Montague Island Research Articles

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Observations of Humpback Whales (<I>Megaptera novaeangliae</I>) Feeding During Their Southward Migration Along the Coast of Southeastern New South Wales, Australia: Identification of a Possible Supplemental Feeding Ground

There is anecdotal evidence of humpback whales (Megaptera novaeangliae) feeding in southeastern New South Wales (NSW) waters on their southward migration (Paterson, 1987). This paper reports the frequency of feeding whales observed from waters just north of Narooma (36° 5' S, 149° 55' E) to just south of Eden (37° 16' S, 150° 17' E). Observations were made from commercial whalewatching vessels from late September to early November in 2002, 2003, and 2005; and from two land-based whale-watching sites, Montague Island (36° 15' S, 150° 14' E) and Green Cape (37° 16' S, 150° 03' E), in the same period for 2002, 2003, 2004, and 2005. Feeding pods were seen on 24.5% of all whale-watching trips and during 14% of all observations made from land-based sites. Whales fed on schools of small pelagic fish as well as the coastal krill species (Nyctiphanes australis). The number of feeding pods observed in 2005 was more than four times that observed in the two previous years and most likely was due to the warmer current systems operating in the area in 2005. All observations from land-based sites were made when no vessels were in the vicinity of the focal pod. Feeding behaviour did not alter in the presence or absence of vessels; however, the time between feeding lunges increased when the movements of the vessel were not consistent with NSW whale-watching regulations and when more than one vessel was present. While many of the reports of humpback whales feeding in mid- to low-latitude waters in both the southern and northern hemisphere classify this behaviour as a rare opportunistic event, it is probable that southeastern NSW is a significant supplemental feeding ground for migrating whales, especially when oceanographic conditions are optimal for food productivity.

Shearwater colonies on Montagu Island; are they being affected by encroaching Kikuyu Grass?

Shearwater colonies on Montagu Island; are they being affected by encroaching Kikuyu Grass?

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

PUP PRODUCTION AND POPULATION TRENDS OF THE AUSTRALIAN FUR SEAL (ARCTOCEPHALUS PUSILLUS DORIFERUS)

We estimated the number of live Australian fur seal pups using capture-markresights, direct ground counts, or aerial photography at all breeding sites following the pupping season of November-December 2002. Pups were recorded at 17 locations; nine previously known colony sites, one newly recognized colony and seven haul-out sites where pups are occasionally born. In order of size, the colonies were Lady Julia Percy Island (5,899 pups), Seal Rocks (4,882), The Skerries (2,486), Judgment Rocks (2,427), Kanowna Island (2,301), Moriarty Rocks (1,007), Reid Rocks (384), West Moncoeur Island (257), and Tenth Island (124). The newly recognized site was Rag Island, in the Cliffy Group, where we recorded 30 pups. We also recorded pups at the following haul-out sites: Cape Bridge-water (7 pups), Bull Rock (7), Wright Rock (5), Twin Islet (1), The Friars (1), He des Phoques (1), and Montague Island (1). In total, we estimate there were 19,819 (SE = 163) live pups at the time of the counts. We discuss trends in pup numbers and derive current population estimates for the Australian fur seal.

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

First recorded eruption of Mount Belinda volcano (Montagu Island), South Sandwich Islands

The MODVOLC satellite monitoring system has revealed the first recorded eruption of Mount Belinda volcano, on Montagu Island in the remote South Sandwich Islands. Here we present some initial qualitative observations gleaned from a collection of satellite imagery covering the eruption, including MODIS, Landsat 7 ETM+, ASTER, and RADARSAT-1 data. MODVOLC thermal alerts indicate that the eruption started sometime between 12 September and 20 October 2001, with low-intensity subaerial explosive activity from the island’s summit peak, Mount Belinda. By January 2002 a small lava flow had been emplaced near the summit, and activity subsequently increased to some of the highest observed levels in August 2002. Observations from passing ships in February and March 2003 provided the first visual confirmation of the eruption. ASTER images obtained in August 2003 show that the eruption at Mount Belinda entered a new phase around this time, with fresh lava effusion into the surrounding icefield. MODIS radiance trends also suggest that the overall activity level increased significantly after July 2003. Thermal anomalies continued to be observed in MODIS imagery in early 2004, indicating a prolonged low-intensity eruption and the likely establishment of a persistent summit lava lake, similar to that observed on neighboring Saunders Island in 2001. Our new observations also indicate that lava lake activity continues on Saunders Island.

WINTER PHILOPATRY OF HARLEQUIN DUCKS IN PRINCE WILLIAM SOUND, ALASKA

Abstract We used capture-mark-recapture data to assess winter philopatry by Harlequin Ducks (Histrionicus histrionicus) in Prince William Sound, Alaska, during winters 1995–1997 and 2000–2001. Philopatry was quantified using homing rates, which were estimated as the proportion of birds recaptured at their original site out of all recaptured birds. Between-year homing rates of 0.95 (95% CI: 0.87–1.00) and 1.00 (0.92–1.00) were estimated for females and males, respectively, at three locations on Montague Island. Similar homing rates were measured in western Prince William Sound, where estimates were 0.92 (0.80–0.98) for females and 0.96 (0.79–1.00) for males, with a scale of detected movements for all recapture birds ranging from 3–52 km. Our results indicate that wintering aggregations may be demographically independent at a much finer spatial scale than genetic data indicate, and that conservation efforts should recognize this degree of demographic separation among population segments. Filopatria Invernal...

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Population size, breeding habitat and nest site distribution of little penguins (Eudyptula minor) on Montague Island, New South Wales

The distribution of little penguin nest sites on Montague Island, New South Wales, was examined in relation to vegetation type, distance to landing sites and local footpaths. Nest site density was negatively correlated with distance to landing sites and positively correlated with distance to footpaths. The latter may be related to disturbance. Comparisons with the transect data of previous years showed a significant shift in nest distribution away from areas dominated by dense kikuyu grass. In October 2000, the little penguin population on Montague Island was estimated at 5000 breeding pairs. However, repeat surveys in November and December showed that single counts underestimate the actual size of the breeding population. This study has demonstrated the value of line transects to examine the relationship between little penguins and their breeding habitat. Transect surveys on Montague Island should continue in future years to monitor the effects of ongoing vegetation changes on nest distribution and population size.

Report on Montagu Island (United Kingdom)

Report on Montagu Island (United Kingdom)

Food limitation and the recovery of sea otters following the 'Exxon Valdez' oil spill

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 241:255-270 (2002) - doi:10.3354/meps241255 Food limitation and the recovery of sea otters following the 'Exxon Valdez' oil spill Thomas A. Dean1,*, James L. Bodkin2, Allan K. Fukuyama3, Stephen C. Jewett4, Daniel H. Monson2, Charles E. O¹Clair5, Glenn R. VanBlaricom3 1Coastal Resources Associates, 5674 El Camino Real, Suite M, Carlsbad, California 92008, USA 2Biological Resources Division, US Geological Survey, Alaska Biological Science Center, 1011 East Tudor Road, Anchorage, Alaska 99503, USA 3Washington Cooperative Fish and Wildlife Research Unit, Biological Resources Division, US Geological Survey, School of Aquatic and Fishery Sciences, PO Box 355020, University of Washington, Seattle, Washington 98195-5020, USA 4Institute of Marine Science, University of Alaska Fairbanks, Fairbanks, Alaska 99775-7220, USA 5National Marine Fisheries Service, Auke Bay Laboratory, 11305 Glacier Highway, Juneau, Alaska 99801, USA *E-mail: coastal_resources@sbcglobal.net ABSTRACT: We examined the potential role of food limitation in constraining the recovery of sea otters Enhydra lutris in Prince William Sound, Alaska, following the 'Exxon Valdez' oil spill. The spill resulted in the removal of a large number of sea otters in 1989, and as of 1998, the portion of the population in the heavily oiled northern Knight Island region had not fully recovered. Between 1996 and 1998, prey consumption rate was higher and the condition of sea otters was better at northern Knight Island than in an unoiled area of the sound (Montague Island). Estimates of prey energy available per unit mass of sea otter were about 4 times higher at Knight than Montague Island, albeit not significantly different between the 2 areas. Over this same period, the number of sea otters remained constant at northern Knight Island but increased at Montague Island. These data suggest that food was at least as abundant at Knight than at Montague Island, and that recovery of sea otters via intrinsic population growth was limited by factors other than food. However, the availability of food, the prey consumption rate, and the condition of sea otters were all much lower at both Knight and Montague Islands than in areas newly occupied by sea otters where the population growth rate was near the theoretical maximum. It is possible that the relatively short supply of food (compared to areas where sea otter population growth rate was high) may have inhibited immigration or interacted with other factors (e.g. oil-induced mortality or predation) to restrict sea otter population growth. Nonetheless, these data suggest that impacts of anthropogenic disturbances on large, often food-limited vertebrate predators can persist in spite of the availability of food resources that are sufficient for intrinsic population growth. KEY WORDS: Prince William Sound · Alaska · Predator-prey interaction · Prey availability · Prey consumption rate · Condition indices Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 241. Online publication date: October 04, 2002 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2002 Inter-Research.

Sea otter population status and the process of recovery from the 1989 'Exxon Valdez' oil spill

Sea otter Enhydra lutris populations were severely affected by the 1989 'Exxon Valdez' oil spill in western Prince William Sound, AK, and had not fully recovered by 2000. Here we present results of population surveys and incorporate findings from related studies to identify current population status and factors affecting recovery. Between 1993 and 2000, the number of sea otters in the spill-area of Prince William Sound increased by about 600 to nearly 2700. However, at Knight Island, where oil exposure and sea otter mortality in 1989 was most severe, no increase has been observed. Sea otter reproduction was not impaired, and the age and sex composition of captured otters are consistent with both intrinsic reproduction and immigration contributing to recovery. However, low resighting rates of marked otters at Knight Island compared to an unoiled reference area, and high proportions of young otters in beach cast carcasses through 1998, suggest that the lack of recovery was caused by relatively poor survival or emigration of potential recruits. Significantly higher levels of cytochrome P4501A (CYP1A), a biomarker of hydrocarbons, were found in sea otters at Knight Island from 1996 to 1998 compared to unoiled Montague Island, implicating oil effects in the lack of recovery at Knight Island. Delayed recovery does not appear to be directly related to food limitation. Although food availability was relatively low at both oiled and unoiled areas, we detected significant increases in sea otter abundance only at Montague Island, a finding inconsistent with food as a principal limiting factor. Persistent oil in habitats and prey provides a source of continued oil exposure and, combined with relatively low prey densities, suggests a potential interaction between oil and food. However, sea otters foraged more successfully at Knight Island and young females were in better condition than those at Montague Island. We conclude that progress toward recovery of sea otters in Prince William Sound is evident, but that in areas where initial oil effects were greatest, recovery may be constrained by residual spill effects, resulting from elevated mortality and emigration. It is evident that internal reproduction and immigration of juveniles has been the primary means of population recovery, as opposed to broad scale redistribution of adults from outside affected areas. The result is a recovery period protracted by long-term spill effects on survival and emigration and intrinsic limits to population growth.

Predation on Pacific herring (Clupea pallasi) spawn by birds in Prince William Sound, Alaska

AbstractWe examined bird diets in areas with Pacific herring (Clupea pallasi) spawn at northern Montague Island in Prince William Sound, Alaska. Diets of the five most abundant bird species consisted primarily of herring spawn. Using a bioenergetics model, we estimated that in spring 1994 the five‐bird species ate 857.1 metric tons (mt), representing 31% of the estimated spawn deposition. The two most numerous consumers, glaucous‐winged gull (Larus glaucescens) and mew gull (Larus canus) consumed 26% and 3%, respectively, of the estimated spawn deposition. Surf scoters (Melanitta perspicillata), surfbirds (Aphriza virgata), and black turnstone (Arenaria melanocephala) together consumed 2% of the spawn deposition. In years with low spawn biomass, such as 1994, the number of herring larvae produced could be significantly affected by normal rates of avian predation. The high consumption by gulls, shorebirds, and surf scoters underscores the importance of herring spawn in the annual cycle of these species and requires further investigation.