The Experts below are selected from a list of 11316 Experts worldwide ranked by ideXlab platform
John M Klinck - One of the best experts on this subject based on the ideXlab platform.
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fishing and bottom water temperature as drivers of change in maximum shell length in atlantic surfclams spisula solidissima
Estuarine Coastal and Shelf Science, 2016Co-Authors: Daphne M Munroe, Roger Mann, Eric N Powell, Diego A Narvaez, Eileen E Hofmann, D Hennen, L Jacobson, John M KlinckAbstract:Abstract Maximum shell length of Atlantic surfclams (Spisula solidissima) on the Middle Atlantic Bight (MAB) continental shelf, obtained from federal Fishery Survey data from 1982-present, has decreased by 15–20 mm. Two potential causes of this decreasing trend, Fishery removal of large animals and stress due to warming bottom temperatures, were investigated using an individual-based model for post-settlement surfclams and a fifty-year hindcast of bottom water temperatures on the MAB. Simulations showed that fishing and/or warming bottom water temperature can cause decreases in maximum surfclam shell length (body size) equivalent to those observed in the fished stock. Independently, either localized fishing rates of 20% or sustained bottom temperatures that are 2 °C warmer than average conditions generate the observed decrease in maximum shell length. However, these independent conditions represent extremes and are not sustained in the MAB. The combined effects of fishing and warmer temperatures can generate simulated length decreases that are similar to observed decreases. Interannual variability in bottom water temperatures can also generate fluctuations in simulated shell length of up to 20 mm over a period of 10–15 years. If the change in maximum size is not genotypic, simulations also suggest that shell size composition of surfclam populations can recover if conditions change; however, that recovery could take a decade to become evident.
Diego A Narvaez - One of the best experts on this subject based on the ideXlab platform.
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fishing and bottom water temperature as drivers of change in maximum shell length in atlantic surfclams spisula solidissima
Estuarine Coastal and Shelf Science, 2016Co-Authors: Daphne M Munroe, Roger Mann, Eric N Powell, Diego A Narvaez, Eileen E Hofmann, D Hennen, L Jacobson, John M KlinckAbstract:Abstract Maximum shell length of Atlantic surfclams (Spisula solidissima) on the Middle Atlantic Bight (MAB) continental shelf, obtained from federal Fishery Survey data from 1982-present, has decreased by 15–20 mm. Two potential causes of this decreasing trend, Fishery removal of large animals and stress due to warming bottom temperatures, were investigated using an individual-based model for post-settlement surfclams and a fifty-year hindcast of bottom water temperatures on the MAB. Simulations showed that fishing and/or warming bottom water temperature can cause decreases in maximum surfclam shell length (body size) equivalent to those observed in the fished stock. Independently, either localized fishing rates of 20% or sustained bottom temperatures that are 2 °C warmer than average conditions generate the observed decrease in maximum shell length. However, these independent conditions represent extremes and are not sustained in the MAB. The combined effects of fishing and warmer temperatures can generate simulated length decreases that are similar to observed decreases. Interannual variability in bottom water temperatures can also generate fluctuations in simulated shell length of up to 20 mm over a period of 10–15 years. If the change in maximum size is not genotypic, simulations also suggest that shell size composition of surfclam populations can recover if conditions change; however, that recovery could take a decade to become evident.
Daphne M Munroe - One of the best experts on this subject based on the ideXlab platform.
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fishing and bottom water temperature as drivers of change in maximum shell length in atlantic surfclams spisula solidissima
Estuarine Coastal and Shelf Science, 2016Co-Authors: Daphne M Munroe, Roger Mann, Eric N Powell, Diego A Narvaez, Eileen E Hofmann, D Hennen, L Jacobson, John M KlinckAbstract:Abstract Maximum shell length of Atlantic surfclams (Spisula solidissima) on the Middle Atlantic Bight (MAB) continental shelf, obtained from federal Fishery Survey data from 1982-present, has decreased by 15–20 mm. Two potential causes of this decreasing trend, Fishery removal of large animals and stress due to warming bottom temperatures, were investigated using an individual-based model for post-settlement surfclams and a fifty-year hindcast of bottom water temperatures on the MAB. Simulations showed that fishing and/or warming bottom water temperature can cause decreases in maximum surfclam shell length (body size) equivalent to those observed in the fished stock. Independently, either localized fishing rates of 20% or sustained bottom temperatures that are 2 °C warmer than average conditions generate the observed decrease in maximum shell length. However, these independent conditions represent extremes and are not sustained in the MAB. The combined effects of fishing and warmer temperatures can generate simulated length decreases that are similar to observed decreases. Interannual variability in bottom water temperatures can also generate fluctuations in simulated shell length of up to 20 mm over a period of 10–15 years. If the change in maximum size is not genotypic, simulations also suggest that shell size composition of surfclam populations can recover if conditions change; however, that recovery could take a decade to become evident.
Guoping Zhu - One of the best experts on this subject based on the ideXlab platform.
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spatial point patterns of antarctic krill Fishery in the northern antarctic peninsula
Journal of Applied Ecology, 2016Co-Authors: Xiao Ming Yang, Guoping ZhuAbstract:As a key species in the Antarctic ecosystem, the spatial distribution of Antarctic krill (thereafter krill) often tends to present aggregation characteristics, which therefore reflects the spatial patterns of krill fishing operation. Based on the fishing data collected from Chinese krill fishing vessels, of which vessel A was professional krill fishing vessel and Vessel B was a fishing vessel which shifted between Chilean jack mackerel (Trachurus murphyi) fishing ground and krill fishing ground. In order to explore the characteristics of spatial distribution pattern and their ecological effects of two obvious different fishing fleets under a high and low nominal catch per unit effort (CPUE), from the viewpoint of spatial point pattern, the present study analyzed the spatial distribution characteristics of krill Fishery in the northern Antarctic Peninsula from three aspects: (1) the two vessels' point pattern characteristics of higher CPUEs and lower CPUEs at different scales; (2) correlation of the bivariate point patterns between these points of higher CPUE and lower CPUE; and (3) correlation patterns of CPUE. Under the analysis derived from the Ripley's L function and mark correlation function, the results showed that the point patterns of the higher/lo-wer catch available were similar, both showing an aggregation distribution in this study windows at all scale levels. The aggregation intensity of krill fishing was nearly maximum at 15 km spatial scale, and kept stably higher values at the scale of 15-50 km. The aggregation intensity of krill Fishery point patterns could be described in order as higher CPUE of vessel A > lower CPUE of vessel B >higher CPUE of vessel B > higher CPUE of vessel B. The relationship of the higher and lo-wer CPUEs of vessel A showed positive correlation at the spatial scale of 0-75 km, and presented stochastic relationship after 75 km scale, whereas vessel B showed positive correlation at all spatial scales. The point events of higher and lower CPUEs were synchronized, showing significant correlations at most of spatial scales because of the dynamics nature and complex of krill aggregation patterns. The distribution of vessel A's CPUEs was positively correlated at scales of 0-44 km, but negatively correlated at the scales of 44-80 km. The distribution of vessel B's CPUEs was negatively correlated at the scales of 50-70 km, but no significant correlations were found at other scales. The CPUE mark point patterns showed a negative correlation, which indicated that intraspecific competition for space and prey was significant. There were significant differences in spatial point pattern distribution between vessel A with higher fishing capacity and vessel B with lower fishing capacity. The results showed that the professional krill fishing vessel is suitable to conduct the analysis of spatial point pattern and scientific Fishery Survey.
Brehmer Patrice - One of the best experts on this subject based on the ideXlab platform.
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Total admissible catches and experimental fishing quotas in the pink lobster (Palinurus mauritanicus, Gruvel 1911) : a new opportunity for economic development in West Africa ?
'Tokyo Dental College', 2020Co-Authors: Kane E.a., Ball A.c., Brehmer PatriceAbstract:International audienceOver the last thirty years, the poor state of certain fish stocks in the Large Marine Ecosystem of the Canary Current gradually revealed the limits of the West African fisheries management. The Ecosystem Approach advocated in Mauritania, calls to change the perception of fisheries management to incorporate participatory management considerations total admissible catches (TACs) and fishing quotas. An experiment around, a total allowable capture of 800 tons of pink lobster (Palinurus mauritanicus) is at the heart of this approach using methodological tools of analysis / assessment of the economic performance of crawfish exploratory Fishery. Survey results show that during the period from February 2015 to January 2016, the Fishery was based on a total of 23 vessels. 52% is held by Mauritanian and the rest is chartered with European (EU) ship owners. The capture of the Mauritanian Fishery is significantly higher than that of the European Union, respectively 393 tons against 390 tons. 98% of the overall production volume is in live lobsters, mainly for the European market. This production generated sales of 4.26 billion MRO Affairs. Overall, experimental rock lobster industry is an important macroeconomic activity. The Turnover (CA) represents approximately 5% of revenue from exports of the Mauritanian Fish Marketing Company in 2015 (US $ 268 million) and 13% of fishing GDP in 2014 (33.47 billion MRO, BCM 2015). Over two thirds of this amount (3.62 billion MRO) is generated by the (VA) Added Value 85% of turnover. The VA created by Mauritanian operators is 10% more than the VA created by European operators. The Fixed Annual Costs and the Estimated Gross Excess (FACEGE) represents 1.3 MRO billion or 32% of sales. More than half (MRO 896.6 million) in FACEGE is generated by Mauritanian. Experimental lobster industry creates 557 direct and indirect jobs. These jobs represent 10% of the industrial fishing jobs, globally estimated at 3764 Live 2014. It is estimated that the Mauritanian segment creates 25% more jobs than the European segment. This assessment of socio-economic performance of the exploratory Fishery in Mauritania lobster is a first step towards a deeper understanding of its cost structure and its dynamics, necessary for the management of TACs and fishing quotas
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Total admissible catches and experimental fishing quotas in the pink lobster (Palinurus mauritanicus, Gruvel 1911): A new opportunity for economic development in West Africa?
'Tokyo Dental College', 2020Co-Authors: Ea Kane, Ac Ball, Brehmer PatriceAbstract:Over the last thirty years, the poor state of certain fish stocks in the Large Marine Ecosystem of the Canary Current gradually revealed the limits of the West African fisheries management. The Ecosystem Approach advocated in Mauritania, calls to change the perception of fisheries management to incorporate participatory management considerations total admissible catches (TACs) and fishing quotas. An experiment around, a total allowable capture of 800 tons of pink lobster (Palinurus mauritanicus) is at the heart of this approach using methodological tools of analysis / assessment of the economic performance of crawfish exploratory Fishery. Survey results show that during the period from February 2015 to January 2016, the Fishery was based on a total of 23 vessels. 52% is held by Mauritanian and the rest is chartered with European (EU) ship owners. The capture of the Mauritanian Fishery is significantly higher than that of the European Union, respectively 393 tons against 390 tons. 98% of the overall production volume is in live lobsters, mainly for the European market. This production generated sales of 4.26 billion MRO Affairs. Overall, experimental rock lobster industry is an important macroeconomic activity. The Turnover (CA) represents approximately 5% of revenue from exports of the Mauritanian Fish Marketing Company in 2015 (US $ 268 million) and 13% of fishing GDP in 2014 (33.47 billion MRO, BCM 2015). Over two thirds of this amount (3.62 billion MRO) is generated by the (VA) Added Value 85% of turnover. The VA created by Mauritanian operators is 10% more than the VA created by European operators. The Fixed Annual Costs and the Estimated Gross Excess (FACEGE) represents 1.3 MRO billion or 32% of sales. More than half (MRO 896.6 million) in FACEGE is generated by Mauritanian. Experimental lobster industry creates 557 direct and indirect jobs. These jobs represent 10% of the industrial fishing jobs, globally estimated at 3764 Live 2014. It is estimated that the Mauritanian segment creates 25% more jobs than the European segment. This assessment of socio-economic performance of the exploratory Fishery in Mauritania lobster is a first step towards a deeper understanding of its cost structure and its dynamics, necessary for the management of TACs and fishing quotas