Will GPS Turtle Eggs ‘Save’ Sea Turtles from Illegal Harvest? Expert Q&A.

November 12, 2020 Ashleigh Bandimere

This story recently received a good deal of press attention pertaining to the use of a new tool called the “InvestEGGator” to track illegal sea turtle egg harvesting in Costa Rica. Here we call upon Costa Rican turtle experts Bibi Santidrián and Rotney Piedra to weigh-in on the importance of this technology.

Thanks, Bibi and Rotney!

Community members legally harvest sea turtle eggs during an arribada at Ostional, Costa Rica. ©Ashleigh Bandimere

SWOT: Egg-sactly how serious a problem is egg harvesting for sea turtles? Are there particular species impacted by it, or regions where it is more prevalent?

Bibi and Rotney: Egg harvest is a common threat to sea turtles worldwide and may have contributed to population declines in some cases (often in combination with other threats). It is very common in some regions, including Latin America, where it impacts sea turtles on both Pacific and Atlantic/Caribbean shores. The eggs of some species are easier to harvest, such as the olive ridley, since nests are shallow and body pits are very small. In contrast, leatherback clutches are much harder to find, but an experienced egg harvester (or “huevero”) is able to find nests of any species. In any case, the most impacted turtle species and populations are those that are already reduced in numbers by other threats, and those for which egg harvest is/was maintained at high levels over long periods of time, for example the Eastern Pacific leatherback.

SWOT: Is sea turtle egg harvest done for subsistence or commercial use? Who are the consumers, and why are turtle eggs important to them?

Bibi and Rotney: Both subsistence and commercial use happens, depending on the area. Subsistence turtle egg consumers are typically people from coastal communities that have harvested eggs for generations as food. Turtle egg consumption has become less common in cities, though it happens, but it is still very common along the coasts. For example, in northern Pacific Costa Rica you can frequently find individuals or small groups of people fishing on the beach at night, outside protected areas. If a turtle crosses their path, they may opportunistically collect the eggs for their own consumption, but they are not there specifically to target the turtles. There are also some “expert harvesters” that go to the beach at night looking for eggs to clandestinely sell at bars in nearby towns. Egg harvesting is part of the local culture; the eggs are considered aphrodisiac (e.g., “nature’s Viagra”) in some areas, but in most cases they are eaten simply because they are readily available and people like them.

SWOT: What is the special situation in Costa Rica where there is a legal harvest allowed at one beach (but not everywhere), and were there any new/unexpected findings from this study that pertain to that legal dichotomy?

Bibi and Rotney: In accordance with the Interamerican Convention for the Conservation and Protection of Sea Turtles (IAC), each of the country parties may allow exceptions to meet subsistence economic needs of traditional communities. In Costa Rica, egg harvesting is legal on only one beach – Playa Ostional in Guanacaste Province – and only eggs of the olive ridley (Lepicochelys olivacea) are allowed to be collected. Controlling the illegal harvesting of eggs on all other beaches in the country has been a latent threat and difficult to eliminate, and Costa Rica does have a problem with illegally harvested eggs being marketed as if they were legal. However, within the framework of the IAC, the country has been working on the development and implementation of a system of traceability of Ostional eggs from the beach to the final distributor in order to prevent illegal trade in eggs of other populations of L. olivacea and other species of turtles as well. The InvestEGGator can help to track illegal egg trade routes and thereby fill gaps in knowledge and pinpoint the people who are falsely claiming that their contraband eggs are legal ones from Ostional.

SWOT: The authors of this study say that the point of this new tool is not necessarily to lead to the prosecutions of criminals - can this work really help in stopping illegal egg harvest?

Bibi and Rotney: A strong link between research and management is needed for successful conservation. We think the study could contribute to stopping the illegal harvest of eggs if (1) the information obtained were provided to the appropriate management agencies and (2) These agencies implement control and protection plans against illegal trade, and also carefully trace, monitor, and enforce the trade of legally harvested eggs. On the other hand, the study won’t be very useful for conservation if results are only published in a scientific paper that is read by other scientists. If the InvestEGGator studies can inform those with the power to control the illegal harvest and distribution of sea turtle eggs, and if those managers are willing to do so, then this could be a very useful tool.

It is also important to remember that conserving a species or a population requires broad protections. Even if illegal egg harvest were to be greatly reduced, human impacts on early life stages (egg, hatchling) are known to be less important, from a population conservation perspective, than impacts on adult turtles (e.g. fisheries bycatch); this is because adult turtles have a far higher ecological value in a population, since they can potentially produce countless thousands of eggs in their lifetimes. While egg harvest alone can have a negative impact, especially if it is severe and long-term, conserving a population will ultimately require actions at all life stages – egg, hatchling, subadult, and especially adult.

SWOT: What other applications do you think this new technology might be good for?

Bibi and Rotney: Perhaps it can also be used to track other species that are threatened by illegal harvest and trade. Similar technology is already used to track products like rhino horn and elephant ivory, as well as animals like seabirds, marine mammals, and much more, and can even send location data directly to a smart phone for real-time monitoring.

Bibi Santidrián (Science Director, The Leatherback Trust) has conducted research on the biology and conservation of sea turtles in Costa Rica for twenty years. She supervises the scientific research conducted by The Leatherback Trust at Parque Nacional Marino Las Baulas and connects research and management by working closely with national park authorities.

Rotney Piedra Chacón is an MSc biologist who has worked on many aspects of sea turtle research and conservation in Costa Rica since 1994 focusing mostly on green and leatherback turtles. He served as administrator of the Las Baulas National Marine Park from 1998-2019, and is now the Director of Protected Areas for the Tempisque Conservation Area, part of Costa Rica's National System of Conservation Area. He also serves as President of the Conference of the Parties to the Inter-American Convention for the Protection and Conservation of Sea Turtles.

The State of the World's Sea Turtles | SWOT