Entanglement::an emerging threat to humpback whales in Scottish waters
Entanglement in static fishing gear, especially shellfish creels (pots), is a known source of mortality and injury for humpback whales (Megaptera novaeangliae) with an apparent rise in recent entanglements of this species in Scottish coastal waters. All available sighting records in Scottish waters...
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International Whaling Commission
2016
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Online Access: | https://pure.uhi.ac.uk/en/publications/2741fec5-6a9a-4b7c-94c2-ab5419e6f843 https://pureadmin.uhi.ac.uk/ws/files/3756894/SC_66b_HIM_01.pdf |
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ftuhipublicatio:oai:pure.atira.dk:publications/2741fec5-6a9a-4b7c-94c2-ab5419e6f843 2023-12-10T09:49:26+01:00 Entanglement::an emerging threat to humpback whales in Scottish waters Rya, Conor Leaper, Russell Evans, Peter G.H. Dyke, Katie Robinson, Kevin P. Haskins, Gary N. Calderan, Susannah van Geel, Catharina Francisca Harries, Olivia Froud, Kerry Brownlow, Andrew Jack, Alistair 2016-05 application/pdf https://pure.uhi.ac.uk/en/publications/2741fec5-6a9a-4b7c-94c2-ab5419e6f843 https://pureadmin.uhi.ac.uk/ws/files/3756894/SC_66b_HIM_01.pdf eng eng International Whaling Commission info:eu-repo/semantics/openAccess Rya , C , Leaper , R , Evans , P G H , Dyke , K , Robinson , K P , Haskins , G N , Calderan , S , van Geel , C F , Harries , O , Froud , K , Brownlow , A & Jack , A 2016 , Entanglement: an emerging threat to humpback whales in Scottish waters . International Whaling Commission . book 2016 ftuhipublicatio 2023-11-16T23:21:04Z Entanglement in static fishing gear, especially shellfish creels (pots), is a known source of mortality and injury for humpback whales (Megaptera novaeangliae) with an apparent rise in recent entanglements of this species in Scottish coastal waters. All available sighting records in Scottish waters from 1992 to 2016 were collated to determine the distribution of the species. A subset of sightings with associated boat-based search effort from the west of Scotland indicated the relative abundance of humpback whales in this region was very low (just four sightings from 86,000 km of search effort). Of the 213 incidental sighting records from 1992 to 2016, 5.6 % (n = 12) comprised known entanglements. For the five most recent years (2012 to 2016), this proportion was higher 7.5 % (n = 10). Over half of the known entanglements (n = 7) involved creels, three others were of ropes consistent with creels, and one involved an aquaculture (salmon) pen. Rescue responses to six of the 12 entangled whales resulted in successful disentanglements, although their long-term survival remains unknown. Three of the 12 entanglement cases (i.e. 25%) were fatal. A gamma distribution was fitted to the frequency of humpback whale ‘visits’ based on the number of different days on which humpbacks were reported. From this, the number of unreported visits in inshore Scottish waters was estimated. Based on the minimum number of reported entanglements, the daily probability that a whale that is present in the area would become entangled was estimated at 0.0017. An independent estimate of entanglement risk, using a subset of effort-related sightings and an assumed effective strip half-width, also suggested the same daily entanglement probability. If a whale were to be resident year-round, these estimates would equate to an annual entanglement probability of 0.46. Based on this probability and the observed proportion of fatal entanglements would suggest a fatal entanglement probability of 0.12. This source of mortality alone is an order of ... Book Humpback Whale Megaptera novaeangliae University of the Highlands and Islands: Research Database of UHI |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
description |
Entanglement in static fishing gear, especially shellfish creels (pots), is a known source of mortality and injury for humpback whales (Megaptera novaeangliae) with an apparent rise in recent entanglements of this species in Scottish coastal waters. All available sighting records in Scottish waters from 1992 to 2016 were collated to determine the distribution of the species. A subset of sightings with associated boat-based search effort from the west of Scotland indicated the relative abundance of humpback whales in this region was very low (just four sightings from 86,000 km of search effort). Of the 213 incidental sighting records from 1992 to 2016, 5.6 % (n = 12) comprised known entanglements. For the five most recent years (2012 to 2016), this proportion was higher 7.5 % (n = 10). Over half of the known entanglements (n = 7) involved creels, three others were of ropes consistent with creels, and one involved an aquaculture (salmon) pen. Rescue responses to six of the 12 entangled whales resulted in successful disentanglements, although their long-term survival remains unknown. Three of the 12 entanglement cases (i.e. 25%) were fatal. A gamma distribution was fitted to the frequency of humpback whale ‘visits’ based on the number of different days on which humpbacks were reported. From this, the number of unreported visits in inshore Scottish waters was estimated. Based on the minimum number of reported entanglements, the daily probability that a whale that is present in the area would become entangled was estimated at 0.0017. An independent estimate of entanglement risk, using a subset of effort-related sightings and an assumed effective strip half-width, also suggested the same daily entanglement probability. If a whale were to be resident year-round, these estimates would equate to an annual entanglement probability of 0.46. Based on this probability and the observed proportion of fatal entanglements would suggest a fatal entanglement probability of 0.12. This source of mortality alone is an order of ... |
format |
Book |
author |
Rya, Conor Leaper, Russell Evans, Peter G.H. Dyke, Katie Robinson, Kevin P. Haskins, Gary N. Calderan, Susannah van Geel, Catharina Francisca Harries, Olivia Froud, Kerry Brownlow, Andrew Jack, Alistair |
spellingShingle |
Rya, Conor Leaper, Russell Evans, Peter G.H. Dyke, Katie Robinson, Kevin P. Haskins, Gary N. Calderan, Susannah van Geel, Catharina Francisca Harries, Olivia Froud, Kerry Brownlow, Andrew Jack, Alistair Entanglement::an emerging threat to humpback whales in Scottish waters |
author_facet |
Rya, Conor Leaper, Russell Evans, Peter G.H. Dyke, Katie Robinson, Kevin P. Haskins, Gary N. Calderan, Susannah van Geel, Catharina Francisca Harries, Olivia Froud, Kerry Brownlow, Andrew Jack, Alistair |
author_sort |
Rya, Conor |
title |
Entanglement::an emerging threat to humpback whales in Scottish waters |
title_short |
Entanglement::an emerging threat to humpback whales in Scottish waters |
title_full |
Entanglement::an emerging threat to humpback whales in Scottish waters |
title_fullStr |
Entanglement::an emerging threat to humpback whales in Scottish waters |
title_full_unstemmed |
Entanglement::an emerging threat to humpback whales in Scottish waters |
title_sort |
entanglement::an emerging threat to humpback whales in scottish waters |
publisher |
International Whaling Commission |
publishDate |
2016 |
url |
https://pure.uhi.ac.uk/en/publications/2741fec5-6a9a-4b7c-94c2-ab5419e6f843 https://pureadmin.uhi.ac.uk/ws/files/3756894/SC_66b_HIM_01.pdf |
genre |
Humpback Whale Megaptera novaeangliae |
genre_facet |
Humpback Whale Megaptera novaeangliae |
op_source |
Rya , C , Leaper , R , Evans , P G H , Dyke , K , Robinson , K P , Haskins , G N , Calderan , S , van Geel , C F , Harries , O , Froud , K , Brownlow , A & Jack , A 2016 , Entanglement: an emerging threat to humpback whales in Scottish waters . International Whaling Commission . |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1784893876467662848 |