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The degradation of coastal habitats, particularly coral reefs raise risks by increasing the exposure of coastal communities to flooding hazards. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered indecision making.

The problems and impacts of marine debris on marine animals and on human activity in the oceans has been reviewed and discussed extensively by Shomura and Yoshida (1985). The purpose of this report is for guidance in development of future surveys to determine the amount, density, composition and spatial-temporal distribution of surface marine debris in the North Pacific ocean particularly the Gulf of Alaska and Bering Sea.

Marine protected areas (MPA) are conservation tools that are increasingly implemented, with growing national commitments for MPA expansion. Perhaps the greatest challenge to expanded use of MPAs is the perceived trade off- between protection and food production.

Many neglected tropical zoonotic pathogens are maintained by introduced mammals, and on islands the most common introduced species are rodents, cats, and dogs. Management of introduced mammals, including control or eradication of feral populations, which is frequently done for ecological restoration, could also reduce or eliminate the pathogens these animals carry. Understanding the burden of these zoonotic diseases is crucial for quantifying the potential public health benefits of introduced mammal management. However, epidemiological data are only available from a small subset of islands where these introduced mammals co-occur with people. We examined socioeconomic and climatic variables as predictors for disease burdens of angiostrongyliasis, leptospirosis, toxoplasmosis, toxocariasis, and rabies from 57 islands or island countries. We found strong correlates of disease burden for leptospirosis, Toxoplasma gondii infection, angiostrongyliasis, and toxocariasis with more than 50% of the variance explained, and an average of 57% (range = 32–95%) predictive accuracy on out-of-sample data. We used these relationships to provide estimates of leptospirosis incidence and T. gondii seroprevalence infection on islands where nonnative rodents and cats are present. These predicted estimates of disease burden could be used in an initial assessment of whether the costs of managing introduced mammal reservoirs might be less than the costs of perpetual treatment of these diseases on islands.

Invasive rats have colonized most of the islands of the world, resulting in strong negative impacts on native biodiversity and on ecosystem functions. As prolific omnivores, invasive rats can cause local extirpation of a wide range of native species, with cascading consequences that can reshape communities and ecosystems. Eradication of rats on islands is now becoming a widespread approach to restore ecosystems, and many native island species showstrong numerical responses to rat eradication. However, the effect of rat eradication on other consumers can extend beyond direct numerical effects, to changes in behavior, dietary composition, and other ecological parameters. These behavioral and trophic effectsmay have strong cascading impacts on the ecology of restored ecosystems, but they have rarely been examined. In this study, we explore how rat eradication has affected the trophic ecology of native land crab communities. Using stable isotope analysis of rats and crabs, we demonstrate that the diet or trophic position of most crabs changed subsequent to rat eradication. Combined with the numerical recovery of two carnivorous land crab species (Geograpsus spp.), this led to a dramatic widening of the crab trophic niche following rat eradication. Given the established importance of land crabs in structuring island communities, particularly plants, this suggests an unappreciated mechanism by which rat eradication may alter island ecology. This study also demonstrates the potential for stable isotope analysis as a complementary monitoring tool to traditional techniques, with the potential to provide more nuanced assessments of the community- and ecosystem-wide effects of restoration.

Human impact on biodiversity usually is measured by reduction in species abundance or richness. Just as important, but much more difficult to discern, is the anthropogenic elimination of ecological interactions. Here we report on the persistence of a long ecological interaction chain linking diverse food webs and habitats in the near-pristine portions of a remote Pacific atoll. Using biogeochemical assays, animal tracking, and field surveys we show that seabirds roosting on native trees fertilize soils, increasing coastal nutrients and the abundance of plankton, thus attracting manta rays to native forest coastlines. Partnered observations conducted in regions of this atoll where native trees have been replaced by human propagated palms reveal that this complex interaction chain linking trees to mantas readily breaks down. Taken together these findings provide a compelling example of how anthropogenic disturbance may be contributing to widespread reductions in ecological interaction chain length, thereby isolating and simplifying ecosystems.

When coastal buildings or roads are threatened, the typical response is to harden the coast with a seawall. Seawalls run parallel to the beach and can be built of concrete, wood, steel, or boulders. Seawalls are also called bulkheads or revetments; the distinction is mainly a matter of purpose. They are designed to halt shoreline erosion caused primarily by wave action. If seawalls are maintained, they may temporarily hold back the ocean from encroaching on shoreline development. In spite of their ability to hold back the ocean, when waves hit a seawall, the waves are reflected back out to sea, taking beach sand with them and eventually causing the beach to disappear. Moreover, seawalls can cause increased erosion at the ends of the seawall on an adjacent beach that is not walled. Alternatives to seawalls exist, such as beach nourishment and managed retreat. Making coastal land use decisions that ensure a seawall will not be needed in the future to protect structures, however, is the most prudent coastal management solution. This can be accomplished by establishing setback lines and conducting managed retreat of structures that are threatened by shoreline erosion before the situation worsens, or structures that have the potential for being threatened in the future. Regional case studies are presented to illustrate.

Recent increases in observations of Acanthaster planci in lagoons on the North Coast of Moorea, French Polynesia have prompted a population survey on both the outer reef slope and inside the lagoon. Nine transects were performed along the coast between (S 17°28.971’, W 149°54.130’; & S 17°28.65’, W 149°50.75’). A. planci population was found to be very patchy. Timed surveys using SCUBA showed the population of stars on the outer reef slope to be concentrated in a depth range between 15-30m, with a high concentration 40/Ha near one of our transects. Measured density transects were performed at this site and the density was shown to be 4,000/km2, higher than the 6/km2 baseline for the western Pacific. Transects inside the lagoon were between 120-220/km2 for three areas surveyed. The overall A. planci population appears slightly higher than normal when sampling difficulty, and error margins are factored in.

Through the Pohnpei Rat Eradication Research and Demonstration Project, The Conservation: Society of Pohnpei (CSP), Island Conservation (IC), and the Pacific Invasives Initiative (PII) are working together to enhance the biosecurity of Pohnpei's island ecosystems, and that of other similar ecosystems throughout the Pacific. This research and demonstration project will help NGO and government conservation organizations develop the capacity to plan. fund, and implement subsequent: rat eradications in threatened island ecosystems. CSP, IC, and PII also partnered with the following organizations to cany out this pioneering conservation project: the Pacific Invasives Learning Network, The Nature Conservancy, the Pohnpei State Government, the Micronesia Conservation Trust, Micronesians in Island Conservation, local government officials, and local landowners.