National Oceanic and Atmospheric Administration National Marine Fisheries Service
Nominal landings of butterfish, PepriZus triaaanthus (Peck), in the Northwest Atlantic increased from 3,209 MT in 1964 to a peak of 19,454 MT in 1973. Most of the catch during this period was taken by Japan, USSR, Poland, and the USA. Unrepor~ed butterfish by-catch in the long-finned squid, LoZigo p...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.423.5028 http://www.nefsc.noaa.gov/publications/series/whlrd/whlrd7729.pdf |
| Summary: | Nominal landings of butterfish, PepriZus triaaanthus (Peck), in the Northwest Atlantic increased from 3,209 MT in 1964 to a peak of 19,454 MT in 1973. Most of the catch during this period was taken by Japan, USSR, Poland, and the USA. Unrepor~ed butterfish by-catch in the long-finned squid, LoZigo peaZei ~ fisheries of several nations, particularly Spain and Italy, were probably significant additionar sources of mortality. Available scientific evidence indicates that during the period 1968-1976, fishing mortality rates increased, while mean weight of individuals in the exploitable population and average age at capture generally declined. Exploitation rates (E) ~uring 1972-1975 ranged from 0.35-0.42. Yield per recruit studies (M=0.8) suggest that Emax and EO.1 values are 0.37 and 0.27 for a 30 mm mesh net, and 0.55 and 0.36 for a 60 mm one. Mean weights of fish in the catch, at EO.1 ' would be 66 % greater for the larger net (9~g), than for the smaller mesh (55{e@- g). Equilibrium catches resulting from the average annual recruitment of 1,138.5 x 106 fish are 14,540 MT (30 mm mesh) and 18,945 MT (60 mm mesh), assuming E o. 1. The maximum long term yield from the stock given stable annual recruitment is 21,635 MT, assuming that FO.1 is the maximum F that will not adversely effect recruitment. Murawski and Waring |
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