A current affair: entanglement of humpback whales in coastal shark‐control nets
Abstract Shark‐control nets pose an entanglement risk to East Australian humpback whales during their annual northward and southward migrations between the Southern Ocean and the Coral Sea. Rates of whale entanglement exhibit seasonal and interannual variation, suggesting that an understanding of th...
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ftdoajarticles:oai:doaj.org/article:e9ebb04999ef40328f1b85f7b467880f 2023-05-15T18:25:45+02:00 A current affair: entanglement of humpback whales in coastal shark‐control nets Jessica A. Bolin David S. Schoeman Carme Pizà‐Roca Kylie L. Scales 2020-06-01T00:00:00Z https://doi.org/10.1002/rse2.133 https://doaj.org/article/e9ebb04999ef40328f1b85f7b467880f EN eng Wiley https://doi.org/10.1002/rse2.133 https://doaj.org/toc/2056-3485 2056-3485 doi:10.1002/rse2.133 https://doaj.org/article/e9ebb04999ef40328f1b85f7b467880f Remote Sensing in Ecology and Conservation, Vol 6, Iss 2, Pp 119-128 (2020) Bycatch dynamic ocean management East Australian Current migration ocean model remote sensing Technology T Ecology QH540-549.5 article 2020 ftdoajarticles https://doi.org/10.1002/rse2.133 2022-12-31T09:04:05Z Abstract Shark‐control nets pose an entanglement risk to East Australian humpback whales during their annual northward and southward migrations between the Southern Ocean and the Coral Sea. Rates of whale entanglement exhibit seasonal and interannual variation, suggesting that an understanding of the influence of variability in the broad‐scale physical environment along the migratory route would be useful in assessing risk of entanglement. This study provides a quantitative spatio‐temporal analysis of the probability of whale entanglement in shark‐control nets relative to the position and characteristics of the East Australian Current (EAC), the dominant oceanographic feature of the region. We use satellite‐derived sea‐surface temperature, and outputs from a data‐assimilating ocean model, to develop multivariate, data‐driven algorithms for detecting the edge of the EAC using Principal Components Analysis. We use outputs from these algorithms to model the likelihood of humpback entanglements in South‐east Queensland. We find that the likelihood of entanglement increases when the EAC edge is locally less structured and closer to shore in the vicinity of the corresponding net, or when the EAC is well resolved over the entire study domain. Our results suggest that migrating humpbacks use the gradient in physical characteristics that marks the EAC inner edge as a navigational aid. Thus, when the EAC inner edge encroaches on the coast, the whales’ migration range is compressed into nearshore waters, increasing the risk of entanglement. Our findings can help predict periods of elevated entanglement risk, which could underpin a more data‐driven approach to the management of shark‐control programs, and other activities that involve static fishing gear. Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Queensland Southern Ocean Remote Sensing in Ecology and Conservation 6 2 119 128 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Bycatch dynamic ocean management East Australian Current migration ocean model remote sensing Technology T Ecology QH540-549.5 |
spellingShingle |
Bycatch dynamic ocean management East Australian Current migration ocean model remote sensing Technology T Ecology QH540-549.5 Jessica A. Bolin David S. Schoeman Carme Pizà‐Roca Kylie L. Scales A current affair: entanglement of humpback whales in coastal shark‐control nets |
topic_facet |
Bycatch dynamic ocean management East Australian Current migration ocean model remote sensing Technology T Ecology QH540-549.5 |
description |
Abstract Shark‐control nets pose an entanglement risk to East Australian humpback whales during their annual northward and southward migrations between the Southern Ocean and the Coral Sea. Rates of whale entanglement exhibit seasonal and interannual variation, suggesting that an understanding of the influence of variability in the broad‐scale physical environment along the migratory route would be useful in assessing risk of entanglement. This study provides a quantitative spatio‐temporal analysis of the probability of whale entanglement in shark‐control nets relative to the position and characteristics of the East Australian Current (EAC), the dominant oceanographic feature of the region. We use satellite‐derived sea‐surface temperature, and outputs from a data‐assimilating ocean model, to develop multivariate, data‐driven algorithms for detecting the edge of the EAC using Principal Components Analysis. We use outputs from these algorithms to model the likelihood of humpback entanglements in South‐east Queensland. We find that the likelihood of entanglement increases when the EAC edge is locally less structured and closer to shore in the vicinity of the corresponding net, or when the EAC is well resolved over the entire study domain. Our results suggest that migrating humpbacks use the gradient in physical characteristics that marks the EAC inner edge as a navigational aid. Thus, when the EAC inner edge encroaches on the coast, the whales’ migration range is compressed into nearshore waters, increasing the risk of entanglement. Our findings can help predict periods of elevated entanglement risk, which could underpin a more data‐driven approach to the management of shark‐control programs, and other activities that involve static fishing gear. |
format |
Article in Journal/Newspaper |
author |
Jessica A. Bolin David S. Schoeman Carme Pizà‐Roca Kylie L. Scales |
author_facet |
Jessica A. Bolin David S. Schoeman Carme Pizà‐Roca Kylie L. Scales |
author_sort |
Jessica A. Bolin |
title |
A current affair: entanglement of humpback whales in coastal shark‐control nets |
title_short |
A current affair: entanglement of humpback whales in coastal shark‐control nets |
title_full |
A current affair: entanglement of humpback whales in coastal shark‐control nets |
title_fullStr |
A current affair: entanglement of humpback whales in coastal shark‐control nets |
title_full_unstemmed |
A current affair: entanglement of humpback whales in coastal shark‐control nets |
title_sort |
current affair: entanglement of humpback whales in coastal shark‐control nets |
publisher |
Wiley |
publishDate |
2020 |
url |
https://doi.org/10.1002/rse2.133 https://doaj.org/article/e9ebb04999ef40328f1b85f7b467880f |
geographic |
Queensland Southern Ocean |
geographic_facet |
Queensland Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Remote Sensing in Ecology and Conservation, Vol 6, Iss 2, Pp 119-128 (2020) |
op_relation |
https://doi.org/10.1002/rse2.133 https://doaj.org/toc/2056-3485 2056-3485 doi:10.1002/rse2.133 https://doaj.org/article/e9ebb04999ef40328f1b85f7b467880f |
op_doi |
https://doi.org/10.1002/rse2.133 |
container_title |
Remote Sensing in Ecology and Conservation |
container_volume |
6 |
container_issue |
2 |
container_start_page |
119 |
op_container_end_page |
128 |
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1766207394553004032 |