Pink (Oncorhynchus gorbuscha), chum (O. keta), and sockeye salmon (O. nerka) represent approximately 90% of the commercial catch of Pacific salmon taken each year by Canada, Japan, the United States, and Russia. Annual all-nation catches of the three species and of each species, from 1925 to 1989, exhibited long-term parallel trends. National catches, in most cases, exhibited similar but weaker trends. The strong similarity of the pattern of the all-nation pink, chum, and sockeye salmon catches suggests that common events over a vast area affect the production of salmon in the North Pacific Ocean. The climate over the northern North Pacific Ocean is dominated in the winter and spring by the Aleutian Low pressure system. The long-term pattern of the Aleutian Low pressure system corresponded to the trends in salmon catch, to copepod production, and to other climate indices, indicating that climate and the marine environment may play an important role in salmon production.

Eighteen genera of metazoan parasites (Monogenea, 1; Digenea, 7; Cestoda, 4; Nematoda, 4; Acanthocephala, 1; Copepoda, 1) were collected from 172 landlocked and anadromous Arctic charr (Salvelinus alpinus Linnaeus) in northern Labrador. Four species (Lecithaster gibbosus, Diphyllobothrium dendriticum, Diphyllobothrium ditremum, and Salmincola carpionis) and one genus (Tetraonchus) have not previously been reported from Arctic charr in Labrador. The dominant parasites in the landlocked charr were Diplostomum sp., Crepidostomum farionis, and Diphyllobothrium ditremum. In the sea-run charr, Bothrimonus sturionis and Brachyphallus crenatus were dominant. Regression analyses indicated that the numbers of parasites were significantly correlated with host age (P < 0.001) for these species. All landlocked charr sampled were infected with parasites by age 1+ years whereas all sea-run charr were infected by age 3+. At 1+ years, 43% of the Arctic charr collected in the Ikarut River were infected with marine or brackish-water parasites, suggesting that some young charr, not yet ready for the annual seaward migration, may make short feeding excursions into salt water.

Seaward-migrating American (silver) eels were collected with fyke nets in Dog Bay and Holyrood Bay on the northeast and south coasts of Newfoundland. In both areas, silver eels evidently undertake their spawning migration at ages 9 to 18 years (mean 12.9 yr), but the mean length and weight of eels from Dog Bay were significantly larger than those from Holyrood Bay. The smallest silver eel in the samples was 56.9 cm long, and all specimens were considered to be females because there are no records of males longer than 40 cm from Newfound land waters. Growth of silver eels from the two areas was compared with the growth of silver and yellow (immature) eels from the Topsail area (near S1.John's) in an earlier study. The size of the watersheds, inhabited by the eels prior to migration, may partly be reflected in the size of eels at the time of migration, because growth of eels was evidently faster in the area with the largest watershed than in the areas with smaller watersheds, probably reflecti ng variation in competition for food and space. Orbit diameter of silver eels from Newfoundland was larger than those of non-silver eels of the same size range from Lake Ontario, indicating that size of the eyes increases with onset of maturity.

The eyes of 273 Arctic charr (Salvelinus alpinus) taken from Charr Lake, the Ikarut River, and Hebron Fiord in northern Labrador were examined for diplostomula. All anadromous charr taken from the Ikarut river and Hebron Fiord were uninfected. The resident fish from Charr Lake were parasitized with large numbers of diplostomula and intensity of infection increased with age and length. Infections of up to 2,852 diplostomula in one fish are the highest recorded. Such infections did not appear to affect the vision of the charr.