TY - JOUR
T1 - Addressing data-deficiency of threatened sharks and rays in a highly dynamic coastal ecosystem using environmental DNA
AU - Leurs, Guido
AU - Verkuil, Yvonne I.
AU - Hijner, Nadia
AU - Saalmann, Franziska
AU - Dos Santos, Lilísio
AU - Regalla, Aissa
AU - Ledo Pontes, Samuel
AU - Yang, Lei
AU - Naylor, Gavin J.P.
AU - Olff, Han
AU - Govers, Laura L.
N1 - Funding Information:
This work was funded through the INNOfonds of the World Wildlife Fund Netherlands, the ‘Waders of the Bijagós’ project of the MAVA Foundation, and the Shark Conservation Fund. LG was funded by NWO grant 016.VENI.181.087. We would like to thank the entire crew of the Instituto da Biodiversidade e das Áreas Protegidas and the local fishers with whom we have collected the samples for this study, for the close collaboration. We thank Peter de Knijff and Rick de Leeuw for their help with designing the sequencing protocol and bioinformatics analyses, and for sequencing our samples at the Department of Human Genetics, Leiden University Medical Centre (The Netherlands). We like to thank Thimo Mulder for assisting in the laboratory, Jolanda Brons and Marco van der Velde for advice on lab procedure and use of equipment. We thank the Center for Information Technology of the University of Groningen for their support and for providing access to the Hábrók high performance computing cluster. Lastly, the authors would like to thank Kasper Meijer for feedback on the analysis.
Funding Information:
This work was funded through the INNOfonds of the World Wildlife Fund Netherlands, the ‘Waders of the Bijagós’ project of the MAVA Foundation, and the Shark Conservation Fund. LG was funded by NWO grant 016.VENI.181.087. We would like to thank the entire crew of the Instituto da Biodiversidade e das Áreas Protegidas and the local fishers with whom we have collected the samples for this study, for the close collaboration. We thank Peter de Knijff and Rick de Leeuw for their help with designing the sequencing protocol and bioinformatics analyses, and for sequencing our samples at the Department of Human Genetics, Leiden University Medical Centre (The Netherlands). We like to thank Thimo Mulder for assisting in the laboratory, Jolanda Brons and Marco van der Velde for advice on lab procedure and use of equipment. We thank the Center for Information Technology of the University of Groningen for their support and for providing access to the Hábrók high performance computing cluster. Lastly, the authors would like to thank Kasper Meijer for feedback on the analysis.
Publisher Copyright:
© 2023 The Authors
PY - 2023/10
Y1 - 2023/10
N2 - Marine biodiversity loss is accelerating, leading to the elevated extinction risks of many species, including sharks and rays. To mitigate these losses, information on their distribution and community composition is needed. Monitoring these (often) mobile species is challenging, especially in remote, highly dynamic and turbid coastal areas. Here, we use an environmental DNA (eDNA) approach to: (1) establish the presence and distribution of elasmobranch species, (2) compare this to a conventional fisheries-dependent approach, and (3) determine the influence of season, area-based protection and habitat on elasmobranch community composition in the highly dynamic Bijagós Archipelago in Guinea-Bissau (West Africa). We collected 127 seawater samples and detected elasmobranch DNA in 58 (45.7%) of these samples, confirming the presence of 13 different elasmobranch species (2 sharks, 11 rays), including seven threatened species. Eight of the species detected by the eDNA-approach were also recorded in a fisheries observer program, which recorded another eight species not detected by the eDNA approach. The most commonly occurring species, based on the number of eDNA sampling locations were the pearl whipray (Fontitrygon margaritella), smalltooth stingray (Hypanus rudis), scalloped hammerhead shark (Sphyrna lewini), and the blackchin guitarfish (Glaucostegus cemiculus). Species composition and richness differed significantly before (January-March) and after the rainy season (November-December). Furthermore, we showed that community composition and species richness did not differ between protected (MPA) and non-protected areas of the archipelago. Thus, we confirm that eDNA approaches are a valuable and non-invasive tool to study threatened shark and ray species in data-deficient and dynamic coastal areas, especially when combined with conventional monitoring methods such as fisheries-dependent information.
AB - Marine biodiversity loss is accelerating, leading to the elevated extinction risks of many species, including sharks and rays. To mitigate these losses, information on their distribution and community composition is needed. Monitoring these (often) mobile species is challenging, especially in remote, highly dynamic and turbid coastal areas. Here, we use an environmental DNA (eDNA) approach to: (1) establish the presence and distribution of elasmobranch species, (2) compare this to a conventional fisheries-dependent approach, and (3) determine the influence of season, area-based protection and habitat on elasmobranch community composition in the highly dynamic Bijagós Archipelago in Guinea-Bissau (West Africa). We collected 127 seawater samples and detected elasmobranch DNA in 58 (45.7%) of these samples, confirming the presence of 13 different elasmobranch species (2 sharks, 11 rays), including seven threatened species. Eight of the species detected by the eDNA-approach were also recorded in a fisheries observer program, which recorded another eight species not detected by the eDNA approach. The most commonly occurring species, based on the number of eDNA sampling locations were the pearl whipray (Fontitrygon margaritella), smalltooth stingray (Hypanus rudis), scalloped hammerhead shark (Sphyrna lewini), and the blackchin guitarfish (Glaucostegus cemiculus). Species composition and richness differed significantly before (January-March) and after the rainy season (November-December). Furthermore, we showed that community composition and species richness did not differ between protected (MPA) and non-protected areas of the archipelago. Thus, we confirm that eDNA approaches are a valuable and non-invasive tool to study threatened shark and ray species in data-deficient and dynamic coastal areas, especially when combined with conventional monitoring methods such as fisheries-dependent information.
KW - Coastal ecology
KW - Conservation
KW - eDNA
KW - Elasmobranchs
KW - Marine biodiversity
KW - Marine protected area
UR - http://www.scopus.com/inward/record.url?scp=85167789076&partnerID=8YFLogxK
U2 - 10.1016/j.ecolind.2023.110795
DO - 10.1016/j.ecolind.2023.110795
M3 - Article
AN - SCOPUS:85167789076
SN - 1470-160X
VL - 154
JO - Ecological indicators
JF - Ecological indicators
M1 - 110795
ER -