Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region

In Antarctica, abundant consumers rely on Antarctic krill for food, but krill are also the subject of a commercial fishery. The fishery overlaps in time and space with the foraging areas of these consumers, thus potential competition between krill fisheries and krill consumers is a major management...

Full description

Bibliographic Details
Main Authors: Ryan R. Reisinger, Philip N. Trathan, Christopher M. Johnson, Trevor W. Joyce, John W. Durban, Robert L. Pitman, Ari S. Friedlaender
Format: Article
Language:English
Published: Frontiers Media S.A. 2022-07-01
Series:Frontiers in Marine Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmars.2022.914726/full
_version_ 1818189548419547136
author Ryan R. Reisinger
Philip N. Trathan
Philip N. Trathan
Christopher M. Johnson
Christopher M. Johnson
Trevor W. Joyce
John W. Durban
Robert L. Pitman
Ari S. Friedlaender
author_facet Ryan R. Reisinger
Philip N. Trathan
Philip N. Trathan
Christopher M. Johnson
Christopher M. Johnson
Trevor W. Joyce
John W. Durban
Robert L. Pitman
Ari S. Friedlaender
author_sort Ryan R. Reisinger
collection DOAJ
description In Antarctica, abundant consumers rely on Antarctic krill for food, but krill are also the subject of a commercial fishery. The fishery overlaps in time and space with the foraging areas of these consumers, thus potential competition between krill fisheries and krill consumers is a major management concern. The fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources with an ecosystem approach, according to which fishing should not interfere with either the population growth of krill, or krill-dependent consumers. Krill catches have become increasingly spatially concentrated in a small number of hotspots, raising concerns about how local depletion of krill impacts consumers. Such concentrated fishing demonstrates that there is a mismatch between the spatial and temporal scale at which krill fisheries are currently managed, and that at which fisheries operate and consumers forage. Information on the seasonal dynamics of predator abundance and their foraging behaviour is fundamental to future precautionary management of the krill fishery. We analysed the spatiotemporal distribution of two major krill consumers – humpback and minke whales – and that of krill fishing, off the Western Antarctic Peninsula. We used whale tracking data (58 humpback whale tracks and 19 minke whale tracks) to develop spatial random forest models predicting the monthly distribution of whale foraging areas from January-July. Using these predictions, we calculated spatiotemporally-explicit geographic overlap between whales and fisheries, the latter represented by krill fishing effort and catch data. Over the krill fishing season, fishing effort and catch hotspots shifted to the southwest, into the Bransfield Strait where effort and catch was highest. Predicted humpback whale foraging areas increased in the Bransfield Strait over the same period, while predicted minke whale foraging areas showed an opposite trend. For both we predicted a whale-fishing interaction hotspot in the Bransfield Strait, strongest in April and May. Our results illustrate the fine spatial scale of likely interactions between baleen whales and the krill fishery, and their concentration over the season, underlining the need for fishery management more closely aligned to the spatiotemporal scale of likely predator-fishery interactions.
first_indexed 2024-12-11T23:44:34Z
format Article
id doaj.art-4b2d3ae0d8784045aa8ad709479ecc08
institution Directory Open Access Journal
issn 2296-7745
language English
last_indexed 2024-12-11T23:44:34Z
publishDate 2022-07-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Marine Science
spelling doaj.art-4b2d3ae0d8784045aa8ad709479ecc082022-12-22T00:45:39ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452022-07-01910.3389/fmars.2022.914726914726Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula RegionRyan R. Reisinger0Philip N. Trathan1Philip N. Trathan2Christopher M. Johnson3Christopher M. Johnson4Trevor W. Joyce5John W. Durban6Robert L. Pitman7Ari S. Friedlaender8Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton, United KingdomOcean and Earth Science, University of Southampton, National Oceanography Centre Southampton, European Way, Southampton, United KingdomBritish Antarctic Survey, Cambridge, United KingdomWorld Wide Fund for Nature, Australia (WWF-Australia), Melbourne, VC, AustraliaCurtin University, Centre for Marine Science & Technology, Perth, WA, AustraliaMarine Mammal Institute, Oregon State University, Newport, OR, United StatesMarine Mammal Institute, Oregon State University, Newport, OR, United StatesMarine Mammal Institute, Oregon State University, Newport, OR, United StatesOcean Sciences & Institute for Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, United StatesIn Antarctica, abundant consumers rely on Antarctic krill for food, but krill are also the subject of a commercial fishery. The fishery overlaps in time and space with the foraging areas of these consumers, thus potential competition between krill fisheries and krill consumers is a major management concern. The fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources with an ecosystem approach, according to which fishing should not interfere with either the population growth of krill, or krill-dependent consumers. Krill catches have become increasingly spatially concentrated in a small number of hotspots, raising concerns about how local depletion of krill impacts consumers. Such concentrated fishing demonstrates that there is a mismatch between the spatial and temporal scale at which krill fisheries are currently managed, and that at which fisheries operate and consumers forage. Information on the seasonal dynamics of predator abundance and their foraging behaviour is fundamental to future precautionary management of the krill fishery. We analysed the spatiotemporal distribution of two major krill consumers – humpback and minke whales – and that of krill fishing, off the Western Antarctic Peninsula. We used whale tracking data (58 humpback whale tracks and 19 minke whale tracks) to develop spatial random forest models predicting the monthly distribution of whale foraging areas from January-July. Using these predictions, we calculated spatiotemporally-explicit geographic overlap between whales and fisheries, the latter represented by krill fishing effort and catch data. Over the krill fishing season, fishing effort and catch hotspots shifted to the southwest, into the Bransfield Strait where effort and catch was highest. Predicted humpback whale foraging areas increased in the Bransfield Strait over the same period, while predicted minke whale foraging areas showed an opposite trend. For both we predicted a whale-fishing interaction hotspot in the Bransfield Strait, strongest in April and May. Our results illustrate the fine spatial scale of likely interactions between baleen whales and the krill fishery, and their concentration over the season, underlining the need for fishery management more closely aligned to the spatiotemporal scale of likely predator-fishery interactions.https://www.frontiersin.org/articles/10.3389/fmars.2022.914726/fullhumpback whale (Megaptera novaeangliae)Antarctic krill (Euphausia superba)Antarctic minke whale (Balaenoptera bonaerensis)competitionfishingtracking
spellingShingle Ryan R. Reisinger
Philip N. Trathan
Philip N. Trathan
Christopher M. Johnson
Christopher M. Johnson
Trevor W. Joyce
John W. Durban
Robert L. Pitman
Ari S. Friedlaender
Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region
Frontiers in Marine Science
humpback whale (Megaptera novaeangliae)
Antarctic krill (Euphausia superba)
Antarctic minke whale (Balaenoptera bonaerensis)
competition
fishing
tracking
title Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region
title_full Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region
title_fullStr Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region
title_full_unstemmed Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region
title_short Spatiotemporal Overlap of Baleen Whales and Krill Fisheries in the Western Antarctic Peninsula Region
title_sort spatiotemporal overlap of baleen whales and krill fisheries in the western antarctic peninsula region
topic humpback whale (Megaptera novaeangliae)
Antarctic krill (Euphausia superba)
Antarctic minke whale (Balaenoptera bonaerensis)
competition
fishing
tracking
url https://www.frontiersin.org/articles/10.3389/fmars.2022.914726/full
work_keys_str_mv AT ryanrreisinger spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT philipntrathan spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT philipntrathan spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT christophermjohnson spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT christophermjohnson spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT trevorwjoyce spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT johnwdurban spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT robertlpitman spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion
AT arisfriedlaender spatiotemporaloverlapofbaleenwhalesandkrillfisheriesinthewesternantarcticpeninsularegion