Presentation For Turtle Beach Lodge

Sea Sea Turtles:Turtles:

Biology and Biology and ConservationConservation

April Stevens, BScH.PhD Candidate

McMaster University

Seven SpeciesSeven Species• 5 spp. globally distributed around

tropics• 2 spp. endemic to specific area

• Kemp’s Ridley – Gulf of Mexico• Flatback – Continental shelf of Australia

http://www.seaturtle.org/cgi-bin/imagelib/index.pl?photo=743&size=big





LeatherbackLeatherback

Pacific vs. Atlantic • Significantly smaller

individuals and population• Possible extinction in

Pacific

Adult Size and Weight: 155cm, 400kg

Age to Maturity: 12-15yrs

Diet: Jellyfish

Conservation Status: Critically Endangered (IUCN)

Presenter�

Presentation Notes�

These are the monsters!! And very unique of the 7 spp. They are the only sea turtle that have a leathery carapace made of cartilage vs. hard keratinous scutes. These animals live in deep open ocean for their entire lives rather than being associated with reefs and/or vegetative beds. Whereas all 6 other spp. are only found in tropical waters, Leatherbacks are more cold resistant and feed as far north as off the coast of Nova Scotia. They are jellivores (they only eat jellyfish). The Pacific Leatherbacks are in serious decline and some estimates suggest that we may see this population go extinct in as low as 10 yrs. However the Atlantic population seems to be recovering somwhat.�

Adult Size and Weight: 105cm, 150kg

Age to Maturity: 30yrs

Diet: Sea grass, algae

Conservation Status: Endangered (IUCN)

Green TurtleGreen Turtle

• Herbivorous adults

• Fat green from diet

• Tortuguero largest rookery in Atlantic

Presenter�


My personal favorite, the green turtle is named after it’s body fat colouration, not the carapace. Although they can have green flecked shells, colours vary from light to blackish. During the juvenile years Greens switch from an ominovorous to strictly herbivorous diet, feeding on sea grass and algae. This diet is what turns the body fat green. �


LoggerheadLoggerheadAdult Size and Weight: 92cm, 115kg

Age to Maturity: 25 - 35yrs

Diet: Mollusks, crustaceans

Conservation Status: Endangered (IUCN)

Presenter�


All sea turtles can bite and many will if given the opportunity. However these are the ones to truly look out for. They have extremely strong jaws, giving them a cheeky look which can be seen when you look at their skulls. They use these powerful jaws to crush shells of mollusks and crustaceans.�



HawksbillHawksbill Adult Size and Weight: 85cm, 70kg

Age to Maturity: 20-30yrs

Diet: Omnivorous (Caribbean sponge specialization)

Conservation Status: Critically Endangered (IUCN)

Presenter�


As you can see from the lower lefthand photo, Hawksbills are adeptly named with their very pointed beak. These turtles came very close to extinction from one major cause. How many of you have heard of tortoiseshell products, jewelry, jewelry boxes, etc. This is actually a misnomer as the shell comes from the hawksbill sea turtle and not a tortoise. Hawksbills are selective foragers in that in the Caribbean they are predominantly spongivores, however in other populations their diet tends to be more omnivorous. �


Generalized lifecycle of sea turtles, (Lanyon, Limpus & Marsh, 1989).

Leatherbacks stay pelagic

Nesting BeachNesting Beach

• Lay multiple clutches (nests)• Species dependent

– Anywhere from 3-8 clutches per season– Average 2 weeks between each clutch

• Female does not eat for the 6 months around and during breeding and nesting– Can have 3 clutches inside the body at one

time!• Typically 2-3 yrs. between nesting seasons

Current ThreatsCurrent Threats

• Fisheries bycatch– Not just sea turtles

• Habitat loss– Beach development– Feeding grounds destroyed (reefs and sea grass beds)

Presenter�


Many threats faced by sea turtles are faced by many other marine animals.�

Threats Threats ConCon’’tt

• Legal and Illegal harvest of adults and eggs

• Pollution– Plastic ingestion (and other debris)– Oil spills, other – chemical pollutants i.e. DDT

Playa NortePlaya Norte• Partnership b/w COTERC and GVI

– Run through Caño Palma Biological Station • Monitor the nesting beach and nesting

females– Patrol beach at night looking for nesting

females– Assess female health and obtain biometric

data (measurements of length and width)– Try to deter poaching of females and eggs

Research Research ConCon’’tt

• Determine nest success from excavations• Education of locals and tourists about sea

turtles and their conservation.

Bringing this to an end!! Questions?

We’re Outta Here!!