Fisheries impacts on China's coastal ecosystems: Unmasking a pervasive ‘fishing down’ effect

by alexandrapounder on May 1, 2018 - 4:54pm

In the article “Fisheries impacts on China's coastal ecosystems: Unmasking a pervasive ‘fishing down’ effect” by Cui Liang and Daniel Pauly, the authors explain how the intensive fishing can greatly impact the marine ecosystems and a lot of other aspects. This indicates that the trophic level of the catches to decrease, and it’s a signal of the existence of the ‘fishing down’ (FD) occurrence. However, even if FD is happening through the world's oceans, it can effortlessly be concealed by various elements, which has misguided a lot of authors to assume that its existence will remain applicable. The authors use the  East China Sea as a reference for their study. The classification of catch data gathered in the area is concealing the effect of intensive fishing on the FD situation. The result of the study is misleading because it implies that, even after increasing the number of fisheries, the sizes of the fishes from the food chain stays roughly the same.In the area under study, only a few species of fish are accounted for separately and the rest of the catch is labeled as ‘mixed fishes’, which doesn’t give any information on their sizes or species. Furthermore, using intensively small fishing nets have reduced the sizes of fish and their mean trophic levels(MTL), and fisheries are proliferating even offshore. Between 1979 and 2014 the decrease of the trophic level is of 0.15 TL per decade, meaning it is one of the highest approximation of FD in the world. This doesn’t come without an ecological price to pay for all of us...

 

In my opinion,  fishing down or fishing up are both harmful to the ocean and for the entire marine ecosystem, because both produce an imbalance in the food chain than took millions of years to develop. We should concentrate on what is really happening in the ecosystem, instead of taking for granted the method based on the sample of the simple catch.

 

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173296

 

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