How does the accuracy of fisher knowledge affect seahorse conservation status?

Publication Type: Journal Article

Year of Publication: 2010

Authors: O'Donnell, KP, Pajaro MG, Vincent ACJ

Journal: Animal Conservation

Volume: 13

Issue: 6

Pagination: 526 - 533

Date Published: 12/2010

Keywords: fishing and conservation, Hippocampus, IUCN Red List, Local knowledge, retrospective bias,small-scale fishery, Syngnathidae

Abstract:

Despite a growing interest in incorporating fisher knowledge into quantitative
conservation assessments, there remain practical impediments to its use. In
particular, there is some debate about the accuracy of fisher knowledge. In this
study, we report an attempt to quantify assumptions about how accurately fishers
report past events (retrospective bias). Then we examine how the assumption we
make about retrospective bias affects the characterization of changes in the fishery
and extinction risk. We link fisher interviews and fisher logbooks to establish a
catch rate (catch per unit of effort) trend for the history of a data-poor, small-scale
seahorse fishery in the Philippines. We find that fishers perceive historic declines in
fishing rate that are not apparent in more recent logbook trends, and the extent of
the decline (and therefore extinction risk) hinges on assumptions we make about
the accuracy of fisher recall. Scenarios that ignore retrospective bias result in the
most severe declines and the most worrying extinction risk classifications.
Furthermore, the historic baseline set by interviews suggests that relying on recent
decades of data alone may underestimate extinction risk for our study species, and
others that have been historically exploited. Attempting to link interviews with
logbooks also illustrates differences between fisher-derived datasets: retrospective
interviews may exaggerate early fishing rates and capture less variability than
logbooks. In addition to being the first seahorse fishery reconstruction, our work
contributes to the emerging interest in how fisher knowledge can guide conservation
assessment. Future studies that incorporate fisher knowledge into quantitative
assessments require (1) clearly stated assumptions about fisher knowledge bias;
(2) clear criteria to compare fisher knowledge collected with different methods;
(3) evaluation of the impact of assumptions on assessments.

DOI: 10.1111/j.1469-1795.2010.00377.x