Sea turtles and survivability in demersal trawl fisheries: Do comatose olive ridley sea turtles survive post-release?

Abstract Incidental capture of air-breathing species in fishing gear is a major source of mortality for many threatened populations. Even when individuals are discarded alive, they may not survive due to direct injury, or due to more cryptic internal physiological injury such as decompression sickness. Post-release mortality, however, can be difficult to determine. In this pilot study, we deployed survivorship pop-up archival tags (sPAT) (n = 3) for an air-breathing species, the olive ridley sea turtle (Lepidochelys olivacea), one of the first studies to do so. We found that at least two of the three turtles survived after being captured in demersal fish trawl nets and being resuscitated from a comatose state following standard UN Food and Agriculture Organization guidelines. One turtle died; however, the absence of a change in light level but continued diving activity suggested that the turtle was likely predated. Whether capture contributed to the turtle’s susceptibility to predation post-release is unknown, and average tow duration during this fishing trip was similar in duration to that of a turtle that survived (1.5 h). The two surviving turtles displayed normal horizontal and vertical movements based on previous tagging studies. This study suggests that resuscitation techniques may be effective; however, additional study is necessary to increase sample sizes, and to determine the severity of decompression sickness across different levels of activity and in other fishing gears. This will result in better population mortality estimates, as well as highlight techniques to increase post-release survivorship

Fulfilling global marine commitments; lessons learned from Gabon

As part of the Post-2020 Biodiversity Framework, nations are assessing progress over the past decade in addressing the underlying drivers that influence direct pressures on biodiversity and formulating new policies and strategies for the decade to come. For marine conservation, global marine protected area (MPA) coverage is still falling short of the 10% target set in 2010. Here we show that while this reflects a lack of progress in many low- and middle-income countries, a few of these nations have met or exceeded international commitments. To provide an in-depth explanation of how this was achieved in Gabon, we summarize the lessons learnt by our consortium of policy makers and practitioners who helped implement a comprehensive and ecologically representative network of 20 MPAs. We show the importance of creating a national framework, building long-term stakeholder support, and focusing on research that guides implementation and policy; and outline a four-step approach that countries and donors could use as an example to help meet international commitments. By responding to calls to share lessons learned to inform future Convention on Biological Diversity targets, we show how Gabon's experiences could inform change elsewhere