Hurricanes Katrina and Rita showed the vulnerability of coastal communities and how human activities that caused deterioration of the Mississippi Deltaic Plain (MDP) exacerbated this vulnerability. The MDP formed by dynamic interactions between river and coast at various temporal and spatial scales, and human activity has reduced these interactions at all scales. Restoration efforts aim to re-establish this dynamic interaction, with emphasis on reconnecting the river to the deltaic plain. Science must guide MDP restoration, which will provide insights into delta restoration elsewhere and generally into coasts facing climate change in times of resource scarcity.

Nest predation may influence population dynamics of birds on the Arctic Coastal Plain (ACP) of Alaska, USA. Anthropogenic development on the ACP is increasing, which may attract nest predators by providing artificial sources of food, perches, den sites, and nest sites. Enhanced populations or concentrations of human-subsidized predators may reduce nest survival for tundra-nesting birds. In this study, we tested the hypothesis that nest survival decreases in proximity to human infrastructure. We monitored 1257 nests of 13 shorebird species and 619 nests of four passerine species at seven sites on the ACP from 2002 to 2005. Study sites were chosen to represent a range of distances to infrastructure from 100 m to 80 km. We used Cox proportional hazards regression models to evaluate the effects of background (i.e., natural) factors and infrastructure on nest survival. We documented high spatial and temporal variability in nest survival, and site and year were both included in the best background model. We did not detect an effect of human infrastructure on nest survival for shorebirds as a group. In contrast, we found evidence that risk of predation for passerine nests increased within 5 km of infrastructure. This finding provides quantitative evidence of a relationship between infrastructure and nest survival for breeding passerines on the ACP. A posteriori finer-scale analyses (within oil field sites and individual species) suggested that Red and Red-necked Phalaropes combined (Phalaropus fulicarius, P. lobatus) had lower productivity closer to infrastructure and in areas with higher abundance of subsidized predators. However, we did not detect such a relationship between infrastructure and nest survival for Semipalmated and Pectoral Sandpipers (Calidris pusilla, C. melanotos), the two most abundant shorebirds. High variability in environmental conditions, nest survival, and predator numbers between sites and years may have contributed to these inconsistent results. We recommend targeted management actions to minimize anthropogenic effects and suggest new research needed on this issue as expanding development is planned for the ACP of Alaska. In particular, we recommend research on demography of key predators and their importance with respect to nest survival, and experimental studies that better address challenges posed by high natural variability.

The westward migration of bowhead whales (Bering Sea stock) was studied during autumn 2001-04 as part of an oil industry monitoring program. An array of Directional Autonomous Seafloor Acoustic Recorders (DASARs) was deployed northeast of the Northstar oil production island near Prudhoe Bay, Alaska. Underwater sounds were recorded continuously for 24-35 days per year, mainly in September. More than 130 000 bowhead calls were detected, and the directional capability of DASARs allowed triangulation of whale position for ~93 500 calls. The migration pathway was closer to shore in 2003-04 than in 2001-02. Calls were clumped in space and time, and there was significantly more calling at night than by day. From 65% to 82% of calls were simple frequency-modulated calls, and the percentage of complex calls was positively related to the daily number of calls. No songs were detected, but in 2004 there were numerous call sequences consisting of repeated identical calls in series and generally lasting up to a few minutes. The DASAR methodology provides detailed information on the temporal and spatial distribution of calling whales and on their acoustic repertoire.

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The arctic cisco (Coregonus autumnalis), known regionally by its Inupiat name qaaqtaq, is the principal target of fall subsistence and commercial fisheries that operate in the Colville River along the Alaskan Beaufort Sea. Our conceptual model of the fisheries is based on more than two decades of continuous scientific study conducted in conjunction with oil industry growth on the North Slope. It expands upon an existing body of published literature to discuss additional factors that affect fishery yields. Long-term data indicate that arctic cisco spawn in Canada's Mackenzie River system. Young-of-the-year are transported westward into Alaska by wind-driven coastal currents. Arctic cisco successfully recruit to Alaska's Colville River when summer winds blow from the east with an average speed greater than 5 km/h. The successful recruitment of these young arctic cisco to central Alaska is a prerequisite for the eventual entry of harvestable five-to eight-year-old fish into the region's subsistence and commercial fisheries. Recruitment into the fisheries also requires that fish survive in central Alaska for the five to six years it takes for them to grow to a harvestable size. Once these fish are recruited into the fisheries, annual harvests are strongly dependent on salinity conditions within the fishing grounds. Although fishing mortality occurs, the loss of older fish from the region is attributed largely to the emigration of sexually mature fish back to Canada.

This paper describes the results of a revegetation experiment involving partial removal of gravel fill followed by various revegetation treatments on five sites in the Prudhoe Bay Oilfield on Alaska's Arctic Coastal Plain. Gravel fill was removed to a residual thickness of approximately 25 cm. Revegetation treatments were transplanted tundra plugs and fertilizer; seeding with indigenous graminoids and fertilizer; seeding with native-grass cultivars and fertilizer; fertilizer only; and no treatment. We monitored surface stability, soil characteristics, and vegetation response from 1990 to 2003. Thaw settlement of 17-40 cm occurred over most areas (with .1 m over areas with ice wedges) between 1990 and 1997; sites had mostly stabilized by 2003. Soil properties important for plant growth generally were poor. The establishment of vegetation dominated by indigenous species was similar when adding only fertilizer as compared to also adding plant materials. Although total live vascular cover was similar among fertilized, tundra-plug transplant, and indigenous graminoid seed treatments (26.1-38.3%), species richness was highest for the indigenous graminoid seed and tundra-plug transplant treatments. The results from this study will drive decisions about planting and fertilization schemes for future North Slope rehabilitation projects.

ABSTRACT. We studied movement rates and the general flight behavior of bird flocks seen on radar and recorded visually at Northstar Island, Arctic Alaska, from 13 to 27 September 2002. Most of this period (13 -19 and 21 -27 September) had no gas-flaring events, but a major gas-flaring event occurred on the night of 20 September. Movement rates of targets on radar and of bird flocks recorded visually in the first ~50% -60% of the night were much lower during the non-flaring period than during the night of flaring, whereas rates in the last ~40% -50% of the night were similar in all periods. The general flight behavior of birds also differed significantly, with higher percentages of both radar targets and bird flocks exhibiting straight-line (directional) flight behaviors during the non-flaring periods and higher percentages of radar targets and bird flocks exhibiting non-straight-line (erratic and circling) flight behaviors during the gas-flaring period. During the night of gas flaring, the bright illumination appeared to have an effect only after sunset, when flocks of birds circled the island after being drawn in from what appeared to be a substantial distance from the island. On both radar and visual sampling, the number of bird flocks approaching the island declined over the evening, and the attractiveness of the light from flaring appeared to decline. The visibility of the moon appeared to have little effect on the behavior of birds. Because illumination from extensive gas-flaring is such a strong attractant to migrating birds and because most bird flocks fly at low altitudes over the water, flaring booms on coastal and offshore oil-production platforms in Arctic Alaska should be positioned higher than the mean flight altitudes of migrating birds to reduce the chances of incineration.Key words: Alaska; behavior; Clangula; collision; eider; gas flaring; gull; light attraction; loon; migration; sea duck; shorebird; Somateria RÉSUMÉ. Nous avons étudié les taux de déplacement et le comportement de vol général des troupeaux d'oiseaux captés par radar ou consignés visuellement à l'île Northstar, dans l'Alaska de l'Arctique, du 13 au 27 septembre 2002. Pendant presque toute cette période (du 13 au 19 et du 21 au 27 septembre), il n'y a pas eu de brûlage de gaz à la torche, mais la nuit du 20 septembre, il y a eu un important brûlage de gaz à la torche. Les taux de déplacement des cibles radar et des troupeaux d'oiseaux consignés visuellement pendant la première tranche d'environ 50 % à 60 % de la nuit étaient beaucoup moins élevés pendant la période où il n'y avait pas de brûlage à la torche que pendant la nuit où il y a eu brûlage à la torche, tandis que pendant la deuxième tranche d'environ 40 % à 50 % de la nuit, les taux de déplacement étaient semblables pendant toutes les périodes. Le comportement de vol général des oiseaux a également affiché une différence considérable. De plus grands pourcentages de cibles radar et de troupeaux d'oiseaux adoptaient un comportement de vol rectiligne (direct) pendant les péri...

Potential responses of marine mammals to anthropogenic underwater sound are usually assessed by researchers and regulators on the basis of exposure to a single, relatively loud sound source. However, marine mammals typically receive sounds from multiple, dynamic sources. We developed a method to aggregate modeled sounds from multiple sources and estimate the sound levels received by individuals. To illustrate the method, we modeled the sound fields of 9 sources associated with oil development and estimated the sound received over 47 d by a population of 10 000 simulated bowhead whales Balaena mysticetus on their annual migration through the Alaskan Beaufort Sea. Empirical data were sufficient to parameterize simulations of the distribution of individual whales over time and their range of movement patterns. We ran 2 simulations to estimate the sound exposure history and distances traveled by bowhead whales: one in which they could change their movement paths (avert) in response to set levels of sound and one in which they could not avert. When animals could not avert, about 2% of the simulated population was exposed to root mean square (rms) sound pressure levels (SPL) ≥180 dB re 1 µPa, a level that regulators in the U.S. often associate with injury. When animals could avert from sound levels that regulators often associate with behavioral disturbance (rms SPL >160 dB re 1 µPa), <1% of the simulated population was exposed to levels associated with injury. Nevertheless, many simulated bowhead whales received sound levels considerably above ambient throughout their migration. Our method enables estimates of the aggregated level of sound to which populations are exposed over extensive areas and time periods.