The fishery and ecology of the Scallop Pecten maximus (L) in Guernsey
The fishery and ecology of the Scallop Pecten maximus (L) in Guernsey
The overall aim of this work was to study the exploitation of the scallop Pecten maximus (L.) in Guernsey and assess the current management of the fishery. In order to achieve this various aspects of the biology of the local scallop populations were studied as well as the type and intensity of fishing methods used. While doing this work, other studies on the impact of scallop dredging and the behaviour of diver fishermen were carried out to gain a more complete understanding of the fishery in Guernsey.
A review of scallop fisheries in general, and more specifically those in the northeast Atlantic, was carried out as a comparison with the situation in the Channel Islands. The emphasis of this concentrated on the Isle of Man scallop fishery due to the similarity in their situation as an independent island with jurisdiction over their territorial waters. This led to the review of the current situation of scallop fisheries in the Channel Islands, which have been subject to very little study. Again, information from the Jersey fishery was used to assess the similarity between their fishery and the situation in Guernsey. The study of Guernsey fishery in chapter two included assessments of catch per unit effort (CPUE) for both dredge and diver fished grounds as well as an analysis of the population structure and scallop densities. These were required to estimate mortality, which was used in the stock assessment equations when analysing different management options.
As well as information about the fishery, details of the basic biology such as growth rates and maturity indexes were also required to enable the scallop stocks to be assessed. Hence, growth curves were calculated for all the grounds studied following an initial tagging experiment to confirm the annual growth rings which were used to age the scallops. The decline in the rate of return of these tagged scallops was also later used to gain estimates of both natural (M=0.2) and fishing (F=0.4 to 1) mortality on this fishing ground. The seasonal reproductive cycle as well as the age at maturity of some of the scallop populations were studied to provide another required input parameter for the stock assessment equations (Beverton-Holt yield per recruit). The study of spat settlement and seasonal gonad cycles provided important information on the recruitment of scallops in Guernsey waters which is required by fisheries managers when assessing management options.
University of Southampton
Jory, Adam Matthew
7eecf7cf-98c6-454c-8f6e-a7664ffbdb1e
2000
Jory, Adam Matthew
7eecf7cf-98c6-454c-8f6e-a7664ffbdb1e
Jory, Adam Matthew
(2000)
The fishery and ecology of the Scallop Pecten maximus (L) in Guernsey.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The overall aim of this work was to study the exploitation of the scallop Pecten maximus (L.) in Guernsey and assess the current management of the fishery. In order to achieve this various aspects of the biology of the local scallop populations were studied as well as the type and intensity of fishing methods used. While doing this work, other studies on the impact of scallop dredging and the behaviour of diver fishermen were carried out to gain a more complete understanding of the fishery in Guernsey.
A review of scallop fisheries in general, and more specifically those in the northeast Atlantic, was carried out as a comparison with the situation in the Channel Islands. The emphasis of this concentrated on the Isle of Man scallop fishery due to the similarity in their situation as an independent island with jurisdiction over their territorial waters. This led to the review of the current situation of scallop fisheries in the Channel Islands, which have been subject to very little study. Again, information from the Jersey fishery was used to assess the similarity between their fishery and the situation in Guernsey. The study of Guernsey fishery in chapter two included assessments of catch per unit effort (CPUE) for both dredge and diver fished grounds as well as an analysis of the population structure and scallop densities. These were required to estimate mortality, which was used in the stock assessment equations when analysing different management options.
As well as information about the fishery, details of the basic biology such as growth rates and maturity indexes were also required to enable the scallop stocks to be assessed. Hence, growth curves were calculated for all the grounds studied following an initial tagging experiment to confirm the annual growth rings which were used to age the scallops. The decline in the rate of return of these tagged scallops was also later used to gain estimates of both natural (M=0.2) and fishing (F=0.4 to 1) mortality on this fishing ground. The seasonal reproductive cycle as well as the age at maturity of some of the scallop populations were studied to provide another required input parameter for the stock assessment equations (Beverton-Holt yield per recruit). The study of spat settlement and seasonal gonad cycles provided important information on the recruitment of scallops in Guernsey waters which is required by fisheries managers when assessing management options.
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Published date: 2000
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Local EPrints ID: 464086
URI: http://eprints.soton.ac.uk/id/eprint/464086
PURE UUID: 49345368-625e-4f89-b331-9020ce531b3c
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Date deposited: 04 Jul 2022 21:02
Last modified: 16 Mar 2024 19:07
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Author:
Adam Matthew Jory
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