During the first six years of atmospheric CO 2 enrichment at the Duke Forest free-air CO 2 enrichment (FACE) experiment, an additional sink of 52 Ϯ 16 g C·m Ϫ2 ·yr Ϫ1 accumulated in the forest floor (O-horizon) of the elevated CO 2 treatment relative to the ambient CO 2 control in an aggrading loblolly pine (Pinus taeda L.) forest near Chapel Hill, North Carolina, USA. The experiment maintained an atmospheric CO 2 concentration 200 L/L above ambient levels in replicated (n ϭ 3) FACE rings throughout the six-year period. This CO 2 -induced C sink was associated with greater inputs of organic matter in litterfall and fine-root turnover. There was no evidence that microbial decomposition was altered by the elevated CO 2 treatment. Consistent with ecosystem recovery following decades of intensive agriculture, the C and N content of the mineral soil increased under both the elevated CO 2 treatment and the ambient CO 2 control during the six-year period. This increase is attributed to accumulation of plant residues derived from fine roots with relatively high turnover rates rather than accumulation of refractory or physically protected soil organic matter (SOM). The elevated CO 2 treatment produced no detectable effect on the C and N content of the bulk mineral soils or of any particulate organic matter size fraction. Because the fumigation gas was strongly depleted in 13 C, the incorporation of new C could be traced within the ecosystem. Significant decreases in ␦ 13 C of soil organic carbon (SOC) under the elevated CO 2 treatment were used to estimate the mean residence times of intra-aggregate particulate organic matter and mineral-associated organic matter as well as the annual C inputs required to produce the observed changes in ␦ 13 C. Our results indicate that forest soils such as these will not significantly mitigate anthropogenic C inputs to the atmosphere. The organic matter pools receiving large annual C inputs have short mean residence times, while those with slow turnover rates receive small annual inputs.

Paralytic shellfish poisoning (PSP) toxins are produced by dinoflagellates of the genus Alexandrium, which form blooms in the Gulf of Maine (Anderson et al., 1994). It is well known that suspension-feeding shellfish can consume toxic cells of Alexandrium spp. and accumulate PSP toxins, and that such contaminated shellfish are a threat to public health and result in economic loss to the fishing and aquaculture industries (Shumway et al., 1988). Zooplankton are also major consumers of phytoplankton, including Alexandrium spp.; the presence of PSP toxins in wild zooplankton populations of the Gulf of Maine has been documented in several studies (White, 1979, 1980, 1984). These studies have shown that mesozooplankton can attain body burdens of these toxins that are inimical or even fatal to vertebrate zooplanktivores such as clupeid fishes and whales. Larval fish are even more susceptible to adverse effects from consumption of zooplankton contaminated by PSP toxins (White et al., 1989; Robineau et al., 1991a,b). Nevertheless, research suggests that only a fraction of the total toxin from Alexandrium spp. cells acquired during feeding activity is retained in the tissues of zooplankton grazers. White conducted toxin accumulation studies with adult copepods, Acartia clausi (= A. hudsonica), and barnacle nauplii, Balanus sp. (= Semibalanus sp.) at high densities (10-13 individuals ml-1), fed Alexandrium fundyense (= Gonyaulax excavata) at ~ 3 ϫ 10 3 cells ml-1 (White, 1981). At such high densities of zooplankton and toxic cells, both grazer species accumulated high toxin levels [19-54 µg saxitoxin equivalents (µgSTXeq) g-1 wet weight] within 6 h. Toxin retained in copepod tissues, expressed as a percentage of total toxin ingested, ranged from ~10% for A. clausi to ~32% for Balanus sp. White used a modification of the Association

Citation: Nishizaki, M. T., S. Barron, and E. Carew. 2015. Thermal stress increases fluctuating asymmetry in marine mussels: environmental variation and developmental instability. Ecosphere 6(5):85. http://dx.doi.org/10.1890/ ES14-00399.1Abstract. Faced with rising environmental temperatures, there is growing evidence that species are exhibiting shifts in ecological distribution, physiological performance, and behavioral strategy. Less is understood, however, about links between environmental conditions and the precision with which organisms are able to fulfill their developmentally programmed phenotype. Here, we report that developmental instability, assessed by the fluctuating asymmetry (FA) of right versus left valves in intertidal mussel shells, increases under elevated thermal stress. In a growth experiment, mussels that were exposed to elevated aerial temperatures (21.58 6 0.18C) for three hours each day displayed higher levels of FA compared to mussels exposed to cooler aerial temperatures (12.68 6 0.18C). Reciprocal field transplant experiments revealed that FA increased under higher aerial temperatures (e.g., on a south facing surface [19.68 6 0.28C]) compared to individuals living in cooler habitats (e.g., on a north facing surface [15.28 6 0.28C] or lower in the intertidal zone [14.18 6 0.68C]). Together, these results imply that the precision of developmental processes can be perturbed by environmental conditions and raise developmental instability as a potential impact of future environmental variability alongside shifts in physiology, behavior and biogeographic distribution.

Coastal ponds are highly susceptible to negative effects from nutrient loading (1). The usual approach for managing such systems is to reduce nutrient input. Another possibility for some low-salinity systems may be to control salinity if salinity has a pronounced influence on phytoplankton growth. Freshwater species generally compose the phytoplankton of low-salinity systems. One might expect growth to slow as salinity increases until the assemblage switches from freshwater to marine. Similarly, phytoplankton native to systems with fairly constant salinity through space and time may not tolerate any change in salinity, as they may be adapted to that specific salinity (Valiela, Boston University, pers. comm.). Oyster Pond (Falmouth, MA) is a brackish pond connected to Vineyard Sound through a lagoon. The pond is currently mesotrophic to eutrophic (based on chlorophyll levels; 1), perhaps due to nutrient loading from the expanding residential population surrounding the pond. Oyster Pond's salinity has decreased from 32‰ (open to the ocean) to less than 2‰ (road restricting Vineyard Sound inflow) (2). Currently, dredging and a weir maintain the salinity at a fairly constant 2.3‰. Oyster Pond managers have the option of manipulating salinity within the pond via the weir. While managers plan to manipulate salinity according to which fish populations they desire in the pond (Barry Norris, Oyster Pond Environmental Trust), we are interested in considering what effects salinity changes might have on resident phytoplankton populations. To determine if the general Oyster Pond phytoplankton population could adapt to changes in salinity, we added excess nutrients (nitrate and phosphate) under three salinity regimes. To determine if cyanobacteria could adapt to changes in salinity under N-depleted conditions, we added excess phosphate. Water was collected from the northern end of Oyster Pond. Three salinity treatments (0.2‰, 2.3‰, and 5.0‰) under two nutrient conditions were created by mixing sieved Oyster Pond water (150-m mesh to remove macrozooplankton), filtered Vineyard Sound water (GF/F), and deionized water in clear polycarbonate bottles. The 0.2‰ treatment

In this paper we conduct a comparison of the rates of suicide for men and women across four settings: the People's Republic of China (PRC), Taiwan, Hong Kong, and Asian groups in the US. The rates for rural PRC women are the highest, followed by urban PRC, Hong Kong, Taiwan, and at the lowest rate, US Asians. The highest rates for men were found in the rural PRC setting, followed by Hong Kong, Taiwan, Asians in the US, and the lowest rate was found in the urban PRC. The high rate among women in rural PRC settings fits with observations on their stressful life circumstances. For these women, local belief systems, life conditions, and lack of social and economic opportunities increase the risk of suicide in the face of intolerable shame and pain.