A new study says that the risk poaching poses to endangered sea turtles is on the decline -- although data on the subject is scarce.
The study, published on September 7 in Global Change Biology, used a meta-analysis of documents published in the last three decades to estimate the number of sea turtles killed illegally over that time period. A research team led by Jesse Senko, the study's lead author and an assistant research professor and senior sustainability scientist at Arizona State University, pored through peer-reviewed studies and media reports about sea turtle poaching, and conducted surveys with experts.
They found that reports of sea turtle poaching had declined 28% from the 2000s to the 2010s, which Senko called "a really encouraging sign."
"We didn't really expect that, in part because we had more information for the 2010s," Senko told CNN. "We found more info in the 2010s than in the 90s or 2000s combined. Yet, we found a decrease."
"What we believe that's saying is that this is not an artifact of available info, in fact there probably is a global decrease in consumption."
The researchers estimated that there were more than 1.1 million reported illegal killings of sea turtles between 1990 and 2020. Sea turtles tend to be killed for two main reasons, Senko told CNN. The first reason: Food -- whether they're eaten by the same person who hunts them or sold at market. Or for their shells, which are used as jewelry or decoration.
But despite how large that number may seem, Senko said that "with few exceptions, most of the illegal take is happening in areas where there are a lot of turtles." So for the most part, sea turtle poaching takes place in healthy, large sea turtle populations and poses relatively little danger to those populations.
Still, this isn't reason to dismiss sea turtle poaching as a problem, or to think that sea turtle populations aren't in danger, Senko said.
The biggest threat all seven species of sea turtle face is "bycatch in fisheries -- Incidental capture of sea turtles in fishing gear," Senko said. "Climate change is also a threat to them, although we don't fully understand the impact. Plastic pollution is a growing threat."
The research project has its limitations: Illegal killings are hard to track by nature. The research only captured killings that were reported -- and often even the information about those killings, like the species of the turtle killed, was scant.
The researchers acknowledged these limitations, writing that "assessing prohibited exploitation is difficult due to its typically clandestine nature" and that "there are significant data gaps due to a lack of reporting in many areas."
Brian Hutchinson, the vice president of outreach at the Oceanic Society, told CNN that as the study found, there likely has been a decline in sea turtle poaching over the last few decades thanks to conservation efforts.
"The long-term trend for sure is a decrease in take," he said. "There's been a huge movement to protect sea turtles over the past 50 years."
But, he added, "there are still some populations that aren't doing well."
"There's a lot that we don't know," Hutchinson said.
Part of the problem is that the main metric sea turtle scientists rely on to monitor the health of the animals' populations is nesting females, Hutchinson explained. They track the females who periodically nest on beaches to lay their eggs and use them as a proxy for the health of the whole population.
But this means that threats to juvenile and male sea turtles can be easily missed. Senko and his team's method of tracking reported killings could help fill in that gap, Hutchinson said.
Hutchinson hopes the study can serve as "a way to identify where we need more information," particularly in remote areas where it is suspected that sea turtle poaching is high but there is literal on-the-ground data collection.
"Meta-analysis is an opportunity to better understand the data as much as to understand the problem," he said.
David Godfrey, the executive director of the Sea Turtle Conservancy, also urged caution in interpreting the results because illegal killings are so seldom reported. Additionally, the study didn't cover the period of the COVID-19 pandemic -- which he said led to an increase in killings due to relaxed enforcement.
In his group's conservation work, he said, "we see a lot more of [illegal killing] than is reported."
And since the pandemic, there has been "a pretty dramatic increase in nests being taken for the eggs and turtles being killed and taken for meat and shells," Godfrey said. This increase is likely due to "the socioeconomic implications of the COVID-19 pandemic, the shutdown of tourism, the effect that's had on people's livelihoods," as well as the decreased "presence of law enforcement" to monitor poaching.
For Godfrey, the research works best as a "global snapshot of what's going on." It's impossible, he said, for every location with sea turtles to monitor poaching as meticulously as his organization does. Given the significant data gaps regarding sea turtle poaching, "using literature, doing questionnaires, is the best way you can do it," he said.
The researchers acknowledged in the paper that "the results herein almost certainly represent only a fraction of actual illegal exploitation" of sea turtles. And they called for greater research and data collection, particularly in areas where poaching data is scarce.
Senko told CNN that he hopes "this study inspires future research and conservation practitioners to try to figure out how can we reduce that demand" for sea turtle products.
"Even though the illegal take does appear to be declining, as long as you have demand for these animals, as long as people are willing to pay a high price, you're going to have a supply from lower income regions," he said.
