Citation
Tropic news. Volume 6. Issue 9.

Material Information

Title:
Tropic news. Volume 6. Issue 9.
Series Title:
Tropic News
Creator:
United States Virgin Islands. Department of Planning and Natural Resources. Division of Fish and Wildlife.
Publisher:
United States Virgin Islands. Department of Planning and Natural Resources. Division of Fish and Wildlife.
Publication Date:
Language:
English

Subjects

Subjects / Keywords:
Caribbean ( LCSH )
Newspapers -- Caribbean ( LCSH )
Genre:
serial ( sobekcm )
Spatial Coverage:
North America -- United States Virgin Islands
Caribbean

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright United States Virgin Islands. Department of Planning and Natural Resources. Division of Fish and Wildlife.. Permission granted to University of Florida to digitize and display this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.

Downloads

This item has the following downloads:


Full Text


TROPIC NEWS


DEPARTMENT OF PLANNING AND NATURAL
RESOURCES


DIVISION OF FISH AND WILDLIFE


Volume 6 Number 9


BLUE FRY; BASIS OF THE FOOD WEB
Blue fry, Jenkinsia lamprotaenia also known as
dwarf herring, are small coastal marine fish of the
family Clupeidae. They are found in the Antillean
Caribbean, Venezuela, and Bermuda in calm, shallow
waters near reef areas, beaches, and in caves. Blue
fry feed on zooplankton and are preyed upon-
by a variety -of fish includ-
i n g lizardfish,
barracuda, grouper,
isnppnr, jnak, tuna, mack- 6rol, and cui piounilsh.
Many species of seabirds also depend on this resource
to feed themselves and their young. In other words, they
are the basis of the food chain for many marine animals.
Blue fry are the most commonly caught bait species
in the U.S. Virgin Islands. It is the preferred species
used by local commercial ard sportfishermen as bait
and chum for yellowtail snapper. Blue fry are thought to
be obligate schoolers, which means that they live in
polarized groups, with all members swimming in
basically parallel courses. Major features of the biology
and life cycle of this species have yet to be established.
The eggs of this species have never been described
nor have the fecundity (numbers of eggs per spawn) and
spawning frequency been studied. Juvenile blue fry are
from 10 to 40 mm (approx. .5 to 1.5 in.) and adults are
usually 55 to 60 mm (approx. 2.25 in.) in standard
length. It is believed that inshore aggregations of blue
fry are comprised of pre-spawning individuals that move
offshore just before the full moon to form spawning
aggregations. Data collected by the Division of Fish and
Wildlife show that fish begin to appear inshore in a fully
ripe or nearly ripe reproductive condition and gradually
move ofshore, at night, to spawn while illuminated by
the full moon.
Recently, fluctuations in numbers offish have been
noted by the Division as well as by fishermen. The
decrease in numbers may result from intense fishing
efforts during lunar spawning aggregations. By remov-
ing individuals before they can spawn, the populations
of this species can only decline. The loss of baitfish in
our waters could have dire affects on the marine food
web as species that feed on them are forced to feed on
otherfish or die due to lack of food. The seabirds that
depend on them will be unable to breed successfully and
might have to nest elsewhere. This potential collapse of
the baitfish populations has created a need for more
accurate information on the population biology of blue
fry to determine the need for conservation management
of the natural stocks. .. ,



y- z _, --


I I


The Sooty Tern, Sterna fuscata is the most abundant tern in the
Virgin Islands. This species is distinguished by appearing to have
nntirrly hlnrlr nppprparts and whitn inicrpi Cs. OutiLy iWrUl nekAt in
the Virgin Islands from May to A'" gust o- c'Jy.lrs civ. and feed out at
sea from the cays. Most of the other tern species here feed inshore on
baitfish. Sooty terns lay a single, spotted egg in a shallow scrape
under vegetation.

A SOOTY PROJECT
The Division of Fish and Wildlife is currently study-
ing the Sooty Tern colony nesting on Saba Cay, 4.1
miles westsouthwest of Charlotte Amalie. Saba Cay is a
designated wildlife sanctuary and has the largest.
nesting colony of Sooty Terns in the U.S. Virgin Islands.
The objectives of the study are to characterize Sooty
Tern nesting habitat on Saba, determine nest abun-
dance and distribution, and estimate nest success in
different habitat types. This information will be used to
manage nesting habitat for sooty terns in order to
maintain or enhance a stable Sooty Tern population by
implementing habitat management practices.
This year Sooty Terns appear to have increased their
nesting numbers from an estimated 30,000 nests per
year since 1991. The increase in numbers may be re-
lated to the extreme dry conditions which have in-
creased available nesting habitat on the island.
Remember, Saba Cay is off-limits to anyone without
a valid visitation permit during the breeding season
from April 1 to November 15 each year. During the rest
of the year, the sandy beach at the northwest end of the
island may be used by the public for reasonable, non-
damaging recreational use only during daylight hours.









QUOTE
"The balance of nature... cannot safelybe-ignored any
more than the law of gravity can be defied with impu-
nity by a man perched on the edge of a cliff."
Rachel Carson
Silent Snrinpr -


June 1994






A WILDLIFE BONANZA
Once a year, in the spring, the dry sides of our is-
lands come alive with the yellow flower stalks
of the century plant (Agave missionum ).
These stalks can reach 15 feet in height and
have hundreds of vivid yellow flowers in
separate bunches on short branches. The
odor and color of the flowers attract
many insects and nectar feeding birds.
The insects in turn attract species of
insectivorous birds. When in full bloom, the
Sl' :-1-i-"'- century plant flower stalk can be swarm-
ing with honey bees, carpenter bees,
hummingbirds, Bananaquits, Gray
Kingbirds and Pearly-eyed Thrashers.
This wildlife bonanza lasts until the flowers are polli-
nated and begin to dry up. The century plant is unusual
in that the pollinated flowers may develop into centi.xv
plantlets bulbilss) right on the stalk and then drop off to
grow around the dying parent plant. The century plant
is so named because people believed that it grew for 100
years before flowering. Actually, the life span of these
plants is more on the order of 10 to 15 years. Here in the
Virgin Islands, people use the dry flower stalk as a
Christmas tree.


RECREATIONAL FISHING
The Division of Fish and Wildlife is continuing the
Recreational Port Sampling Project. We will be inter-
viewing fishermen and sampling their catches at tour-
naments and other times this summer. We would
greatly appreciate your assistance and cooperation in
sharing your fishing activities and information with us.
This information is vital in assessing the productivity
and health of our recreational fishery. To find out how
you can help us help you, please call or stop by our
offices on St. Thomas or St. Croix. New catch logs are on
order and will be here soon.

Trees were saved by printing on r ?cy.-d paper


LIZARDS IN PARADISE
Recently, Division staff and Mike Evans, Refuge
Manager for Sandy Point and Green Cay, St. Croix,
went looking for lizards. The lizard being sought was
the endangered and endemic St. Croix Ground Lizard
(Ameiva polops ). This lizard is only still naturally
found on Protestant and Green Cays off St. Croix. It was
once abundant near Fredericksted but may have been
extirpated by mongoose and human activities. Three
surveys were made for'each cay on three different days.
The surveys involved counting all lizards seen during
a four minute observation period in three meter diam-
eter plots along transects. There are 44 plots on Greeen
Cay and 20 on Protestant Cay. The data is used to
.calculate density and population sizes.
The population estimates are 500 lizards on Green
Cay and 75 on Protestant Cay. Unfortunately, this
lizrrd is difRnhlt to count because it sp5,nf ri1h of +n
time in burrows or under leaf litter or rocks. When
above ground, it is difficult to detect due to its colora-
tion. As a result, the data is not exact and in fact may be
low. There is some evidence that the most accurate
estimates would be obtained by combining counts which
would give us 1,000 lizards on Green Cay and 175 on
Protestant Cay. This would be good news.
Whatever the results, the data and other observa-
tions indicate that the populations are healthy on Green
Cay and seemingly doing well on Protestant Cay. Com-
parisons with previous counts also indicate that the
populations are stable. With additional funding from the
U.S. Fish and Wildlife Service, we may continue to
monitor the populations of this endangered
e- species and assist in its population
recovery. A small, third population
has been established
K.... ./ on Ruth Cay.
I I I


(YI9&


This newsletter was funded by the US
Fish and Wildlife Service, Sport Fish and
Wildlife Restoration Acts, the Caribbean
Fishery Management Couicil and the
GovernmPnrt of the VI


GOVERNMENT OF THE VIRGIN SLADS
OF THE UNITED STATES
+**<**
Department of Planning and Natural Resources
Division of Fish and Wildlife
6291 Estate Nazareth 101
St Thomas, USVI 00802-1104
(809)775-6762 (ST.T.), (809)772-1955 (ST.X.)


BULK RATE
U.S. POSTAGE PAID
CHARLOTTE AMALIE, V
PERMIT NO. 35


Address Correction Requested


-- I c cLvL--- -c~, I ---b_-g~srs~ sa~e~b- I ~e e~e~


19P- ---~-_-- _




Full Text

PAGE 1

,i:' ~'.:i ::: k-~ DEPARTMENT OF PLANNING AND "NAnJRAL RESOURCES DIVISION OF FISH AJ...TD WILDLIFE Volume 6 Number 9 June 1994 ~ The Sooty Tern, Sterna {uscata ,is the most abundant tern in the Virg'..n Islands. This species is distinguished by appearing to have nnt.in"ly hl nr~ l'r~rpnrtR Ilnd ',...hitJ\ "l1'Jr:r~Ul(tI. Ol/l,Ly IA!J..li~ l1e!St in the Virgin J.slands from May to .A" gust o~ (.~""-'1~~ c:~v.~ at\d feed out at sea from the cays. Most of the other tern speci~s here feed inshore on baitfish. Sooty terns lsy a single, spot~d egg in a shallow scrape under vegetation. A SOOTY PROJECT The Division of Fish and Wildlife is currently stndying the Sooty Tern colony nesting on Saba Cay, 4.1 miles westsouthwest of Charlotte Amalie. Saba Cay is a designated wildlife sanctuary and has the largest nesting colony of Sooty Terns in the U.S. Virgin Islands. The objectives of the study are to characterize Sooty Tern nesting habitat on Saba, determine nest abundance and distribution, and estimate nest success in different habitat types. This information will be used to manage nesting habitat for sooty terns in order to . maintain or enhance a stable Sooty Tern population by implementing habitat management practices. This year Sooty Terns appear to have increased their nesting numbers from an estimated 30,000 nests per year since 1991. The increase in numbers may be related to the extreme dry conditions which have increased available nesting habitat on the island. R .~~-"";' b "'c:!-1-"'~ y ] . s " ff ':""' l ."t ,.. ~ c .",..L'., t .v...c... ~'., uuua; va; "'" '.L.u "" '" c...~.rViJ.v "...;.i"u~ a valid visitation permit during the breeding season from April 1 to November 15 each year. During the rest ofth~ year, the sandy beach at the northwest end of the island may be used by the public for reasonable. nondamaging recreational use only during daylight hours. ~ QUOTE "The balance of nature... cannot safely-bt!"ignore-d any more than the law ofgravjty can be defied with jrnpunjty by a man perched on the edge ora cliff." Rachel Carson . Silent Snr;nv BLUE FRY; BASIS OF THE FOOD WEB Blue fry, Jenkinsia lamprotaenia , also known as dwarf herring, are small coastal marine fish of the family Clupeidae. They are found in the Antillean Caribbean, Venezuela, and Bennuda in calm, shallow waters near reef areas, beaches, and in caves. Blue fry feed on zoop1ankton and are preyed upon. by a variety .~. """" . = offish inc1ud. . . ,: .., ~.. :.~~~ r I . dfi h 1 n g , """ . :!.. .:; ""'---""' , ..;'"'.,.~'-=_. ~~ lzar 1S , ._,., ""... ~ barrac~da, ,-, ~:~ ~ouper, ~n:tppnr. J(\l:\lt, tuna, m.!lck~ 6r~l, utiU :cil:UfV1UIillg!1. lvIany species of seabirds also depend on this resource to feed themselves .and their young. In other words, they are the basis of the food chain for many marine animals. Blue fry are the most commonly caught bait species in the U.S. Vir~n Islands. It is the preferred species used by local commercial arid sportfishermen as bait and chum for yellowtai1 snapper. Blue fry are thought to be obligate schoolers, which means that they live in polarized groups, with all members swimming in b~sical1y parallel courses. Major features of the biology and life cycle of this species have yet to be established. The eggs of this species have never been described nor have the fecundity (numbers of eggs per spawn) and spawning frequency been studied.' Juvenile blue fry are from 10 to 40 mm (approx. .5 to 1.5 in.) and adults are usually 55 to 60 mm (approx. 2.25 in.) in standard length. It is believed that inshore aggregations of blue fry are comprised of pre-spawning individuals that move offshore just before the full moon to fonn spawning aggregations. Data collected by the Division of Fish and Wildlife show that fish begin to appear inshore in a fully ripe or nearly ripe reproductive condition and gradually ..no',,'e OnSJ10Te, at night, to spawn whi1~ illuminated by the full moon. Recently, fluctuations in numbers offish have been noted by the Division as well as by fishermen. The decrease in numbers may result from intense fishing efforts during lunar spawning aggregations. By removing individuals before they can spawn, the populations of this species can only decline. The loss of bait fish in our waters could have dire affects on the marine food web as species that feed on them are forced to feed on other.fish or die due to lack of food. The seabirds that depend on them will be unable to breed successfully and might have to nest e1sewhere. This potential colJapse of the baitfish populations has created a need for mOTe accurate information on the population biology of blue fry to determine the need fOT conservation management of the natural' stocks. ,-:;:~ '-"::;;:~ .,.,If.'7o1: '"':"~'~.~ ~ f.'\ ...' "'~~-:.~"':"-: ~~~~:;--"""';", ~'\~ .~\-=_~~!'::.~'~..= ;.~~ '. ~;.,.eI ~=;?> . -""J'Y ..'"-~~ --. --'7-':~ " '-:i:~-= .-:-":\0.:= :i~.,

PAGE 2

",~i!} A WILDLIFE BONANZA Once 13. year, in the spring, the dry sides of our islands come alive with the yellow flower staJks i f the century plant (Agave missionU:m ('). ~ These stalks can reach 15 feet in height and have hundreds of vivid yellow flowers in ~ separate bunches on short branches. The odor and color of the flowers attract ~ ~ many insects and nectar feeding birds. The insects in turn attract species of insectivorous birds. Whel1ll full bloom, the century plant flower stalk can be swarm~ ing with honey bees, carpenter bee.s, -hummingbirds, Bananaquits, Gray Kingbirds and Pearly-eyed Thrashers. This wildlife bonanza lasts until the flowers are pol)i-: nated and begin to dry up. The century plant is unusual in that the pollinated flowers may develop iDt/) c~v.hLry plarltlets (bulbils) right on the stalk and then drop off to grow around the dying parent plant. The century plant is so named because people believed that it grew for 100 years before flowering. Actually, the life span of these plants is more on the order of 10 to 15 years. Here in the Virgin Islands, people use the dry flower stalk as a Christmas tree. RECREATIONAL FISHING The Division ofFish and Wildlife is continuing the Recreational Port Sampling Project. We will be interviewingfish~rmen and sampling their catches at tournaments and other times this summer. We would ~eatly appreciate your assistance and cooperation in sharing your fishing activities and information with us. This information is vital in assessing the productivity and health of our recreational fishery. To find out how you can help us help you, please call or stop by our offices on St. Thomas or St. Croix. New catch logs are on order and will be here soon. . . . . . . . . . . . . . . . . .. . . ~ . . . . . .. . . . . Trees were 1Javoo by printing (ju;r~o/c}ed paper ~!_:-~iI. GOVERNMENT OF -rnE VIRGtNISLM'DS OF 11m UNITED ST A 1'ES ****** Department of Planning and Natural Resources Division of fish and Wi]d1ife 6291 Estate Nazareth 101 St. Thomas. USVI 00802-1104 (809)775-6762 (ST.T.), (809)772-1955 (ST_X.) ~' y~"",,This newsletter was funded by the US Fish and Wildlife Service, Sport Fish and Wildlife Restoration Acts, the Caribbean Fishery Management Co1.JT'C'iJ. :'Iud tb.~ G<>veTT1rnP-1"1t fifth.. VI. BULKRA1E u.s. POSTAGE PAID CHARLOT1E AMALIE, V PERMIT NO. 35 Address Correction Requested I.. LIZARDS IN PARADISE : R,ecently, Division staff and Mike Evans, Refuge Manager for Sandy Point and Green Cay, St: Croix, went looking for lizards. The lizard being sought was the endangered and endemic St. Croix Ground Lizard CAmeiva polops ). This lizard is only still naturally foU.Iid on Protestant and Green Cays off St. Croix. It was once abundant near Fredericksted but may have been extirpated by mongoose and human activities. Three surveys were made for'(Sjach cay on three different days. The surveys involved counting all lizards seen during a four minute observatjon period jn three meter diameter plots along transects. There are 44 plots on Greeen Cay and 20 on Protestant Cay. The data is used to calculate density and population sizes. The population estimates are 500 lizards on Green Cay and 75 on Protestant Cay. Unfortunately, this fj~RTn i~ niffi~"lt to r:OLlnt bec,-au.si) it BDQryc)" ~"rn ofi+!1 time in burrows or under leaf litter or rocks. Whe:n above ground, it is difficult to detect due to its coloration. As a result, the data is not exact and in fact may be low. There is some e\iidence that the most accurate estimates would be obtained by combining counts which would give us 1,000 lizards on Green Cay and 175 on Protestant Cay. This would be good news. Whatever the results, the data and other observations indicate that the populations are healthy on Green Cay and seemingly doing well on Protestant Cay. Comparisons with previous counts also indicate that the populations are stable. With additional funding from the U.S. Fish and Wildlife Service, we may continue to monitor the populations of this endangered ~ species and assist in its population recovery. A small, third population has been established ) on Ruth Cay.