By Jesse Senko and Kayla Burgher

In the wake of significant media attention by CNN, The Guardian, and other outlets to a scientific publication led by Arizona State University’s Jesse Senko and Kayla Burgher, SWOT reached out to the co-first authors to learn more.
See their original publication, Global patterns of illegal marine turtle exploitation, here.

An illegal Chinese fishing vessel with 397 dead turtles aboard was seized in East Kalimantan, Indonesia, in May 2007. The captain of the boat was later sentenced to 4 years in prison by the Tarakan Court in East Kalimantan, and 22 members of the vessel’s crew were deported to China. © WWF-TNC Joint Marine Program, Berau

SWOT: Please summarize the study’s purpose, methods, and key findings.

Jesse and Kayla: We analyzed three decades of data on illegal sea turtle exploitation from many sources to:

Evaluate the magnitude and potential trends of this threat at several scales - global, national, by Regional Management Unit (RMUs, or subpopulations), and by sea turtle species impacted.
Characterize geographic and temporal patterns in reported trafficking.
Assess potential population-level impacts.

There were 4 key findings: 1) >1.1 million turtles have been illegally exploited in at least 65 countries and territories and in 44 of the world’s 58 sea turtle populations; 2) Almost all of this exploitation targeted green and hawksbill turtles; 3) illegal exploitation appears to have declined over the past decade; and 4) most of the current exploitation has been documented in large, stable, and genetically diverse sea turtle populations.

SWOT: Given the illegality of the threat in most places, data must have been scarce. How did you handle this, and how confident are you in the findings? Were there any limitations or biases in the types of data available?

Jesse and Kayla: Right, and we knew going in that assessing illegal activities was going to be challenging, especially on a global scale! But we felt that synthesizing data from scientific journal articles, grey literature, news sources, and expert opinions could still be a valuable exercise. We highlight a number of caveats, including: 1) we were only able to assess available information in English; 2) we discovered profound data gaps in many areas and, even in areas with data, reports of sea turtle take tend to be limited in geographic scope; 3) we were only able to include whole turtles or turtle products that could be linked to individual turtles (e.g., heads, shells, or tails), and thus were unable to account for eggs or tortoiseshell products such as jewelry. As such, our analysis almost certainly underestimates the number of turtles taken, especially in data-poor regions.

However, we are confident that our assessment generally reflects the current state of available information regarding illegal take of marine turtles worldwide. And we’re also reasonably confident that illegal take is decreasing, since more information was available for the most recent decade compared to the 1990s and 2000s, yet there was still a 28% reduction in take from the 2000s to the 2010s. Hopefully this is a result of worldwide efforts to increase protections for sea turtles through improved legislation and grassroots conservation.

SWOT: What data gaps could be filled to improve our understanding of sea turtle take?

Jesse and Kayla: We found that published data on illegal sea turtle exploitation was lacking in the majority of countries we assessed. We attempted to fill some of these gaps with online questionnaires administered to sea turtle experts in 46 countries. While these surveys helped us fill data gaps for over 20 countries, it would have been great if we could have interviewed experts in key countries like China and Japan, given their high demand for turtle products.

The surveys also helped us identify countries with data gaps by examining the discrepancies between estimates provided by experts through questionnaires and published data. There were several countries with high exploitation reported by experts, but little or no published data. Haiti is perhaps the most extreme example, with experts estimating 350,000 turtles taken from 2000-2020 even though we found zero published data. Madagascar, Papua New Guinea, and Mexico also had large discrepancies between questionnaire and published data (> 100,000 turtles per decade), revealing the need for more robust assessments of sea turtle exploitation in those and other countries. Furthermore, we lack the genetic or spatial data that would allow us to ascribe exploited turtles to their respective RMUs, thereby preventing us from doing a more robust analysis of the effects of sea turtle exploitation at population scales.

SWOT: How did traditional sea turtle take/use factor into your research, if at all?

Jesse and Kayla: It’s important to understand that sea turtles are threatened largely because of industrial-scale commercial exploitation that began in the 1800s, rather than traditional take regimes. In this study, sea turtles that were exploited under cultural or indigenous take provisions were not included in the analysis.

SWOT: What is one key takeaway about this threat from your research?

Jesse and Kayla: I think a big takeaway is that, with some important exceptions, most of the world’s illegal exploitation appears to be happening in relatively large and stable populations. The threat of illegal exploitation is also likely less of a problem than mortality caused by fisheries.

SWOT: Is there any conservation action that you hope this paper catalyzes?

Jesse and Kayla: Yes, we hope this paper can catalyze international and domestic conservation action to reduce trafficking of sea turtles going into China and Japan, where nearly 90% of trafficked turtles ended up. The paper also identified some major hotspots where conservation action is needed, including southeast Asia and east Africa, where hawksbill take is especially high. Unfortunately, there are several low-income countries in those regions, so in addition to increased support for governments to adequately protect sea turtles, it is important that we develop conservation strategies that benefit both people and turtles, including support for communities to sustain human well-being in the face of restrictions, bans, or increased enforcement on illegal sea turtle take. Finally, apart from researchers filling in the obvious data gaps, we hope the paper inspires research into understanding how to reduce demand for sea turtle products from a human behavior standpoint, particularly in China and southeast Asia.

SWOT: Do you plan any follow up research on this topic to build on your findings?

Jesse and Kayla: Not specifically, but we are interested in the socioeconomic and cultural drivers behind illegal sea turtle exploitation, and how research into human behavior change could help reduce this demand.

For more information, see: https://onlinelibrary.wiley.com/doi/10.1111/gcb.16378

AUTHOR AFFILIATIONS

JESSE SENKO, School for the Future of Innovation in Society, Arizona State University, Tempe, AZ, USA

KAYLA BURGHER, School of Life Sciences, Arizona State University, Tempe, AZ, USA

Expert Q&A: Global Patterns and Impacts of Illegal Sea Turtle Take