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In British Columbia, Canada, salmon purse seiners line up at fishing access points, forming well defined queues. These queues were measured over time, using a [url=http://www.corsodiesperanto.it/moncleroutlet/]moncler outlet[/url] one-dimensional recording scale. Sixty-one overflights of Johnstone Strait and Queen Charlotte Strait were attempted; 51 flights were completed.
Two models were presented for exploitation rates in relation to queuing patterns. The overflight model was fit to the line-up distributions. One underlying assumption was that the skippers possessed fairly accurate information regarding the distribution of catches (analysis of variance methods utilizing skippers' logbook data showed that [url=http://www.corsodiesperanto.it/hoganit.html]hogan outlet[/url] line-up lengths reflected catch rates). [url=http://www.marrakech-hotel.fr]www.marrakech-hotel.fr[/url] The model fit well and the parameter estimates reflected anecdotal and statistical information about fish behavior. The exploitation [url=http://www.anepf.fr]doudoune moncler pas cher[/url] rates saturated at an effort level of 100 vessels (whereas the [url=http://www.mxitcms.com/abercrombie/]www.mxitcms.com/abercrombie/[/url] maximum effort observed was 363 boats) and indicated that (at saturation) the fleet caught 80% [url=http://www.sandvikfw.net/shopuk.php]hollister outlet sale[/url] to 90% of [url=http://www.par5club.com/louboutin.php]louboutin pas cher[/url] the vulnerable migrating salmon present in Johnstone and Queen Charlotte Straits during what were commonly 48- or 72-hour fishing openings. (Note: Salmon successfully migrating through the strait on days that were closed to seiners and salmon that were not vulnerable to the gear--e.g., below the depth of the nets--escaped the purse-seine fleet.)
In general, traditional assumptions were rejected. Vessels did not operate independently. Boats were not distributed in a random fashion. The overflight model [url=http://www.teatrodeoro.com/hollisterde.php]www.teatrodeoro.com/hollisterde.php[/url] provided predicted exploitation rates. The exploitation response to effort was qualitatively distinct from the forms incorporated in traditional models.
In partial summary, the question is one of fishing power--the ability of gear, boats, or fleets, in the B.C. and P.E.I. cases and others, to exploit or overexploit fish stocks. Without a historical perspective based on quantitative (and innovative) field research, we are doomed to repeat [url=http://www.rtnagel.com/louboutin.php]louboutin[/url] our work loads: In [url=http://www.ttcarpets.co.uk]mulberry sale[/url] the absence of extensive (and often necessarily alternative) time series of fishing effort and effectivity (fishing [url=http://www.diecastlinks.co.uk]hollister outlet[/url] power), stock assessment and fisheries management become absurd. Like they said on P.E.I., a fleet (or transient [url=http://www.riad-marrakesh.fr]abercrombie pas cher[/url] cluster) of purse seiners can wipe out a stock (anywhere in the world).
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