Overfishing has a damaging effect on marine ecosystems around the world. Since fishers have depleted the stocks of larger predators such as cod and haddock, they are forced to target other species. The loss of biodiversity means that marine environments are becoming increasingly dominated by shellfish, algal blooms, gelatinous plankton and jellyfish – and unless fisheries target these species, the fishers themselves will begin to decline.
The decline of large fish predators has led to a rise in prawn fishery in the UK and a rise in lobster, scallops and crab in the US and Canada. A shellfish collapse could bring devastating consequences. However, research conducted by the University of York notes that shellfish are highly risky.
This is due to the long-term instability of shellfisheries that are at risk of collapse from invasive species, disease and climate change. Ocean acidification means shellfish cannot form proper shells, which could result in widespread mortality.
Although the rise of shellfish has brought economic benefits to the fishing industry, it comes as a result of failing to protect fish stocks from overfishing. Putting the fish back into fisheries and rebuilding the ocean’s biodiversity could restore the world’s damaged ecosystem and increase the stability of fisheries.
Source: http://www.sciencedaily.com/releases/2013/05/130519194828.htm