Up close and personal with an adult hawksbill, WCS Canada
Up close and personal with an adult hawksbill © WCS Canada

WCS in Nicaragua: Canadian scientist leads endangered turtle conservation project


Related

Biodiversity

Published

2015-03-12

My work is dedicated to protecting one of the Caribbean’s most important nesting populations of hawksbills - the world’s most endangered sea turtle.

contributed by Laura Irvine, Hawksbill Project Coordinator at WCS

My family and friends are getting used to me moving from place to place for new adventures. I have worked in or studied international development or environmental conservation in 10 different countries in 13 years. However, unlike many of the places I’ve lived before, Nicaragua is less well-known. To be honest, I didn’t know much about Nicaragua, Costa Rica’s northern neighbour, before seeing an incredible Wildlife Conservation Society (WCS) job advertised. I was happily working at a biological station near Tortuguero, on Costa Rica’s Caribbean coast, when I saw the job opportunity for WCS in Nicaragua. I jumped at the chance to expand my scope of research and conservation, increase my level of responsibility and hands on work, and to get the opportunity to work for one of the most reputable conservation NGOs in the world. That is how, within a week, I picked up and moved to Nicaragua to become the Hawksbill Project Co-ordinator at WCS.

My work is dedicated to protecting one of the Caribbean’s most important nesting populations of hawksbills - the world’s most endangered sea turtle. I’m not the first Canadian to co-ordinate the project, but the THIRD! There must be something in the water in the Caribbean that attracts Canadians (oh wait, yes, it’s the turtles!). I will outline some conservation issues and challenges for sea turtles, but promise you that this story does have a happy ending! If you want a sneak peek of our success, check out this short video clip.

The International Union for the Conservation of Nature has declared the hawksbill sea turtle (Eretmochelys imbricata)–critically endangered – meaning populations have had an observed, estimated, inferred or suspected population size reduction of ≥80% over the last 10 years or three generations (IUCN, 2012; Mortimer & Donnelly, 2015). Hawksbills face the same threats as most sea turtles: degradation of feeding habitat, loss of nesting habitat from erosion or development, fisheries bycatch, marine pollution, climate change, light pollution on nesting beaches, poaching for their eggs and meat, and predation of eggs by domestic animals. Hawksbill turtles have an added threat, as their beautiful carapaces (shells) are sought after for tortoiseshell jewellery. On the Caribbean coast of Nicaragua, some communities also have a legal right to harvest green turtles (Chelonia mydas). Although fishing hawksbills is illegal in Nicaragua, there is still a chance that they will be caught as bycatch in nets set for green turtles or by lost/abandoned nets (also called "ghost fishing"). Although this list of threats is not exhaustive, we can see that human activity produces the primary threats to sea turtles.

If these threats weren’t bad enough, hawksbill biology adds fuel to the fire. It takes hawksbills 25-30 years before they can reproduce. All the while they face the aforementioned threats. When you also add in the natural predators from when they are eggs to adults (crabs, rodents, birds, fish, sharks, orcas), only 1 out of 1000 eggs is estimated to survive to adulthood. Needless to say, turtles do NOT have it easy. That is exactly why initiatives like the Hawksbill Conservation Project here in the Pearl Cays, Nicaragua, are critical for the species’ survival.
The Pearl Cays, an idyllic group of small islands 3-22km from the mainland, are home to one of the largest rookeries of hawksbills in the Caribbean (Fig.1). The cays are located inside in the Pearl Cays Wildlife Refuge (PCWR), a 700km² marine protected area that WCS helped establish in 2010. The varieties of marine and terrestrial habitats in the PCWR are used for feeding, breeding, migration and spawning events for countless species. Hawksbills nest on 12 of these cays each year.\

A hawksbill lays an average of 150 eggs per nest. On top of that, each female lays 3-5 nests per season. These are some hard working mothers! Females will breed and nest every 2-3 years, and spend the other years resting and gaining back energy for the next nesting event. Many of you have probably seen a documentary on the nesting process, or maybe even witnessed the magic first-hand. The turtles arduously crawl from the water and walk until they find a good site then dig a pit and a deep egg chamber before depositing their eggs, covering the nest and area in sand and finally returning to sea. It takes tremendous effort. However, their job ends there – females do not look after the eggs or hatchings after nesting. That’s where WCS comes in!

The WCS Hawksbill Conservation Project was founded in 2000, after a preliminary study in the cays found that almost 100% of the nests were poached for local consumption. The project was made possible by the support from the local communities in the area, as well as the local and national authorities. WCS employs local staff and conducts awareness and education activities in surrounding communities. William McCoy, our Field Supervisor and one of the founding team members, is a retired turtle fishermen turned local conservation hero. The National Police also accompany us on surveys to enforce conservation regulations. Our teams patrol the beaches looking for nesting activity, then collect scientific data. For example, we measure the distance from the nest to the high tide line and whether to the nest is on the open beach or nestled in the vegetation. From these measurements, we can determine the risk of flooding and what kind of shading and temperature the eggs will receive as they develop and hatch. The sex of a sea turtle is dependent on temperature. If it’s over a certain pivotal temperature (~28ºC) in a nest there will be more females, if it’s less than that temperature there will be more males, and closer to the pivotal temperature will produce a mix of males and females. We always train our teams to remember it as: “hot ladies, cool guys”.

If the nests are laid in a threatened place (too close to the high tide or in a place obvious to would-be poachers), we very carefully move the eggs to a simulated nest in a better location on the beach. We check the condition of each nest every day, and then we look for signs of hatching after around 60 days. When we think the nest has hatched out, we dig up the contents to determine how successful the nest was. With this data we can tell what parts of the beach, what cays, and what conditions might yield the best environments for hatchling development in our study site.

The WCS Hawksbill Conservation Project also works with juvenile and adult turtles. When we encounter them in the water or on the cay, we tag them with metal and microchip tags (of Passive Integrative Transponder – ‘PIT’ tags), conduct a health assessment and measure them so we can track their progress and well-being over time. To date, we have almost 3000 tagged turtle encounters in our database!
This WCS project is a great success story for hawksbill turtle conservation. Over the past 15 years, we have seen the total number of nests per season increase over 200%, from 152 in 1999 to 475 in 2014. Because of this increase we have seen more and more hatchlings enter the population, including almost 43,000 in 2014. Local fishermen have also donated hundreds of turtles to be tagged and released (hawksbills and juveniles of different species). And, most impressive of all, the poaching rate has been decreased by between 75-95% since the start of the project,depending on the year. In 2014, the poaching rate was the lowest in project history at 5.7%. These figures show the difference that a locally-supported conservation project and dedicated staff can make to a species on the brink of extinction, but what they don’t show is how humbling – and rewarding – it is to be a part of a project that makes a difference for a critically endangered species and its habitat.

For more information:
IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1. Second edition.Gland, Switzerland and Cambridge, UK: IUCN. iv + 32pp.
Mortimer, J.A & Donnelly, M. (IUCN SSC Marine Turtle Specialist Group) 2014. Eretmochelys imbricata. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>.
Florida Fish and Wildlife Services. 2015. Hawksbill sea turtle (Eretmochelys imbricata) factsheet: <www.fws.gov/northflorida/seaturtles/turtle%20factsheets/hawksbill-sea-turtle.htm>.

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