Abstract
Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1582-1587 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 113 |
| Issue number | 6 |
| DOIs | |
| State | Published - Feb 9 2016 |
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Keywords
- Animal telemetry
- Conservation
- Distribution
- Fisheries
- Predator-prey
ASJC Scopus subject areas
- General
Cite this
Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots. / Queiroz, Nuno; Humphries, Nicolas E.; Mucientes, Gonzalo; Hammerschlag, Neil; Lima, Fernando P.; Scales, Kylie L.; Miller, Peter I.; Sousa, Lara L.; Seabra, Rui; Sims, David W.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 113, No. 6, 09.02.2016, p. 1582-1587.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots
AU - Queiroz, Nuno
AU - Humphries, Nicolas E.
AU - Mucientes, Gonzalo
AU - Hammerschlag, Neil
AU - Lima, Fernando P.
AU - Scales, Kylie L.
AU - Miller, Peter I.
AU - Sousa, Lara L.
AU - Seabra, Rui
AU - Sims, David W.
PY - 2016/2/9
Y1 - 2016/2/9
N2 - Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.
AB - Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.
KW - Animal telemetry
KW - Conservation
KW - Distribution
KW - Fisheries
KW - Predator-prey
UR - http://www.scopus.com/inward/record.url?scp=84957818618&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84957818618&partnerID=8YFLogxK
U2 - 10.1073/pnas.1510090113
DO - 10.1073/pnas.1510090113
M3 - Article
VL - 113
SP - 1582
EP - 1587
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 6
ER -