Immature Steller sea lion (<i>Eumetopias jubatus</i>) dive activity in relation to habitat features of the eastern Aleutian Islands

Fadely, Brian S.; Robson, B. W.; Sterling, Jeremy T.; Greig, Angie; Call, Katherine A.

doi:10.1111/j.1365-2419.2005.00379.x

Cited by 39 publications

(66 citation statements)

References 43 publications

(103 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Fish at these sites were collected with a bottom trawl at depths ranging from 74 m to 160 m as part of a major survey of commercial fish distributions and abundance (Table 1). Sea lions typically forage within 16 km of these habitats (Fadely et al, 2005) and as deep as 288 m, although average diving depths are 26 m for pups and 63 m for yearlings (Loughlin et al, 2003. ).…”

Section: Methodsmentioning

confidence: 99%

Parasites of Forage Fishes in the Vicinity of Steller Sea Lion (Eumetopias Jubatus) Habitat in Alaska

Moles

Heintz

2007

Journal of Wildlife Diseases

View full text Add to dashboard Cite

ABSTRACT:Fish serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as Steller sea lions (Eumetopias jubatus). We examined the prevalence of parasites from 229 fish collected between March and July 2002 near two islands used by Steller sea lions in Southeast Alaska and island habitats in the Aleutian Islands. Sea lion populations have remained steady in Southeast Alaska but have been declining over the last 30 yr in the Aleutian Islands. Even though the fish samples near the Southeast Alaska haul-outs were composed of numerous small species of fish and the Aleutian Islands catch was dominated by juveniles of commercially harvested species, the parasite fauna was similar at all locations. Eleven of the 20 parasite taxa identified were in their larval stage in the fish hosts, several of which have been described from mammalian final hosts. Four species of parasite were more prevalent in Southeast Alaska fish samples, and seven parasite species, including several larval forms capable of infecting marine mammals, were more prevalent in fish from the Aleutian Islands. Nevertheless, parasites available to Steller sea lions from common fish prey are not likely to be a major factor in the decline of this marine mammal species.

show abstract

Section: Methodsmentioning

confidence: 99%

Parasites of Forage Fishes in the Vicinity of Steller Sea Lion (Eumetopias Jubatus) Habitat in Alaska

Moles

Heintz

2007

Journal of Wildlife Diseases

View full text Add to dashboard Cite

show abstract

“…Assuming complete dependence, regional differences in pup blubber FA profiles would be a reflection of regional differences in the FA composition of adult female diets that were passed on to offspring through milk (Puppione et al 1996, Iverson et al 2001. However, recent studies of maternal attendance patterns (Trites & Porter 2002) and the dispersal and movement patterns of young SSLs (Loughlin et al 2003, RaumSuryan et al 2004, Fadely et al 2005 have suggested that some individuals may wean during the spring of :1n-11, 20:1n-11 and 20:5n-3; second function accounted for an additional 17.9% of variation and was most influenced by 16:1n-7, 18:1n-9 and 22:6n-3 their first year of life. If this is true, regional differences in the blubber FA profile of pups may also result from regional differences in prey consumption or in the timing of when pups begin to forage independently.…”

Section: Differences In Fa Profiles By Regionmentioning

confidence: 99%

Blubber fatty acid profiles reveal regional, seasonal, age-class and sex differences in the diet of young Steller sea lions in Alaska

Beck¹,

Rea²,

Iverson³

et al. 2007

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Blubber fatty acid (FA) profiles of young Steller sea lions Eumetopias jubatus (< 24 mo old; n = 477) were investigated to determine whether regional, seasonal, age-class and sex differences occur in the diets of these demographic groups. Blubber FA profiles of spring (March to May) pups differed significantly by region, probably reflecting regional differences in the diet of adult females, who provide their pups with milk. While there were statistically significant seasonal and age-class differences in both Prince William Sound (PWS) and SE Alaska (SEA), differences in FA profiles between sexes were only evident in the blubber of yearlings from PWS. Within SEA, blubber FA profiles of summer pups differed significantly from all other seasonal/age-class groups in that region. This is consistent with movements of female-pup pairs from rookeries to haul-outs and hence differences in female foraging. In SEA, seasonal differences in blubber FA composition were evident and similar between yearlings and pups. In contrast, there was a gradual change in the FA profile of pup blubber from summer to spring in PWS, which did not follow the same seasonal pattern of yearling profiles. These differences in FA profiles suggest either differences in the timing of weaning between the 2 areas or shifts in the diets of lactating females, or both. KEY WORDS: Fatty acids · Dietary intake · Eumetopias jubatus · Independent foragingResale or republication not permitted without written consent of the publisher

show abstract

“…In turn, under the bottom-up concept, patterns in the changes of oceanography and fish populations should be reflected in patterns of sea lion foraging ecology and abundance (Fadely et al 2005, Gende and Sigler 2006, Womble and Sigler 2006. The objective of this study, therefore, was to investigate these possible linkages by examining the spatial and temporal heterogeneity of sea surface temperature (SST) and chlorophyll a (chl a) associated with habitat use of Steller sea lions from four regions of the western DPS.…”

Section: Introductionmentioning

confidence: 99%

Regional differences in the spatial and temporal heterogeneity of oceanographic habitat used by Steller sea lions

Lander

Loughlin

Logsdon

et al. 2009

Ecological Applications

Self Cite

View full text Add to dashboard Cite

Abstract. Over the past three decades, the decline and altered spatial distribution of the western stock of Steller sea lions (Eumetopias jubatus) in Alaska have been attributed to changes in the distribution or abundance of their prey due to the cumulative effects of fisheries and environmental perturbations. During this period, dietary prey occurrence and diet diversity were related to population decline within metapopulation regions of the western stock of Steller sea lions, suggesting that environmental conditions may be variable among regions. The objective of this study, therefore, was to examine regional differences in the spatial and temporal heterogeneity of oceanographic habitat used by Steller sea lions within the context of recent measures of diet diversity and population trajectories. Habitat use was assessed by deploying satellite-depth recorders and satellite relay data loggers on juvenile Steller sea lions (n ¼ 45) over a five-year period (2000)(2001)(2002)(2003)(2004) within four regions of the western stock, including the western, central, and eastern Aleutian Islands, and central Gulf of Alaska. Areas used by sea lions during summer months (June, July, and August) were demarcated using satellite telemetry data and characterized by environmental variables (sea surface temperature [SST] and chlorophyll a [chl a]), which possibly serve as proxies for environmental processes or prey. Spatial patterns of SST diversity and Steller sea lion population trends among regions were fairly consistent with trends reported for diet studies, possibly indicating a link between environmental diversity, prey diversity, and distribution or abundance of Steller sea lions. Overall, maximum spatial heterogeneity coupled with minimal temporal variability of SST appeared to be beneficial for Steller sea lions. In contrast, these patterns were not consistent for chl a, and there appeared to be an ecological threshold. Understanding how Steller sea lions respond to measures of environmental heterogeneity will ultimately be useful for implementing ecosystem management approaches and developing additional conservation strategies.

show abstract

Immature Steller sea lion (Eumetopias jubatus) dive activity in relation to habitat features of the eastern Aleutian Islands

Cited by 39 publications

References 43 publications

Parasites of Forage Fishes in the Vicinity of Steller Sea Lion (Eumetopias Jubatus) Habitat in Alaska

Parasites of Forage Fishes in the Vicinity of Steller Sea Lion (Eumetopias Jubatus) Habitat in Alaska

Blubber fatty acid profiles reveal regional, seasonal, age-class and sex differences in the diet of young Steller sea lions in Alaska

Regional differences in the spatial and temporal heterogeneity of oceanographic habitat used by Steller sea lions

Contact Info

Product

Resources

About