Citation
Tropic news. Volume 13. Issue 1.

Material Information

Title:
Tropic news. Volume 13. Issue 1.
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

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

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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.

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Full Text



low-;i


First Quarter 2002


I


The Environmental Protection Agency's (EPA)
Ocean Survey Vessel (OSV) Peter W. Anderson
was in St. Thomas and St. John area from Febru-
ary 17-24, 2002. The OSVAnderson is a 167 foot
Vietnam War era converted gunship. All of the
guns have been removed and the entire ship has
been refitted for scientific research. USVI Divi-
sion of Fish and Wildlife staff were invited on
board to conduct seafloor mapping of an artificial
reef site southeast of Saba Island, St. Thomas and
a portion of the shelf south of St. John.






Min -
.'1" -
I' [ "I .










OSV Peter W. Anderson in port

The seafloor mapping was conducted using
side scan sonar. Side scan sonar (SSS)is a method
of producing an image of the seafloor using acous-
tic signals. Essentially, sound is emitted from
transducers towed behind the vessel in a "tow
fish". An acoustic signal is transmitted from the
tow fish and bounces back off of objects on the
seafloor. The return signal is then received by the
tow fish, interpreted by computers on the ship
and displayed as an image. Side scan sonar works
similar to a depth sounder but projects a signal
out away from the ship rather than directly under
it. The frequency used is harmless to marine life
and each sound wave or "ping" does not last more
than fraction of a second. Combined with a global
positioning satellite (GPS) system, we are able to
to map the exact locations of reefs, wrecks, or
other features on the seafloor.


Volume 13 Number 1


ip
Deploying the side scan sonar "tow fish"

An artificial reef site that measures approxi-
mately 1 square nautical mile southeast of Saba
Island was mapped. Artificial reefs are important
because they provide habitat for many species of
fish and invertebrates in areas otherwise devoid of
structure. The Side Scan Sonar provides informa-
tion on the type of bottom communities at the site
and the size and location of the artificial reef
material (ships, barges, I-beams, etc.) previously
deployed. Further information is gathered by Fish
and Wildlife staff by scuba diving the artificial
reefs and recording what corals, sponges, etc. have
settled on the material and what fish, lobsters, etc.
inhabit the reefs. This information is required in
order for the Division of Fish and Wildlife to
renew its permit for artificial reef construction so
that fishing opportunities can be improved for
everyone.


Image of a wreck in the artificial reef site SE
of Saba Island


TROPIC NEWS
DEPARTMENT OF PLANNING AND NATURAL RESOURCES
DIVISION OF FISH AND WILDLIFE






A portion of the shelf south of St. John was
also surveyed using side scan sonar (SSS).
Approximately eight square nautical miles
were surveyed. Over the next several years an
area totaling almost 64 square nautical miles
will be surveyed south of St. John using the
Division's 27' research vessel RV. Lindsey. The
SSS images collected will be put together to
create a geographically referenced map of the
sea floor. This map will be used to determine
the location and extent of coral reefs, algal
beds, hard bottom, etc. on the shelf. This
knowledge will be useful in recommending
management strategies for various fisheries
and marine resources.
-Waewantto thank all the fishermen who
kindly moved their traps so we could conduct
this critical research.



6



A v^J-^ St.Thomas



X
xo>
South St. Thomas
Artificial Reef Site


Artificial reef site SE of Saba Island


GOVERNMENT OF THE VIRGIN ISLANDS
OF THE UNITED STATES
******
Department of Planning and Natural Resources
Division of Fish and Wildlife
6291 Estate Nazareth 101
St. Thomas, USVI 00802-1104
(340)775-6762 (ST.T.), (340)772-1955 (ST.X.)


Area south of St. John that was surveyed.


4f & This newsletter was funded by
.'jiS^ Fish and Wildlife Service, Sport Fi
S toration Act and the Governmen
,e, VI.
Donna M. Griffin Editor
William CollA Chief of Environmental Educatinn


the US
sh Res-
t of the


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

Division of Fish and Wildlife
45 Mars Hill
St. Croix VI 00840


Address Correction Requested


Trees were saved by printing on recycled paper


Mapped Area





Shel f edge


I


- -- ,,




Full Text

PAGE 1

The Environmental Protection Agency's (EPA) Ocean Survey Vessel (OSV) Peter W. Anderson was in St. Thomas and St. John area from February 17-24, 2002. The OSV Anderson is a 167 foot Vietnam War era converted gunship. All of the guns have been removed and the e~tire ship has been refitted for scientific research. USVI Division ofFish and Wildlife staff were invited on board to conduct seafloor mapping of an artificial reef site southeast of Saba Island, St. Thomas and a portion of the shelf south of St. John. Deploying the side scan sonar "tow fish" An artificial reef site that measures approximately 1 square nautical mile southeast of Saba Island was mapped. Artificial reefs are important because they provide habitat for many species of fish and invertebrates in areas otherwise devoid of structure. The Side Scan Sonar provides information on the type of bottom communities at the site and the size and location of the artificial reef material (ships, barges, I-beams, etc.) previously deployed. Further information is gathered by Fish and Wildlife staff by scuba diving the artificial reefs and recording what corals, sponges, etc. have settled on the material and what fish, lobsters, etc. inhabit the reefs. This information is required in order for the Division of Fish and Wildlife to renew its permit for artificial reef construction so that fishing opportunities can be improved for everyone. OSV Peter W. Anderson in port The seafloor mapping was conducted using side scan sonar. Side scan sonar (SSS)is a method of producing an image of the seafloor using acoustic signals. Essentially, sound is emitted from transducers towed behind the vessel in a "tow fish". An acoustic signal is transmitted from the tow fish and bounces back off of objects on the seafloor. The return signal is then received by the tow fish, interpreted by computers on the ship and displayed as an image. Side scan sonar works similar to a depth sounder but projects a signal out away from the ship rather than directly under it. The frequency used is harmless to marine life and each sound wave or "ping" does not last more than fraction of a second. Combined with a global positioning satellite (GPS) system, we are able to to map the exact locations of reefs, wrecks, or other features on the seafloor. Image of a wreck in the artificial reef site SE of Saba Island DEPARTMENT OF PLANNING AND NATURAL RESOURCES DIVISION OF FISH AND WILDLIFE First Quarter 2002 Volume 13 Number 1

PAGE 2

A portion of the shelf south of St. John was also surveyed using side scan sonar (SSS). Approximately eight square nautical miles were surveyed. Over the next several years an area totaling almost 64 square nautical miles will be surveyed south of St. John using the Division's 27' research vessel RV. Lindsey. The SSS images collected will be put together to create a geographically referenced map of the sea floor. This map will be used to determine the location and extent of coral reefs, algal beds, hard bottom, etc. on the shelf. This know ledge will be useful in recommending. management strategies for various fisheries and marine resources. --We w~_ntio thank alithe fIShermen who kindly moved their traps so we could conduct this critical research. ~ Area south of St. John that was surveyed. ~f~~ ~ This newsletter was funded by the US Fish and Wildlife Service, Sport Fish Restoration Act and the Government of the VI. Artificial reef site SE of Saba Island Donna M. Griffin Editor WilliAm ~nl~R ~hi~f nf Environmental Educatinn BULKRAlE U.S. POSTAGE PAID CHARLOTfE AMALIE. V.I. PERMIT NO. 35 GOVERNMENT OF THE VIRGIN ISLANDS OF THE UNITED STATES ****** Department of Planning and Natural Resources Division of Fish and Wildlife 6291 Estate Nazareth 101 St. Thomas, US VI 00802-1104 (340)775-6762 (ST.T.), (340)772-1955 (ST.X.) Division of Fish and Wildlife 45 Mars Hill St. Croix VI 00840 Address Correction Requested Trees were saved by printing on recycled paper