Juvenile salmonid distribution, growth, condition, origin, and environmental and species associations in the Northern California Current

Information is summarized on juvenile salmonid distribution, size, condition, growth, stock origin, and species and environmental associations from June and August 2000 GLOBEC cruises with particular emphasis on differences related to the regions north and south of Cape Blanco off Southern Oregon. Juvenile salmon were more abundant during the August cruise as compared to the June cruise and were mainly distributed northward from Cape Blanco. There were distinct differences in distribution patterns between salmon species: chinook salmon were found close inshore in cooler water all along the coast and coho salmon were rarely found south of Cape Blanco. Distance offshore and temperature were the dominant explanatory variables related to coho and chinook salmon distribution. The nekton assemblages differed significantly between cruises. The June cruise was dominated by juvenile rockfishes, rex sole, and sablefish, which were almost completely absent in August. The forage fish community during June comprised Pacific herring and whitebait smelt north of Cape Blanco and surf smelt south of Cape Blanco. The fish community in August was dominated by Pacific sardines and highly migratory pelagic species. Estimated growth rates of juvenile coho salmon were higher in the GLOBEC study area than in areas farther north. An unusually high percentage of coho salmon in the study area were precocious males. Significant differences in growth and condition of juvenile coho salmon indicated different oceanographic environments north and south of Cape Blanco. The condition index was higher in juvenile coho salmon to the north but no significant differences were found for yearling chinook salmon. Genetic mixed stock analysis indicated that during June, most of the Chinook salmon in our sample originated from rivers along the central coast of Oregon. In August, chinook salmon sampled south of Cape Blanco were largely from southern Oregon and northern California; whereas most chinook salmon north of Cape Blanco were from the Central Valley in California.

Time series analyses of biological and environmental variables for Suisun Bay and the Sacramento and San Joaquin rivers

EXTRACT (SEE PDF FOR FULL ABSTRACT): Arima analysis was used to compute cross-correlations between principal component axes that described environmental variables, chlorophyll concentration and zooplankton density for the Sacramento and San Joaquin rivers and Suisun Bay. ... Cross-correlations among the time series may provide information about links between environmental and biological variables within the estuary and the possible influence of climate.

Transboundary diagnostic analysis. Vol. 2. Background and environmental assessment

The Transboundary Diagnosis Analysis(TDA) quantifies and ranks water-related environmental transboundary issues and their causes according to the severity of environmental and/or socio-economic impacts. The three main issues in BOBLME are; overexploitation of marine living resources; degradation of mangroves, coral reefs and seagrasses; pollution and water quality. Volume 2 contains background material that sets out the bio-physical and socio-economic characteristics of the BOBLME; an analysis of the legal,policy and administrative context; and an assessment of the status of marine living resources and marine environment in coastal areas

The study of Indian shrimp larvae feeding by enriched rotifer with vitamin C and unsaturated fatty acid (epa, dha) and its effects on growth factors, survival rate and environmental stresses

In this experiment, the feeding of Indian white shrimp larvae by unenriched rotifers (treatment 1) and enriched with highly unsaturated fatty acid (treatment 2) and highly unsaturated fatty acid along with vitamin C (treatment 3) on the growth factors, survival and resistance against salinity and formalin stress tests were studied and their differences with control treatment including newly hatched Artemia nauplii is compared. In this the study four treatments in a completely randomized design with 3 replicates per treatment were used. Farming of shrimp larvae of Zoea II to postlarvae 5 was done in 20 liter plastic bucket. Present results indicated that growth factors and survival rate of stage Zoea II to postlarvae 1 in treatments 1, 2 and 3 improve rather than control in which this case was due to optimal size rotifer rather than Artemia nauplii. Also, treatments 2 and 3 feeding with oil liver cod emulsion enriched rotifer have the highest concentration of DHA (mg/g DW) and the ratio DHA/EPA in which due to have shown the highest growth factors and a significant difference (P<0.05) with treatments 1 and control. The highest survival at stage PL1 were observed in treatment 3 that was enriched with ascorbyl palmitate in which have to the synergistic properties of vitamin C rather than treatments 2, 1 and control and showed a significant difference (P<0.05). But in stage PL5 the highest amount of growth and survival rates were related to control treatment which showed a significant difference (P<0.05) with other treatments that control has higher size rather than treatments 1, 2 and 3. Also, among experiment treatments that the two treatments 2 and 3 due to enrichment had higher growth and survival rates compared with treatment 1 in which their differences have also been significant (P<0.05). In the case of stress tests, results indicated that the highest survival rate has been reported when specimens were offered a diet containing high levels of highly unsaturated fatty acids with vitamin C. So that in stage PL1 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3. As for the second, treatment 2 showed a significant difference (P<0.05) with treatment 3. It is worth mentioning that treatment 3 showed a higher survival rate compared to treatment 2 due to the synergistic properties of vitamin C. The difference between these two treatments with treatment 1 and control was also significant. No significant difference was observed in formalin stress test 100 ppm in this stage between treatments 3 and 2 which shows the highest survival rate. But their difference with treatments 1 and control was significant (P<0.05). Also, in stage PL5 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3 which showed no significant difference (P<0.05) with control treatment. While their difference in the amount of survival rate with treatment 1 and 2 was significant (P<0.05). In this stage, the highest observed survival rate in formalin stress test 100 ppm included treatments control, 3 and 2 among which there were no significant differences (P<0.05). While the difference between these three treatments with treatment 1 was significant.