Sustainability of deep-sea fisheries

Abstract

As coastal fisheries around the world have collapsed, industrial fishing has spread seaward and deeper in pursuit of the last economically attractive concentrations of fishable biomass. For a seafood-hungry world depending on the oceans' ecosystem services, it is crucial to know whether deep-sea fisheries can be sustainable.The deep sea is by far the largest but least productive part of the oceans, although in very limited places fish biomass can be very high. Most deep-sea fishes have life histories giving them far less population resilience/productivity than shallow-water fishes, and could be fished sustainably only at very low catch rates if population resilience were the sole consideration. But like old-growth trees and great whales, their biomass makes them tempting targets while their low productivity creates strong economic incentive to liquidate their populations rather than exploiting them sustainably (Clark's Law). Many deep-sea fisheries use bottom trawls, which often have high impacts on nontarget fishes (e.g., sharks) and invertebrates (e.g., corals), and can often proceed only because they receive massive government subsidies. The combination of very low target population productivity, nonselective fishing gear, economics that favor population liquidation and a very weak regulatory regime makes deep-sea fisheries unsustainable with very few exceptions. Rather, deep-sea fisheries more closely resemble mining operations that serially eliminate fishable populations and move on.Instead of mining fish from the least-suitable places on Earth, an ecologically and economically preferable strategy would be rebuilding and sustainably fishing resilient populations in the most suitable places, namely shallower and more productive marine ecosystems that are closer to markets

The fish fauna of Ampère Seamount (NE Atlantic) and the adjacent abyssal plain

“…There is an ongoing concern that seamount stocks are overfished, and fishing is impairing the benthic communities (e.g. Clark 2001;Clark and Koslow 2007;Clark and Rowden 2009;Clark et al 2006;Norse et al 2012).…”

Sustainability of port activities within the framework of the fisheries sector: Port of Vigo (NW Spain)

“…An evaluation of fishing sustainability is needed to know which are the main aspects influencing the depletion of marine resources. Therefore, recovery of marine ecosystems is essential to achieve oceans sustainability [2][3][4][5]. A study developed by Swartz et al [6] showed that the worldwide development of marine fisheries through the past years was conducted by a continuous exploitation of new fishing sites.…”

Why are Brazilian deep demersal fish resources valuable? An analysis of the size of edible flesh and its chemical composition

“…Such increased activity tends to consume a considerable fraction of food energy and compromise somatic growth and reproduction, typically low and inefficient among seamount fish. In a sense, seamount fishers, while selecting firm-textured flesh fishes, are taking advantage of particular deep seamount selective pressures, which in turn also favour life-history features that limit opportunities for productive and sustainable catches (Norse et al, 2012).…”

“…Historically, this contribution has been sustained by intense harvesting of coastal, productive and accessible resources. However, because these resources have been exhaustively exploited and demands for marine products have increased by the world's growing population, fisheries globally expanded seaward, to remote deep areas (Pauly et al, 2005;Morato et al, 2006;Norse et al, 2012). Such expansion was initially driven by the search for better catches of shelf demersal resources in the rim of the continental margin.…”

“…Gradually, this process also led to the identification of concentrations of fish and shellfish species, usually dwelling on the slope and seamounts, that encouraged the development of specialized (most notably trawl) 'deep-water fisheries' (DWF) (Japp & Wilkinson, 2007). Because deep ecosystems are generally food-limited, deep water species were shown to be less productive and less resilient than shallow-water species, hence clearly not capable to replace economic losses at overfished continental shelves (Norse et al, 2012). Nonetheless, important trawl fisheries have persisted in deep areas of the Pacific, Atlantic, Indian and Southern oceans as driven by aggregation patterns of some fish stocks, economic subsidies to the fishing industry and the high value sometimes attributed to commercial deep-water species (Koslow et al, 2000;Gianni, 2004;Norse et al, 2012).…”