Growth in Fish Farming Raises Concerns for Environment

Growth in Fish Farming Raises Concerns for Environment

Fish - CC license by Joost J. Bakker IJmuiden (Flickr)

Large-scale farming of fish that themselves have low environmental impact can nonetheless lead to higher environmental damage, according to an assessment of farmed fish and the countries that produce them.

The research, performed by the University of Victoria's Seafood Research Ecology Group, also found that regions with the fastest-growing fish farming sectors are linked to more negative impacts.

The Seafood Research Ecology Group, led by marine ecologist John Volpe, used the Global Aquaculture Performance Index, which it created, to assess 20 fish species and 22 countries, based on 10 indicators.

The research focused on finfish like salmon, cod and grouper, and looked at criteria like reliance on capturing wild fish to stock farms, antibiotics use, water pollutants discharge and industrial energy use.

Each species and country received two overall scores: the normalized score is based on per ton produced, and the cumulative score looks at the total impact. Scores range from 0-100, with 100 meaning lowest impact. Scores were based on data from 2007, the last year that complete data on all indicators was available.

The assessment found that even in areas where best farm fishing practices are used, massive production of fish can cause more negative impacts than multiple small, poorly-performing farms. Atlantic salmon, for instance, gets a score of 70 based on per ton performance, but its cumulative score is 36.

The researchers also found that some of the worst countries, particularly China and Japan, are those with the newest and fastest-growing aquaculture production. Fish like groupers, red drum and cobia have some of the worst scores, but production of them has increased 40 percent in the five years before 2007.

Atlantic salmon has the top normalized (72) and cumulative (91) scores among the fish species. Following on the normalized side is flathead grey mullet (71) and Atlantic salmon (70), while the next highest scores on the cumulative side are turbot (89) and Atlantic cod (88).

The highest-scoring countries on the normalized side are New Zealand (73), the United Kingdom (72) and Norway (72), while the highest cumulative scores go to France (96), Iceland (96) and Israel (91).

The researchers findings are available in the inaugural Global Aquaculture Performance Index report.

Fish - CC license by fabbio