Most fisheries in China do not have maximum sustainable yield（MSY） estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch（TAC） for fishery management is ...Most fisheries in China do not have maximum sustainable yield（MSY） estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch（TAC） for fishery management is necessary. MSYs of three important fisheries in the East China Sea were evaluated through a catch-based model.Estimates for intrinsic rate of increase（r） and five levels of process error were considered. Results showed hairtail Trichiurus japonicas（Temminck and Schlegel） and small yellow croaker Larimichthys polyactis（Bleeker） fisheries experienced overfishing from the mid-1990 s to the early 2000 s, and the suggested TACs were 55.8×10^4 t and9.06×10^4 t, respectively. Decades of overfishing in wintering and spawning grounds of large yellow croaker Larimichthys crocea（Richardson） caused the fishery＇s collapse in the 1980 s, and it has not recovered until today.The Catch–MSY model generated similar estimated MSYs with other methods and may be a useful choice for the assessment of regional stocks in China.展开更多
Many fish stocks in the world are depleted as a result of overexploitation, which reduces stock productivity and results in loss of potential yields. In this study we analyzed the catch trends and approximate threshol...Many fish stocks in the world are depleted as a result of overexploitation, which reduces stock productivity and results in loss of potential yields. In this study we analyzed the catch trends and approximate thresholds of sustainable fishing for fished stocks to estimate the potential loss of catch and revenue of global fisheries as a result of overexploitation during the period of 1950–2010 in 14 FAO fishing areas. About 35% of stocks in the global marine ocean have or had suffered from overexploitation at present. The global catch losses amounted to 332.8 million tonnes over 1950–2010, resulting in a direct economic loss of US$298.9 billion（constant 2005 US$）.Unsustainable fishing caused substantial potential losses worldwide, especially in the northern hemisphere.Estimated potential losses due to overfishing for different groups of resources showed that the low-value but abundant small-medium pelagics made the largest contribution to the global catch loss, with a weight of 265.0 million tonnes. The geographic expansion of overfishing not only showed serial depletion of world＇s fishery resources, but also reflected how recent trends towards sustainability can stabilize or reverse catch losses.Reduction of global fishing capacity and changes in fishery management systems are necessary if the long-term sustainability of marine fisheries in the world is to be achieved.展开更多
<span style="font-family:Verdana;">This study was used</span><span style="font-family:Verdana;"> to</span><span style="font-family:;" "=""><...<span style="font-family:Verdana;">This study was used</span><span style="font-family:Verdana;"> to</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> lift nets and trap net fishing at intertidal zone of lagoon and estuarine regions of southern Taiwan. From July 2013 to July 2018, a total 420 specimens of </span><i><span style="font-family:Verdana;">Pisodonophis</span></i><span style="font-family:Verdana;"> were analyzed, the average total body length (TL) and average body weight (W) of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels are 68.4 ± 11.9 cm and 140.4 ± 86.1 g (N = 194), respectively. Typically, </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> eels are smaller (TL = 52.8 ± 9.2 cm) and lighter (W = 107.9 ± 73.7 g [N = 119]) than </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels. The natural logarithmic linear relationships between the TL and W of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> are respectively expressed as ln(W)</span><sub><span style="font-family:Verdana;">b</span></sub><span style="font-family:Verdana;"> = 2.4405 ln(TL) <span style="white-space:nowrap;">−</span> 5.4448 (R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.796, N = 194) and ln(W)</span><sub><span style="font-family:Verdana;">c</span></sub><span style="font-family:Verdana;"> = 3.2168 ln(TL) <span style="white-space:nowrap;">−</span> 8.2027, (</span><i><span style="font-family:Verdana;">R</span></i><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.934, N= 119). </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> typically preys on shrimp, crab, and fish;lab assessment revealed that the frequencies of occurrence of these foods in their guts were 49%, 21%, and 15%, respectively (N = 100). The main catch months of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> were during the rainy season, and that of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> were the winter season in Taiwan. The average W values of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> from Jhuoshuei and Puzih estuaries were 343.2 ± 218.8 g (N = 91) and 140.4 ± 86.1 g (N = 194), respectively. Furthermore, the results of the study revealed that the Puzih estuary is overfished. </span><span style="font-family:Verdana;">We suggest that fishery management units should develop some protection measures for the conservation of aquatic ecosystems in estuarine regions. For example, </span><span style="font-family:Verdana;">the </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> weighing less than 113 g will be released back to the estuary.</span></span>展开更多
The Yangtze River is the longest river in China,with abundant water resources,high water energy reserves,and rich biodiversity.Human activities have greatly changed the hydrology and ecology of the Yangtze River Basin...The Yangtze River is the longest river in China,with abundant water resources,high water energy reserves,and rich biodiversity.Human activities have greatly changed the hydrology and ecology of the Yangtze River Basin since the 1950s.The aquatic biodiversity in the Yangtze River Basin has declined sharply,while the amount offishery in the Yangtze River has been maintained due to higher intense offishing,artificial proliferation intervention,and other factors.Human activities including overfishing,water polluting,damming,reclaiming wetlands,shipping and shoreline development,species introduction,and so forth have had great influence on aquatic ecosystems.This paper also reviewed the measures implemented to protect the aquatic ecosystems of the Yangtze River.By reviewing the evolutionary trend of aquatic organisms in the Yangtze River Basin and the related human activities,this paper helps to better understand the biodiversity of the Yangtze River,and requires more attention on the continuous impact of human activities,as well as the effectiveness of protection measures under the new situation of Yangtze River protection.展开更多
The Perhentian Islands located in the East coast of Peninsular Malaysia. They are well-known for their rich coral reef ecosystems. Marine resources of Malaysia have been overexploited in general due to overfishing and...The Perhentian Islands located in the East coast of Peninsular Malaysia. They are well-known for their rich coral reef ecosystems. Marine resources of Malaysia have been overexploited in general due to overfishing and other development activities. Such no-take marine protected areas (MPAs) were established in Malaysia including Perhentian Islands Marine Park to enable overexploited marine resources to recover and to conserve coral reef ecosystems. This paper examines the current level of activities causing damages to the coral reef habitats in the Perhentian MPA. This study used paired comparison method to elicit the perception of the local stakeholders on the activities harmful to the marine habitats. The results of the analysis showed that various respondent groups had similar preference rankings on the harmful activities: littering, discarding fishing equipments, excess fishing and too many divers that cause damage to the habitats in the MPA area. The findings suggest that policy makers should take cognizance of the local stakeholders’ concern in planning and designing of marine protected areas in Malaysia.展开更多
Despite Zambia＇s recent policies for optimizing sustainable management of fisheries, their success has been modest in practice. Artisanal and industrial fleets have led to decline in fish catches in the presence of c...Despite Zambia＇s recent policies for optimizing sustainable management of fisheries, their success has been modest in practice. Artisanal and industrial fleets have led to decline in fish catches in the presence of currently prescribed management possibilities. Among other factors, excessive fishing and unsustainable fishing methods attributed to common property and free access to the resources are key. The country adopted co-management approach to fisheries management in the 1990s with a view to improve the fisheries stocks through community enforcement of fishery management regulations. Neither the success of co-management has been easy to measure nor its results appreciated. In view of overfishing, it is required to continue providing a range of empirical evidence of area-specific co-management interventions as basis for designing realistic and innovative solutions for the nation. This implies that new policies and institutions need to be developed by research to understand fisheries systems and better promote sustainable trajectories. The following review recommendation to central government is a coherent approach that uses and crystallizes the multiple interests and skills of co-management stakeholders. Most stakeholder groups have been involved in an ad hoc fashion through workshops, public meetings and consultative processes mainly organized by Department of Fisheries. Stakeholders should be involved from the design of the process to each step in the process, including the ongoing monitoring and evaluation. A form of memorandum of understanding is suggested. This will formally set out a process that acknowledges each stakeholder＇s interests and provide forums to facilitate discussion, consultation and monitoring of management activities.展开更多
Fish species diversity can be lost through interacting stressors including habitat loss, stocking and overfishing. Although a multitude of stressors have played a role in the global decline of coregonid (Coregonus spp...Fish species diversity can be lost through interacting stressors including habitat loss, stocking and overfishing. Although a multitude of stressors have played a role in the global decline of coregonid (Coregonus spp.) diversity, a number of contemporary studies have identified habitat loss stemming from eutrophication as the primary cause. Unfortunately, reconstructing the role of fishing and stocking practices can be difficult, because these records are incomplete or appear only in hard-to-access historic grey literature. Based on an illustrative set of historic and contemporary studies, we describe how fisheries management practices may have contributed to coregonid diversity loss in European and North American lakes. We provide case studies examining how fishing and stocking may reduce coregonid diversity through demographic decline and introgressive hybridization. In some lakes, fisheries management practices may have led to a loss of coregonid diversity well before issues with habitat degradation manifested. Our review suggests that fish conservation policies could beneficially consider the relative importance of all stressors, including management practices, as potential drivers of diversity loss.展开更多
Sardinella maderensis is one of the fish species well appreciated in Benin. In recent years, this species has experienced a decrease in its production in the coastal waters of this country. To search for the causes of...Sardinella maderensis is one of the fish species well appreciated in Benin. In recent years, this species has experienced a decrease in its production in the coastal waters of this country. To search for the causes of this decline in production, a standard survey was carried out using Computed Assisted Personal Interviewing with the 38 artisanal fishermen at the artisanal fishing port of Cotonou who targets this species in order to inquire about the fishing gear and techniques of production. The current stock status of this species was determined using FiSAT from a sample of 1240 specimens collected randomly in commercial catches from January to December 2021. The typical survey revealed a massive use of non-regulatory fishing mesh gear (86.85%). The fishing effort is also sustained and results in a fishing mortality rate (F = 2.88 yr<sup>-1</sup>) higher than the rate of natural mortality (M = 2.22 yr<sup>-1</sup>) suggesting overfishing of the stock. Sustainable management through capacity building of fishermen and application of regulations in terms of gear mesh size and respect for fishing seasons could be stated.展开更多
A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing,diving fishing,underwater video,and eDNA detection,combined with historical data from 1979 and archival records from the South...A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing,diving fishing,underwater video,and eDNA detection,combined with historical data from 1979 and archival records from the South China Sea Fisheries Research Institute of the Chinese Academy of Fisheries Sciences for the years of 1998,1999,2003,and 2005.Successional characteristics of coral reef fishes through time were also explored.The findings revealed:(1)A total of 299 coral reef fish species were identified in Huaguang Reef,categorized into 2 classes,16 orders,and 56 families,with Perciformes exhibiting the highest species count(234),constituting 78.26%of all species.(2)In comparison to the period of 1979–2005,there was a reduction in the number of species at the order and family levels in 2023 at Huaguang Reef.Both the average taxonomic distinctness(Δt)and the variation in taxonomic distinctness(Λt)exhibited a declining trend,indicating disturbances in the fish ecosystem.(3)The proportion of herbivorous fish at Huaguang Reef remained relatively stable in 2023 compared to the 1979–2005 period.Notably,the similarity coefficient of herbivorous fish was the highest among different feeding types,signifying a degraded state of the Huaguang Reef habitat.(4)In contrast to the 1979–2005 period,a significant decline was observed in large-sized and carnivorous fish species at Huaguang Reef in 2023.The low similarity coefficients for both categories,with undiscovered fish species accounting for 58.49%and 45.76%of their respective taxa in the total list,respectively,suggested a notable impact of overfishing on coral reef fishes.The succession patterns revealed in this study provide a theoretical foundation for advancing the sustainable development of coral reef fish resources in the Xisha Islands and offer valuable insights for the protection and management of coral reef fishes.展开更多
Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances.However,long-term variati...Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances.However,long-term variation in fish community structure in this Bay remains uncertain.In this study,we aimed to explore the changing characteristics of fish species composition and community structure in Daya Bay during the past 30 years using data from 1989 to 2021 from bottom trawl surveys and historical literature data.As of now,a total of 544 species of fish have been identified in the Bay,belonging to 24 orders and 125 families.The structure of the fish community in the bay has changed over time.Firstly,there has been a clear decrease in the number of species and biomass of large fish.Secondly,the number of fish constituent orders and families has decreased.Moreover,both the average taxonomic distinctness and variation in taxonomic distinctness decreased from 1989 to 2021.Thirdly,there is low similarity among fishes at different time phases and distinct changes in the composition of dominant species.Present results indicate that the fish community structure in Daya Bay has tended to reflect a decline in diversity,shifts in composition,and shrinking of fish body size in the past 30 years.This study improves our understanding of fish species composition and its drivers over time in Daya Bay,providing important knowledge to support the protection and restoration of this ecosystem and the important ecosystem services it provides.展开更多
基金The National Natural Science Foundation of China under contract No.31602157the Special Fund for Agroscientific Research in the Public Interest under contract No.201403008the Central Public-interest Scientific Institution Basal Research Fund of South China Sea Fisheries Research Institute under contract No.2016TS06
文摘Most fisheries in China do not have maximum sustainable yield（MSY） estimates due to limited and poor data.Therefore, finding a common method to estimate MSY or total allowable catch（TAC） for fishery management is necessary. MSYs of three important fisheries in the East China Sea were evaluated through a catch-based model.Estimates for intrinsic rate of increase（r） and five levels of process error were considered. Results showed hairtail Trichiurus japonicas（Temminck and Schlegel） and small yellow croaker Larimichthys polyactis（Bleeker） fisheries experienced overfishing from the mid-1990 s to the early 2000 s, and the suggested TACs were 55.8×10^4 t and9.06×10^4 t, respectively. Decades of overfishing in wintering and spawning grounds of large yellow croaker Larimichthys crocea（Richardson） caused the fishery＇s collapse in the 1980 s, and it has not recovered until today.The Catch–MSY model generated similar estimated MSYs with other methods and may be a useful choice for the assessment of regional stocks in China.
基金The National Natural Science Foundation of China under contract Nos NSFC41306127 and NSFC41276156the Funding Program for Outstanding Dissertations in Shanghai Ocean University+1 种基金the Funding Scheme for Training Young Teachers in Shanghai Colleges and Shanghai Leading Academic Discipline Project(Fisheries Discipline)the involvement of Y.Chen was supported by the SHOU International Center for Marine Studies and Shanghai 1000 Talent Program
文摘Many fish stocks in the world are depleted as a result of overexploitation, which reduces stock productivity and results in loss of potential yields. In this study we analyzed the catch trends and approximate thresholds of sustainable fishing for fished stocks to estimate the potential loss of catch and revenue of global fisheries as a result of overexploitation during the period of 1950–2010 in 14 FAO fishing areas. About 35% of stocks in the global marine ocean have or had suffered from overexploitation at present. The global catch losses amounted to 332.8 million tonnes over 1950–2010, resulting in a direct economic loss of US$298.9 billion（constant 2005 US$）.Unsustainable fishing caused substantial potential losses worldwide, especially in the northern hemisphere.Estimated potential losses due to overfishing for different groups of resources showed that the low-value but abundant small-medium pelagics made the largest contribution to the global catch loss, with a weight of 265.0 million tonnes. The geographic expansion of overfishing not only showed serial depletion of world＇s fishery resources, but also reflected how recent trends towards sustainability can stabilize or reverse catch losses.Reduction of global fishing capacity and changes in fishery management systems are necessary if the long-term sustainability of marine fisheries in the world is to be achieved.
文摘<span style="font-family:Verdana;">This study was used</span><span style="font-family:Verdana;"> to</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> lift nets and trap net fishing at intertidal zone of lagoon and estuarine regions of southern Taiwan. From July 2013 to July 2018, a total 420 specimens of </span><i><span style="font-family:Verdana;">Pisodonophis</span></i><span style="font-family:Verdana;"> were analyzed, the average total body length (TL) and average body weight (W) of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels are 68.4 ± 11.9 cm and 140.4 ± 86.1 g (N = 194), respectively. Typically, </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> eels are smaller (TL = 52.8 ± 9.2 cm) and lighter (W = 107.9 ± 73.7 g [N = 119]) than </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels. The natural logarithmic linear relationships between the TL and W of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> are respectively expressed as ln(W)</span><sub><span style="font-family:Verdana;">b</span></sub><span style="font-family:Verdana;"> = 2.4405 ln(TL) <span style="white-space:nowrap;">−</span> 5.4448 (R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.796, N = 194) and ln(W)</span><sub><span style="font-family:Verdana;">c</span></sub><span style="font-family:Verdana;"> = 3.2168 ln(TL) <span style="white-space:nowrap;">−</span> 8.2027, (</span><i><span style="font-family:Verdana;">R</span></i><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.934, N= 119). </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> typically preys on shrimp, crab, and fish;lab assessment revealed that the frequencies of occurrence of these foods in their guts were 49%, 21%, and 15%, respectively (N = 100). The main catch months of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> were during the rainy season, and that of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> were the winter season in Taiwan. The average W values of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> from Jhuoshuei and Puzih estuaries were 343.2 ± 218.8 g (N = 91) and 140.4 ± 86.1 g (N = 194), respectively. Furthermore, the results of the study revealed that the Puzih estuary is overfished. </span><span style="font-family:Verdana;">We suggest that fishery management units should develop some protection measures for the conservation of aquatic ecosystems in estuarine regions. For example, </span><span style="font-family:Verdana;">the </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> weighing less than 113 g will be released back to the estuary.</span></span>
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:52025092Beijing Outstanding Youth Funding Project,Grant/Award Number:JQ19034。
文摘The Yangtze River is the longest river in China,with abundant water resources,high water energy reserves,and rich biodiversity.Human activities have greatly changed the hydrology and ecology of the Yangtze River Basin since the 1950s.The aquatic biodiversity in the Yangtze River Basin has declined sharply,while the amount offishery in the Yangtze River has been maintained due to higher intense offishing,artificial proliferation intervention,and other factors.Human activities including overfishing,water polluting,damming,reclaiming wetlands,shipping and shoreline development,species introduction,and so forth have had great influence on aquatic ecosystems.This paper also reviewed the measures implemented to protect the aquatic ecosystems of the Yangtze River.By reviewing the evolutionary trend of aquatic organisms in the Yangtze River Basin and the related human activities,this paper helps to better understand the biodiversity of the Yangtze River,and requires more attention on the continuous impact of human activities,as well as the effectiveness of protection measures under the new situation of Yangtze River protection.
文摘The Perhentian Islands located in the East coast of Peninsular Malaysia. They are well-known for their rich coral reef ecosystems. Marine resources of Malaysia have been overexploited in general due to overfishing and other development activities. Such no-take marine protected areas (MPAs) were established in Malaysia including Perhentian Islands Marine Park to enable overexploited marine resources to recover and to conserve coral reef ecosystems. This paper examines the current level of activities causing damages to the coral reef habitats in the Perhentian MPA. This study used paired comparison method to elicit the perception of the local stakeholders on the activities harmful to the marine habitats. The results of the analysis showed that various respondent groups had similar preference rankings on the harmful activities: littering, discarding fishing equipments, excess fishing and too many divers that cause damage to the habitats in the MPA area. The findings suggest that policy makers should take cognizance of the local stakeholders’ concern in planning and designing of marine protected areas in Malaysia.
文摘Despite Zambia＇s recent policies for optimizing sustainable management of fisheries, their success has been modest in practice. Artisanal and industrial fleets have led to decline in fish catches in the presence of currently prescribed management possibilities. Among other factors, excessive fishing and unsustainable fishing methods attributed to common property and free access to the resources are key. The country adopted co-management approach to fisheries management in the 1990s with a view to improve the fisheries stocks through community enforcement of fishery management regulations. Neither the success of co-management has been easy to measure nor its results appreciated. In view of overfishing, it is required to continue providing a range of empirical evidence of area-specific co-management interventions as basis for designing realistic and innovative solutions for the nation. This implies that new policies and institutions need to be developed by research to understand fisheries systems and better promote sustainable trajectories. The following review recommendation to central government is a coherent approach that uses and crystallizes the multiple interests and skills of co-management stakeholders. Most stakeholder groups have been involved in an ad hoc fashion through workshops, public meetings and consultative processes mainly organized by Department of Fisheries. Stakeholders should be involved from the design of the process to each step in the process, including the ongoing monitoring and evaluation. A form of memorandum of understanding is suggested. This will formally set out a process that acknowledges each stakeholder＇s interests and provide forums to facilitate discussion, consultation and monitoring of management activities.
文摘Fish species diversity can be lost through interacting stressors including habitat loss, stocking and overfishing. Although a multitude of stressors have played a role in the global decline of coregonid (Coregonus spp.) diversity, a number of contemporary studies have identified habitat loss stemming from eutrophication as the primary cause. Unfortunately, reconstructing the role of fishing and stocking practices can be difficult, because these records are incomplete or appear only in hard-to-access historic grey literature. Based on an illustrative set of historic and contemporary studies, we describe how fisheries management practices may have contributed to coregonid diversity loss in European and North American lakes. We provide case studies examining how fishing and stocking may reduce coregonid diversity through demographic decline and introgressive hybridization. In some lakes, fisheries management practices may have led to a loss of coregonid diversity well before issues with habitat degradation manifested. Our review suggests that fish conservation policies could beneficially consider the relative importance of all stressors, including management practices, as potential drivers of diversity loss.
文摘Sardinella maderensis is one of the fish species well appreciated in Benin. In recent years, this species has experienced a decrease in its production in the coastal waters of this country. To search for the causes of this decline in production, a standard survey was carried out using Computed Assisted Personal Interviewing with the 38 artisanal fishermen at the artisanal fishing port of Cotonou who targets this species in order to inquire about the fishing gear and techniques of production. The current stock status of this species was determined using FiSAT from a sample of 1240 specimens collected randomly in commercial catches from January to December 2021. The typical survey revealed a massive use of non-regulatory fishing mesh gear (86.85%). The fishing effort is also sustained and results in a fishing mortality rate (F = 2.88 yr<sup>-1</sup>) higher than the rate of natural mortality (M = 2.22 yr<sup>-1</sup>) suggesting overfishing of the stock. Sustainable management through capacity building of fishermen and application of regulations in terms of gear mesh size and respect for fishing seasons could be stated.
基金supported by Natural Science Foundation of Hainan Province(323MS124,322CXTD530)Financial Fund of the Ministry of Agriculture and Rural Affairs,P.R.of China(NHZX2024)+3 种基金The Nan-Fan Aquaculture Joint Open Fund Project,Hainan Tropical Ocean University(2023SCNFKF06)Fundamental and Applied Fundamental Research Major Program of Guangdong Province(2019B030302004-05)Central Public-interest Scientific Institution Basal Research Fund,CAFS(2023TD16)Central Public-interest Scientific Institution Basal Research Fund,South China Sea Fisheries Research Institute,CAFS(2021SD04 and 2019TS28).
文摘A list of coral reef fish species of Huaguang Reef was compiled in 2023 using hand fishing,diving fishing,underwater video,and eDNA detection,combined with historical data from 1979 and archival records from the South China Sea Fisheries Research Institute of the Chinese Academy of Fisheries Sciences for the years of 1998,1999,2003,and 2005.Successional characteristics of coral reef fishes through time were also explored.The findings revealed:(1)A total of 299 coral reef fish species were identified in Huaguang Reef,categorized into 2 classes,16 orders,and 56 families,with Perciformes exhibiting the highest species count(234),constituting 78.26%of all species.(2)In comparison to the period of 1979–2005,there was a reduction in the number of species at the order and family levels in 2023 at Huaguang Reef.Both the average taxonomic distinctness(Δt)and the variation in taxonomic distinctness(Λt)exhibited a declining trend,indicating disturbances in the fish ecosystem.(3)The proportion of herbivorous fish at Huaguang Reef remained relatively stable in 2023 compared to the 1979–2005 period.Notably,the similarity coefficient of herbivorous fish was the highest among different feeding types,signifying a degraded state of the Huaguang Reef habitat.(4)In contrast to the 1979–2005 period,a significant decline was observed in large-sized and carnivorous fish species at Huaguang Reef in 2023.The low similarity coefficients for both categories,with undiscovered fish species accounting for 58.49%and 45.76%of their respective taxa in the total list,respectively,suggested a notable impact of overfishing on coral reef fishes.The succession patterns revealed in this study provide a theoretical foundation for advancing the sustainable development of coral reef fish resources in the Xisha Islands and offer valuable insights for the protection and management of coral reef fishes.
基金funded by Fundamental and Applied Fundamental Research Major Program of Guangdong Province(2019B030302004-05)Science and Technology Planning Project of Guangdong Province(2019B121201001)+2 种基金Central Public-interest Scientific Institution Basal Research Fund,CAFS(2023TD16)Central Public-interest Scientific Institution Basal Research Fund,South China Sea Fisheries Research Institute,CAFS(2021SD04 and 2019TS28)Financial Fund of the Ministry of Agriculture and Rural Affairs,P.R.of China(NFZX2021).
文摘Daya Bay is a semi-enclosed bay in the South China Sea which is a coastal ecosystem with significant ecological and economic value that is subjected to a variety of anthropogenic disturbances.However,long-term variation in fish community structure in this Bay remains uncertain.In this study,we aimed to explore the changing characteristics of fish species composition and community structure in Daya Bay during the past 30 years using data from 1989 to 2021 from bottom trawl surveys and historical literature data.As of now,a total of 544 species of fish have been identified in the Bay,belonging to 24 orders and 125 families.The structure of the fish community in the bay has changed over time.Firstly,there has been a clear decrease in the number of species and biomass of large fish.Secondly,the number of fish constituent orders and families has decreased.Moreover,both the average taxonomic distinctness and variation in taxonomic distinctness decreased from 1989 to 2021.Thirdly,there is low similarity among fishes at different time phases and distinct changes in the composition of dominant species.Present results indicate that the fish community structure in Daya Bay has tended to reflect a decline in diversity,shifts in composition,and shrinking of fish body size in the past 30 years.This study improves our understanding of fish species composition and its drivers over time in Daya Bay,providing important knowledge to support the protection and restoration of this ecosystem and the important ecosystem services it provides.
