Haul-out Areas Research Articles

Characterisation of the ringed seal (Pusa hispida) acoustic repertoire during spring in the Western Canadian Arctic

ABSTRACT Understanding the acoustic repertoire of a species is crucial for comprehending its ecology and can also provide a valuable tool in the analysis of passive acoustic monitoring data. Despite being the most abundant seal species in the Arctic, the call repertoire of ringed seals (Pusa hispida) remains poorly studied. This paper aims to provide a comprehensive and quantitative description of the calls produced by ringed seals. Data collection occurred in May 2022 near Ulukhaktok in the Western Canadian Arctic. Acoustic recorders were deployed in cracks in the sea ice that were regularly used by ringed seals as haul-out areas. All calls were counted and classified into one of three categories: yelps, barks and growls. High-quality calls were further analysed with ten acoustic parameters calculated for each signal. Cluster and classification and regression tree (CART) analyses were used to assess if the visual classification of calls was supported by the acoustic parameters calculated. The cluster and CART analyses affirmed the presence of all three distinct call types in the ringed seal acoustic repertoire. Classification of unseen calls using the CART model demonstrated an accuracy of 98%. The findings presented here serve as foundational information on the acoustic repertoire of ringed seals.

Occurrence of recreational water quality monitoring general fecal indicator bacteria and fecal source identification genetic markers in gray seal scat

The number of gray seals (Halichoerus grypus) observed along the United States Northwest Atlantic region has been increasing for decades. These colonial animals often haul-out on beaches seasonally in numbers ranging from a few individuals to several thousands. While these larger aggregations are an important part of gray seal behavior, there is public concern that haul-outs could lead to large amounts of fecal waste in recreational areas, potentially resulting in beach closures. Yet, data to confirm whether these animals contribute to beach closures is lacking and minimal information is available on the occurrence of key water quality monitoring genetic markers in gray seal scat. This study evaluates the concentration of E. coli (EC23S857), enterococci (Entero1a), and fecal Bacteroidetes (GenBac3) as well as six fecal source identification genetic markers (HF183/BacR287, HumM2, CPQ_056, Rum2Bac, DG3, and GFD) measured by qPCR in 48 wild gray seal scat samples collected from two haul-out areas in Cape Cod (Massachusetts, U.S.A.). Findings indicate that FIB genetic markers are shed in gray seal scat at significantly different concentrations with the Entero1a genetic marker exhibiting the lowest average concentration (−0.73 log10 estimated mean copies per nanogram of DNA). In addition, systematic testing of scat samples demonstrated that qPCR assays targeting host-associated genetic markers indicative of human, ruminant, and canine fecal pollution sources remain highly specific in waters frequented by gray seals (>97 % specificity).

Diminishing numbers of male southern elephant seals (Mirounga leonina Pinnipedia: Phocidae, Linnaeus, 1758) at the Vestfold Hills, East Antarctica (1957–2022)

Abstract A proportion of the southern elephant seal (Mirounga leonina) population that breeds in the Kerguelen Plateau region seasonally migrates between their natal sub-Antarctic islands and moult haul-out locations on the Antarctic coastline. Analyses of survey data collated for one moult location at the Vestfold Hills, East Antarctica, showed that there had been no appreciable change in the timing (phenology) of maximum seal arrivals between 1974 and 2022; however, the maximum number of seals moulting at that site had declined by ~90% over the same time interval. Spatial analyses showed rates of population change were survey area dependent, as seal numbers decreased most rapidly at haul-out areas closest to the permanently occupied Davis Station, suggesting that a relationship exists between seal numbers and human activities. The range of potential factors that contribute to population change for southern elephant seals moulting at the Vestfold Hills includes changes in status at primary source populations, one of which has not been surveyed since the 1990s, and species relocation. Should numbers of southern elephant seals in the Vestfold Hills continue to decrease at the current average rate of change (-7.78 seals/year) the species could vanish from the area by c. 2040.

Seasonal habitat use of a lagoon by ringed seals Pusa hispida in Svalbard, Norway

Climate change is impacting ice-affiliated marine mammal habitats throughout the Arctic, with sea ice declines reducing traditional haul-out and breeding habitats, putting a premium on alternative useable areas. In the Arctic, ice forms early in the season and is retained late into the spring in coastal lagoons, but little information is available regarding how this nature type is used by marine mammals. This study documents use of a lagoon by 20 ringed seals tracked for an average of 188 d via satellite-linked GPS tags. Overall, tagged seals spent 8.9 ± 0.4% (±SD) of their time per day inside the lagoon, with strong summer and autumn peaks that dropped off in winter and ceased in spring. Inside the lagoon, seals spent significantly larger proportions of their time hauled out and less time diving in comparison to when they were outside the lagoon. Additionally, the seals dove deeper (19 vs. 7 m) and for longer periods (4 vs. 2.5 min) when outside the lagoon, indicating that most feeding took place out in the fjord. However, residency periods in the lagoon of up to 43 d as well as more intense diving than would be expected for transport to and from haul-out areas within the lagoon suggest that ringed seals also feed in the lagoon. Regular opportunistic sightings of ringed seals in lagoons around Svalbard, Norway, together with the quantitative behavioural documentation of lagoon use in the present study, suggest that lagoons may serve as refugia areas, which might become increasingly important as climate change continues to alter Arctic marine ecosystems.

Anisakids (Nematoda: Anisakidae) from stomachs of northern fur seals (Callorhinus ursinus) on St. Paul Island, Alaska: parasitological and pathological analysis.

Anisakid nematodes parasitize the alimentary tracts of aquatic vertebrates, including northern fur seals (Callorhinus ursinus) (NFS). The main purpose of this study was to estimate the prevalence, intensity, and species composition of anisakids in NFSs on St. Paul Island, Alaska, and to analyze changes in NFS infection with these nematodes during the last decades. The study was carried out on St. Paul Island, Alaska, in July-August 2011-2013. Stomachs of 443 humanely harvested NFS males were collected from five separate haul-out areas. A total of 4,460 anisakid specimens were collected and identified by morphological criteria. Gross and histological examinations of stomachs were also performed. The overall prevalence of NFS infection was 91.2%; overall mean intensity 10.9, and overall median intensity 6. Five species, Anisakis simplex s. l., Contracaecum osculatum s. l., Pseudoterranova decipiens s. l., P. azarazi and Phocascaris cystophorae, were found. The prevalence of Anisakis was 46.5%, its intensity 7.5. The prevalence and intensity of Contracaecum, Pseudoterranova, and Phocascaris were 33.6% and 3.5, 81.9% and 6.5, and 5.2% and 1.7, respectively. Significant differences in the prevalence of NFS infection were observed between separate haul-outs. Comparison of the present data with the results of studies performed in the North Pacific in the 1960s, showed a significant decrease in the intensity of NFS infection with anisakids during the last decades. The prevalence of mucosal lesions in NFS stomachs caused by anisakids also decreased from 92 to 20.9%. Possible reasons for the changes in NFS infection with anisakids are discussed.

Using movement data of Baltic grey seals to examine foraging-site fidelity: implications for seal-fishery conflict mitigation

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 507:297-308 (2014) - DOI: https://doi.org/10.3354/meps10846 Using movement data of Baltic grey seals to examine foraging-site fidelity: implications for seal-fishery conflict mitigation Sari M. Oksanen1,*, Markus P. Ahola2, Esa Lehtonen3, Mervi Kunnasranta1 1Department of Biology, University of Eastern Finland, PO Box 111, 80101 Joensuu, Finland 2Finnish Game and Fisheries Research Institute, Itäinen Pitkäkatu 3, 20520 Turku, Finland 3Finnish Game and Fisheries Research Institute, PO Box 2, 00791 Helsinki, Finland *Corresponding author: sari.oksanen@uef.fi ABSTRACT: Knowledge of the intensity of spatial overlap between aquatic top predators and fisheries is required to efficiently alleviate the negative effects of marine mammal-fishery interactions. We used satellite telemetry to study the movements and habitat use of Baltic grey seals Halichoerus grypus, with special focus on the degree of site fidelity to foraging and haul-out areas and spatio-temporal overlap with coastal fisheries. Most of the tracked seals (14/16 individuals) were ‘residents’, which remained within 120 ± 62 km (mean ± SD) of their capture sites during the open-water season, whereas 2 ‘transient’ seals occupied much larger areas, over 400 km from their capture sites. Residents used on average 4.3 ± 2.5 haul-out sites, indicating high haul-out site fidelity during the open-water season. Residents had active core areas (58 ± 35 km2, 50% local nearest-neighbour convex hull [LoCoH], excluding haul-out locations) near river estuaries or at other shallow water areas, indicating foraging-site fidelity to these foraging grounds. They overlapped both spatially and temporally with trap-net fishing. The high site fidelity of grey seals indicates that foraging and haul-out areas should be taken into account in population management. Selective removal of seals overlapping with fishery could be a locally focused method to mitigate seal-fishery interactions. However, removal of individuals in foraging areas may also compromise the conservation needs of the population by targeting the same animals that are hauling out in seal sanctuaries. KEY WORDS: Baltic Sea · GPS phone tag · Habitat preference · Halichoerus grypus · Home range · Seal-fishery overlap · Trap-net fishery Full text in pdf format Erratum PreviousCite this article as: Oksanen SM, Ahola MP, Lehtonen E, Kunnasranta M (2014) Using movement data of Baltic grey seals to examine foraging-site fidelity: implications for seal-fishery conflict mitigation. Mar Ecol Prog Ser 507:297-308. https://doi.org/10.3354/meps10846 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 507. Online publication date: July 17, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.

Haulout patterns of Saimaa ringed seals and their response to boat traffic during the moulting season

Conservation of the Critically Endangered ringed seal Phoca hispida saimensis pop- ulation in Lake Saimaa in Finland requires broader knowledge of the behavioural ecology of this subspecies. Understanding Saimaa ringed seal haulout patterns and their response to boat traffic is crucial for designing sustainable land use and tourism guidelines. Responses of unidentified seals to small outboard motor boat traffic were studied during the moulting season. The median distance at which the seals responded to an approaching boat was 240 m. GPS-phone tags were used to study both circadian and seasonal haulout behaviour patterns of individual seals (n = 8) during the open-water season. The average post-moulting haulout duration was 6 ± 5 h (SD), with a maximum of over 26 h. The seals spent more time hauled out at night (between 21:00 and 06:00 h) after the moult. The time spent hauled out and the haulout frequency declined from early summer to autumn. An individual seal had an average of 13 haulout sites, which were an average of 2.5 km apart. Approximately half of these haulout sites were located in the core 50% of the indi- vidual seals' home ranges. The high level of site fidelity emphasizes the need to identify suitable haulout areas and to develop measures for protecting the main resting sites of this endangered population. Additionally, guidelines for seal watching should be developed in order to mitigate the potential disturbance caused by increasing tourism on Lake Saimaa.

Status of the harbour seal (<i>Phoca vitulina</i>) in Southern Scandinavia

The harbour seal population in Southern Scandinavia has experienced repeated declines caused by hunting and epizootics. These events have shaped the current distribution and abundance of the population. This paper assesses the current status of the population. We estimate trends in abundance of harbour seals from long term survey data, compare these with historic trends inferred from previously published material, and discuss past and potential threats to the harbour seal population of Southern Scandinavia. It is evident that harbour seals have disappeared from haulout areas along the Danish shores of Kattegat and in the westernmost part of the Baltic Sea, where they were previously numerous. In the 1920-30s, when abundance was at its lowest, the population is estimated to have been only a fraction of its original size. Following 30 years of protection the population is currently approaching historic abundance and might have reached the carrying capacity in some areas. Further development depends largely on effects of future epizootics, anthropogenic disturbance, and availability of suitable haulout sites.

Ecological, morphological, and molecular studies of Acanthocheilonema odendhali (Nematoda: Filarioidea) in northern fur seals (Callorhinus ursinus) on St. Paul Island, Alaska

Studies of northern fur seal (Callorhinus ursinus Linnaeus, 1758) infection by the filariid nematode Acanthocheilonema odendhali were carried out in 2011-2012 on St. Paul Island, Pribilof Archipelago, Alaska. Skins of 502 humanely harvested northern fur seals from haul-out areas of five rookeries, Polovina (n = 122), Morjovi (n = 54), Zapadni (n = 72), Lukanin (n = 109), and Gorbatch (n = 145), were examined. A. odendhali was found in 18% of northern fur seals. The prevalence of infection ranged from 12.5% up to 22.9% on different haul-out areas on the island. The mean intensity of infection was 1.3 (range 1-7). Detailed morphological examination of collected specimens was performed using light microscopy. Several characters were added to the morphological description of the species, among them lateral thickening of the body cuticle, especially prominent in males, variations in number and position of genital papillae in males, transverse striation of the cuticle, and terminal dilation on tail end in microfilariae. The adult specimens studied had a shorter esophagus than type specimens from the California sea lion described by Perry (1967). Comparison of partial sequences of the mitochondrial cox1 gene from specimens collected from five sampling sites on St. Paul Island and a specimen from the type host and territory in California showed no significant differences and strongly supported conspecificity of the material from Alaska with A. odendhali.

Acanthocephalans in northern fur seals (Callorhinus ursinus) and a harbor seal (Phoca vitulina) on St. Paul Island, Alaska: species, prevalence, and biodiversity in four fur seal subpopulations

Monitoring studies of acanthocephalans in northern fur seals (Callorhinus ursinus Linnaeus, 1758) (NFSs) and a harbor seal (Phoca vitulina Linnaeus, 1758) were performed on St. Paul Island, Alaska, in July-August 2011. Gastrointestinal tracts of 105 humanely harvested NFS subadult males (SAMs) (3-4 years old) were collected during the annual Aleut subsistence harvest at four haul-out areas (HOAS): Lukanin (n = 26 NFSs), Polovina (n = 28), Gorbatch (n = 30), and Morzhovyi (n = 21). One gastrointestinal tract collected from a harbor seal (about 3-4 years old) found dead at Morzhovyi HOAS was also examined. The total prevalence of infection in NFSs with acanthocephalans was 29.52 % with variations from 7.69 % to 47.62 % between the four different HOAS. Eight acanthocephalan species of two genera-Corynosoma Lühe, 1904 (Corynosoma strumosum, Corynosoma alaskensis, Corynosoma cameroni, Corynosoma semerme, Corynosoma similis, Corynosoma validum, and Corynosoma villosum), and Bolbosoma Porta, 1908 (Bolbosoma nipponicum)-were found in the NFSs and a harbor seal. This is a new record of C. alaskensis for the NFSs. Short biological notes of the species found are presented. Differences in species composition as well as in prevalence of acanthocephalans parasitizing NFSs were observed in subpopulations from four different HOAS on St. Paul Island. The highest biodiversity of acanthocephalans and infection were found in subpopulations on Polovina and Morzhovyj HOAS, the lowest was on Lukanin HOAS. From 3.2 % (for C. validum) to 19.4 % (for C. villosum) of NFSs were infected by one acanthocephalan species; two species were found in 22.6 %; three in 9.7 %; and four in 3.2 %. Further studies of NFS parasites are necessary to follow the trends in parasitic infection rates and diversity in NFS population on the Pribilov Islands and for monitoring the influence of various ecological factors on NFS populations in Alaska.

Conflicts in natural and cultural resource management: Archaeological site disturbances by seals and sea lions on California's Northern Channel Islands

California's Channel Islands currently have around 150,000 breeding seals and sea lions (pinnipeds). Driven to near extinction by 20th-century exploitation, many pinniped populations have recovered dramatically under federal and state management and continue to expand in number and distribution. Some of these pinniped populations are damaging or destroying coastal archaeological sites as they establish new breeding and haul-out areas—places occupied between periods of foraging activity—on upland landforms. We use archaeological excavations from a prehistoric village on San Miguel Island to illustrate the adverse effects pinnipeds can have on archaeological sites. Estimates based on excavations at Otter Point suggest that in one year nearly 10,000 kg of shellfish remains, 840,000 animal bones, and 1700 formal artifacts were lost to erosion caused by the activities of seals and sea lions. Our study documents potential conflicts between natural and cultural resource management suggesting the need for collaborative efforts between archaeologists and biologists to balance the conservation of both resources.

Abundance, distribution and haul-out behaviour of grey seals (Halichoerus grypus) in Cornwall and the Isles of Scilly, UK

This study investigated the phenology, patterns of haul-out habitat use and distribution of the grey seal around Cornwall and the Isles of Scilly. A full census of the coast was carried out by boat over 4 days, in order to make a full count of seals hauled out and close to the coast, and to document all haul-out sites. Regular land-based surveys were made of three haul-out sites in Cornwall, to investigate the effects of spatial, temporal and environmental factors on seal haul-out behaviour. Data from 2004 to 2007 were analysed to describe long-term temporal variation in seal abundance at two haul-out sites. A total of 592 sightings were made along the coast of Cornwall and the Isles of Scilly over the four-day census period; 476 of these sightings (80.4%) were recorded at six main haul-out sites. The highest proportion of seals was observed at three haul-out areas on the Isles of Scilly. In Cornwall, seals were observed in higher numbers on the north coast, where the three largest mainland haul-out sites were documented, than on the south coast. At one key haul-out site in Cornwall, a distinct seasonal pattern was evident in data collected between 2004 and 2007, with higher numbers of seals present during the moulting and breeding seasons than over the summer months. There was considerable inter-annual variability in peak seal abundance, during the moulting season, at this site. There was no significant variation in haul-out behaviour with tidal state at this site, although haul-out counts were generally highest at mid-ebb tides. Data on seal abundance, distribution and haul-out behaviour may aid the designation of Special Areas of Conservation for the protection of grey seals in Cornwall and the Isles of Scilly.

Foraging-Related Activity of Bald Eagles at a Washington Seabird Colony and Seal Rookery

Abstract From 1980 to 1998, Washington's Bald Eagle (Haliaeetus leucocephalus) population increased at an annual rate of 10%. Over the same time period, foraging activity of Bald Eagles at marine bird breeding colonies also increased. From 1993 to 2008, we observed foraging-related behavior of Bald Eagles on Violet Point, Protection Island. This island hosts more than 70% of the breeding seabirds in Washington's inner seaways and serves as an important rookery for harbor seals (Phoca vitulina). We found that (1) eagles landed more frequently in seal haul-out (beach) areas than in gull-nesting (non-beach) areas of Violet Point, and that subadult eagles were more likely to land in gull-nesting areas than were adult eagles; (2) the presence of eagles on the beach was positively related to the presence of harbor seals on the beach; (3) a greater-than-expected number of adult eagles as compared with subadult eagles preyed on gull chicks; (4) subadult and adult eagles that attempted prey capture were equally su...

Long-distance movements of harbour seals (Phoca vitulina) from a seasonally ice-covered area, the St. Lawrence River estuary, Canada

Previous studies of harbour seal (Phoca vitulina L., 1758) movements indicate that this species is relatively sedentary throughout the year. However, few investigations have examined their movements and seasonal distribution patterns in ice-covered areas. This study used spatial analysis of ice data and movement data from harbour seals collected via satellite (n = 7) and VHF radiotelemetry (n = 15) to explore this species' spatial use patterns in a seasonally ice-covered region, the St. Lawrence River estuary, Canada. When solid ice formed within the bays of the estuary, four of the seven satellite-tagged animals (all adult males) left their summer haul-out areas, migrating 266 ± 202 km (range 65–520 km) to over-wintering sites. The seals exhibited preference for areas of light to intermediate ice conditions during the winter months; at least six of the seven seals occupied areas with lighter ice conditions than those that prevailed generally in the study area. Evidence of high abundance of potential prey for harbour seals in the estuary during winter suggests that reduced availability of adequate food resources is not the primary factor which influences the movement and distribution patterns of harbour seals. Movement patterns observed during the ice-free period concur with previously reported harbour seal behaviour; the seals remained near the coast (<6.1–11.0 km from shore) in shallow water areas (<50 m deep in 100% VHF and 90% SLTDRs (satellite-linked time-depth recorders)) and travelled only short distances (15–45 km) from capture sites. None of the VHF- or satellite-tagged seals crossed the 350 m deep Laurentian channel, which suggests that this deep body of water might represent a physical barrier to this coastal population.

Haulout behaviour of High Arctic harbour seals ( Phoca vitulina vitulina ) in Svalbard, Norway

Haulout behaviour of harbour seals, living at the northern limit of their distributional range on Svalbard, Norway, was investigated from June to August 2000 using a combination of low-tide counts performed during boat surveys, hourly counts through 12- or 24-h cycles at specific haulout sites, and telemetric data from 37 VHF-tagged seals. The largest aggregations of seals were found at Skarvnes, a site where numbers increased steadily through the summer, reaching a peak during the moulting period in August. At this site, season/date, time of day, tidal state and temperature all significantly influenced the number of animals ashore. At the second most frequented haulout site, at Soroya, season/date, time of day, temperature and cloud cover significantly affected the number of seals using the site. Pups were found predominantly at Soroya (7.8 pups±6.3 SD, N=53 counts); they were less common at Skarvnes (1.0 pups±0.2 SD, N=95 counts). Haulout patterns varied by age and sex class in accordance with the demands of lactation, mating and moult. Our limited data on mother-pup pairs suggest that they are closely associated during the nursing period, spending approximately 50% of their time hauled out together. Post lactation, most adult females left haulout areas for periods of up to several days. The haulout behaviour of adult males suggested that they adjusted their behaviour to follow female distribution and movement patterns during the breeding period. Most juveniles and adults of both sexes stayed ashore for prolonged periods during moulting, which took place first in juveniles, then in adult females and finally in adult males. The results of our study show that the basic haulout behaviour patterns of harbour seals at Svalbard are similar to this species’ behaviour at lower latitudes.

A top–down, multidisciplinary study of the structure and function of the pack-ice ecosystem in the eastern Ross Sea, Antarctica

We used a top–down, multidisciplinary approach to examine the physical and biological environment of the pack ice of the eastern Ross Sea (approximately 125–170°W) during the austral summer of 1999/2000 from RVIB Nathaniel B. Palmer and its ship-based helicopters. The approach focused on pack-ice seals while incorporating studies of biotic and abiotic factors that may influence the distribution and abundances of these apex predators in the Ross Sea to yield a holistic understanding of the structure and function of this complex, large marine ecosystem. This research represented the US component of the international Antarctic Pack Ice Seal (APIS) program, which was designed to document the circumpolar distribution and abundance of Antarctic pack-ice seals. The eastern Ross Sea is one of the two major areas in the Southern Ocean where substantial pack ice exists throughout summer. We found that vast multi-year ice floes (>20 km diameter) and smaller floes north of the shore-fast ice front provide a unique habitat for seals and penguins (apex predators) to forage and haul out while molting in late summer. Farther north, more Ross seals were observed than in any previous surveys in the circumpolar pack ice, perhaps because they are attracted to the area in summer to molt on large stable first-year ice floes. Extensive fast ice along the coastline and drifting pack ice in the shelf–slope boundary zone provided haul-out areas for seals and penguins with access to feeding in the coastal shelf region. Distributions of potential prey for seals and penguins varied over the study area, as determined by nets, acoustics, and diving surveys. Antarctic krill (Euphausia superba) were found throughout the survey region, overlapping the distributions of two smaller species, Thysanoëssa macrura (primarily off-shelf) and E. crystallorophias (primarily found on-shelf). In some locations, E. superba occurred at high densities underneath ice floes, where they foraged on the sea-ice microbial community. Two general fish communities, oceanic and shelf, were distinguished. Off-shelf fishes were members of the classic oceanic midwater fish fauna, whereas on-shelf fishes were Antarctic endemics. The abundance of pelagic fishes was relatively low throughout the study area compared with other Southern Ocean ecosystems. In contrast, benthic fish biomass and diversity on-shelf were high (41 species, 6 families). Hydroacoustic analyses indicated that densities of potential prey were highest in the coastal shelf region where large aggregations of euphausiids (primarily E. crystallorophias) and individual juvenile Antarctic silverfish (Pleuragramma antarcticum) occurred.

Pup development and timing of pupping in harbour seals (Phoca vitulina) in the St. Lawrence River estuary, Canada

Surveys to estimate the daily growth rate of harbour seal (Phoca vitulina) pups from birth to weaning and to determine the distribution of births were carried out from early May to late August 1998, 1999, and 2000 at two haulout areas in the St. Lawrence River estuary, Canada. Pups gained mass at a rate of 0.544 kg/day (standard error (SE) = 0.141, range 0.118–0.875 kg/day, N = 110). Births began between 12 and 17 May. The median dates of birth were 28 May (95% confidence interval (CI), 27–30 May) in 1998, 25 May (95% CI, 24–28 May) in 1999, and 26 May (95% CI, 24–27 May) in 2000. Births followed a normal distribution in 2000, but late pupping led to an extended tail in both 1998 and 1999. Pupping occurred at the same time in the St. Lawrence River estuary as at Sable Island, a colony located 600 km to the south, but occurred earlier than predicted by the relationship of Temte et al. (1991). The estimated median dates of weaning were 1 July (95% CI, 20 June to 12 July) in 1998, 30 June (95% CI, 19 June to 11 July) in 1999, and 26 June (95% CI, 20 June to 2 July) in 2000. Pooling years resulted in an average lactation duration of 34 days (SE = 1.8).

MAPPING THE DISTRIBUTION OF PROTECTED AND VALUABLE, OIL-SENSITIVE COASTAL FISH AND WILDLIFE

ABSTRACT An approach has been developed to produce a map series that displays known, pertinent information concerning the distribution, seasonality, and habits of protected and valuable coastal fish and wildlife that are sensitive to oil spill impacts. This involves a compilation of all literature on the protected and oil-sensitive fish and wildlife for a region. Distribution and abundance data are then evaluated for each species, and all point localities, aggregations, and home ranges are shown on maps. These data include marine mammal haul-out and pupping areas, terrestrial mammal feeding areas, marine bird rookeries, salmon and herring streams and intertidal spawning sites, marine turtle nesting beaches, and intertidal shellfish beds. Aerial surveys are then made of the sites located during the literature search to verify the mapped literature data, as well as to add new wildlife localities. Information on the species, their distribution and ecological type, their habits, and seasonality is color coded on the maps. This approach has been applied to coastal areas in Shelikof Strait (Alaska), Puget Sound (Washington), southeastern Florida, and Massachusetts, and is underway for South Carolina and Norton Sound (Alaska).

Mass Natural Mortality of Walruses (<i>Odobenus rosmarus</i>) at St. Lawrence Island, Bering Sea, Autumn 1978

In October-November 1978, several thousand living walruses came ashore in at least four localities on St. Lawrence Island where they had not been present before in this century. They hauled out also at two other sites which they have occupied annually but in much smaller numbers. At least 537 animals died on the haulout areas at that time, and approximately 400 other carcasses washed ashore from various sources. This was by far the greatest mortality of walruses ever recorded in an event of this kind. At least 15% of the carcasses on the haulouts were aborted fetuses, 24% were 5-6-month-old calves; the others were older animals ranging in age from 1 to 37 years old. About three-fourths of the latter on the haulouts were females; in the non-haulouts areas the sex ratio was about 1:1. Forty of the best preserved carcasses were examined by necropsy. The principal cause of death was identified as extreme torsion of the cervical spine, with resultant cerebrospinal hemorrhage, apparently due to traumatization by other walruses. Nearly all of the dead were extremely lean, having less than half as much subcutaneous fat as healthy animals examined in previous years.

Sea Lions Wintering Along the Outer Coast of Vancouver Island

Aerial counts conducted on the north and west coasts of Vancouver Island during four periods in the 1970–71 winter indicated that more than 1980 sea lions used a total of 15 haul-out areas. Evidence is presented indicating that many winter haul-out areas are often deserted in summer.