Mapping bycatch risk hotspots for marine megafauna in the Mediterranean: contrasting artisanal and industrial fisheries
Abstract
Direct and indirect mortality through bycatch in fishing gears is one of the most acute threats to marine megafauna worldwide. This is especially so in the Mediterranean Sea, where pelagic fauna is in an alarming state, in part because of intense over-fishing. Reliably harnessing the bycatch issue is essential to safeguard Mediterranean megafauna biodiversity. Yet, knowing where and when bycatch events are likely to occur is notoriously difficult, due to the elusive nature of interactions between non-target species and fisheries. This gap has long hindered the implementation of adequate measures to limit bycatch events. Here, we mapped the exposure of ten megafauna species to bycatch risk in the Mediterranean (two seabirds, one sea turtle, two fishes and five cetaceans), comparing artisanal and industrial fisheries while accounting for gear-specific bycatch sensitivity. We thereby built on recent international efforts to census megafauna at the Mediterranean scale and on unprecedented reconstruction of historical fishing effort provided by the Global Fishing Effort (GFE) initiative. The Mediterranean fishery sector is mostly composed of small-scale artisanal fisheries (82% of vessels), while the industrial fleet only accounts for 18% of vessels, but lands > 85% of catches. Efforts from both sectors mostly occur in shelf areas, though with regional differences between gears and sectors. Artisanal fisheries mostly operate midwater trawls and seines, while industrial fisheries mostly use seines, midwater and bottom trawls. For all species, exposure to bycatch risk by artisanal fisheries was overall highest in the southern shelves, from the Alboran to the Levantine Seas, while exposure to industrial fishing was more widespread. These results underscore the necessity of sector-specific and regionally tailored mitigation measures to effectively reduce bycatch across the Mediterranean, and particularly so in its southern parts.
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BibTeX
@misc{lambert2026mapping,
title = {{Mapping bycatch risk hotspots for marine megafauna in the Mediterranean: contrasting artisanal and industrial fisheries}},
author = {Charlotte Lambert and Justine Depierrefixe and Nicolas Courbin and Ana Cañadas and Andrew Di Matteo and Laura Sparks and Auriane Virgili and David Grémillet},
howpublished = {HAL},
year = {2026},
month = nov,
url = {https://hal.science/hal-05853953v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Mapping bycatch risk hotspots for marine megafauna in the Mediterranean: contrasting artisanal and industrial fisheries
AU - Charlotte Lambert
AU - Justine Depierrefixe
AU - Nicolas Courbin
AU - Ana Cañadas
AU - Andrew Di Matteo
AU - Laura Sparks
AU - Auriane Virgili
AU - David Grémillet
PY - 2026
DA - 2026/11/02
PB - HAL
UR - https://hal.science/hal-05853953v1
AB - Direct and indirect mortality through bycatch in fishing gears is one of the most acute threats to marine megafauna worldwide. This is especially so in the Mediterranean Sea, where pelagic fauna is in an alarming state, in part because of intense over-fishing. Reliably harnessing the bycatch issue is essential to safeguard Mediterranean megafauna biodiversity. Yet, knowing where and when bycatch events are likely to occur is notoriously difficult, due to the elusive nature of interactions between non-target species and fisheries. This gap has long hindered the implementation of adequate measures to limit bycatch events. Here, we mapped the exposure of ten megafauna species to bycatch risk in the Mediterranean (two seabirds, one sea turtle, two fishes and five cetaceans), comparing artisanal and industrial fisheries while accounting for gear-specific bycatch sensitivity. We thereby built on recent international efforts to census megafauna at the Mediterranean scale and on unprecedented reconstruction of historical fishing effort provided by the Global Fishing Effort (GFE) initiative. The Mediterranean fishery sector is mostly composed of small-scale artisanal fisheries (82% of vessels), while the industrial fleet only accounts for 18% of vessels, but lands > 85% of catches. Efforts from both sectors mostly occur in shelf areas, though with regional differences between gears and sectors. Artisanal fisheries mostly operate midwater trawls and seines, while industrial fisheries mostly use seines, midwater and bottom trawls. For all species, exposure to bycatch risk by artisanal fisheries was overall highest in the southern shelves, from the Alboran to the Levantine Seas, while exposure to industrial fishing was more widespread. These results underscore the necessity of sector-specific and regionally tailored mitigation measures to effectively reduce bycatch across the Mediterranean, and particularly so in its southern parts.
ER -