Fisheries Sustainability

2019 ◽  
pp. 91-111
Keyword(s):  
Fisheries Sustainability

scholarly journals Short Communication: Genetic structure of Longtail Tuna Thunnus tonggol (Bleeker, 1851) in Java Sea, Indonesia

2020 ◽  
Vol 21 (8) ◽  
Author(s):  
M. DANIE AL MALIK ◽  
NI PUTU DIAN PERTIWI ◽  
ANDRIANUS SEMBIRING ◽  
NI LUH ASTRIA YUSMALINDA ◽  
ENEX YUNIARTI NINGSIH ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Short Communication ◽  
Management Plan ◽  
P Value ◽  
High Genetic Diversity ◽  
Population Structure Analysis ◽  
Fisheries Sustainability ◽  
Java Sea ◽  
Longtail Tuna

Abstract. Al Malik MD, Pertiwi NPD, Sembiring A, Yusmalinda NLA, Ningsing EY, Astarini IA. 2020. Short Communication: Genetic structure of Longtail Tuna Thunnus tonggol (Bleeker, 1851) in Java Sea, Indonesia. Biodiversitas 21: 3637-3643. Thunnus tonggol (Longtail Tuna) is an economically important fish found in Indonesia waters, however, the information regarding this fish is lacking. Known to be a neritic fish and found in shallow water, Java Sea is one of the ideal habitats for T. tonggol species. Due to high fishing rates activities in Java Sea, a better management plan to ensure the conservation and fisheries sustainability around this area is needed, especially to protect T. tonggol population. In order to complete the Indonesian tuna data, we aim to study the diversity and genetic structure of T. tonggol in Java Sea at three different locations; i.e. Semarang, Banjarmasin, and Jakarta. In this study, population genetic methods with the marker of mitochondrial DNA (mtDNA) control region were used in population structure analysis. A total of 115 specimens were collected from the fish market around the area of study locations and amplified using polymerase chain reaction (PCR) and sequenced using Sanger methods. The result showed genetic diversity (Hd) value of 0.99366, and nucleotide diversity (π) value of 0.01906. Both of these values indicated high genetic diversity. Population analyses using Analysis of Molecular Variance (AMOVA) showed nonsignificant differences between the three populations of study (mixing population), with the ΦST value of 0,00375 (p-value > 0.05). Based on this result, the fisheries management for T. tonggol in Java Sea needs to be managed as one single population management.

Effects of economics and demographics on global fisheries sustainability

2017 ◽  
Vol 31 (4) ◽  
pp. 799-808 ◽  
Author(s):  
Qi Ding ◽  
Yali Wang ◽  
Xinjun Chen ◽  
Yong Chen
Keyword(s):  
Fisheries Sustainability

Fishery Resources, Environment, and Conservation in the Mississippi and Yangtze (Changjiang) River Basins

2016 ◽  
Keyword(s):  
Time Management ◽  
Management Strategies ◽  
Water Diversion ◽  
Conservation Strategies ◽  
Fish Farms ◽  
Danjiangkou Reservoir ◽  
Fisheries Resources ◽  
Fisheries Sustainability ◽  
Hanjiang River ◽  
Major Carps

<em>Abstract</em>.—The Hanjiang River is the largest tributary of the Yangtze River and contains Danjiangkou Dam, which forms Danjiangkou Reservoir in the middle and upper reaches of the river. During the past 50 years, fisheries resources have changed significantly in the middle and lower Hanjiang River and in Danjiangkou Reservoir. Spawning grounds for major carps and other commercially important fishes have disappeared. Downstream of Danjiangkou Dam, total egg quantity spawned by major carps and other commercially im portant fishes have decreased while similar measures from small-bodied fishes have increased. Important commercial fishes have experienced delayed spawning times and decreased growth. Overall catches of commercial fishes have decreased downstream of the dam, though increased upstream. Some exotic fishes captured in the Danjiangkou Reservoir were likely escapees from cage-culture fish farms in the reservoir or from land-based fish farms around the reservoir. Changes in fisheries resources were presumed related to reservoir management strategies, which produced a narrower range of year-round water temperatures and caused decreases in seasonal water flow variation downstream, overfishing, and eutrophication in the reservoir. To implement a national water diversion policy in central China, the height of the Danjiangkou Dam was increased 15 m in 2012, which significantly increased the impoundment area of the Danjiangkou Reservoir at the end of 2014. Further changes in fisheries resources can be expected in the future. At the present time, management and conservation strategies for fisheries resources need to be developed to ensure future fisheries sustainability for both the Hanjiang River and the Danjiangkou Reservoir.

scholarly journals Avoiding misinterpretation of climate change projections of fish catches

2019 ◽  
Vol 76 (6) ◽  
pp. 1390-1392 ◽  
Author(s):  
Manuel Barange
Keyword(s):  
Climate Change ◽  
Climate Change Impacts ◽  
Productive Capacity ◽  
Improve Performance ◽  
Climate Change Projections ◽  
Upper Limit ◽  
The Future ◽  
Fisheries Sustainability ◽  
Do So

Abstract It is common to assume that climate change impacts on future fish catches, relative to current levels of catch, are directly proportional to changes in the capacity of the ocean to produce fish. However, this would only be the case if production was optimized, which is not the case, and continues to do so in the future, which we do not know. It is more appropriate to see changes in the ocean’s productive capacity as providing an upper limit to future fish catches, but whether these catches are an increase or a decrease from present catch levels depends on management decisions now and in the future, rather than on the ocean’s productive capacity alone. Disregarding the role of management in driving current and future catches is not only incorrect but it also removes any encouragement for management agencies to improve performance. It is concluded that climate change provides one of the most powerful arguments to improve fisheries—and environmental—management, and thus fisheries sustainability globally.

Fishing through (and up) Alaskan food webs

2009 ◽  
Vol 66 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Michael A. Litzow ◽  
Daniel Urban
Keyword(s):  
Time Series ◽  
Trophic Level ◽  
High Trophic Level ◽  
Climate Index ◽  
Climate Regime ◽  
Fisheries Sustainability ◽  
Competing Hypotheses ◽  
Mean Trophic Level ◽  
Highly Correlated ◽  
Historical Periods

We used a 112-year time series of Alaskan fishery catches to test competing hypotheses concerning trends in mean catch trophic level, a widely used indicator of fisheries sustainability. We found that mean trophic level has generally remained steady or increased in recent decades on Alaska-wide and regional scales, indicating stable catches of high trophic level taxa. During historical periods of declining mean trophic level, catches of upper trophic level taxa either increased or remained steady, contrary to the predictions of the “fishing down the food web” hypothesis. Further, a climate index was highly correlated (r = 0.69–0.97) with mean trophic level and (or) the related fisheries in balance (FIB) index across climate regime shifts in the 1940s and 1970s, indicating that climate effects, particularly on high trophic level taxa, can act as the major driver of variability in these parameters. These results provide a contrast to the view of ubiquitous declines in mean trophic level of fishery catches, driven by overexploitation and serial stock replacement.

scholarly journals Using a climate attribution statistic to inform judgments about changing fisheries sustainability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael A. Litzow ◽  
Michael J. Malick ◽  
Alisa A. Abookire ◽  
Janet Duffy-Anderson ◽  
Benjamin J. Laurel ◽  
...  
Keyword(s):  
Climate Adaptation ◽  
Climate Extremes ◽  
Gulf Of Alaska ◽  
Fish Population ◽  
Bayesian Regression ◽  
Pacific Cod ◽  
Gadus Macrocephalus ◽  
Fisheries Sustainability ◽  
Population Processes ◽  
Historical Range

AbstractSustainability—maintaining catches within the historical range of socially and ecologically acceptable values—is key to fisheries success. Climate change may rapidly threaten sustainability, and recognizing these instances is important for effective climate adaptation. Here, we present one approach for evaluating changing sustainability under a changing climate. We use Bayesian regression models to compare fish population processes under historical climate norms and emerging anthropogenic extremes. To define anthropogenic extremes we use the Fraction of Attributable Risk (FAR), which estimates the proportion of risk for extreme ocean temperatures that can be attributed to human influence. We illustrate our approach with estimates of recruitment (production of young fish, a key determinant of sustainability) for two exploited fishes (Pacific cod Gadus macrocephalus and walleye pollock G. chalcogrammus) in a rapidly warming ecosystem, the Gulf of Alaska. We show that recruitment distributions for both species have shifted towards zero during anthropogenic climate extremes. Predictions based on the projected incidence of anthropogenic temperature extremes indicate that expected recruitment, and therefore fisheries sustainability, is markedly lower in the current climate than during recent decades. Using FAR to analyze changing population processes may help fisheries managers and stakeholders to recognize situations when historical sustainability expectations should be reevaluated.

Sign in / Sign up

Export Citation Format

Share Document