Predicting climate change impacts on polar bear litter size

Predicting the ecological impacts of climate warming is critical for species conservation. Incorporating future warming into population models, however, is challenging because reproduction and survival cannot be measured for yet unobserved environmental conditions. In this study, we use mechanistic energy budget models and data obtainable under current conditions to predict polar bear litter size under future conditions. In western Hudson Bay, we predict climate warming-induced litter size declines that jeopardize population viability: ∼28% of pregnant females failed to reproduce for energetic reasons during the early 1990s, but 40–73% could fail if spring sea ice break-up occurs 1 month earlier than during the 1990s, and 55–100% if break-up occurs 2 months earlier. Simultaneously, mean litter size would decrease by 22–67% and 44–100%, respectively. The expected timeline for these declines varies with climate-model-specific sea ice predictions. Similar litter size declines may occur in over one-third of the global polar bear population

A bald encounter : hairless southern sea lion at the Falkland Islands

A hairless adult male southern sea lion (Otaria flavescens) was sighted at Sea Lion Island, Falkland Islands, on the 14th of August 2009. The sea lion was observed on several further occasions and was defending a small harem consisting of four females. To our knowledge, this is the first report of an apparently healthy sea lion being entirely hairless with the exception of vibrissae on the muzzle

Skin histology and its role in heat dissipation in three pinniped species

<p>Abstract</p> <p>Background</p> <p>Pinnipeds have a thick blubber layer and may have difficulty maintaining their body temperature during hot weather when on land. The skin is the main thermoregulatory conduit which emits excessive body heat.</p> <p>Methods</p> <p>Thorough evaluation of the skin histology in three pinniped species; the California sea lion-<it>Zalophus californianus</it>, the Pacific harbor seal-<it>Phoca vitulina richardsi</it>, and the Northern elephant seal-<it>Mirounga angustirostris</it>, was conducted to identify the presence, location and distribution of skin structures which contribute to thermoregulation. These structures included hair, adipose tissue, sweat glands, vasculature, and arteriovenous anastomoses (AVA). Thermal imaging was performed on live animals of the same species to correlate histological findings with thermal emission of the skin.</p> <p>Results</p> <p>The presence and distribution of skin structures directly relates to emissivity of the skin in all three species. Emissivity of skin in phocids (Pacific harbor and Northern elephant seal<it>s</it>) follows a different pattern than skin in otariids (California sea lions). The flipper skin in phocids tends to be the most emissive region during hot weather and least emissive during cold weather. On the contrary in otariids, skin of the entire body has a tendency to be emissive during both hot and cold weather.</p> <p>Conclusion</p> <p>Heat dissipation of the skin directly relates to the presence and distribution of skin structures in all three species. Different skin thermal dissipation patterns were observed in phocid versus otariid seals. Observed thermal patterns can be used for proper understanding of optimum thermal needs of seals housed in research facilities, rescue centers and zoo exhibits.</p

Preparing for The Inevitable: Ecological and Indigenous Community Impacts of Oil Spill-Related Mortality in The United States’ Arctic Marine Ecosystem

While hydrocarbon exploration and extraction in the Arctic ebb and flow, reduced sea ice has opened new travel routes across the Arctic. The opening of the Northwest Passage has allowed larger ships (including oil tankers) and higher traffic into remote regions. More ice loss is expected in the future. With this comes the potential for hydrocarbon spills. To quantify the ecosystem impacts of a spill in the Alaska North Slope region, an Ecospace model using the Ecopath with Ecosim software was developed. We highlight the impacts of four potential hydrocarbon contamination scenarios: a subsurface crude oil pipeline release, a surface platform oil spill, a surface cruise ship diesel spill, and a surface tanker oil spill. Hydrocarbon contamination was modeled using SIMAP (Spill Impact Model Analysis Package), which was developed from the oil fate sub-model in the Natural Resource Damage Assessment Model for the US Department of the Interior and under the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA). Spatial-temporal SIMAP results were coupled to the Ecospace model. We show that in all four hydrocarbon contamination scenarios, there are spatial changes in harvested species resulting in long-term declines in harvest levels for the communities within the model area (Nuiqsut, Kaktovik, and Barrow Alaska), depending on the severity of the scenario. Responses to hydrocarbon events are likely to be slow in the Arctic, limited by the ice-free season. We highlight this area for scenario testing as ecological impacts are also an issue of food security to the local communities and human health issue