured over
the water to smooth surface chop for better vision. The pole is used
mainly to keep the hooker in the center of the oil slick which moves








with the tide. Recently, the use of small outboard motor boats has be-
come extremely popular with sponge hookers (Figure 8).

2) Diving. Historically, the diving suit has been employed in the
sponge fisheries of the Mediterranean since about 1866, but it was not
until 1905 that it was successfully introduced in Florida.. Diving boats
from Tarpon Springs are basically of the same design as boats used by
the Greeks 2,500 years ago. The only modifications are the addition
of diesel-power and the air pump, which is powered by the main engine.

Sponge divers wear the standard diving gear consisting of a thick
rubberized suit with bronze shoulder piece and metal helmet. The diver
uses a hook attached to a pole about two feet in length, which is simi-
lar to the one used by the hooker. The shortness of the pole enables
the diver to handle it adeptly. Also, he can uproot the sponge with a
sideways motion which insures against rips and tears.

The suit diver can descend to depths of over 100 ft. However, at
this depth, he can remain no more than several minutes due to physio-
logical limitations. In water thirty feet deep or shallower, he may,
however, remain for two hours or longer. In good weather, two divers
work a twelve-hour day, with each diver making an average of five de-
cents a day. When a bag is filled, the diver signals by tugging on his
lifeline. The tender then hauls up the bag and sends down another. A
good day's catch for one boat is estimated at one hundred and seventy
sponges (Shubow, 1969).

The advantages of diving are: 1) it permits the exploitation of
deeper waters, and 2) operations may be conducted under weather condi-
tions which would prohibit the use of hooking. Sponges collected in
deep water by diving are of a larger size, higher quality, and command
a higher price than those collected by surface hookers. There are
several reasons for this difference:

a) the highest quality of wool sponge naturally occurs in the
deep water sponging grounds off the west coast of Florida;

b) hookers are restricted to shallow, consistently harvested areas
where sponges do not have a chance to grow to a large size;

c) sponges collected by hooking usually suffer more damage than
those collected by diving.

The invention of self-contained underwater breathing apparatus
(SCUBA) in the 1940's has provided a newer and possibly more efficient
method of gathering sponges. Shubow (1969) reported that in 1964,
James S. Cullison, Florida Development Commission, experimented with
using SCUBA diving for sponge harvesting. Cullison found that SCUBA
divers brought up more sponges in less time and with faster boats were
able to put into shore each night. Recently, one sponger in the Tarpon
Springs area has reported the use of small, fast, trailable boats and
snorkling gear.

Diving can be a particularly effective harvesting method. Since
sponges can be cut from the bottom rather than torn, a higher quality











Figure 8. Small Boat Used By Sponge Hooker In The Key West Area.





.4.-







.,- .4. .. .,





':1 '.
---- ,4-
10 ,








sponge can be obtained. Also, cutting the sponge free usually enhances
the chance that the remaining sponge material will be able to grow back
(pers. bbs.).

A Florida state statute (Florida Statutes, 370.17;2) prohibits in
Florida's territorial waters, "apparatus used by deep sea divers, in
taking commercial sponges". The law was passed to prevent damage to
young sponges by divers walking on them with heavy lead boots. However,
the applicability of this law to SCUBA or hooka gear seems subject to
question. An informal legal opinion requested by the writers from the
University of Florida, under the auspice of, Dr. Maloney, Dean Emeritus
of the School of Law, indicates that this law does not apply to these
methods because: 1) SCUBA or hooka gear did not become a viable method
of extended underwater diving until many years after enactment of the
law; 2) the purpose of the law was not to prohibit reasonable methods
of harvesting sponges, but to prohibit the use of harvesting equipment
which would damage young sponges.

Summer, including May, is the time of year when most sponges are
collected. Two reasons explain this: 1) the weather at this time of
year is best for sponging activities; and 2) the season-on spiny
lobster and stone crab are closed and people involved in these fisheries
turn to sponging.

5.1.2. Cleaning and Marketing

The sponge of commerce is the skeleton of the living animal. The
process of removing the "skin" covering the sponge, and the living matter
within the skeleton once sponges are collected is a simple process.
When the sponges are brought aboard, any foreign matter is squeezed out,
and the sponges are placed with the base down to allow the "gurry", or
decaying matter, to drain from the sponge. Next, the sponges are sus-
pended in seawater or covered with wet burlap. During these procedures,
the skin and internal matter decompose. After a couple of days (addi-
tional time is required in cool weather) they are ready for the final
cleaning. This is done by rinsing the sponges in clean seawater and
beating with a stick to remove all debris. The skin of the sponge is
scraped off with a dull knife. Finally, the sponges are dried, sorted,
and strung on a piece of yarn 6 ft long. The ends of this yarn are
tied together to form a wreath that is called a "bunch".

Traditionally, sponges were sold in lots to dealers at auction.
More recently, due to low sponging activity, organized auctions are be-
comming increasingly infrequent (Tarpon Springs Sponge Exchange, pers.
comm.). In Monroe County, many spongers sell their product to middle-
men in the Keys and Miami rather than transport them to Tarpc' Springs.
Prices are extremely variable depending on size, type, and even geographic
location of collection.

In the hands of the dealers, the sponges are trimmed with sheep
shears to remove the irregularities, torn parts, and foreign bodies
such as shells and pieces of coral. If the whole sponge is trimmed
into a regular shape it is called a "form". In the case of irregularly







shaped sponges, those with crab holes, or very large sponges, the sponge
is trimmed and cut into regularly shaped pieces. These are called "cuts".
They are then baled and shipped to the customer. Some sponges are
bleached for marketing. However, chemical bleaching injures the fiber of
the sponge and results in an inferior sponge.

5.2. History and Pattern of Exploitation

The history of sponging is an ancient one. The occurrence, prop-
erties, and uses of the sponge were familiar to the Ancient Greeks.
There was an extensive, lucrative, and well recognized sponge trade
several centuries before the Christian Era, not infrequently mentioned
in early Greek literature.

Commercial sponging originated in the Aegean Islands.of the east-
ern Mediterranean Sea. The Greeks in this area gradually, over the
centuries, extended their field of operations to the north coast of
Africa and the central Mediterranean. Until 1841, the world sponge
supply was derived solely from the waters of the Mediterranean. In
that year, a French sponge merchant, impressed with the native sponges,
shipped a sample lot of sponges from the Bahamas to Paris. Eight years
later, exports of sponges from the Bahamas were valued at $10,000.
In 1849, the first Florida sponges were shipped from Key West to New
York. The sponges' quality and good price established a growing market
and a large group of men began to rely on gathering sponges for their
livelihood. By 1890, sponging was a business that annually netted Monroe
County nearly one million dollars (Shubow, 1969). In 1897, sponges
were the most important fishery product of Florida, representing one-
third of the annual value of the fishery industry (Smith, 1898).
At first the fishery was confined to the waters adjacent to the Florida
Keys, and until about 1900 Key West was the center of sponging activity
in Florida. However, from 1868 to 1879 extensive beds of superior sheeps-
wool sponges were found in the Gulf of Mexico northward from Anclote Key
to Cedar Key (Figure 9). Because of Tarpon Springs proximity to the
valuable Gulf of Mexico sponge grounds it soon became an important spong-
ing center (Table IV). Introduction of diving in 1905, and establishment
of Tarpon Springs as the headquarters for Greek divers, resulted in Tarpon
Springs surpassing Key West as the principal market in the early 1900's
(Moore, 1951).

Table IV. Sponge Landings in Key West, Tarpon Springs, and Other
Areas, 1883 1918 (Schroeder, 1924).


1883 1887 1902 1918

Locality Num- Per Num- Per Num- Per Num- Per
ber of cent of ber of cent of ber of cent of ber of cent of
pounds total pounds total pounds total pounds total
landed catch landed catch landed catch landed catch

Key West 238,038 94 270,906 82 266,841 77 107,743 24
Tarpon ....... 56,000 16 67,218 19 344,445 76
Springs 5,65 6
Others 15,652 6 4,640 2 12,830 4 ....... ...








Sponge Producing Areas Of Florida.


/ ++
+ + +


++"+
+ + +-c Tarp
BAY GROUNDS ++ ......

*-. +
-t- +
'* ** +


Cape Sable


+*- + ri'
+- + + 4 + + +
KEY GROUNDS +4 + + 4t
t + + 4 + + +
+ t+ + + + +S t f-+
+ 4 4 + + 4 +



++ +- + + --.

D+ +


Springs


i/



Biscayne Bay

/


t
+
-
+ +
-4- I


Key
West


Tortugas
Tortugas


Figure 9.


. _. -.. -..-.. -.._J







Sponge production in Florida reached its maximum in 1936 1937
when 324,000 kg (600,000 Ib) of sponges valued at more than $1.2 million
were collected (Figure 10). In 1939, a blight, attributed to a fungus
disease, struck all western Atlantic commercial sponge populations and
severely reduced production (Figure 10). Also, removal of Greek sponges
from the U.S. market during World War II caused an even greater shortage
of supply. In spite of the reduced landings, sponging remained one of
the major industries in the state during World War II because increases
in prices more than offset the reduction in production. The value of
sponges landed reached a peak of almost $3,000,000 in the years 1945 to
1946. At one point, high quality sheepswool sponges were commanding a
price as high as $30/lb. As a result, the number of boats actively
engaged in sponging increased by more than 50% (Storr, 1957). This in-
creased pressure further depleted the grounds. Despite increased fishing
effort, the total number of sponges taken per year from 1941 to 1946 re-
mained about the same. According to the reports of the Sponge and Chamois
Institute, undersized sponges were being taken indiscriminately in large
numbers during this time (Shubow, 1969).

A wide spread mortality struck the sponges again in 1947 Produc-
tion of commercial sponges declined rapidly thereafter, and many spongers
withdrew from the fishery. By 1951, a low point was reached in product-
ion and dollar value. Total return for 1951 was estimated at 5,940 kg
(11,000 lb) with a value of $80,000. This was less than 3% of previous
maximum landings and dollar value. Storr (1957) stated:

"it seems fairly certain now that had the sponge beds
been in as good condition to start with as they were before
the first disease in 1938 the remaining sponges would have
repopulated the sponge beds at a rapid rate. With the beds
already depleted by overfishing there were such few sponges
left after the additional losses by disease, that even today
(in 1956) large areas have never become repopulated with
commercial sponges. It is significant that the non-commercial
sponge population shows every sign of healthy growth."


5.3. Present Status of the Sponge Fishery in Florida

Production of sponges has remained extremely low since the 1947
sponge mortality. By 1962, landings were down to 21,600 kg (40,000 lb).
In 1976, landings were 11,022 kg (21,000 lb) or 2.6% of the 1938 total.
Several interrelated factors were responsible for this decline:

1) The blights of 1939 and 1947 severely reduced sponge populations.

2) The increase in price after the blight of 1939 attracted
a large number of people to sponging. As a result, fishing
pressure was maximized just as the sponge grounds were recovering.
This reduced the population to such an extent that repopulation
was an extremely slow process.

3) After the blight of 1947 and failure to return to normal pro-
duction levels, people involved in sponging took to other jobs.









Figure 10. Dry Weight And Dollar Value Of Sponges Harvested In Florida
From 1926 Until 1977.


Dry Weight Harvested
kg x 1,000
(lb x 1,000 in parentheses)


324
(600)"





270
(500)




216
(400)-




162
(300) -




108
(200)




54
(100)


'I
'I
I I
It(
I I
I
I
I,
U
I
I
I
a
I
*






1,'


Dry Weight
---- -- Dollar Value






















S.
r


I I I I I I I
30 35 40 45 50 55 60 65 70 75

Source: Storr (1964) and Florida Department of Natural Resources Landing
Statistics.


Il

I t \
el I
\I
S
I
Vi


- 2,400





-2,000






-1,600






-1,200





-800






-400


Dollar Value x 1,000







Sponge buyers in the Tarpon Springs area claim that the sponges
have been slowly returning to the area, but that as the old
Greek spongers retire, they are not being replaced by younger
men. Due to hard work, separation from families during long
stays at sea, and low monetary return, no new people are
being attracted to the industry in this area.

4) Introduction of the synthetic sponge at a significantly lower
price reduced the overall demand for natural sponges.

In 1945, after the first blight, Monroe County produced 44,200 lbs of
sheepswool sponges valued at $256,000. In the years after the second blight,
recorded production was non-existant (Figures 11 and 12). However by 1975, for
the first time since the 1900's, Tarpon Springs (Pinellas County) lost its
position as number one producer of sponges in Florida, with both Monroe
and Dade Counties sponge production exceeding that of Tarpon-Springs. Pro-
duction of sponges in Monroe County began increasing in the 1960's reaching
a value of $90,000 in 1964 and averaged $34,000 per year from 1973 1976.
Sponges collected in Monroe County are sold to buyers in Miami and Tarpon
Springs or local sponge dealers.

From information gathered in interviews with people connected with
the sponge industry, it appears that there are approximately 50 people
in the Keys earning part of their income from collecting and selling
sponges. Most of these spongers'derive the greater part of their income
from other enterprises such as trapping the spiny lobster or other fishery
related occupations.

In 1962, Dade County began making a significant contribution to
sponge production in Florida. At this time, Cuban refugees began
arriving in Miami. A number of them were sponge hookers and they began
harvesting sponges for a livelihood. The Arellano Brothers, former sponge
merchants in Cuba, established their own sponge market in Miami during
the early 1960's. They began buying sponges in the Keys and helped outfit
fellow Cubans with boats to collect sponges in Biscayne Bay and along the
Keys, at least as far south as Marathon. These sponge beds had lain un-
exploited since most spongers left the fishery in 1946 (Shubow, 1969).

Statistics for sponge production in Monroe County compiled by the
National Marine Fisheries Service are supplied by the Arellano Brothers.
Since some sponges are sold through other outlets, it is possible that
sponge production in Monroe County is underestimated.

There is a considerable difference in prices paid to fishermen for
sponges collected from different geographic areas of Florida (Figure 13).
Sheepswool sponges collected from Tarpon Springs have always commanded
a higher price than those collected in Dade and Monroe Counties, and
the difference has become even more pronounced in the past five years
(Figure 13). Members of the sponging industry have indicated that this
is the result of three factors:

1) The highest quality sheepswool sponge occurs in the deep water
sponging grounds off the west coast of Florida. Sheepswool
sponges collected in the Keys exhibit a red-brown discoloration










Figure 11.












22
(40)








16 -
C (30)
0


-I

O

11

(20)








5.4
(10)


Sponge Production From Sponge Producing Counties Of Florida
1953 1977 (Florida Department of Natural Resources Landing
Statistics).


Year







Figure 12. Total Dollar Value Of Sponges Harvested From Sponge Producing
Counties Of Florida..


400 -- .
4I Source: Florida Department
Sof Natural Resources
SI Landing Statistics.
I i
350-- I

I i

i \ I
300- I \






250 -


S200 ON

0

-*-*--* PINELLAS
w150I
-----------MONRDE M
S0 -0---- DADE


100 \


55 60 65 70 75







Figure 13.


Dollars
per lb


18.00-


Dry Weight Value (Per Kilogram And Per Pound) Of Sheepswool
Sponges Harvested In Different Counties of Florida, 1953-1977.


Dollars
per kg


-33.30


i


- .--. -.-.. Pinellas County
Monroe County
- -- ---- Dade County


15.00 27.75


12.00 4- 22.20


9.00 --16.65


6.00 4- 11.10


3.00 4-5.55


/


., I \!\ ,%

.- I *L


i ''"

'4


60


65


* I I I I '
70 75


Source: Florida Department of Natural Resources Landing Statistics.


xI


I


5 I
55


- -~ -~- ` -~ ---


21.00 --?1.85








of the inner fibers and are usually smaller and have a weaker
fiber.

2) In Monroe and Dade Counties, all sponges are collected by hooking.
Sponges collected by hooking are usually of inferior quality as
previously discussed.

3) Sponges collected in Monroe County are often sold through middlemen.

One Tarpon Springs buyer indicated to the present authors that al-
though he paid a higher price for Tarpon Springs sponges, the difference
was not nearly as much as reported by the National Marine Fisheries Ser-
vice(Figure 13). Over the phone a price of $2.40 was quoted for a Tarpon
Springs sponge 7 7 in. in diameter while a Keys sponge of the same
size was worth $1.80. This would indicate that, to a substantial degree,
the difference in price is the result of middlemen buying. To verify
this, price quotations for the same sponges were obtained from the Are-
llano Brothers in Miami and a sponge buyer in Tarpon Springs.' However,
the results were confusing. One sponge approximately 8 in. in diameter
was quoted as being worth $1.30 in Miami, while the price in Tarpon Springs
was quoted at $2.00. Other sponges approximately 6 in. in diameter were
quoted at the identical price by both sources. While the extent of these
results are inconclusive in determining the extent of middlemen mark up,
it appears that in some cases it can be considerable. It is significant
to note that some spongers feel it worth their time to drive to Tarpon
Springs from the Keys in order to obtain a higher price for their sponges.

5.4. Present Market Outlook

Although natural sponges have generally been eliminated from wide-
spread household use, there are some markets for natural sponge in which
an acceptable substitute has never been found. Shubow (1969) pointed out
that:

"Synthetic sponges have never posed a threat to the
future of natural sponges, since the demand for natural
sponges has always been greater than supply. There is a
tremendous market for natural sponges regardless of the
success of the synthetic sponge."

Natural sponges are in demand in hospitals, since they can withstand
the high temperatures needed for sterilization. Other users of natural
sponges are painters, lithographers, janitors, artists, ceramic and leather
workers, window cleaners, and tile setters. Sponges are also used in the
cosmetics, medical, and automotive fields, and by other miscellaneous
manufacturers (Shubow, 1969).

Industry continues to demand natural sponges. The sponge industry
of Florida has not been able to produce enough sponges to meet this de-
mand, and large quantities of them have to be imported from other sponge
producing countries. In 1975, sponges valued at $682,000 were imported
into this country (Table V),.








Table V. U.S. Sponge Imports in 1975


Country kg lb Dollar Value

Bahamas 7,032 13,022 19,000
Egypt 2,503 4,636 64,000
Greece 15,435 28,583 417,000
J-oan 4,855 8,991 75,000
Tunisia 3,821 -7,076 66,000
Other 3,238 5,997 41,000

Total 36,884 68,305 682,000



The high prices during the 1940's and shortage of supply during
the 1950's resulted in the synthetic sponge capturing the market for
house-hold use. Consequently, it has been widely held that natural
sponges are no longer competitive. However, if efficient collection
methods were introduced, that would provide a greater supply at a reason-
able price, there is evidence to indicate that natural sponges would be
competitive. Natural sponges exhibit superior qualities of durability
and absorbtion. They are also. more hygenic due to their porous nat-
ure which allows water to be drawn through che sponge in a cleansing
action.

James S. Cullison, manager of the Department of Marine Science and
Technology, Florida Development Commission has expressed the opinion
that there will always be a demand for natural sponges, even at a higher
price, due to their superior qualities. He felt that the key to the
revival of the sponge industry was in the modernization of both the
production and marketing methods, particularly the old fashioned diving
techniques (Shubow, 1969).

To prove that the retail market in sponges still exists, Cullison
directed a survey for the Florida Development Commission. One thousand
sheepswool sponges averaging 12.8 cm (5 in) in diameter were distributed
from door to door. The results of this survey indicated that a large
market would exist if sheepswool sponges were made available through
retail outlets for household use at a competitive price (there was no
indication of what a competitive price would be). The survey indicated
that 95% of those who tried.the sponges would purchase them at retail
stores if they-were available (Shubow, 1969).

Communication with sponge buyers has indicated a desire on their
part to obtain more sponges. The Arellano Brothers, sponge buyers in
Miami, have indicated that they could sell more sponges than they pre-
sently are able to buy (pers. comm.). Mrs. Myrtle Perry, a sponge
buyer in Tarpon Springs, Florida (pers. comm.) provided the following
observations on the sponge market:







1) there may be a market for as much as 54,000 kg (100,000 Ib) of
sponges a year, five times the current landings;

2) presently customers have to wait to have their orders filled,
and many customers are being lost due to the industry's in-
ability to fill orders;

3) no new people are entering the business.

Comparison of prices paid for sponges gathered in Florida to the
Consumer Price Index (the C.P.I. is a relative measure of price changes
compared to the base year, 1967) indicates that the price of sponges has
not kept pace with the inflation rate experienced by the U. S. economy
(Figure 14). Dade County is excluded from the graph but displays essen-
tially the same pattern as Monroe County. The result has been a de-
crease in the "real" return to the sponge harvester for his efforts.
The dramatic decline in production in the Tarpon Springs area beginning
in 1972, is probably the cause of the more recent upward surge in the
price for sponges from all areas of Florida (Figure 13, page 40).

The inflation rate ((ie; the CPI increase) of chemicals and
allied products (Figure 14) in recent years has been even more dramatic
than that for all commodities. Perhaps this will enable the natural
sponge to compete more effectively with the synthetic varieties and re-
sult in higher prices and returns to the sponge harvester.

In summary, although natural sponges have been eliminated from
widespread use, current production is insufficient to meet existing de-
mand, and large quantities have to be imported. Despite this need for
sponges, there has been continual decline in sponge production, and an
inability of prices paid for sponges to keep pace with inflation. Mod-
ernization of production and marketing methods might result in: 1) in-
creased utilization of Florida sponges to meet current demand, and; 2)
expansion of the presently existing market.


6. SPONGE CULTURE POTENTIAL

6.1. History of Sponge Culture

In order to insure a more consistent and cheaper supply of sponges
men in the past experimented with sponge culture. The basis for these
sponge culture attempts was the fact that sponges cut into pieces would
attach to foreign bodies and grow.

The first practical suggestion that sponges' regenerative capabil-
ities might be utilized in the development of a sponge culture system
was made by Oscar Schmidt in 1862(Moore, 1910b). This led to the
establishment of a research station on the island of Lesina by the
Austrian Government and certain merchants of Trieste in 1863 (Moore,
1910b). It was found that, indeed, pieces cut from commercial sponges
could survive and grow to commercial size.

No specific information was reported on growth and mortality,
although it was noted that seven years would be required to grow a







1) there may be a market for as much as 54,000 kg (100,000 Ib) of
sponges a year, five times the current landings;

2) presently customers have to wait to have their orders filled,
and many customers are being lost due to the industry's in-
ability to fill orders;

3) no new people are entering the business.

Comparison of prices paid for sponges gathered in Florida to the
Consumer Price Index (the C.P.I. is a relative measure of price changes
compared to the base year, 1967) indicates that the price of sponges has
not kept pace with the inflation rate experienced by the U. S. economy
(Figure 14). Dade County is excluded from the graph but displays essen-
tially the same pattern as Monroe County. The result has been a de-
crease in the "real" return to the sponge harvester for his efforts.
The dramatic decline in production in the Tarpon Springs area beginning
in 1972, is probably the cause of the more recent upward surge in the
price for sponges from all areas of Florida (Figure 13, page 40).

The inflation rate ((ie; the CPI increase) of chemicals and
allied products (Figure 14) in recent years has been even more dramatic
than that for all commodities. Perhaps this will enable the natural
sponge to compete more effectively with the synthetic varieties and re-
sult in higher prices and returns to the sponge harvester.

In summary, although natural sponges have been eliminated from
widespread use, current production is insufficient to meet existing de-
mand, and large quantities have to be imported. Despite this need for
sponges, there has been continual decline in sponge production, and an
inability of prices paid for sponges to keep pace with inflation. Mod-
ernization of production and marketing methods might result in: 1) in-
creased utilization of Florida sponges to meet current demand, and; 2)
expansion of the presently existing market.


6. SPONGE CULTURE POTENTIAL

6.1. History of Sponge Culture

In order to insure a more consistent and cheaper supply of sponges
men in the past experimented with sponge culture. The basis for these
sponge culture attempts was the fact that sponges cut into pieces would
attach to foreign bodies and grow.

The first practical suggestion that sponges' regenerative capabil-
ities might be utilized in the development of a sponge culture system
was made by Oscar Schmidt in 1862(Moore, 1910b). This led to the
establishment of a research station on the island of Lesina by the
Austrian Government and certain merchants of Trieste in 1863 (Moore,
1910b). It was found that, indeed, pieces cut from commercial sponges
could survive and grow to commercial size.

No specific information was reported on growth and mortality,
although it was noted that seven years would be required to grow a








Figure 14. Dockside Price of Sheepswool Sponges (adjusted to Consumer
Price Index) And Important Price Indices, 1960-1976.











185
/

175 Key /
____ Monroe County Sponges

165 -- - Pinellas County Sponges
............... All Commodities *7 I
155 I
155 -. -...-.-- Chemical and Allied I
14 Products I




135 ll

cO I
I*



S125 ft



/
115 -- ,.
...5 .



.... ........ I




85 -e


75 --







60 5 70 75
Year









commercial product (Moore, 1910b). Experimentation was ended after nine
years because of the hostile attitude of local inhabitants, the inability
to develop materials suited for commercial production, and the long per
of time required for growth to an adequate size (Moore, 1910b).

The failure of this work ended experiments in Europe, however, a
number of men began experimenting with sponge culture in the Florida
Keys in the 1880's and 1890's. These efforts failed because of the un-
suitable nature of the bottom and materials used, and vandalism by local
inhabitants (Shubow, 1969).

Although these early attempts were unsuccessful, in 1910, Dr. H.F.
Moore, the director of the U.S. Bureau of Fisheries, established a re-
search facility on Sugarloaf Key, FL/ to experiment with sponge culture
(Moore, 1910b). Supplied with ample resources, equipment, and manpower
(this had not been the case in many of the previous privately conducted
experiments), he was able to develop a successful method of sponge
culture. The planting process consisted of cutting live adult sponges
into pieces and attaching them to cement slabs with alunimum or lead
wire (Figure 15). Dr. Moore concluded that sponge culture was feasible
if the following conditions were met:

1) selecting an area that.could be guarded-against vandals;

2) absence of fresh water run-off;

3) firm bottom to prevent concrete discs from sinking;

4) use of concrete 4iscs 25.4 cm (10 in) in diameter and 5.0 cm
(2 in) thick tied with alunimum wire (Figure 15);

5) water shallow enough for -quick and easy planting and harvesting.

Impressed by these findings several Englishmen established the Florida
Sponge and Fruit Company and began a sponge farm on Sugarloaf Key, Florida.
By 1912, over 100 persons were employed in the enterprise and the site
was on its way to becoming the largest community in the Keys east of Key
West (Shubow, 1969). The firm expected to enter the commercial sponge
business with an anticipated annual output of 2,000,000 sponges, however,
financial disaster was precipitated by the outbreak of World War I. The
majority of stockholders were British citi ens with their assets in British
banks. At the start of the war Great Britdn froze the firms assets and
the company was left with insufficient financial resources to continue
operation. Attempts to raise capital from American investors were unsucc-
essful and several hundred thousand sponges were left to poachers who fish-
ed the waters in this area for many years afterwards (Shubow, 1969).

Failure of the sponge culture venture on Sugarloaf Key marked the
end of attempts to raise sponges in America. However, from 1927 until
1943, the Japanese carried on extensive experimentation on sponge culture
in the South Pacific. Although early experimentation was unsuccessful
due to selection of unsuitable sponge habitat, sponges were successfully
raised at Ailinglapalap'Atoll in'the&Marshall Islands '(Cahn, 1948). The
most successful method developed by the Japanese was the floating bottle







method. This entailed stringing sponges on a piece of aluminum wire
which was anchored on one end and supported at the other end by a float
(usually a sealed beer bottle). All of the Japanese sponge research in
the South Pacific ended with the occupation of Japan at the end of World
War II (Cahn, 1948).


Figure 15.


Cement Disc Used for Growing Sponges in the Sugarloaf Key
Area. Such discs were typically 25.4 cm (10 in) in ~dameter.
Note wire in center of disc for attaching sponge cutting
This disc was found intact after remaining under water for
nearly 60 years.


The practicality of sponge farming was further demonstrated by the
British Government in the Bahamas and British Honduras. The planting
method was similar to that developed by Dr. Moore. Sponge cuttings were
tied to concrete discs with a length of palmetto string (made from split-
ting a palmetto string) and placed on firm mud bottom in about 6 feet of
water where there was good but not excessive tidal flow. The raw surface
of the cut was found to heal over within 2 weeks, with the new sponge
being rounded out with new growth within 6 months. Approximately three
years was required to grow a commercially valuable sponge (Walton Smith,
pers. comm.).

Although large numbers of sponges were raised around Andros Island,
Bahamas and at Turneffe Lagoon, British Honduras, from 1935 until 1939,
the sponge blight of 1939 completed wiped out the planted sponges (Storr,
1964). Apparently there have been some sponges grown at a plantation at
Pot Cay, Andros Island, in the years since the blight, but not on an active







commercial basis (Storr, 1964).


To the best of our knowledge there are no commercial sponge culture
ventures in existence today.

6.2. Present Day Practicality of
Sponge Culture

Past experimentation with the culture of sponges has shown that,
due to their regenerative power, sponges may be artificially cultivated
from cuttings. Unfortunately, the occurence of disease and/or war have
prevented sponge culture programs from realizing their potential. Since
harvesting of natural sponges in Florida has proven insufficient to meet
current demands (see section 5.4), sponge culture ventures might be able
to supply the sponges currently imported from other countries. However,
a number of disadvantages as well as advantages of sponge culture can
be identified.

6.2.1. Advantages Of Sponge Culture

1) The planting operation has been successfully demonstrated and is
a relatively simple operation.

2) Sponges can be concentrated in a small area and therefore loss
of time in harvesting is minimized. Also, sponges can be collect-
ed as needed while the remaining sponges continue to grow.

3) When sponges are cut from a rock or cement disc, the remaining
base produces a new sponge. Therefore, the operation of harvest-
ing and planting would be accomplished at the same time.

4) Cultivation of sponges allows for some control over quality, size,
and shape through the proper selection of the seed sponges,
the growth area, and the growth period.

5) Cultivation of sponges would provide a reliable and increasing
supply of sponges. This might enable natural sponges to expand
their market into areas dominated by the synthetic varieties.

6) Cultivation of sponges would provide an opportunity to increase
quality and value by selective breeding. It would not be un-
reasonable to expect reduction of time from planting to harvest-
ing by selection of sponges exhibiting rapid growth rates.

7) Heavy concentration of sponges in the cultivation area would
result in a large number of naturally growing sponges occurring
in the surrounding area.

8) Sponges planted using the cement disc method would in no way
interfere with boating activities and reduce legal conflicts.

9) Sponge culture is a clean and non-polluting enterprise that
would not conflict with new laws concerning alteration of the
natural water supply.








6.2.2. Disadvantages Of Sponge Culture

1) The selection of a growing area that would assure the fastest
growth of good quality sponges might require considerable ex-
perimentation.

2) A long term lease providing for the cultivation of sponges would
have to be obtained. However, this has been provided for by the
Mariculture Bill of 1969.

3) Arrangements would have to be made for patrolling the area to
prevent theft. This has been a serious problem in sponge culture
ventures in the past.

4) Due to the slow growth rate of sponges, harvesting could not
begin until the third or fourth year of operation. Full pro-
duction might not be reached until several years after the first
harvest.

5) Sponge disease, although it appears infrequently, would be a
constant threat. Disease would probably spread very quickly
among densely planted sponges.

6) If large numbers of people turn once again to collection of
"wild" sponges, the market might become flooded.

7) Large scale production would require an increased market size
to ensure obtaining a reasonable price.

6.3 A Sponge Farm Model

In order to evaluate the potential monetary return of a sponge
farm the costs and.returns of a hypothetical sponge farm were calcul-
ated (Table VI). The planting schedule and labor requirements are
based on Storr's (1964) description of the planting operation used by
the British Government in the Bahamas and British Honduras. During
the first three years five men would be required to collect sponges
and plant 50,000 cuttings per year. Assuming an 80% survival rate and
that three years would be required to grow a commercial size sponge,
40,000 sponges would be harvested in the fourth year of operation.
From the sponges harvested 10,000 to 15,000 would be used to increase
plantings to 100,000 sponges per year (this would probably require 10
men). This same schedule would be continued during the 4th, 5th, 6th,
and 7th year. After the seventh year no additional cuttings.would be
necessary since sponges could be cut from the concrete disc so that a
new sponge would grow from the sponge material left behind.

The calculations presented in Table VI show that a profit would
not be obtained until after seven years. Full production would not be
reached until the tenth year of operation. Considering the potential
problems that could be encountered (section 6.2.2.) sponge culture
would appear to be a risky undertaking. It should be noted that the
major expense is labor. Therefore a sponge culture venture in a lesser






Table VI.


Summary of Pertinent Information For A Hypothetical Sponge
Farm Employing The Concrete Disc Method.


Year Year Class kg. (lbs.) Cost Gross Net
Harvested Harvested Return Return

1 ---- ---- 66,500 0 -66,500

2 ---- ---- 54,500 0 -54,500

3 ----- ---- 54,500 0 -54,500

4 1 945 117,000 27,287 -89,713
(2,083)

5 2 945 109,000 27,287 -81,713
(2,083)

6 3 945 109,000 27,287 -81,713
(2,083)

7 4, & 1 4,536 109,000 131,000 +22,000
(10,000)

8 5, & 2 4,536 47,000 131,000 +84,000


9 6, & 3 4,536 47,000 131,000 +84,000
(10,000)

10 7,4, & 1 7,560 47,000 218,000 +171,000
(16,667)

ASSUMPTIONS:

1) One sponge planted per 0.836 m2 (1.0 yd2) ; 2) end of 7th year
45.98 hectares (113.3 acres) under cultivation; 3) 26.4 sponges 1 kg
(12 sponges/lb.); 4) $28.82 kg ($13.10 lb), average.of ex-vessel prices
paid for Tarpon Springs sponges and Monroe County sponges. 5) 80% sur-
vival rate over the three year time span required to grow a commercial
size sponge; 6) labor, 5 men needed for years 1-3 to plant 50,000 cut-
tings per year, 10 men needed for years 4-7 to plant 100,000 cuttings
per year, after 7th year 5 men needed for farm operation; salary-$8,000
per year. 7) concrete discs- $0.15/disk 50,000 needed years 1-3; 100,
000 needed years 4 7; none needed after 7 years; 8) boats and boat
maintenance -2 boats used years 1 3; 4 boats used years 4 75 2 boats
used thereafter; maintenance $1,000 per boat per year; gas and oil -
$2,500 per boat per year.

* Assumptions pertaining to labor, number of sponges planted, and return
in lbs, of sponges from Storr, 1964.








developed country with substantially lower labor costs would appear
considerably more attractive.


7. CONCLUSIONS AND RECOMMENDATIONS


Conclusion 1

The sponge fishery of Florida has been reduced to a small fraction
of its former importance. This condition has existed for the past 30
years and has been the result of a combination of several factors:

1) decimation of natural populations due to disease in 1939 and 1947;

2) heavy fishing pressure acting in conjunction with the sponge
disease resulting in an almost total elimination of the natural
sponge supply and precluding quick recovery to former production
levels.

3) people leaving the industry when production fell and then did
not immediately return to levels adequate to support them;

4) introduction of the synthetic sponge at a significantly lower
price reduced demand for natural sponges.

Conclusion 2.


Sponge production from Monroe and Dade Counties now surpasses prod-
uction from the Gulf of Mexico sponge grounds off Tarpon Springs, the
traditional sponging center in Florida for the past 70 years. This
has been the result of decreasing fishing effort in Tarpon Springs while
fishing effort has increased in Monroe and Dade Counties due to the est-
ablishment of a Cuban sponging community beginning in the mid 1960's.

Conclusion 3.

Although the market for natural sponges is only a fraction of its
former size, current sponge production levels are insufficient to meet
demand. Considerable quantities of sponges are imported into the U.S.
from other sponge producing countries, and Florida sponge buyers have
indicated the ability to sell more sponges than they currently are
capable of buying. The magnitude of currently existing demand as indi-
cated by sponge imports (68,000 lbs in 1975) only represents a fraction
of sponge production prior to the sponge blight of 1939. If sponge stocks
have fully recovered in the last 30 years, this demand could easily be
met while providing a yearly return to fishermen of approximately
$500,000 $600,000. (the 1975 value of sponge imports).

Recommendation A. Field research should be undertaken to objective-
ly determine if sponge stocks have recovered from past mortalities and
intensive fishing pressure.

Recommendation B. In light of the inability of current sponge pro-








duction to meet demand, and the possibility that sponge stocks have
recovered due to decreased fishing pressure (this will have to be ob-
jectively verified), commercial sponges should be considered an under-
utilized fishing resource. Since the Gulf of Mexico Fishery Management
Council will probably be considering a management plan for commercial
sponges in the future (Mr. Terrance Leary, Gulf of Mexico Fishery Man-
agement Council, pers. comm.), the potential for increased utilization
of this resource should be carefully considered in the preparation of
that management plan.

Conclusion 4

SCUBA and surface supplied air diving gear may be a more efficient
harvesting method than the methods used in the past.

Recommendation A. Field research aimed at evaluating the efficiency
of SCUBA and/or surface supplied air diving gear for harvesting sponges
should be undertaken.

Conclusion 5.

A considerable difference in prices paid to fishermen for Tarpon
Springs sponges vs. Florida Keys sponges exists. Part of this difference
is due to the inherently superior qualities of Tarpon Springs sponges.
However, to an undetermined degree (see section 5.3), different prices
may be obtained for sponges of equal quality, depending on whether the
sponges are sold to wholesalers in Tarpon Springs or Miami.

Recommendation A. In preparing a commercial sponge management plan,
the Gulf of Mexico Fishing Management Council should carefully examine
sponge marketing, and determine if there is potential for increased
monetary returns to the fishermen for Florida Keys sponges.

Conclusion 6.

Past experimentation has proven that sponge culture is possible.
However, high labor costs, and length of time required to attain a
profitable operation, and threat of sponge disease are major drawbacks.
Sponge culture would be far more practical in a lesser developed country
with low labor costs.








8. BIBLIOGRAPHY


8.1 Literature Cited

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Brice, John J., 1898.
The fish and fisheries of the coastal waters of Florida. U.S.
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Cahn, A. R., 1948.
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Cotte, J., 1908.
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Crawshay, L. R., 1939.
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Dawes, C. J., 1974.
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de Laubenfels, M. W., 1953.
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Galstoff, Paul S., 1940.
Wasting disease causing mortality of sponges in the West Indies and
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Moore, H. F., 1910b.
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Moore, H. F., 1951.
Commercial sponges. In: Marine Products of Commerce.
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Pearse, A. S., 1934.
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Pearse, A. S. and L. G. Williams, 1951.
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Reiswig, H. M., 1973.
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Shubow,, D., 1969.
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Smiths H. M., 1898.
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Smith, G. B., 1976.
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8.2. Additional References


Brien, P., 1968.
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Cahn, A. R., 1946.
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Daur, D. M., 1972.
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Dawson, C. E. and F. G. Walton Smith, 1953.
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de Laubenfels, M. W., 1936.
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de Laubenfels, M. W., 1947.
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de Laubenfels, M. W., 1948.
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de Laubenfels, M. W., 1949.
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de Laubenfels, M. W., 1953.
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Frantzis, George, 1962.
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Fry, W. G., 1970.
The biology of the Porifera. Academic Press.

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Galstoff, P. S., 1960.
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