The Salmon Purse Seine - Competition and Information Among British Columbia Salmon Purse Seiners

In British Columbia, Canada, salmon purse seiners lineeffort level of 100 vessels (whereas the maximum
up at fishing access points, forming well definedeffort observed was 363 boats) and indicated that (at
queues. These queues were measured over time,saturation) the fleet caught 80% to 90% of the
using a one-dimensional recording scale. Sixty-onevulnerable migrating salmon present in Johnstone and
overflights of Johnstone Strait and Queen CharlotteQueen Charlotte Straits during what were commonly
Strait were attempted; 51 flights were completed.48- or 72-hour fishing openings. (Note: Salmon
Two models were presented for exploitation rates insuccessfully migrating through the strait on days that
relation to queuing patterns. The overflight model waswere closed to seiners and salmon that were not
fit to the line-up distributions. One underlying assumptionvulnerable to the gear--e.g., below the depth of the
was that the skippers possessed fairly accuratenets--escaped the purse-seine fleet.)
information regarding the distribution of catchesIn general, traditional assumptions were rejected.
(analysis of variance methods utilizing skippers' logbookVessels did not operate independently. Boats were not
data showed that line-up lengths reflected catch rates).distributed in a random fashion. The overflight model
The model fit well and the parameter estimatesprovided predicted exploitation rates. The exploitation
reflected anecdotal and statistical information aboutresponse to effort was qualitatively distinct from the
fish behavior. The exploitation rates saturated at anforms incorporated in traditional models.