Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects
More and more fishery researchers begin to acknowledge that one-dimensional biomass models may omit key information when generating management guidelines. For the more complicated age-structured models, numerous parameters require a proper estimation or a reasonable assumption. In this paper, the ef...
Main Author: | |
---|---|
Format: | Report |
Language: | English |
Published: |
FOR
2019
|
Subjects: | |
Online Access: | http://hdl.handle.net/11250/2612461 |
id |
ftnorgehandelshs:oai:openaccess.nhh.no:11250/2612461 |
---|---|
record_format |
openpolar |
spelling |
ftnorgehandelshs:oai:openaccess.nhh.no:11250/2612461 2023-05-15T17:41:28+02:00 Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects Ni, Yuanming 2019-09-03 application/pdf http://hdl.handle.net/11250/2612461 eng eng FOR Discussion paper;4/19 urn:issn:1500-4066 http://hdl.handle.net/11250/2612461 24 Age-structured bioeconomic recruitment optimization Working paper 2019 ftnorgehandelshs 2021-10-19T20:05:17Z More and more fishery researchers begin to acknowledge that one-dimensional biomass models may omit key information when generating management guidelines. For the more complicated age-structured models, numerous parameters require a proper estimation or a reasonable assumption. In this paper, the effects of recruitment patterns and environmental impacts on the optimal exploitation of a fish population are investigated. Based on a discrete-time age-structured bioeconomic model of Northeast Atlantic mackerel, we introduce the mechanisms that generate 6 scenarios of the problem. Using the simplest scenario, optimizations are conducted under 8 different parameter combinations. Then, the problem is solved for each scenario and simulations are conducted with constant fishing mortalities. It is found that a higher environmental volatility leads to more net profits but with a lower probability of achieving the mean values. Any parameter combination that favours the older fish tends to lend itself to pulse fishing pattern. The simulations indicate that a constant fishing mortality around 0.06 performs the best. A comparison between the optimal and the historical harvest shows that for more than 70% of the time, the optimal exploitation precedes the historical one, leading to 43% higher net profit and 34% lower fishing cost. Report Northeast Atlantic NHH Brage Open institutional repository (Norwegian School of Economics) |
institution |
Open Polar |
collection |
NHH Brage Open institutional repository (Norwegian School of Economics) |
op_collection_id |
ftnorgehandelshs |
language |
English |
topic |
Age-structured bioeconomic recruitment optimization |
spellingShingle |
Age-structured bioeconomic recruitment optimization Ni, Yuanming Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
topic_facet |
Age-structured bioeconomic recruitment optimization |
description |
More and more fishery researchers begin to acknowledge that one-dimensional biomass models may omit key information when generating management guidelines. For the more complicated age-structured models, numerous parameters require a proper estimation or a reasonable assumption. In this paper, the effects of recruitment patterns and environmental impacts on the optimal exploitation of a fish population are investigated. Based on a discrete-time age-structured bioeconomic model of Northeast Atlantic mackerel, we introduce the mechanisms that generate 6 scenarios of the problem. Using the simplest scenario, optimizations are conducted under 8 different parameter combinations. Then, the problem is solved for each scenario and simulations are conducted with constant fishing mortalities. It is found that a higher environmental volatility leads to more net profits but with a lower probability of achieving the mean values. Any parameter combination that favours the older fish tends to lend itself to pulse fishing pattern. The simulations indicate that a constant fishing mortality around 0.06 performs the best. A comparison between the optimal and the historical harvest shows that for more than 70% of the time, the optimal exploitation precedes the historical one, leading to 43% higher net profit and 34% lower fishing cost. |
format |
Report |
author |
Ni, Yuanming |
author_facet |
Ni, Yuanming |
author_sort |
Ni, Yuanming |
title |
Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
title_short |
Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
title_full |
Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
title_fullStr |
Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
title_full_unstemmed |
Optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
title_sort |
optimization of age-structured bioeconomic model: recruitment, weight gain and environmental effects |
publisher |
FOR |
publishDate |
2019 |
url |
http://hdl.handle.net/11250/2612461 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_source |
24 |
op_relation |
Discussion paper;4/19 urn:issn:1500-4066 http://hdl.handle.net/11250/2612461 |
_version_ |
1766143048268382208 |