George H. Allen

Seawater Inhibition of Nitrite Toxicity to Chinook Salmon

Abstract The relative toxicity of nitrite to chinook salmon fingerlings (Oncorhynchus tshawytscha) in both freshwater ([Ca++] = 32 mg liter-1) and natural seawater (32.5‰, [Ca++] = 396 mg liter-1) was measured by 48-h static bioassay. The percentage of hemoglobin oxidized to methemoglobin was also determined. In freshwater, the 48-h median lethal nitrite concentration was 19 mg liter-1. In natural seawater, 1,070 mg liter-1 nitrite caused only 10% mortality in 48 h. In freshwater with 27 mg NO2- liter-1, 44% methemoglobin occurred with 70% mortality. In natural saltwater with 815 mg NO2- liter-1, 74% methemoglobin occurred with 10% mortality. Adding calcium sulfate to the freshwater decreased the toxicity of nitrite but did not reduce methemoglobinemia. Nitrite in calcium-free artificial seawater (100 mg NO2- liter-1) was highly toxic but did not induce appreciable methemoglobinemia. Adding calcium to this medium decreased the acute toxicity of nitrite. These results suggest nitrite toxicity mortalities r...

Return of Silver Salmon, Oncorhynchus Kisutch (Walbaum) to Point of Release

Abstract Silver salmon, Oncorhynchus kisutch (Walbaum), of the 1950 brood year were reared at the Soos Creek Hatchery, State of Washington Department of Fisheries, until January 19, 1952. On that date, approximately 72,000 fingerlings were divided between the State of Washington salmon hatchery on Issaquah Creek and the ponds of the School of Fisheries, University of Washington. After two months of orientation, the two lots of fish were released to migrate to sea on March 18 and 19, 1952. The movement of the fish in the sea were followed by noting the return of the marked fish to the sport and commercial fisheries. Adult salmon returning during the winter of 1953–1954 were examined for marks. None of the marked fish returned to Soos Creek, their native stream. Those fish released at the School of Fisheries returned up the ladder to the rearing ponds and those released at Issaquah migrated to the head of the watershed, returning to the area of release.

Survival through Hatching of Eggs from Silver Salmon (Oncorhynchus Kisutch)

Abstract During the 1953–54 migration season 63 female silver salmon (Oncorhynchus kisutch) of the 1950 brood year were recovered in the traps at the University of Washington. Eggs from each female were fertilized by one male only and the eggs maintained as separate lots through hatching. Hatching was completed in most lots from 40 to 43 days after fertilization in water of about 52.5°F. The mortality of eggs was studied during three stages of development. Mortality appeared to be related more to the female than the male parent. Females arriving during the first portion of the run produced eggs that had higher survival than females arriving during the last portion of the run. Survival through hatching was 48 percent for about 198,000 eggs produced by the 63 females. This survival was considerably less than survival rates reported in the literature. A delayed entry into the ponds was associated with increased water temperature. Over-retention of the eggs may have caused the below-normal survival.

Growth of Marked Silver Salmon (Oncorhynchus kisutch) of the 1950 Brood in Puget Sound

Abstract Silver salmon (Oncorhynchus kisutch) of two different stocks were marked by excision of fins and released during the spring of 1952 into Minter Creek and Lake Washington drainages of Puget Sound, Washington. Over 800 of the marked salmon were recovered during 1952 and 1953 from the sport and commercial fisheries of Puget Sound, the Pacific Ocean, and closely adjoining waters. Mature adults returning to spawn were recovered at traps and weirs at the hatcheries where they were originally released. The growth over the entire 3-year life cycle of the salmon released into the Lake Washington drainage when plotted graphically showed variation in length at maturity from less than 40 to over 80 centimeters in fork length. Salmon from the Lake Washington drainage taken in salt water at the same time and place were larger than salmon from Minter Creek. The average relative lengths of salmon from Minter Creek and Lake Washington recovered in the Pacific Ocean were the same as recorded for the mature salmon ...

Amino Acids in the Food Web of a Wastewater Aquaculture System for Rearing Juvenile Salmon

Abstract We analyzed and compared the amino acid content of (1) water from oxidation and aeration ponds in a domestic sewage treatment system, (2) a mixture of Humboldt Bay estuarine water and sewage treatment wastewater supplying fish ponds, and (3) selected invertebrates living in those waters. We identified 17 amino acids in water samples and 20 amino acids in crustaceans. Levels of amino acid in the water samples were highest in the aeration pond, much lower in the oxidation pond, and then only slightly lower in watewater-seawater mixtures from the fish ponds. The amino acid values for the water flea (Daphnia magna) from the oxidation pond were higher than those of a tube-dwelling amphipod (Corophium spinicorne) and a gammarid amphipod (Anisogammarus confervicolus) from fish ponds. The amino acid value of isopods (Rocilina) from fish ponds was relatively low.

Notes on Sampling Amphipods and Euphausiids in the North Pacific Ocean

Abstract Amphipods and euphansiids caught in Clarke-Bumpus, 1-meter, and 1/2-meter nets fished at the same stations within the North Pacific Ocean and the Gulf of Alaska during the spring of 1956, were compared by simple correlation analysis. Variable correlation in the catch of amphipods by day or night was probably due to patchiness and diurnal migration. A good correlation in catch of euphausiids in the three nets was found for stations sampled at night with coarse mesh and in areas devoid of phytoplankton blooms. There was some evidence that a low catch of euphausiids during the day was a function of availability rather than net avoidance.

Estimating Error Associated with Ocean Recoveries of Fin-marked Coho Salmon

Abstract Errors associated with the recovery of fin-marked fish include “unauthentic” recoveries, duplication of marks, and fin regeneration. Establishing validity of recoveries has been difficult, especially for Pacific salmon marked by the excision of a single fin and recovered in samples from ocean troll fisheries. Studies of error were made for recoveries of coho salmon of the 1950 brood that were marked by fin excision, planted into Puget Sound (Washington) streams in 1952, and recovered mainly in coho salmon fisheries in 1953. The total number of recoveries was large in comparison to the maximum estimated number of recoveries from traditional sources of error. On this basis analysis of recoveries from ocean fisheries would not be precluded even though the absolute magnitude of error was not known.

Catch-to-Escapement Ratios of Fin-Marked 1950-Brood Puget Sound Coho Salmon

Abstract Five groups of fin-marked coho salmon (Oncorhynchus kisutch) were released as fingerlings in 1952 into two Puget Sound (Washington) drainages. Three groups were released into Minter Creek (southern Puget Sound) and two into Lake Washington drainage (middle Puget Sound). About 90% of the salmon released into the Lake Washington drainage migrated to the Pacific Ocean, whereas, only 45% of those planted into Minter Creek migrated to the Pacific Ocean. Catch-to-escapement ratios for salmon from the five groups which remained as feeding fish within Puget Sound varied from about 2 to 5:1. For salmon released at Minter Creek, the catch-to-escapement ratio was 4:1 and for those released into the Lake Washington drainage, it was 3:1. In contrast, catch-to-escapement ratio for those salmon migrating to the Pacific Ocean was roughly ten time greater for fish released into Lake Washington watershed (14.1:1) than for fish released at Minter Creek (1.4:1). This large difference was due in part to their time an...

Contribution of Puget Sound Coho Salmon, Oncorhynchus kisutch, to the 1953 Pacific Coast Commercial Troll Fishery

Abstract Contribution of coho salmon (Oncorhynchus kisutch) produced by river systems entering Puget Sound, Washington, to the commercial troll fishery off the coasts of Washington and Vancouver Island in 1953 was estimated using the recoveries of fin-marked salmon. A commercial fishery in Puget Sound was used as a sampling tool. The production area was defined by the percentage exploitation by the Puget Sound fishery of runs of coho salmon to river systems in the Puget Sound area. Puget Sound streams as defined produced about 9% of the coho troll fishery catch off Washington and Vancouver Island in 1953. Major limitation of this study was the degree of accuracy in defining the production area.