Chum Salmon Research Articles

Return Rates of Chum Salmon are Affected by Different Timings of Juvenile Release

Return Rates of Chum Salmon are Affected by Different Timings of Juvenile Release

The Utilization of Cold-water Zooplankton as Prey for Chum Salmon Fry in Yamada Bay, Iwate, Pacific Coast of Northern Japan

The Utilization of Cold-water Zooplankton as Prey for Chum Salmon Fry in Yamada Bay, Iwate, Pacific Coast of Northern Japan

Downstream Migration and Spatial Distribution of Juvenile Chum Salmon in the Otsuchi Bay, the Sanriku Coast of Iwate, Japan

Downstream Migration and Spatial Distribution of Juvenile Chum Salmon in the Otsuchi Bay, the Sanriku Coast of Iwate, Japan

Does Long-distance Downstream Migration Influence the Survival of Chum Salmon? Comparison of Adult Returns between the Upper and Lower Reaches Release Sites

Does Long-distance Downstream Migration Influence the Survival of Chum Salmon? Comparison of Adult Returns between the Upper and Lower Reaches Release Sites

Recovery from a Critical Disaster and Sustainable Conservation Management for Chum Salmon under a Warming Climate on the Sanriku Coast, Japan

Recovery from a Critical Disaster and Sustainable Conservation Management for Chum Salmon under a Warming Climate on the Sanriku Coast, Japan

Development of Age Determination Technique Part 2: Image Processing for Age Determination Based on the Annuli of a Chum Salmon Scale

Development of Age Determination Technique Part 2: Image Processing for Age Determination Based on the Annuli of a Chum Salmon Scale

Characteristics of Prey Environment during the Early Ocean Life of Juvenile Chum Salmon in Two Coastal Areas around Hokkaido, Northern Japan

Characteristics of Prey Environment during the Early Ocean Life of Juvenile Chum Salmon in Two Coastal Areas around Hokkaido, Northern Japan

Low Nutritional Status in the Freshwater Phase and Temperature at Seawater Entry Reduce Swimming Performance of Juvenile Chum Salmon

Low Nutritional Status in the Freshwater Phase and Temperature at Seawater Entry Reduce Swimming Performance of Juvenile Chum Salmon

Survival of Japanese Chum Salmon during Early Ocean Life in 2011–2017

Survival of Japanese Chum Salmon during Early Ocean Life in 2011–2017

Stock Identification of Chum Salmon Overwintering in the Gulf of Alaska by Using a New SNP Baseline

Stock Identification of Chum Salmon Overwintering in the Gulf of Alaska by Using a New SNP Baseline

Development of Age Determination Technique Part 1: Neural-Network Based Prediction of Chum Salmon Age by Scale Images

Development of Age Determination Technique Part 1: Neural-Network Based Prediction of Chum Salmon Age by Scale Images

Recent Trend in Variability of Chum Salmon Stock and its Potential Mechanism in Hokkaido, Japan

Recent Trend in Variability of Chum Salmon Stock and its Potential Mechanism in Hokkaido, Japan

Projected Impacts of Global Warming on Chum Salmon Stocks in Hokkaido, Japan

Projected Impacts of Global Warming on Chum Salmon Stocks in Hokkaido, Japan

The Identification of Individuals with Hatchery and Natural Origin in a Mixed Sample of Amur River Chum Salmon by Otolith Microchemistry

The Identification of Individuals with Hatchery and Natural Origin in a Mixed Sample of Amur River Chum Salmon by Otolith Microchemistry

Effective Hatchery Releases to Increase Adult Returns of Chum Salmon in the Ishikari River, Hokkaido, Japan

Effective Hatchery Releases to Increase Adult Returns of Chum Salmon in the Ishikari River, Hokkaido, Japan

Quantitative Estimation of the Ecosystem Services Supporting the Growth of Japanese Chum Salmon

Quantitative Estimation of the Ecosystem Services Supporting the Growth of Japanese Chum Salmon

The effects of temperature and salinity of hatchery water on early development of chum salmon (Oncorhynchus keta)

Chum salmon Oncorhynchus keta is the most abundant and industrially important salmonid in Japan, of which Japanese hatcheries release about 1.8 × 109 fry annually. However, recent global warming and earthquake-induced crustal movement might have changed hatchery water environments. To sustainably maintain and operate hatcheries in Japan, we report the effects of rearing water temperature and salinity on the early development of chum salmon derived from the Chitose River. Effects are evaluated in terms of eyed-egg (Eer), hatching (Htr), and survival (Sur) rates, alevin body size, and the quality of the egg envelope. Fertilized eggs were reared in groundwater (GW) at different temperatures (4, 7, 10, 13, 16 °C). Alevin reared at 4 °C were larger but had less yolk, while those reared at 16 °C were smaller but hatched precociously. A significant decrease in Htr and Sur was observed in the 4 °C treatment, which we regard to be because of the small amount of residual egg yolk at the time of hatching. Eggs were also fertilized in GW or different concentrations of brackish groundwater (BGW 0.5, 1.0, 2.1, 4.1, 8.3 psu), and continuously reared under the same salinity conditions at fertilization. Those BGW treatments at 1.0 and 2.1 psu had much lower Htr values than those reared in GW and salinities of 0.5 psu, despite their having a comparable Eer. Mortality in BGW treatments of 1.0 and 2.1 psu occurred during hatching, because of precocious hatching. No change in egg membrane proteins occurred after fertilization in 4.1 and 8.3 psu treatments, and embryos did not develop to an eyed-egg stage. These results suggest that constant temperatures of 4 and 16 °C, and salinities exceeding 1.0 psu during fertilization can prevent or interfere with the normal early development of chum salmon eggs and larvae in the Chitose River. To avoid the adverse effects of salination, fertilization with GW and hardening of the egg envelope effectively increase Sur dramatically, even after transfer to BGW.

Indigenous sex-selective salmon harvesting demonstrates pre-contact marine resource management in Burrard Inlet, British Columbia, Canada

To gain insight into pre-contact Coast Salish fishing practices, we used new palaeogenetic analytical techniques to assign sex identifications to salmonid bones from four archaeological sites in Burrard Inlet (Tsleil-Waut), British Columbia, Canada, dating between about 2300–1000 BP (ca. 400 BCE–CE 1200). Our results indicate that male chum salmon (Oncorhynchus keta) were preferentially targeted at two of the four sampled archaeological sites. Because a single male salmon can mate with several females, selectively harvesting male salmon can increase a fishery’s maximum sustainable harvest. We suggest such selective harvesting of visually distinctive male spawning chum salmon was a common practice, most effectively undertaken at wooden weirs spanning small salmon rivers and streams. We argue that this selective harvesting of males is indicative of an ancient and probably geographically widespread practice for ensuring sustainable salmon populations. The archaeological data presented here confirms earlier ethnographic accounts describing the selective harvest of male salmon.

On the Issue of Efficiency of Large-Scale Hatchery Rearing of Chum Salmon (Oncorhynchus keta, Walbaum, 1792) on Iturup Island, Kuril Islands

On the Issue of Efficiency of Large-Scale Hatchery Rearing of Chum Salmon (Oncorhynchus keta, Walbaum, 1792) on Iturup Island, Kuril Islands

Effects of topical application of different molecular weight marine fish skin collagen oligopeptides on UVB-induced photoaging rat skin.

The objective of this work was to develop a peptide production process of the exact molecular weight propitious to topical application for cosmetics and to investigate the effects of enzymolysis-derived peptide on UVB-induced photoaging rat skin. The chum salmon fish skins were hydrolyzed by alkaline protease and neutral protease and spray-dried at different conditions, and three kinds of molecular weight peptide (MFSOP) were obtained. A total of 66 ICR rats (female, 20 ± 1g) were randomly divided into eleven groups, including the normal, model, and experimental groups. The three kinds of MFSOP were dissolved at different dosages (5‰, 2.5%, and 5%) and then applied on the ICR hairless back skins prior to exposing UVB irradiation of 3000mJ/cm2 to them 4h later. After 8weeks, the rats were killed and the hair-shaved skins were tested for skin moisture, hyaluronic acid, hydroxyproline, antioxidant activity, and RNA expression. Three kinds of MFSOP were obtained, with the average molecular weights of 495.16, 1194.00, and 2032.46Dalton, respectively. The MFSOPs, especially the MFSOP of average molecular weight of 1194.00Dalton, played an important role in the recovery of the UVB-injured skin tissue in lock in moisture, in antioxidant activity and in promotion in collagen and elastin protein to some extent. MFSOPs, especially MFSOP of average molecular weight of 1194.00Dalton, derived from enzymolysis are potential materials to apply in cosmetics for the UVB9-induced anti-photoaging activity (lock in moisture, antioxidant activity, and promotion in collagen and elastin protein).