a script and a powerpoint about a marine specie
RCY7
SLIDES_Example_Species_Project_Presentation.pptxHawksbill Turtle
(Eretmochelys imbricata)
By Sara Maxwell
BIS 306
Species Overview
Beak-like mouth, useful for foraging for sponges (primary food source) in coral reef habitats; found in tropical regions of Atlantic, Pacific, and Indian oceans.
(NOAA 2020)
Weigh up to 75 kg, and reach sexual maturity around 25 years
(NOAA 2020)
Return to natal beaches to lay eggs 4-5 times per season, each clutch consisting of roughly 140-200 eggs
(FWS 2018)
Image credit: Rayes Caye Resort
Video credit: Oates 2016, https://youtu.be/uZglGXT4IXk
Image credit: WWF
Focused Ecology Topic: Spongivores
Interdependent relationship with reefs: hawksbills regulate sponge populations, prevent overpopulation
(Mortimer and Donnely 2008)
Juveniles spend most of their time in and around reefs; sponges account for roughly 67% of a juvenile hawksbill’s diet
(Becker et al. 2019 and Leon and Bjorndal 2002)
Also feed on reef-dwelling fish, crustaceans, algae
(NOAA 2020)
Image credit: NWF 2020
Overview of Threats
Critically endangered
(Mortimer and Donnely 2008)
Coral reef destruction, subsequent loss of food
(Mortimer and Donnely 2008)
Habitat destruction and bycatch from fisheries
(Gaos et al. 2012)
Egg collection for food and cultural means
(Hamilton et al. 2015)
Shell harvesting and trade
(NOAA 2020)
Image credit: NOAA 2020
Focused Conservation Topic: ‘Tortoiseshell’ Trade
According to cites, harvesting and trade is illegal though it still continues
(NOAA 2020)
Exploited for their shells, used for making luxury items, trinkets, and jewelry
(Mortimer and Donnely 2008)
Harvesting and trade was unregulated until the 1970s which led to the species’ rapid decline
(Hamilton et al. 2015)
Image credit: Kathryn Greeley
Image credit: NOAA 2020
Conservation & Species Outlook
The Solomon Islands in the South Pacific is a large breeding ground for hawksbills, and is implementing conservation efforts (Hamilton et al. 2015)
Since banning the take and trade of hawksbill shells in 1991, rookeries in the Solomon Islands have doubled. Females have been observed to return to nest, with the number of nests per season growing twofold (Hamilton et al. 2015)
Migratory patterns have been tracked to see whether or not hawksbills frequent marine protected areas, in order to see if these areas need to be created or extended (Gaos et al. 2012)
Nest growth rates, Solomon Islands
Image credit: Hamilton et al. 2015
Sources:
Becker, Sarah L., Russell E. Brainard, and Kyle Van Houtan S. "Densities and Drivers of Sea Turtle Populations Across Pacific Coral Reef Ecosystems." PLoS
One, vol. 14, no. 4, 2019. ProQuest, https://search.proquest.com/docview/2214461048?accountid=14784,
doi:http ://dx.doi.org/10.1371/journal.pone.0214972.
Gaos, Alexander R., et al. “Spatial Ecology of Critically Endangered Hawksbill Turtles Eretmochelys Imbricata: Implications for Management and
Conservation.” Marine Ecology Progress Series, vol. 450, 2012, pp. 181–194. JSTOR, www.jstor.org/stable/24875904. Accessed 3 Feb. 2020.
Hamilton, Richard J., et al. "Solomon Islands Largest Hawksbill Turtle Rookery shows Signs of Recovery After 150 Years of Excessive Exploitation." PLoS
One, vol. 10, no. 4, 2015. ProQuest, https://search.proquest.com/docview/1982246138?accountid=14784,
doi:http ://dx.doi.org/10.1371/journal.pone.0121435.
“Hawksbill Sea Turtle (Eretmochelys Imbricata).” Official Web Page of the U S Fish and Wildlife Service, 17 Feb. 2018,
https://www.fws.gov/northflorida/SeaTurtles/Turtle%20Factsheets/hawksbill-sea- turtle.htm.
“Hawksbill Sea Turtle.” National Wildlife Federation, The National Wildlife Federation,
www.nwf.org/Educational-Resources/Wildlife-Guide/Reptiles/Sea-Turtles/Hawksbill-Sea-Turtle.
“Hawksbill Turtle.” NOAA, www.fisheries.noaa.gov/species/hawksbill-turtle#overview.
León, Yolanda M., and Karen A. Bjorndal. “Selective Feeding in the Hawksbill Turtle, an Important Predator in Coral Reef Ecosystems.” Marine Ecology
Progress Series, vol. 245, 2002, pp. 249–258. JSTOR, www.jstor.org/stable/24866409. Accessed 3 Feb. 2020.
Mortimer, J.A & Donnelly, M. “Eretmochelys imbricata.” The IUCN Red List of Threatened Species 2008, IUCN, 2008,
https://www.iucnredlist.org/species/8005/12881238#text-fields, e.T8005A12881238, https://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T8005A12881238.en.
Oates, Jim. “Yongala Hawksbill Turtle Eating Sponge.” YouTube, 2 March 2016, https://youtu.be/uZglGXT4IXk
