scholarly journals Novel Biorefinery Approach Aimed at Vegetarians Reduces the Dependency on Marine Fish Stocks for Obtaining Squalene and Docosahexaenoic Acid

2020 ◽  
Vol 8 (23) ◽  
pp. 8803-8813 ◽  
Author(s):  
Alok Patel ◽  
Liwen Mu ◽  
Yijun Shi ◽  
Ulrika Rova ◽  
Paul Christakopoulos ◽  
...  
Keyword(s):  
Docosahexaenoic Acid ◽  
Marine Fish ◽  
Fish Stocks

scholarly journals Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary

2010 ◽  
Vol 68 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Anna Gårdmark ◽  
Anders Nielsen ◽  
Jens Floeter ◽  
Christian Möllmann
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Assessment Model ◽  
Fishing Mortality ◽  
Fish Stocks ◽  
The Road ◽  
Stock Status ◽  
Ecosystem Based Management ◽  
Management Plans ◽  
On The Road

Abstract Gårdmark, A., Nielsen, A., Floeter, J., and Möllmann, C. 2011. Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary. – ICES Journal of Marine Science, 68: 212–220. Precautionary management for fish stocks in need of recovery requires that likely stock increases can be distinguished from model artefacts and that the uncertainty of stock status can be handled. Yet, ICES stock assessments are predominantly deterministic and many EC management plans are designed for deterministic advice. Using the eastern Baltic cod (Gadus morhua) stock as an example, we show how deterministic scientific advice can lead to illusive certainty of a rapid stock recovery and management decisions taken in unawareness of large uncertainties in stock status. By (i) performing sensitivity analyses of key assessment model assumptions, (ii) quantifying the uncertainty of the estimates due to data uncertainty, and (iii) developing alternative stock and ecosystem indicators, we demonstrate that estimates of recent fishing mortality and recruitment of this stock were highly uncertain and show that these uncertainties are crucial when combined with management plans based on fixed reference points of fishing mortality. We therefore call for fisheries management that does not neglect uncertainty. To this end, we outline a four-step approach to handle uncertainty of stock status in advice and management. We argue that it is time to use these four steps towards an ecosystem-based approach to fisheries management.

scholarly journals Effective fisheries management instrumental in improving fish stock status

2020 ◽  
Vol 117 (4) ◽  
pp. 2218-2224 ◽  
Author(s):  
Ray Hilborn ◽  
Ricardo Oscar Amoroso ◽  
Christopher M. Anderson ◽  
Julia K. Baum ◽  
Trevor A. Branch ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Food System ◽  
Fish Stock ◽  
Management Tools ◽  
Fish Stocks ◽  
Fisheries Science ◽  
The World ◽  
Fish Catch ◽  
Intensively Managed

Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported global marine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.

Short-term Forecasting in Marine Fish Stocks

1981 ◽  
Vol 38 (10) ◽  
pp. 1247-1254 ◽  
Author(s):  
Max Stocker ◽  
Ray Hilborn
Keyword(s):  
Time Series ◽  
Marine Fish ◽  
Management Practice ◽  
Model Fitting ◽  
Production Model ◽  
Catch Per Unit Effort ◽  
Short Term ◽  
Fish Stocks ◽  
Production Models ◽  
The Difference

The predictive power of stock production models and simple time series methods was considered for five marine fish stocks. The distinction between model fitting and forecasting future short-term catch is discussed, as is the difference between techniques to forecast short-term yield, and techniques to calculate long-term management practice. Fox's procedure for fitting Pella and Tomlinson's stock production model, Schnute's method for fitting Schaefer's model, and Gulland's method are all considered. We found that all methods except that of Gulland work well for some stocks, and the relative performance of the methods depends upon the exploitation history of the stock. In several instances one of the best forecasts of next year's catch per unit effort (CPUE) was the previous year's CPUE, emphasizing the fact that a good forecasting technique may have no utility in determining management policies.Key words: production models, catch and effort, fisheries, management, catch forecasting, time series

Protection of Marine Fish Stocks at Risk of Extinction

Fisheries ◽  
2000 ◽  
Vol 25 (3) ◽  
pp. 6-8 ◽  
Author(s):  
J. A. Musick ◽  
S. A. Berkeley ◽  
G. M. Cailliet ◽  
M. Camhi ◽  
G. Huntsman ◽  
...  
Keyword(s):  
At Risk ◽  
Marine Fish ◽  
Fish Stocks ◽  
Risk Of Extinction

scholarly journals Let more big fish sink: Fisheries prevent blue carbon sequestration—half in unprofitable areas

2020 ◽  
Vol 6 (44) ◽  
pp. eabb4848
Author(s):  
Gaël Mariani ◽  
William W. L. Cheung ◽  
Arnaud Lyet ◽  
Enric Sala ◽  
Juan Mayorga ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Fuel Consumption ◽  
Marine Fish ◽  
Deep Ocean ◽  
Blue Carbon ◽  
Fish Stocks ◽  
Carbon Pump ◽  
Natural Carbon ◽  
High Seas

Contrary to most terrestrial organisms, which release their carbon into the atmosphere after death, carcasses of large marine fish sink and sequester carbon in the deep ocean. Yet, fisheries have extracted a massive amount of this “blue carbon,” contributing to additional atmospheric CO2 emissions. Here, we used historical catches and fuel consumption to show that ocean fisheries have released a minimum of 0.73 billion metric tons of CO2 (GtCO2) in the atmosphere since 1950. Globally, 43.5% of the blue carbon extracted by fisheries in the high seas comes from areas that would be economically unprofitable without subsidies. Limiting blue carbon extraction by fisheries, particularly on unprofitable areas, would reduce CO2 emissions by burning less fuel and reactivating a natural carbon pump through the rebuilding of fish stocks and the increase of carcasses deadfall.

Current Approaches to Multispecies Analyses of Marine Fisheries

1989 ◽  
Vol 46 (3) ◽  
pp. 528-534 ◽  
Author(s):  
S. R. Kerr ◽  
R. A. Ryder
Keyword(s):  
Marine Fish ◽  
External Environment ◽  
External Factors ◽  
Marine Fisheries ◽  
Major Focus ◽  
Substantial Evidence ◽  
Biotic Community ◽  
Fish Stocks ◽  
Community Theory

There is an increasing tendency to recognize that the dynamics of a fishery are not solely determined by intrinsic population factors, but that the external environment, which can include the effects of other species in the biotic community, plays an important role in determining the yield performances of marine fish stocks. Recognition of the role of external factors represents an important departure from the single-stock concepts of fishing theory, which have traditionally been used to manage marine stocks. We review a variety of examples of recent initiatives in the application of community concepts in marine fisheries, setting these in the context of four arbitrary categories which range from statistical description through multispecies extensions of single-stock fishing theory, to integral applications of community theory. Taken together, there is substantial evidence that the application of multispecies concepts to marine fisheries is now a major focus of international effort. The multispecies approach offers identifiable promise in resolving some outstanding problems, but it is not clear yet what the major consequences will be, in terms of changes in the ways that fisheries will be managed in the future.

Parasites as biological tags of fish stocks: a meta-analysis of their discriminatory power

Parasitology ◽  
2013 ◽  
Vol 142 (1) ◽  
pp. 145-155 ◽  
Author(s):  
ROBERT POULIN ◽  
TSUKUSHI KAMIYA
Keyword(s):  
Marine Fish ◽  
Meta Analysis ◽  
Discriminatory Power ◽  
Correct Classification ◽  
Fish Stocks ◽  
Clear Cut ◽  
Stock Discrimination ◽  
High Discriminatory Power ◽  
Discriminant Analyses ◽  
Biological Tags

SUMMARYThe use of parasites as biological tags to discriminate among marine fish stocks has become a widely accepted method in fisheries management. Here, we first link this approach to its unstated ecological foundation, the decay in the similarity of the species composition of assemblages as a function of increasing distance between them, a phenomenon almost universal in nature. We explain how distance decay of similarity can influence the use of parasites as biological tags. Then, we perform a meta-analysis of 61 uses of parasites as tags of marine fish populations in multivariate discriminant analyses, obtained from 29 articles. Our main finding is that across all studies, the observed overall probability of correct classification of fish based on parasite data was about 71%. This corresponds to a two-fold improvement over the rate of correct classification expected by chance alone, and the average effect size (Zr = 0·463) computed from the original values was also indicative of a medium-to-large effect. However, none of the moderator variables included in the meta-analysis had a significant effect on the proportion of correct classification; these moderators included the total number of fish sampled, the number of parasite species used in the discriminant analysis, the number of localities from which fish were sampled, the minimum and maximum distance between any pair of sampling localities, etc. Therefore, there are no clear-cut situations in which the use of parasites as tags is more useful than others. Finally, we provide recommendations for the future usage of parasites as tags for stock discrimination, to ensure that future applications of the method achieve statistical rigour and a high discriminatory power.

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