The international trade and fishery management of spiny dogfish: A social network approach

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The management of the spiny dogfish (Squalus acanthias) is a matter of international concern, as this species was a candidate for inclusion in lists for trade regulation. The major demand for its meat is from the European Union (EU) market, with the U.S. and Canada as two major contributors. The U.S. has yet to support a spiny dogfish listing, although the U.S. Atlantic stock (including Florida) is under a Fshery Management Plan (FMP) that proved to be successful in providing a certified sustainable fishery.

This study employed a cumulative sum technique to compare trade data for frozen spiny dogfish export from the U.S. and Canada to the EU in relation to the FMP adoption. The study also constructed a social network to visualize changes in the European trade scenario for spiny dogfish after adoption of the FMP and to predict future trade flow potentially affecting the conservation status of regional dogfish stocks in relation to recent management measures introduced in Europe.

The social network analysis revealed that the exclusion of spiny dogfish from trade regulation lists eventually will affect the conservation status of dogfish stocks in Africa, Asia, South America, and the Mediterranean and Black Seas. Study results suggest that the species listing would provide an economic benefit for the U.S. Northwest Atlantic fishery, and will eventually foster the conservation status of other regional stocks worldwide and the search for a more sustainable global exploitation of spiny dogfish.



One-mode network for the pre-FMP period (1990 – 1999) in Fig a, and for the post-FMP period (2000 – 2010) in Fig. b. Nodes represent countries and edges represent link-relationships between countries based on quantities of dogfish exported, with arrows pointing from the exporter to the importer country. Countries are displayed based on their geographical location: North America (red ellipse), Central America (red rectangle), South America (red triangle), Africa (brown ellipse), Asia (yellow rectangle in Fig.a and yellow polygon in Fig. b), Europe (blue polygon), and Oceania (green triangle).

The adoption of the U.S.-FMP for the Northwest Atlantic spiny dogfish stock corresponds to significant changes in the species international trade. As a direct result, Canada increased its dogfish exports to the EU market appreciably, while U.S. exports declined because of planned management quota reductions. In light of the effectiveness of the US-FMP in achieving sustainability  for the Northwest Atlantic spiny dogfish stock, and given the current state of the international exploitation and trade, global and local conservation status, the U.S. government would reap economic benefit from the species inclusion in Convention on International Trade in Endangered Species (CITES’s Appendix II).

The network analysis also indicated that new areas increased exploitations to supply the EU market demand as U.S. exports declined, potentially affecting the conservation status of regional and local spiny dogfish stocks in African, Asian and South American coastal areas. Although there is no directed fishery for spiny dogfish off South Africa, our results, and available information on the species biology and management regulations introduced in the Northeast Atlantic, suggest that the South African-Namibian coastal area may be a potential fishing ground for dogfish in the future. This fishery should be considered for the employment of a management strategy prior to exploitation to ensure the fishery is sustainable and will help preventing the species overexploitation.

Considering both the reported and forecasted increased exploitation of spiny dogfish stocks in the Mediterranean and Black Seas (e.g. Spain, Romania, and Bulgaria), awareness in the conservation status of these spiny dogfish stocks is also needed in order to encourage the introduction of conservation measures in this area, which is under the authority of the EU fishery management but lacking behind in terms of spiny dogfish conservation measures.

Effective and successful management systems are based on finding the best trade-off between contrasting biological, socio- economic, and political objectives. The case for managing the international trade of spiny dogfish shows that a major goal for managers should be to aim at integrating all these different aspects to effectively contributing to the analysis of risks related to global exploitation.

This study indicated that the employment of new analytical techniques, such as social network analysis of available trade data, can be useful in the discussion for implementing the fishery management and international biodiversity protection.

Dell’Apa, A, J.C. Johnson, D. G. Kimmel, R.A. Rulifson.  The international trade and fishery management of spiny dogfish: A social network approach. Ocean and Coastal Management 80 (2013): 65-72.

ACKNOWLEDGEMENT:  Photo from Andrea Dell’Apa, artwork by Elaine A. Porter, editing by Joeffery Ibisagba

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Publication Date: 
Tuesday, April 14, 2015
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