Measuring seining strategies and fishing success in the Philippines

Human Organization, Summer 1998 by Russell, Susan D, Alexander, Rani T

Maritime anthropologists often have argued that different fishing strategies or skipper skills partly account for variability in fishing success within a fleet, but statistical support for such strategies has been difficult to acquire. This article analyzes a mixed species, tropical seine fishery in south central Luzon, Philippines where boat size is similar and electronic fish-finding gear, mechanized hauling, and formal navigational training of skippers are absent. We review the qualitative and quantitative evidence for different fishing strategies in this fleet and then examine the degree to which these strategies account for differential fishing success. We suggest that one way to detect the existence of different seining strategies is to measure the locations fished, number of trips and type of species caught per time period. In fisheries where one is concerned to determine the degree to which fishing strategy accounts for variability in catch, we suggest that defining fishing success as mean catch per trip is more useful than conventional definitions of total catch over a season. The advantage of measuring fishing success as mean catch per trip rather than total catch is that it controls for effort, thereby allowing one to discern more clearly the variables that explain fishing strategy. Key words: maritime anthropology, fishing; Philippines, Luzon

The maritime anthropological literature has long held opposed positions about the causes of variation in fishing success within a fleet, and the "skipper effect" debates arise out of the desire to explain the reason why some boats catch far more fish than others. The "skipper effect" refers to the contribution of a skipper's skill to fishing success irrespective of boat size and effort (Durrenberger 1993). One group of scholars argues that a skipper's skill is a significant factor in explaining the variance in catch among boats (e.g., Acheson 1977, 1988; Hilborn and Ledbetter 1985; Jepson et al. 1987; Thorlindsson 1988; White 1992; Bjarnason and Thorlindsson 1993). Another group claims that the variance in catch is largely a function of quantifiable, impersonal variables such as differences in fishing effort and the size of a boat (e.g., Pilsson and Durrenberger 1982; Durrenberger and Palsson 1983; Durrenberger 1993). The latter authors argue that there may be a strong skipper effect in some fisheries and a negligible effect in others, while a social construction that attributes fishing success to a skipper may vary independently from empirical evidence (Palsson and Durrenberger 1984). They complain, however, that "no one has presented any definitive statistical demonstration that skippers do make a difference aside from differences of effort and boats"(Pilsson and Durrenberger 1990:138).

There are many reasons why the statistical measurement of a "skipper effect" has created a charged debate (e.g., Gatewood 1984a; McNabb 1985; White 1992). First, the variables that a captain must take into account in deciding where to fish, when to fish and how to fish can be listed, but the process by which a captain actually makes such decisions has been characterized as "reasonable" rather than rational owing to the multiplicity of variables to consider (Gatewood 1983). Second, the kind of data that lend themselves to statistical analyses is often limited in scope, duration, and largely confined to industrialized settings where the landings of fishing catches are regularly recorded. Hence, to date, almost all of the discussion of a skipper effect has focused on more technologically advanced fisheries in Iceland and North America rather than in the householdoperated fleets in developing countries (Russell and Alexander 1996). Third, White (1989) suggests that fisheries that target mobile species may experience a "fleet effect," wherein the tendency of boats to congregate in an area once another boat has found fish may level catches throughout the fleet, thus disguising the effects of differential skill in finding fish.

Few studies have examined comparatively the different skills and strategies that adhere to different kinds of fishing. Acheson (1988:101) notes that trap placement is an important skill in the lobster fishing industry, while good eyesight on the part of a skipper is significant in many peasant seining fleets that lack fish-finding gear (Kottak 1983). Palsson and Durrenberger (1990) note that a skipper effect may be more likely in places where captains are not subject to rigorous training prior to becoming qualified to operate a boat, while Bjarnason and Thorlindsson (1993:377) argue that a skipper's skill may be easier to detect in fleets composed of small boats rather than larger boats.

Most studies of fishing strategy have directly or indirectly focused on the issue of whether searching for fish independently is more successful than searching for fish with a larger group of boats. In contrast to Barth's (1966) earlier observation, studies by Orbach (1977), Gatewood (1984b), McGoodwin (1989), and White (1989) all suggest that independent fishing is generally less successful or desirable compared to relying and acting on information about where other boats are catching fish. These suggestions, like Barth's (1966) observation, are based on qualitative ethnography rather than a representative sample of where and when skippers actually fish. The few quantitative studies available have been conducted with industrialized, capitalized fishing fleets only in Maine (Acheson 1977), Iceland (Durrenberger and Pllsson 1983, 1986; Thorlindsson 1988; Bjarnason and Thorlindsson 1993) and British Columbia (Hilborn 1985; Hilborn and Ledbetter 1985). These studies provide important insights into the nature of fishing strategies, but complicate comparative analyses by dealing with cases where 1) variability in boat size or the grid system used for locations are so great that they may disguise the existence of intrafleet tactics (Durrenberger and Palsson 1986; Palsson 1988), 2) quotas artificially restrict variation in effort (Gatewood 1984b; Hilborn 1985), or 3) informal territorial rules or established "hook-offs" constrict the range of tactics available in terms of where a skipper decides to fish (e.g., Acheson 1988; Gatewood 1983).