Bottlenose dolphin (Tursiops truncatus) strandings in South Carolina, 1992-1996

From 1992 to 1996, 153 bottlenose dolphin stranded in South Carolina, accounting for 73% of all marine mammal strandings during this period. The objectives of our study were to evaluate data from these strandings to deter-mine 1) annual trends in strandings, 2) seasonal and spatial distribution trends, 3) life history parameters such as sex ratio and age classes, 3) seasonal trends in reproduction, and 4) the extent to which humans have played a role in causing these strandings (human inter-actions). The results showed that 49% of the bottlenose dolphin strandings occurred between April and July; the greatest number of strandings occurred in July (n=22). There was a significant seasonal increase in the distribution of bottlenose dolphin strandings in the northern portion of the state from November to March. Bottlenose dolphin neonates stranded in every month of the year, except March and October, and represented 19.6% of the total number of strandings with known length (n=138). Fifty-five percent (n=15) of bottlenose dolphin neonatal strandings occurred between May and July. Bottlenose dolphins determined to have died as the result of human interaction accounted for 23.1% of the total number of bottlenose dolphin strandings (excluding those for which a determination could not be made).Incidents of bottlenose dolphin entanglements in nets accounted for 16 of these cases.

Changes over time in the spatial distribution of walleye pollock (Theragra chalcogramma) in the Gulf of Alaska, 1984-1996

Triennial bottom trawl survey data from 1984 to 1996 were used to evaluate changes in the summer distribution of walleye pollock in the western and central Gulf of Alaska. Differences between several age groups of pollock were evaluated. Distribution was examined in relation to several physical characteristics, including bottom depth and distance from land. Interspecies associations were also analyzed with the Bray-Curtis clustering technique to better understand community structure. Our results indicated that although the population numbers decreased, high concentrations of pollock remained in the same areas during 1984–96. However, there was an increase in the number of stations where low-density pollock concentrations of all ages were observed, which resulted in a decrease in mean population density of pollock within the GOA region. Patterns emerging from our data suggested an alternative to Mac-Call’s “basin hypothesis” which states that as population numbers decrease, there should be a contraction of the population range to optimal habitats. During 1984–96 there was a concurrent precipitous decline in Steller sea lions in the Gulf of Alaska. The results of our study suggest that decreases in the mean density of adult pollock, the main food in the Steller sea lion diet, combined with slight changes in the distribution of pollock (age-1 pollock in particular) in the mid-1980s, may have contributed to decreased foraging efficiency in Steller sea lions. Our results support the prevailing conceptual model for pollock ontogeny, although there is evidence that substantial spawning may also occur outside of Shelikof Strait.

Proceedings of the Thirteenth Annual Pacific Climate (PACLIM) Workshop, Asilomar, California - April 14-17, 1996 [abstracts]

Abstracts of 24 oral presentations and 25 poster presentations.

Proceedings of the Thirteenth Annual Pacific Climate (PACLIM) Workshop, Asilomar, California - April 14-17, 1996 [appendices]

The appendices include the workshop agenda, a list of poster presentations, and a list of attendees.