Use of catch reconstruction for west African fisheries
Artisanal fisheries are generally assumed to generate a lower fishing effort in comparison to the industrial sector. This study aims to comparing catch, fishing effort, and catch-per-unit-of-effort (CPUE) for each sector, using kWdays as a metric for fishing effort, and kg/kWdays for CPUE. The study, which covers West Africa (1950–2010), finds that the artisanal sector spends 4.7•109kWdays/year versus 1.3•109kWdays/year by the industrial sector, due to increasing numbers and size of artisanal boats, which in Senegal and Ghana can exceed that of (smaller) industrial vessels. The artisanal total fishing effort increased by 10-fold between 1950 and 2010, in contrast to a decrease in the industrial effort since the 1990s, which points to the occurrence of Malthusian overfishing, a form of fishing that favors excess labor instead of capital. This analysis finds that the CPUE declined by 1/3 since 1950 driven by a strong decline in the artisanal CPUE, which is 11 times lower than industrial CPUE.