Conservation and Ecology of Marine Reptiles MARE 494 Dr. Turner Summer 2006

1. Conservation and Ecology of Marine Reptiles MARE 494 Dr. Turner Summer 2006

2. Health & Disease Sea turtles are affected by variety of health problems Combination of natural & anthropogenic effects Captive & wild animals

3. 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”

4. Bacterial Diseases Rare in free ranging turtles Very common in captive animals Salmonella Pseudomonas Vibrio

5. Mycotic Diseases Found in both captive & wild animals Can be fatal to eggs/embryos Hatchlings/juveniles in captivity are extremely susceptible

6. Viral Diseases Several occurring Herpes respiratory, gray-patch viral Fibropapillomatosis – green turtle (GTFP) Found in loggerhead, olive ridley, hawksbill, & flatback

7. GTFP 1st described in green turtles in Florida (1938) & Hawaii 1958 Now worldwide Increased significantly since 1980’s Not in all populations; other 92% of animals

8. 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

9. What is It? Thought to be caused by herpes virus (papillomavirus) Possibly transferred by “cleaner” fishes picking at tumors (e.g. – Kole, Labroides sp.

10. Why ask Why? Why higher prevalence since 1980’s? Environmental effects of nutrient runoff Invasive species – seaweed Unknown stressors Parachute pants/bad music (Wham!, etc.)

11. 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

12. Disease Investigations

13. Environmental Health Traumatic injuries – shark bites, etc

14. Environmental Health Cold stunning – coma-like state

15. Anthropogenic Problems Chemical Pollutants – DDT, PCBs, oil

16. 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

17. 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

18. 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

19. 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

20. Royal Hawaiian Ali‘i (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

21. Anthropogenic Problems Entanglement in fishing gear

22. Anthropogenic Problems Ingestion of man-made debris

23. 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 gov’t prohibited harming species or habitat Recovery plan Includes “critical habitat”

24. 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

25. 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

26. 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.

27. 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

28. 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

29. 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 > 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)

30. 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

31. Problem Trawls are nets pulled along the bottom to catch shrimp and other invertebrates Turtles become trapped and drown As tow duration ↑ Turtle mortality ↑

32. 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

33. TED Turtle Excluder Device Originally developed by NMFS in MS Several modifications from Feds & shrimpers Allows for turtles & large bycatch to escape

34. What about the Wee Turtles? “If I don’t save the wee turtles, who will? Ah! Save me from the wee turtles. They were too quick for me. Ahh!” – Groundskeeper Wille

35. World Production of Farmed Penaeid Shrimp 1000 800 600 Live weight (thousand tonnes) 400 Shrimp! 200 83 86 88 89 84 85 87 90 91 92 93 94 95 Year What’s 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

36. Longlining Miles of line with baited hooks suspended at depth Turtles become hooked on baits Also tangled in lines In Hawai‘i – 1° - loggerhead & leatherback also green, olive ridley, & hawksbill

39. Longline

40. 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)

41. We Gots Your Baits “Where can I get some Damn bait?” – Cousin Eddie Colored baits deterred captive turtles Ineffective in longline trials