Making history count: The shifting baselines of Turkish fisheries

New evidence for 'shifting baselines' from different marine fisheries sectors in Turkey is presented, based on field interviews of local fishers with careers spanning up to 69 years. First, total fishing effort and catch per unit effort (CPUE) trends are presented for Turkey as a whole, and by sea. Then, using fisher survey data, the ratios of initial (i.e., early career) to current CPUE of individual fishers are presented along with their shifts in perceived change in resource abundance (PCRA), by sector. Total Turkish effort increased from 25 million kW days in 1967 to nearly 190 million kW days in 2010, while CPUE declined from about 16 kg/kW/day−1 in 1967 to 4 kg/kW−1/day−1 in 2010. The artisanal, recreational and bottom trawl sectors of Turkey were shown to experience the most profound changes, representing approximately a 40 to 50-fold decline in CPUE since about 1950, while their PCRA also declined significantly. Shifting baselines was verified to have occurred for all sectors, except the purse seiners, which is attributed to overfishing triggering a trophic cascade in the underlying ecosystem.