Sea Turtles in the Pacific:
By Maria Wojakowski
Sea turtles travel long distances to forage and reproduce. They are considered the ancient mariners of our oceans, but right now, they are not doing very well. All sea turtle species are listed as vulnerable, endangered, critically endangered, or data deficient on IUCN's Red List. Four of the eleven most endangered populations of sea turtles are found in the Pacific Ocean: East Pacific Hawksbill sea turtles (Eretmochelys imbricata), East Pacific Leatherback sea turtles (Dermochelys coriacea), North Pacific Loggerhead sea turtles (Caretta caretta), and West Pacific Hawksbill sea turtles (Eretmochelys imbricata).
Even if we prioritize sea turtle conservation, it is difficult to propose specific strategies when we often do not know basic information about populations at risk. Satellite tag data, the source of most knowledge concerning sea turtle movement, has thus far only been representative of adult females, which are easy to tag since they come to us when they nest. Since satellite tags are so expensive, our sample sizes for these studies tend to be very small. The result is that we do not know enough about the migration paths of many populations and we cannot estimate how many turtles there are left. My work focuses on these two issues.
Green Sea Turtles in El Ñuro, Peru
The small fishing community of El Ñuro is an in-shore hotspot for juvenile green sea turtles. We do not know which beach they come from, though we believe they may be coming from the Galapagos and, to a lesser extent, the East Pacific. By placing satellite tags on these turtles, I hope to find their migrations paths and later identify which areas they prefer. This is particularly important since the El Ñuro area is one of three proposed to form a new national marine sanctuary. Identifying where these turtles go and which habitats are particularly important will be critical in protecting them.
Loggerhead Sea Turtles in the North Pacific
North Pacific Loggerhead sea turtles are listed as endangered in both the IUCN redlist and under the US Endangered Species Act. A main reason for the decline of this species has been bycatch, or incidental capture, in both the large-scale fisheries of the Central North Pacific (CNP) and the small-scale fisheries of Baja California Sur (BCS). While regulations are in place for US fisheries in the CNP, bycatch remains a problem in BCS. Bahia de Ulloa, BCS, is a juvenile loggerhead sea turtle hotspot, a critical nursery for endangered loggerheads. It overlaps with intense small-scale fisheries in one of the most productive regions for Mexican fisheries, contributing to the highest bycatch rates recorded worldwide.
In order to protect these loggerheads, we need to better understand their population structure. The most basic question is "How many are left?" I will use statistical models to answer this question. Hopefully, further modeling will also show us how many turtles there will be in the future given different conservation strategies.
see also: Petri Dish Project