Northwest Fisheries Science Center

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Document Type: Report
Center: NWFSC
Document ID: 6872
Title: Final report on analyses of salmon collected in Taiwan, Republic of China, 31 August-5 September 1989
Author/Editor: Robin S. Waples, P. B. Aebersold, N. Davis, Lee W. Harrell, F. William Waknitz
Year: 1989
Institution: Report of the Coastal Zone and Estuarine Studies Division, Northwest Fisheries Science Center, U.S. National Marine Fisheries Service
Date: 1989

A team of five NMFS scientists traveled to Kaohsiung, R.O.C., to sample salmon and steelhead confiscated by Taiwanese authorities from two Taiwanese boats (Sung Ching No. 1 and Ta Feng No. 11) suspected of involvement in illegal high-seas drift net fisheries.  The objectives were to  1) determine the species composition of the catch,  2) determine the continent of origin for the fish, and  3) look for fin clips, indicative of hatchery-reared fish from North America, possibly carrying coded-wire tags.  Laboratory analyses of scale patterns and genetic and parasite characters were performed in Seattle at the Northwest Fisheries Science Center. 

Based on a sample of 1,059 fish (about 2% of the total), almost 90% of the catch consisted of two species, coho salmon (50.3%) and chum salmon (38.6%), with the balance comprised of pink salmon (4.9%), sockeye salmon (2.6%), chinook salmon (2.5%), and steelhead (1.0%). Thirteen fin-clipped steelhead were found after sampling a total of about 5,500 fish (approximately 10% of the total catch).  No coded-wire tags were detected.

Strong inferences about continent or region of origin can be made for some species, but such determinations are hindered by a general lack of adequate baseline information, primarily for Asian stocks and to a lesser extent for those from Alaska and northern British Columbia. 

Age data, morphological examination, and genetic and parasitic analyses as appropriate indicate that an Asian, probably a Soviet, origin appears likely for at least a substantial portion of the chum and chinook salmon analyzed, and perhaps the coho salmon as well.  The presence of fin-clipped fish and the prevalence of steelhead with a single freshwater growth ring on their scales indicate that a substantial proportion of the steelhead came from hatcheries in North America, and genetic data confirm that a Kamchatkan origin is unlikely. 

The data for pink salmon are inconclusive regarding place of origin, and for sockeye salmon there is sufficient information from age and genetic data only to rule out southern British Columbia and Washington as major contributors.

Notes: Evaluation by NMFS scientists of catch from suspected illegal high seas drift net fishing.