Conservation and Ecology of Marine Reptiles

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Conservation and Ecology of Marine Reptiles MARE
490 Dr. Turner Summer 2011
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Health Disease
Sea turtles are affected by variety of health
problems Combination of natural anthropogenic
effects Captive wild animals
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Health Disease
Several disease health problems
common Nutritional requirements captive
pelleted food wild changing environments
quantity versus quality For example emaciated
animals found dead with stomachs full of food
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Bacterial Diseases
Rare in free ranging turtles Very common in
captive animals Salmonella Pseudomonas Vibrio
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Mycotic Diseases
Found in both captive wild animals Can be
fatal to eggs/embryos Hatchlings/juveniles in
captivity are extremely susceptible
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Viral Diseases
Several occurring Herpes respiratory, gray-patch
viral Fibropapillomatosis green turtle
(GTFP) Found in loggerhead, olive ridley,
hawksbill, flatback
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GTFP
1st described in green turtles in Florida (1938)
Hawaii 1958 Now worldwide Increased
significantly since 1980s Not in all
populations other 92 of animals
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GTFP
3 primary lesions Fibromas (fibrous tissue),
cutaneous papillomas (warty connective tissue),
fibropapillomas (combination) From single to
many When present externally visceral lesions
occur in lugs, liver, GI tract kidneys
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What is It?
Thought to be caused by herpes virus
(papillomavirus) Possibly transferred by
cleaner fishes picking at tumors (e.g. Kole,
Labroides sp.
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Why ask Why?
Why higher prevalence since 1980s? Environmental
effects of nutrient runoff Invasive species
seaweed Unknown stressors Parachute pants/bad
music (Wham!, etc.)
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Stressors!
Environmental stressors are thought to cause
outbreak Bacterial infections UV-B
radiation Blood-fluke eggs Leeches Chemical
contaminants Combination of Weaken immune
system maybe genetic susceptibility
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Disease Investigations
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Environmental Health
Traumatic injuries shark bites, etc
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Environmental Health
Cold stunning coma-like state
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Anthropogenic Problems
Chemical Pollutants DDT, PCBs, oil
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Historical Uses of Honu
Green turtles were a source of food, tools, and
ornamentation for early Hawaiians With the
arrival of western culture, however, the level of
exploitation of this resource increased
dramatically
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Historical Uses of Honu
Large numbers of green turtles were harvested
throughout the Hawaiian Islands through the
nineteenth and early twentieth centuries In
1974, the State of Hawaii passed a regulation
providing some protection Not heavily protected
until 1978, when the Hawaiian green turtle was
placed on the list of threatened species
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Hawaiian Legends
Legend tells about a green sea turtle, Kauila,
who could change herself into a girl to watch
over the children playing at Punalu'u Beach on
the Big Island When Kauila's mother dug her
nest, a fresh water spring surged upward,
quenching the children's thirst
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Hawaiian Legends
Kauila is the "mythical mother" of all turtles
children as well Turtles were said to be the
guides for the first voyagers to Hawaii
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Royal Hawaiian
Alii (chiefs and leaders) in the years of
monarchy feasted on green turtles Petroglyphic
"honu" of the Hawaiians After monarchy
millions of turtles in soup pots
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Anthropogenic Problems
Entanglement in fishing gear
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Anthropogenic Problems
Ingestion of man-made debris
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Endangered Species Act
Purpose Recovery of endangered and threatened
species USFWS (Fish Wildlife) NOAA
(Fisheries) ID Publish list of threatened or
endangered spp Species given full legal
protection no take Federal govt prohibited
harming species or habitat Recovery
plan Includes critical habitat
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What is Endangered?
Well, that's why I asked. That's how you learn,
by asking.. you dumbass. - Carl Carlson
Threatened is the classification provided to an
animal or plant likely to become endangered
within the foreseeable future throughout all or a
significant portion of its range Endangered is
the classification provided to an animal or plant
in danger of extinction within the foreseeable
future throughout all or a significant portion of
its range
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CITES
CITES (the Convention on International Trade in
Endangered Species of Wild Fauna and Flora) is an
international agreement between Governments Its
aim is to ensure that international trade in
specimens of wild animals and plants does not
threaten their survival
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CITES
Works by subjecting international trade in
specimens of selected species to certain
controls. All import, export, re-export and
introduction from the sea of species covered by
the Convention has to be authorized through a
licensing system Important? Hawksbill shell
highly prized 100/lb Until 1992 20 net
tons/Japan Since 1992 (joined CITES) seizures
of 10K lb Still take in many Caribbean
countries Jamaica, Cuba, Virgin Islands, Puerto
Rico, Mexico, etc.
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IAC
The Inter-American Convention for the Protection
and Conservation of Sea Turtles is an
intergovernmental treaty which provides the legal
framework for countries in the American Continent
to take actions in benefit of sea turtles The
IAC entered into force in May of 2001 and
currently has eleven Contracting Parties, in
addition to two countries awaiting national
ratification
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Bycatches and Discards
Do yourself a favor don't turn around, Keep
America Beautiful Native American
The aim of most fishers is to capture species
that have financial or energetic value target
species
Target species are often associated with
non-target species (organisms not intended catch
of that fishery)
Can become part of the catch known at incidental
catch
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Trawling effects
It has been estimated that across fisheries
worldwide, up to ¼ of any given catch is bycatch
Much higher in trawling operations shrimp
fisheries gt 35 of global fisheries discards
Kg discard per Kg landed
Fishery
Trinidadian shrimp trawl 14.70 GOM shrimp
trawl 10.30 NW Atlantic fish trawl
5.30 Atlantic Menhaden purse seine 0.30 NW
Atlantic Hake trawl 0.01
Case Study GOM shrimp fisheries discarded 19
million red snapper and 3 million Spanish
mackerel in 1989 (Alverson 1994)
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What about the Wee Turtles?
450 stranded sea turtles washed up on Texas
beaches in 1999 - 95 of them endangered Kemp's
ridleys Kemp's ridley - fewer than 2,000
females over 40,000 recorded in 1947 Shrimping
activity has increased 400 in Texas bays and 95
in adjacent gulf waters since 1961
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Problem
Trawls are nets pulled along the bottom to catch
shrimp and other invertebrates Turtles become
trapped and drown As tow duration ? Turtle
mortality ?
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Solution
Area closures or reduced tow times So good do
that! Shorter trawls hauls in a given time
? wear on gear, crew Ultimately reduced
bottom line () Therefore additional
solutions required
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TED
Turtle Excluder Device Originally developed by
NMFS in MS Several modifications from Feds
shrimpers Allows for turtles large bycatch to
escape
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What about the Wee Turtles?
If I dont save the wee turtles, who will? Ah!
Save me from the wee turtles. They were too quick
for me. Ahh! Groundskeeper Wille
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Whats the solution?
Well, that's why I asked. That's how you learn,
by asking.. you dumbass. - Carl Carlson
Limited to a change in fisheries resources (stop
eating shrimp) or a switch to another source of
shrimp (aquaculture)
Is aquaculture the solution?
Disease outbreaks Environmental
issues Habitat destruction Invasive species
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Longlining
Miles of line with baited hooks suspended at
depth Turtles become hooked on baits Also
tangled in lines In Hawaii 1 - loggerhead
leatherback also green, olive ridley,
hawksbill
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Longline
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Longline
Estimated Fleetwide Turtle Takes and Kills in the
Hawaiian Longline Fishery, 1994-1998
                                                  
                            
Other Take/yr Green (35-45) Olive Ridley
(100-150) Hawksbill (1)
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We Gots Your Baits
Where can I get some Damn bait? Cousin Eddie
Colored baits deterred captive turtles
Ineffective in longline trials