New database of marine aquaculture launched

The new Global Mariculture Database (GMD), released by the Sea Around Us Project, offers detailed information on the where and what of mariculture around the world since 1950. By mapping the production of marine aquaculture at smaller scales than the usual national scale and by digging deeper into the species being farmed, the GMD provides room for new insights into marine aquaculture.  And all of this information is now available online for anyone to browse on the Sea Around Us Project website!

The GMD confirms reports by the Food and Agriculture Organization of the UN (FAO) that the amount of seafood produced by marine aquaculture has tripled since 1950 – a massive increase. During this time, there has also been a shift in the type of seafood produced globally, with a larger percentage of predatory species, such as salmon and tuna, farmed around the world today compared to 1950. In the past, the relative production of species lower on the food chain, like mussels and oysters, was higher. This phenomenon has been described as “farming up the food web” a term derived from the concept of fishing down marine food webs.

In keeping with the Sea Around Us Project’s goal of improving public access to global fisheries and aquaculture information, this Global Mariculture Database (GMD) is freely available online at www.seaaroundus.org.

To find out more about the GMD and how it was created, you can read the paper recently published in the journal Marine Policy:

Campbell B and Pauly D (2012) Mariculture: a global analysis of production trends since 1950. Marine Policy 39: 94-100.

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Check out our new website!

Fishing down marine food webs

A new website (www.fishingdown.org), hosted by the Sea Around Us Project, has been launched. This website helps clear up misconceptions about the concept of “fishing down” in marine ecosystems – whereby fisheries have a tendency to deplete longer lived, high-trophic level species first, causing a decline in the mean trophic level of catches from an ecosystem.

Since it was first published, the fishing down concept has been documented and adopted by a broad community of marine and freshwater scientists around the world. Thus, the website also aggregates many case studies illustrating the phenomenon in marine ecosystems all over world, from Argentina to the North Sea, from Greece to the Caribbean. In 2010, the fishing down concept was challenged in a publication in the journal Nature. The objections that were raised are based mainly on imputations and misunderstandings, and the Fishing Down website is dedicated to clearing up the misunderstandings behind much of the controversy. One apparent problem is that fishing down can be masked by extraneous factors, such as the taxonomic over-aggregation of catch statistics. The website is intended as a response to the voiced concerns and provides scientific references about the fishing down phenomenon, including a link to the original article, led by biologist Daniel Pauly and published in the journal Science in 1998, titled “Fishing down marine food webs.”

We welcome you to visit www.fishingdown.org.

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Analysis of FAO Report on Fisheries Statistics

Global fisheries statistics must be viewed with a critical eye. Fisheries landings data are collated by FAO and contributed by all member countries, which have varying resources and motives. In a new paper recently published in Marine Policy, Daniel Pauly and Rainier Froese take a close look at FAO’s State of the Worlds Fisheries and Aquaculture’ (SOFIA) report from 2010 and discuss the FAO’s history, as well as the implications, imperfections, and possible improvements to be made to fisheries data.

Pauly and Froese are both complimentary and critical. They point out the misleading use of the word ‘stability’ in the report as it refers to global catch data from 2005-2008, and point out that even if that global catches are indeed stable, fishing effort is rapidly expanding. They note the FAO’s acceptance of scientific data that showed China does not know how much its fisheries catch, and the large degrees of uncertainty around global trends this problem creates. Pauly and Froese point approvingly to SOFIA’s position on assemblage overfishing and their statement: ‘ We do not disagree that a general decline in mean trophic level of marine landings is likely to have occurred in many regions.’ Finally, Pauly and Froese call for cooperation between institutions, e.g., U.N. technical organization and civil society, as represented by universities and non-government organizations, to improve SOFIA reports and potentially the management of fisheries globally.

To read the full article click here.

Citation: Pauly, D. & Froese, R. 2012. Comments on FAO’s State of Fisheries and Aquaculture, or ‘SOFIA 2010’ Marine Policy 36: 746-752.

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Sumaila responds to Branch et al. in Nature

Economist Rashid Sumaila recently responded to the paper by Trevor Branch and colleagues in the journal Nature:

The trophic fingerprint of marine fisheries’ (Nature, 468, 431-435, 2010), has intensified the debate on how best to measure the impact of commercial fishing on ocean biodiversity: Is catch data useful in telling us what is happening in the ocean or do we need stock assessment information in order to say something meaningful? As an economist, I cannot contribute to this debate but I can ask some questions: What conclusion does one come to if one uses one or the other of these approaches?If one ends up with the same conclusion then the debate is only of academic interest. If the conclusions reached are different, what are the potential costs to the world should one or the other be incorrect? In general, proponents of the use of stock assessments for measuring the ‘health’ of ocean fish populations, led by Ray Hilborn of the University of Washington, conclude that ocean fish populations are doing just fine, while those who use catch data, spearheaded by Daniel Pauly of the University of British Columbia, come to the conclusion that global fish stocks are in bad shape. Depending on which of these two camps wins the argument, the world would either stick to the status quo and continue to manage global fisheries as we currently do, or the world community would double its efforts to manage global fisheries sustainably. Should the former conclusion turn out to be incorrect, the world would have saved some costs by continuing to fish without further management restrictions, with the consequence that ocean biodiversity would be eroded further, thereby supplying less and less fish with time. On the other hand, if the latter turns out to be incorrect, the world would have incurred unnecessary cost due to stricter management but would have an ocean rich in biodiversity that is capable of supplying fish into the future.

Read more on this issue here.

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