Toxic blue-green algae blooms in...
 Toxic blue-green algae blooms in...
 Boating and waterway managemen...
 Trophic dynamics of the Atlantic...
 Researchers hope to reel in high-performance...

Group Title: Waterworks
Title: Waterworks. December, 2005.
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00067314/00011
 Material Information
Title: Waterworks. December, 2005.
Uniform Title: Waterworks
Physical Description: Serial
Creator: Institute of Food and Agricultural Sciences
Affiliation: University of Florida -- College of Agricultural and Life Sciences -- Floida Cooperative Extension Service -- Department of Fisheries and Aquatic Sciences -- Institute of Food and Agricultural Sciences
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Publication Date: 2005
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067314
Volume ID: VID00011
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Table of Contents
    Toxic blue-green algae blooms in Florida waters
        Page 1
    Toxic blue-green algae blooms in Florida waters
        Page 2
    Boating and waterway management
        Page 3
    Trophic dynamics of the Atlantic angel shark
        Page 4
    Researchers hope to reel in high-performance perch
        Page 5
        Page 6
Full Text

Newsletter of the UF/IFAS Department of Fisheries and Aquatic Sciences December 2005

LToxicN iu OrI

/ A / Ho ii%. I -hi or1 "I-

D during summer 2005, many
Floridians noticed bright green
scum on the surfaces of lakes, rivers and
estuaries (Figure 1). Newspaper articles
reported widely on the 'toxic blue-green
algae blooms' observed in the St. Lucie
River, Caloosahatchee River, St. Johns
River, Lake Okeechobee and many
other systems. This situation resembled
an event that occurred four years earlier
(see WaterWorks 2001 Volume 5, No.4,
The Toxic Algae Threat in Florida: A
Tempered View, by Ed Phlips). Given
the publicity surrounding this year's
blooms and concerns about ecosystem
and human health impacts expressed
by citizens and management agencies,
we revisit the issue and address four key

1. What are toxic blue-green algae
blooms and why do they occur?

Blue-green algae are actually
microscopic bacteria containing
photosynthetic pigments that produce
the characteristic color that gives rise to
their name. Microbiologists classify them
as "cyanobacteria," but the name blue-
green algae stems from their ability to
carry out the same type of photosynthesis
as most algae. Blue-green algae are
among the oldest life forms on earth,
with records dating back over 3 billion
years. In many water bodies throughout
the world, blue-green algae are the
dominant photosynthetic organism,
and they occur naturally in almost all of
Florida's aquatic ecosystems.

Hundreds of species of blue-green algae
inhabit Florida's waters, and several can

produce toxins, including neurotoxins,
which affect animals' central nervous
systems, and hepatotoxins, which affect
animals' livers and digestive tracts.
Neurotoxins have rarely been detected
in Florida, and they are normally
associated with certain species and
strains of blue-green algae in the genus
Anabaena (Figure 2a). Hepatotoxins,
on the other hand, have often been
detected in Florida, most commonly in
association with the blue-green algal
species Microcystis aeruginosa (Figure
2b) and to a lesser extent with species
of Cylindrospermopsis (Figure 2c).
Microcystin was the focus of the greatest
concern during summer 2005, due to the
high levels detected in lakes, rivers and
estuaries suffering from extensive algal
blooms. Microcystin levels of over 500
micrograms/liter were observed in some
samples of surface scum. These values
exceed the World Health Organization
guidelines of 1 microgram/liter for
drinking water. Although untreated
lake water is rarely
consumed in
Florida, the high
levels of microcystin
observed in some
blooms raise
important questions
about impacts on
the ecology of
affected aquatic
environments and
potential threats to
human health.

Algae can bloom
wherever the Figure 1. A surface
temperature is high in the St. Lucie River

enough and nutrients and light are
abundant. Shallow waters in subtropical
Florida, especially the hundreds of
shallow lakes that dot the landscape,
often provide the temperature and
light needed for blooms. The necessary
nutrients can come from several
sources, some natural and some of
human origin. The phosphorus-rich
geological formations present in many
regions of Florida provide some of the
fuel for blooms. Human development
and other activities have added nutrients
in many areas and heightened the
bloom potential. The latter trend began
over 100 years ago, has accelerated
in parallel with the burgeoning of
Florida's population, and correlates with
an increase in blooms. However, the
frequency and intensity of blooms have
not increased linearly. The occurrence
and strength of algal blooms wax and
wane, in large part due to changes in
weather. Weather influences the severity
of blooms by changing inputs of nutrients
in runoff, altering the amount of water in
lakes, and changing the flow of rivers.
The impressive blooms in 2005 can be
attributed, in part, to a combination
of ideal meteorological conditions for
blooms, analogous to a "perfect storm."

,- .-..7,-- \\ .-
bloom caused by the cyanobacteria Microcystis
during July 2005 (photo courtesy Richard Harvey, USEPA)

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ CONTINUED FROM PAGE 1

Figure 2. Species of algae that commonly form toxic
blooms in Florida lakes, rivers and estuaries.

]FTaculty Fr

Staff fNe ws
Chuck Jacoby
andShirley Baker
received an Award
of Excellence from
the Florida Association of
Natural Resource Extension
Professionals for their
publication "A Primer on
Invasive Species in Coastal
and Marine Waters."

H Shirley Baker
participated in a
panel discussion
of "thefine art of
balancing a scientific career
withfamily," sponsored
by the Women in Science
and Engineering student

Florida Sea Grant
funding for a
proposal titled
/.i.11,. it. Production
of Cultured Hard Clams
in Florida by Triploidy"
that was submitted by Dr.
Shirley Baker (FAS), Leslie
Sturmer (FAS) and Dr. John
Scarpa (Harbor Branch
Oceanographic Institution).

The first-ever
"National Marine
[ f i.. ,'"
were (ri..,,I-., by Bill
Seaman in November
2005 in Washington, D.C.,
as a means of building
awareness ofproducts and
processes derived from the
ocean's biodiversity for
stakeholders ranging from
biomedical producers to
fishery population managers
to aquaculturists.

2. Are toxic cyanobacterial blooms
hazardous to people, fish and other

Unlike marine algal toxins associated with
some red tides, which definitely have been
linked to human health issues and animal
deaths, only one person's death has been
linked with cyanobacterial toxins. In this case,
water contaminated with toxins was used for
dialysis of a patient with kidney failure in
Brazil. We know little about non-lethal effects
on human health aside from rare reports of
illness related to people drinking water with
high toxin levels, primarily in Australia. Beyond
drinking contaminated water, potential routes
for exposure to algal toxins include accidental
consumption of water while swimming,
inhaling aerosolized toxins (e.g., showering
with raw lake water), eating contaminated fish
or shellfish, and prolonged exposure of skin to
algal scums. However, knowing the potential
routes for exposure and understanding health
effects are quite different things. Part of the
problem is that blooms contain more than
just toxic algae. They tend to be a mixture of
bacteria, algae, fungi and chemicals, any one of
which could cause the aforementioned effects.
At this time, the effects of short-term and long-
term exposure are poorly understood, and they
remain a subject of ongoing research in Florida
and other places where cyanobacterial toxins
commonly occur.

There have been numerous reports of dogs, cows
and other domesticated animals dying after
drinking water from lakes or ditches with dense
cyanobacterial blooms and some reports of
dead waterfowl coincident with bloom events.
Research on the effects of toxins has occurred
primarily in laboratories, where particular
species of animals, both terrestrial (including
mice) and aquatic (including invertebrates
and fish), have been exposed to toxins. These
studies indicate that high levels of toxin can
impact behavior, ability to gather food, normal
functioning of organs, reproductive success,
and survival. Although the results of these
studies provide critical information on the
effects of toxins on certain species of animals,
attempts to extend these results to predict the
response of natural aquatic ecosystems have
been limited, and such predictions remain a
challenging research issue. Defining the impact
of toxins in natural environments becomes
complicated because algal blooms can also
be associated with a host of other effects

a. Anabaena

c. Cylindrospermopsis

that negatively impact animal communities.
Clearly, much remains to be learned about how
toxins contribute to biological stress in aquatic
environments during algal blooms.

3. Can blooms be reduced in occurrence,
prevented, or even eliminated?

The most direct way to prevent or reduce the
occurrence of blooms is to reduce the availability
of nutrients that fuel the growth of algae. The
feasibility of reducing nutrient availability in
large natural aquatic ecosystems depends, in
large part, on their sources. Some of the most
dramatic reductions in algal blooms have
involved the control of point sources of nutrients,

I .... N ."
**** ~~~~i: "' : ::.,.

Faculty Focus

Florida's economy is inextricably\ Ilinked
to its coastal and marine resoi,.ices-
and balancing their use and pro.ec ton i
one of the critical challenges fac 1? tlhe
state, now and into the future Floind
is the number one U.S. destination tor
marine recreation activity, including
recreational boating. In addition to the
nearly one million boats registered in
Florida (about one per 17 residents), an
estimated 400,000 tourist boats use state
waterways annually.
Indeed, since 1970,
the 82% increase
in the number of
registered boats
that ply Florida's
waterways has
outpaced the
56% boom in
population. Boal Rrestrictions

The increasing'
use of Florida's
waterways has
created competing Channel Restrictions
and conflicting r =,.
pressures among '*"" '""'
boaters, waterfront
users, and the natural ."'ock
environment. The
Boating and Waterway Management
Program (BWMP)-a joint venture of
Florida Sea Grant and the Department
of Fisheries and Aquatic Sciences-is
intended to help the state meet such
challenges. The program is led by Dr.
Robert Swett. Bob and his colleagues,
Dr. Charles Sidman and David Fann,
have built a solid foundation of boating
and waterway policy, applied research,
and outreach activities. A key to the
program's success has been collaborative
partnerships established both within UF
and with a diversity of federal, state,
regional, and local stakeholders.

One long-term project began when
Florida's West Coast Inland Navigation
District (WCIND) and the BWMP
recognized the need for comprehensive
waterway management and planning,
similar in scope and purpose to terrestrial
efforts. In response, they developed

a 5(-:enc(e-bal>ed
Re,_ional \\:Itel\\ t \. .-
A\:I a l l ;, e rImi eln [a :- '^ "
S'. stem i R\\t \ 1

'ia(inctioned I:) le hl
State ot Florida, that
resulted in innovative state policy meant
to balance the simultaneous use and
protection of estuarine environments,
while maintaining the economic vitality
of coastal communities.

The RWMS combines
on-water censuses of
boat locations and
characteristics with
surveys of water depths
in channels. Boat
drafts and waterway
depths are analyzed
in a geographic
information system
(GIS) to identify, for
individual channels,
which boats are
blocked at mean lower
low water, and by how
much; and conversely,
for each boat, which
.. .. as channel segments may
block it and by how
much. Counties use this information,
along with statistical analyses and
recommendations, to identify and
quantify actual or potential problems.
The scientific approach provides
unbiased information for rational,
objective waterway management
and allows local decision-makers
to assign maintenance priorities
on a regional basis.

Field applications of the RWMS
along 1000+ miles of waterways
in Manatee, Sarasota, and Lee
Counties led to Chapter 62-
341.490 of Florida's Administrative
Code: "Noticed General Permit
for Dredging by the West Coast
Inland Navigation District." The
rule applies to 51 boat source Progi
areas (canal systems, for example) anal
that have high-priority needs
for maintenance dredging and boa

;- .---
minimal potential for environmental
impacts, as identified by the RWMS.
To qualify for the general permit, the
rule explicitly states that environmental
restoration and enhancement projects
must comply with the science-based
procedures and methods outlined in
technical documents developed by the

The adoption of the RWMS by the State
of Florida and implementation of the
Administrative Code rule demonstrate
that sound science and its extension can
guide management of state waterways.
Benefits include: (1) state policy based
on the "best available science," (2)
more efficient and effective dredging
and waterway maintenance, (3) savings
in dollars and staff time, and (4)
better public policy through holistic,
ecologically-based decision making that
is predictable, fair, and cost effective.



ram lead Bob Swett applies fieldwork and
'sis to tackle daunting problems facing
la's waterways and a growing recreational
ng population.


Student Spotlight

vy Baremore began her graduate work with Dr.
Debra Murie in the fall of 2004. Her Master's
thesis focuses on the trophic dynamics of the
Atlantic angel shark, Squatina dumerili. The
Atlantic angel shark is a bottom-dwelling shark
that inhabits waters of the Gulf of Mexico and
the U.S. Atlantic Ocean. Of the 11 described
species of angel sharks found throughout the
world, the Atlantic angel shark is the only one
known to occupy the Gulf of Mexico. Due to
a lack of biological information, it is listed as a
prohibited species by the Fisheries Management
Plan for Sharks (NMFS 1993), which means that
it cannot be landed by fishers in U.S. waters.

In a collaborative effort, angel sharks caught by
trawl vessels from Raffield's Fishery (Port St. Joe,
Florida) are collected for biological research
by the National Oceanic and Atmospheric
Administration's (NOAA) Fisheries Service
in Panama City, Florida. A special scientific
exempted fishing permit was issued to Raffield's,
which allows them to keep the sharks for research
purposes. This endeavor has provided the first
scientific data on this species, and it continues to
be a valuable resource. Ivy's previous work as a
biological technician with NOAA Fisheries and
an ongoing collaborative association with the
Panama City laboratory allow her to continue
research on this species at the University of

Because the Atlantic angel shark is a benthic
ambush predator that is caught in trawls, it
may be possible to describe prey availability by
quantifying the trawl catch (Fig 1). Inferences
about prey selectivity can be made by comparing
the prey items caught in trawls to the items found
in angel shark stomachs. This information is
important because fish with highly selective diets
are likely to be more vulnerable to changes in
food availability due to fishing or environmental
variations. Although the Atlantic angel shark is
currently off-limit to fishers, this information

I-ia' help 1 -,a nagtei p e)I cf

I saI FI I i tl t1ps s 0tIl, thalt 1an el
sharks teed primarily on bony
fishes (77% by occurrence), including croakers,
goatfishes, lizardfishes, porgies, seabasses (Fig.
2), eels, scorpionfishes, snappers, and hakes.
Squid are also an important component of
the diet (14%), and some crustaceans, such
as shrimps and crabs, are also consumed
(9%). The diet does not appear to be highly
specialized, and it reflects some of the most
abundant species found in the trawl catches.
Other areas of Ivy's thesis research concentrate
on testing for selection of prey by size and
assessing changes in diet as sharks grow and
mature (ontogenetic shifts). Gaining knowledge
of the trophic dynamics of the Atlantic angel
shark will help to ensure proper management
of this species in the future.

Reference: NMFS. 1993. Fisheries Manage.
Plan for sharks of the Atlantic Ocean.

Figure 1. Trawl bycatch

Figure 2. Seabass from stomach contents

5ltldle nt


was recently
awarded a SURF
Travel Grant
and an IFAS Travel Grant
to attend the American
Zoo and Aquarium
Association's Annual
Conference in ( I. .,... IL
to present "Sound, Stress,
Sex, and Seahorses: The
Consequences of a Noisy
Environment on Animal

JeffHill (PhD,

20024) received
ment the American
Fisheries Society
Southern Division "Best
S paper, Runner-up Award"
for his paper titled "Prey
vulnerability to peacock
cichlids and .,.. .,... i,. m
bass based on predator
gape and prey body depth."

received a
grant from
the American
Association of Zoo
Veterinarians, to conduct
experiments on seahorse

Chanda Littles
(MS, 2005) is

i, li,. as an
intern in the
USEPA Office of Water,
Wetlands Strategies and
State Programs Branch.


Researchers hope to reel in

high-performance perch

The following article, written by Candace Pollock of Ohio State
University, focuses on the research of Geoff Wallat, a 1998 MS
graduate of the Dept. of Fisheries and Aquatic Sciences (faculty
advisor Frank Chapman).

Ohio State University Ohio Agricultural Research and
Development Center aquaculturists Han-Ping Wang and Geoff
Wallat are leading a team of researchers in a U.S. Department of
Agriculture-funded project to make sure that Ohio's most popular
fish yellow perch meets those

"Markets want fish that are 8-11
inches long and produce a 4-
5 ounce filet. And it's expected
that 90 percent of the fish reach
that size within 18 months," said
Wallat with OSU South Centers
at Piketon, Ohio. "In Ohio,
usually only 50 percent of pond-
raised perch reaches that market
size and it takes them 18 months to do it. The purpose of our
study is to improve the consistency of size and reduce the time it
takes to reach that size."

In orderto do that, researchers are crossbreeding strains of yellow
perch found throughout the country, in the hope that genetics

Assessment of the Southern

e Snapper Fishery in
S' Queensland, Australia

Dr. Mike Allen (FAS/IFAS) is visiting Australia on a sabbatical where he
is working with the stock assessment team at the Southern Fisheries
Centre, Queensland Department of Primary Industries.

Dr. Allen is conducting an assessment of the Queensland southern
snapper Pagrus auratus fishery. Southern snapper support important
recreational and commercial fisheries throughout New Zealand and
centrallsouth Australia, and represent the largest recreational fishery
south of the Great Barrier Reef. In Queensland,
recreational landings of southern snapper exceed
commercial landings by a factor of two to four.

The southern snapper is associated with rocky
reefs at water depths ranging from 10 to 200
meters. The species has a long life span with
low natural mortality (M=0.1 to 0.15), and thus
are potentially vulnerable to overfishing. There
is cause for concern because most harvest is
focused on fish ages 2-4, and fish over age 10 are
rare in the catch.

Alumni Alert
will create the perfect fish. Strains of yellow perch from Maine,
New York, Pennsylvania, Wisconsin, Nebraska, North Carolina
and Ohio are being studied through a number of crossbreeding
variations to determine which, if any, would make a faster-
growing, larger-growing yellow perch.

"It's not uncommon for pond-raised perch to have variable growth
rates," Wallat said. "But because of those variable growth rates,
it takes longer for some of the fish to reach market size and the
population that does reach market size is not high enough for
market standards. There are also some problems with semi-wild
brood stock being used with
pond-raised fish, which also
may inhibit optimum market
size. Not a lot of work has been
done with genetics and we
are hoping that genetics will
produce a more uniform fish."

In a recent study conducted
at Purdue University, data has
shown that at watertemperatures
of 72 to 74 degrees Fahrenheit,
North Carolina strains of yellow perch grew quicker than several
other geographical strains being studied. Preliminary data
from the Ohio State study has shown that the Ohio strain has
outperformed geographically related strains such as Pennsylvania
and New York.

Dr. Allen is using a stochastic stock reduction analysis (SRA) to
assess the stock status and potential remedial management actions.
The SRA uses historical and current fishery data to estimate what
past recruitment (i.e., number of age-1 fish per year) would have been
required to produce the landings history and result in the current stock
status (e.g., population size or age structure).

His results show that the southern snapper stock is heavily fished
with fishing mortality currently exceeding sustainable levels. The
current population biomass is predicted to be only 20-30% of the virgin
biomass levels. The simulations indicate that measures to reduce
fishing mortality such as size limits and bag limits would have to be
very restrictive to reverse a declining population trajectory.
Because very restrictive size or bag limits would cause more fish to be
caught and released by anglers, the impact of discard mortality could
have strong implications for the snapper stock. Dr. Allen is modeling the
impact of discard mortality on fish caught and released and evaluating
the potential for discard mortality to negate the benefits management
actions. If discard mortality would nullify benefits of sizelbag limits,
then fishery managers would need to consider timelarea closures to
protect the stock.

Results of this work will be used to improve the management of southern
snapper fishery in Queensland. Dr. Allen returns to Gainesville this
month and will present a seminar on this project at FAS next spring, so
tune in for the results!

1- &



such as the introduction of advanced
sewage treatment facilities. By contrast,
environments subject to diffuse inputs
of nutrients, such as agricultural or
suburban runoff, are more difficult to
manage because sources are harder to
control. Another complication in many
lakes, such as Lake Okeechobee, comes
from the accumulation of nutrient-rich
sediments over long periods of time.
These sediments represent a pool of
nutrients that can sustain algal blooms
for extended periods even after sources
of external nutrients are eliminated.
Developing a management plan to
control nutrient availability requires
careful consideration of all of these
issues, as well as a clear vision of the
desired and realistically attainable goals.

Besides long-term management of
nutrient inputs as a means of limiting algal
blooms, individual blooms can be treated
ex-post-facto with chemical algicides,
such as copper sulfate. Herbicides
are widely used in Florida to control
aquatic weeds like Hydrilla, but the use
of algicides to control blooms is less
common and generally limited to small
water bodies due, in large part, to high
costs. There are also potentially negative
consequences from the use of chemicals
to control blooms. Mass mortality of
algae resulting from treatment can result
in a rapid increase in bacteria feeding on
and decomposing the dead algae. These
bacteria can use oxygen and release

In one aspect of the project, researchers
are crossbreeding the North Carolina
strain with the Ohio strain, banking that
genetics and geography will produce a
high-performance fish.

"Sometimes geographically related
species, such as Ohio and Pennsylvania,
are close genetically, which may not
be what we always want," Wallat said.
"It may be that the least-related is what
performs the best."

Ohio strains have so far outperformed
Pennsylvania and New York strains of
yellow perch.

ammonia at levels that pose threats to
animals. Decomposition of algae also
leads to release of nutrients that can
stimulate subsequent blooms unless
chemical treatments are repeated on a
regular basis. In the case of toxic algae
blooms, chemical treatments also can
cause a sudden release of toxins from the
algal cells into the water column, which
may cause undesirable changes.

4. What are scientists in the
Department of Fisheries and
Aquatic Sciences doing about toxic
cyanobacterial blooms?

One of the central goals of the
Department of Fisheries and Aquatic
Sciences is to provide objective
information that citizens and resource
managers can use to make informed
decisions about water resources and to
develop effective programs that protect
the integrity of aquatic environments
and human health. For 20 years, we
have studied the occurrence, causes
and control of cyanobacterial blooms in
Florida's aquatic systems, including Lake
Okeechobee, the St. Lucie River and
Estuary, the St. Johns River, the Kissimmee
River, Florida Bay and numerous inland
lakes. Our work documents links
between bloom formation and various
environmental factors, including water
column stability, water residence time,
dissolved nutrient concentrations, and
meteorological conditions. At the present
time, we are working with scientists

"We also have to be careful with what
we take with us when we select for
certain traits," Wallat said. "We don't
want to produce a fish that is susceptible
to disease or produces poor muscle

Researchers are in their second year of
the four-year study, selecting the top 10
percent group for growth per generation
and using that group as the basis for the
next breeding generation.

Written Friday, September 09, 2005

Source: http://www.agriculture.
story. asp?storyID 4035

and managers from State and Federal
agencies to establish a statewide program
to assess the distribution and frequency
of non-toxic and toxic cyanobacterial
blooms and the relationship between
these outbreaks and variations in weather
and land use. We also contribute to
an understanding of how toxins affect
fish, shellfish, aquatic plants, and other
components and processes in aquatic
ecosystems. Unanswered questions
include: How many blooms in Florida's
waters are toxic? Are these blooms more
or less toxic than those in other regions
of the world? What are the ecological
effects of toxins, including both direct
effects and indirect effects that might
occur if toxins change predator-prey
or competitive interactions in aquatic
food webs? How high are toxin levels in
different species of fish that are regularly
caught by recreational and commercial
fishers? The broad range of expertise
available within the Department of
Fisheries and Aquatic Sciences, in
combination with the substantial physical
and intellectual resources in IFAS and the
University of Florida community, provide
unique opportunities for meaningful,
state-of-the-art research to address these
important questions.

Current and past issues

of WaterWorks

can be found on the

Department's website at:

http://fishweb. ifas. uf. edu

To receive notification when

new issues are available, please

send your email address to:





University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs