3 resultados para Red Giants. Activity. Abundance of lithium
em DigitalCommons - The University of Maine Research
Resumo:
Abundance of the Ommastrephes bartramii winter-spring cohort fluctuated greatly from 1995 to 2004. To understand how abundance was influenced by sea surface conditions, we examined the variations in the proportion of thermal habitats with favourable sea surface temperature (SST). The SST data of both the spawning and feeding grounds were used to calculate the monthly proportion of favourable-SST areas (PFSSTA). Catch per fishing day per fishing boat (catch per unit effort, CPUE) of the Chinese mainland squid-jigging fleet was used as squid abundance index. The relationships between CPUE and monthly PFSSTA at spawning and feeding grounds were analyzed, and the relationship between CPUE and selected PFSSTA was quantified with a multiple linear regression model. Results showed that February PFSSTA at the spawning ground and August to November PFSSTA at the feeding ground could account for about 60% of the variability in O. bartramii abundance between 1995 and 2004, that February was the most important period influencing squid recruitment during the spawning season, and that feeding ground PFSSTA during the fishing season would influence CPUE by causing squid to aggregate. Our forecast model was found to perform well when we compared the model-predicted CPUEs and the average CPUEs observed during August to November in 2005 and 2006 from the Chinese squid-jigging fishery.
Resumo:
The daytime abundance and localized distribution of fishes in relation to temperature were studied in a small tidal cove by beach seining on seven dates in the Back River estuary, Maine, during the summers of 1971 and 1972. Temperatures on the seven dates ranged from 15.1–26.2 C, and salinities ranged from 17.3–24.7‰. Eighteen species of fishes were captured, with mummichogs, smooth flounders, Atlantic silversides and Atlantic herring together comprising over 98% of the catch. Mummichogs and Atlantic silversides were captured primarily near the inner end of the cove, while other abundant species were caught mainly at the outer end of the cove. Several species seem well adapted to naturally warm cove temperatures. Others seem now virtually excluded because of warm temperatures. Winter flounder, Atlantic herring, and Atlantic tomcod might be excluded from the cove during daytime in summer if artificial warming of the cove were permitted.
Resumo:
Management plans to reduce human-caused deaths of North Atlantic right whales Eubalaena glacialis depend, in part, on knowing when and where right whales are likely to be found. Local environmental conditions that influence movements of feeding right whales, such as ultra-dense copepod patches, are unpredictable and ephemeral. We examined the utility of using the regional-scale mean copepod concentration as an indicator of the abundance of right whales in 2 critical habitats off the northeastern coast of the United States: Cape Cod Bay and Great South Channel. Right whales are usually found in Cape Cod Bay during the late winter and early spring, and in the Great South Channel during the late spring and early summer. We found a significant positive relationship between mean concentration of the copepod Calanus finmarchicus in the western Gulf of Maine and the frequency of right whale sightings in the Great South Channel. In Cape Cod Bay we found a significant positive relationship between the mean concentration of other copepods (largely Pseudocalanus spp. and Centropages spp.) and the frequency of right whale sightings. This information could be used to further our understanding of the environmental factors that drive seasonal movement and aggregation of right whales in the Gulf of Maine, and it offers a tool to resource managers and modelers who seek to predict the movements of right whales based upon the concentration of copepods.