Mammal and Seabird Consumption of Small Pelagic Fishes

Following a brief historical review of the emergence of fisheries for forage fish that are primarily destined for reduction, and their competition with fisheries for human consumption, an account is given of landing trends in various parts of the world, and catch maps are provided for the 1970s and 2000s which allow spatial and temporal comparisons. A brief account is also given of the changing species composition of the landings, the exploitation status of the fisheries, the trophic levels trends of species destined for reduction, the fuel consumption of the global fleet exploiting forage fish which are primarily small pelagics, the fishing gear they use, and the ex-vessel prices they fetch. The discussion, finally, attempts to amalgamate this material, which is further discussed in the other chapters in this report. INTRODUCTION Historically, all fish that could be caught, including small pelagic fish, were used as a source of food for humans (see Chapter 2), and the reduction of fish to fishmeal and fish oil for indirect use is relatively recent. Seasonally abundant catches of herring and sardines, which could not be absorbed by local markets, started the fish oil industry in northern Europe and North America at the beginning of the 19th century (Huntington et al., 2004). The oil was used for lubrication of machinery and leather tanning, soap production and other non-food products, and the by-products of fish oil production were used as fertilizer. In the early 20th century the production of fishmeal for animal feed began in Northern Europe, based on Herring (Clupea harengus), and in North America, based on Atlantic menhaden (Brevoortia tyrannus) in Chesapeake Bay and South American pilchard (Sardinops sagax) in California. Once the benefits of fishmeal as an inexpensive feed supplement for animal production were realized and demand increased, the fisheries began to deliberately target fish for reduction to fishmeal, with fish oil more as a by-product. In the early 1950s, a huge reduction fishery for Peruvian anchoveta (Engraulis ringens) developed in Peru, then in Chile, which at first complemented, then replaced, the earlier indirect exploitation of this fish, in the form of guano produced by fish-eating birds (Muck and Pauly, 1987; Muck, 1989). In California, the benefits of fishmeal in the animal feed sector were quickly realized and demand for fishmeal with corresponding demands for increased landings raised concern over food supplies and sustainability of the industry (Radovich, 1981). The California legislature responded in the early 1920s with the introduction of legislation prohibiting the processing of fish for reduction if it was fit for human consumption. The controversial issue of competition between human and industrial consumption for raw material such as the ‘California sardine’ (which led to similar legislation in other areas and times) became moot when, due to excess fishing and the ‘changes in environmental conditions’ that are always evoked in such cases (see e.g., Radovich, 1981), catches peaked in the 1930s, and collapsed in the late 1940s, and the ghost of this fishery, through the works of John Steinbeck and Ed ‘Doc’ Ricketts, entered the realm of legend (Tamm, 2004). 1 Cite as: Watson, R., Alder, J., Pauly, D. 2006. Fisheries for forage fish, 1950 to the present, p. 1-20. In: Alder, J., Pauly, D. (eds.) On the multiple uses forage fish: from ecosystems to markets. Fisheries Centre Research Reports 14(3). Fisheries Centre, University of British Columbia [ISSN 1198-6727]. 2 Fisheries for forage fish, 1950 to the present, R. Watson, J. Alder and D. Pauly The same scenario was replayed a few decades later, off Peru, where the annual catch of Peruvian anchoveta grew to 17 million tonnes (t) in 1970 (Castillo and Mendo, 1987), about 6 million t higher than the official catch of 12 million t–itself higher than recommended by experts at the time (Gulland, 1968; Murphy, 1967; Schaefer, 1967). The fishery collapsed in 1972/73, following an El Niño event that was subsequently seen by many as solely responsible for the collapse. As earlier in California, the Peruvian reduction fishery was seriously contested by those who felt that Peruvian anchoveta should somehow be processed for human food, e.g., in the form of fish protein concentrate (FPC) that could be used to fortify flours, an obvious product in a country with an animal protein deficiency in its highlands. Moreover, not only juvenile South American pilchard (Sardinops sagax) and Horse mackerel (Trachurus murphyi), which frequently occur in anchoveta schools (Bakun and Cury, 1999), were caught by the anchoveta reduction fishery, but also pure schools of full-sized S. sagax sardine and T. murphyi, adding to the controversy. Landing S. sagax for reduction has long been prohibited in Peru, and recently, regulations were announced which also limit the catch of T. murphyi to vessels fishing the stocks for human consumption, and not fishmeal (Fishing Information and Service, 2004). This, however, is not the main research area for scientists working on the small pelagic fishes which support the most important reduction fisheries. Rather, it is their extraordinary responsiveness to environmental fluctuations, and their apparent resilience to fishing, notwithstanding collapses in South America, California, Southern Africa, and Europe. This research has yielded some powerful generalizations (Bakun, 1996), but still does not allow for prescription on how to ensure ‘sustainable’ catch levels in the face of environmental variability, growing industry demand and climate change. In the following, we briefly review various aspects of the fisheries for ‘forage’ fish, based on geo-referenced catches, from 1950 to the present, and analyze some features of these catches and of the fleets that made them. FORAGE FISH Forage fish is a term used to describe schooling fish that are often the prey for larger fish, seabirds and marine mammals. These larger animals often ’forage’ on smaller fish because they are found in large schools and are easy to capture. Small pelagic fish (< 30 cm in length) such as Peruvian anchoveta make up the bulk of forage fish, but some medium-sized fish (30-90 cm in length) such as mackerels are also considered forage fish. Many populations of forage fish, especially small pelagics, fluctuate in response to changing oceanographic conditions, which affect their planktonic food (Cury et al., 2000). Other factors such as predation levels, current patterns for larval retention, food availability and water conditions such as temperature affect the annual abundance of these fish (Fréon et al., 2005). The schooling behaviour of forage fish allows them to be easily caught so that the fishing fleets do not require as much fuel as, for example, trawlers (Tyedmyers et al., 2005; see also Chapter 2). This translates to lower operating costs and hence cheaper fish. Forage fish that are not consumed directly by humans are extremely inexpensive compared to other fish to the extent that they can be reduced to fishmeal and fish oil and still be price-competitive with soymeal. Some of these small and medium pelagic fish are also consumed by humans (Chapter 2), and caught using the same gear, often on the same fishing grounds. GEO-REFERENCED CATCHES Reported catch data from FAO, ICES, NAFO and other regional/national sources were allocated to a global system of 30-minute spatial cells using a rule-based approach that utilized databases of fish distributions and fishing access agreements as filters (Watson et al., 2004b; see also www.seaaroundus.org). Emphasis was given to small pelagic fishes, and other species used in reduction fisheries, i.e., forage fish as defined in this report (Table 1). Also, the fuel consumed by the various gears used to catch forage fishes was estimated, based on the approach and data in Tyedmers et al. (2005). Fisheries for forage fish, 1950 to the present, R. Watson, J. Alder and D. Pauly 3