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.Output Status: Forthcoming/Available Online Additional co-authors: Tim Collins, Philip D. Doherty, Angela Formia, Mark Gately, Micheline Schummer Gnandji, Innocent Ikoubou, Judicael Régis Kema Kema, Koumba Kombila, Pavlick Etoughe Kongo, Jean Churley Manfoumbi, Sara M. Maxwell, Georges H. Mba Asseko, Catherine M. McClellan, Gianna Minton, Samyra Orianne Ndjimbou, Guylène Nkoane Ndoutoume, Jean Noel Bibang Bi Nguema, Teddy Nkizogho, Jacob Nzegoue, Carmen Karen Kouerey Oliwina, Franck Mbeme Otsagha, Diane Savarit, Stephen K. Pikesley, Philippe du Plessis, Hugo Rainey, Lucienne Ariane Diapoma Kingbell Rockombeny, Howard C. Rosenbaum, Dan Segan, Guy-Philippe Sounguet, Emma J. Stokes, Dominic Tilley, Raul Vilela, Wynand Viljoen, Sam B. Weber, Matthew J. Witt, Brendan J. Godle

Informing Marine Protected Area Designation and Management for Nesting Olive Ridley Sea Turtles Using Satellite Tracking

Understanding the horizontal and vertical habitat of olive ridley sea turtles (Lepidochelys olivacea), a threatened species, is critical for determining regions for protection and relevant gear modifications that may effectively reduce bycatch, the largest threat to this species. Satellite transmitters were used to determine the movement and dive behavior of 21 female olive ridley turtles tagged in Pongara National Park, Gabon during the 2012, 2013, and 2015 nesting seasons. A switching state-space model was used to filter the tracking data and categorize the internesting and post-nesting movements. Gridded utilization distribution (UD) home range analysis of tracking data revealed that the entire core habitat occurred in the Komo Estuary during the internesting period. Within the Komo Estuary, 58% of this core UD occurred in shipping lanes. Dive data from the 2015 tagging season revealed that during the internesting period, turtles spent the majority of their time resting on the estuary seabed. Approximately 20% of all dive time was spent on the bottom and all maximum dive depths corresponded to the depth of the seabed, indicating that bottom set gear during the internesting period may pose the greatest potential for fisheries interactions. National parks currently protect many of the nesting sites and the Gabon Bleu initiative has formally designated 10 new marine parks and a network of community and industrial fishing zones; this data was a layer used in determining the park and zone boundaries. Shared use of the estuary by fisheries, shipping, and olive ridley turtles creates a need for management measures to reduce interactions. Thus, the results from this study can further provide detailed information that can be used to support the development of evidence-based management plans

An annotated checklist of the fishes of Gabon

International audienceUsing all data sources available, we collected 2,189 nominal scientific names that have been applied to the fishes from Gabon. Data from the literature and online database indicate that 1,062 valid species of fishes live in Gabonese waters, with 288 of these strictly restricted to freshwaters, 592 strictly restricted to marine environments and 182 species euryhaline species. Among the latter one finds 121 species inhabit in both marine and brackish environments, 16 that occur in both freshwater and brackish environments and 45 found in all salinities. These 1,062 species represent 60 orders and 224 families. An additional 202 species, mostly marine, may be present in Gabon although they have not been yet recorded. Endemic species represent 7% (75) of the 1,062 valid described species for Gabon, within just one of these from marine waters and 74 freshwaters species (mostly killifish within the genus Aphyosemion – 33 species). Regarding the IUIUCN status, 135 present (+19 possible) species (12.7%) are considered as endangered (from near threatened to critically endangered), and 135 (+24 possible) (12.7%) species are not evaluated or data deficient. The remaining species are least concern. Continued descriptions of new species from the waters of Gabon demonstrate that the present total most likely underestimates the species level diversity of the fish fauna.En utilisant toutes les sources disponibles des données, nous avons répertorié 2 189 noms scientifiques de poissons du Gabon. Les données de la littérature et des bases de données montrent que 1 062 espèces de poissons sont actuellement connues des eaux du Gabon, avec 288 strictement en eaux douces et 592 strictement marines, 182 espèces sont euryhalines avec 121 connues des eaux marines et saumâtres, 16 des eaux douces et saumâtres et, pour finir, 45 sont trouvées dans tous les milieux, quel que soit la salinité. Ces 1 062 espèces représentent 60 ordres et 224 familles auxquelles il est possible de rajouter 202 espèces, principalement marines, qui sont peut-être présentes au Gabon mais n’y ont pas encore été observées. Les espèces endémiques représentent 7% (75) du nombre des 1 062 espèces décrites et valides du Gabon : une seule espèce marine et 74 espèces des eaux douces (principalement des “killis” du genre Aphyosemion – 33 espèces). À propos du statut de l’IUCN, 135 des espèces présentes (+19 possibles) (12,7%) sont considérées comme en voie de disparition (de quasi-menacées à en danger critique), et 135 (+24 possibles) (12,7%) ne sont pas évaluées ou bien avec des données insuffisantes. Les autres sont de préoccupation mineure. Des descriptions continuelles de nouvelles espèces provenant des eaux du Gabon démontrent que la diversité de la faune des poissons du Gabon est fortement sous-estimée

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

A first estimate of sea turtle bycatch in the industrial trawling fishery of Gabon

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Gabon hosts nesting grounds for several sea turtle species, including the world’s largest rookery for the leatherback turtle (Dermochelys coriacea), Africa’s largest rookery for the olive ridley turtle (Lepidochelys olivacea) and smaller aggregations of the hawksbill turtle (Eretmochelys imbricata) and green turtle (Chelonia mydas). To assess the level of incidental captures of turtles by the Gabonese trawl fishery, an onboard observer program was conducted in the period 2012–2013. A total of 143 turtles were captured by 15 trawlers during 271 fishing days. The olive ridley turtle was the main species captured (80% of bycaught turtles), with mostly adult-sized individuals. The remaining 20% included green turtles, hawksbill turtles, leatherback turtles and undetermined species. Bycatch per unit of effort (BPUE) of olive ridley turtles varied greatly depending on the period of the year (range of means: 0.261–2.270). Dead and comatose turtles were 6.2 and 24.6% respectively (n = 65). By applying the available fishing effort to two BPUE scenarios (excluding or considering a seasonal peak), the total annual number of captures was estimated as ranging between 1026 (CI 95% 746–1343) and 2581 (CI 95% 1641–3788) olive ridley turtles, with a mortality ranging from 63 (CI 95% 13–135) to 794 (CI 95% 415–1282) turtles per year depending on the scenario and on the fate of comatose turtles. Such a potential mortality may be reason for concern for the local breeding population of olive ridley turtles and recommendations in terms of possible conservation measures and further research are given.Funding for the observer program and training was provided by the Government of Gabon, the Marine Turtle Conservation Fund (Fish and Wildlife Service, US Department of the Interior), NOAA (US Department of Commerce, Division of International Affairs), UK Darwin Initiative (Department for Environment Food and Rural Affairs), and the World Wide Fund for Nature

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