Three-spined stickleback armour predicted by body size, minimum winter temperature and pH

Similar phenotypes evolve under equivalent environmental conditions through parallel evolution. Because they have repeatedly invaded and adapted to new freshwater environments, the three-spined stickleback (Gasterosteus aculeatus) offers a powerful system for understanding the agents of selection in nature that drive parallel evolution. Here we examine the ecological and environmental variables responsible for morphological variation in three-spined stickleback populations across its European range. We collected fish from 85 populations, encompassing much of the European latitudinal range of the species and including lowland rivers and lakes, coastal lagoons, and moorland ponds. We measured biotic and environmental variables at all sites along with morphological traits for 2,358 individuals. Using an information theory approach, we identified body size, minimum average winter temperature and pH as primary predictors of stickleback armour evolution, challenging current hypotheses for stickleback morphological diversification and demonstrating the fundamental role played by body size and scaling in mediating responses to selection. Stickleback lateral plate phenotype represents a potentially powerful tool for monitoring change in climate variables across the northern temperate region

Ocean Acidification Risk Assessment for Alaska's Fishery Sector

The highly productive fisheries of Alaska are located in seas projected to experience strong global change, including rapid transitions in temperature and ocean acidification-driven changes in pH and other chemical parameters. Many of the marine organisms that are most intensely affected by ocean acidification(OA) contribute substantially to the state’s commercial fisheries and traditional subsistence way of life. Prior studies of OA’s potential impacts on human communities have focused only on possible direct economic losses from specific scenarios of human dependence on commercial harvests and damages to marine species. However, other economic and social impacts, such as changes in food security or livelihoods, are also likely to result from climate change. This study evaluates patterns of dependence on marine resources within Alaska that could be negatively impacted by OA and current community characteristics to assess the potential risk to the fishery sector from OA. Here, we used a risk assessment framework based on one developed by the Intergovernmental Panel on Climate Change to analyze earth-system global ocean model hindcasts and projections of ocean chemistry, fisheries harvest data, and demographic information. The fisheries examined were: shellfish, salmon and other fin fish. The final index incorporates all of these data to compare overall risk among Alaska’s federally designated census areas. The analysis showed that regions in southeast and southwest Alaska that are highly reliant on fishery harvests and have relatively lower incomes and employment alternatives likely face the highest risk from OA.Although this study is an intermediate step toward our full understanding, the results presented here show that OA merits consideration in policy planning, as it may represent another challenge to Alaskan communities, some of which are already under acute socio-economic strains.This study is part of the Synthesis of Arctic Research (SOAR) and was funded in part by the U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program through Interagency Agreement No. M11PG00034 with the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA), Office of Oceanic and Atmospheric Research (OAR), Pacific Marine Environmental Laboratory (PMEL).Ye