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We measured depressive symptoms with the Beck Depression Inventory in 17,348 university students from 23 high-, middle-, and low-income countries, and assessed associations with individual level and ecological level factors using multi-level random effects regression modelling. Wide variations in depressive symptoms were observed between countries, with lower levels in Western and Southern Europe and South and North America, intermediate levels in Central and Eastern Europe, and higher levels in Pacific-Asian samples. Poorer socio-economic background and low sense of control were associated with depressive symptoms within each country. Independently of individual level effects, higher depressive symptoms were recorded in countries with greater income inequality and with less individualistic cultures. Personal circumstances, beliefs, and cultural factors may all contribute to depressive symptoms in this population.

Temporal and spatial variation of the macrofaunal community was investigated in seagrass meadows in Akkeshi-ko estuary and coastal area of Akkeshi Bay, northern Japan. We specifically addressed the question of how the salinity gradient in seagrass meadows affects the species richness, abundance and similarity of faunal groups classified based on the degree of association with the seagrasses, i.e. highly motile species that drift in the water column among seagrass blades (drift-fauna, DF group) and less motile species that are tightly associated with seagrass substrates (seagrass-associated fauna, SA group).A total of 70 species were collected semi-quantitatively using an epibenthic sledge, among which more than one third of the species were captured in all areas, and a quarter of species only in the marine area. Significant spatial variation in species richness, as well as a positive relationship between salinity and species richness was found for most sampling occasions and for both functional groups. Whereas, relationship between salinity and abundance of macrofauna was not clear although significant time and site interactions were found for both functional groups. Patterns of similarity of assemblages varied between the functional groups: clear differences by sampling sites were discerned for DF group but not for SA group. These results provided evidence that the macrofaunal community structures in seagrass beds varied with the salinity gradient, but the pattern differed with time and between functional groups, possibly due to the effect of biotic and abiotic factors that also changed with salinity.

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[1] The influence of mangrove forests on the dynamics of dissolved inorganic carbon (DIC) in tropical estuaries was estimated quantitatively using newly developed isotope (d 13 C) mass balance models that take into account both the input of DIC and the air-water exchange of CO 2 . To this aim, the concentration and d 13C of DIC were determined across the salinity gradient of two river estuaries facing the Andaman Sea. The longitudinal distribution of DIC could be explained by conservative mixing of the river water and seawater DIC in the low-discharge period (March 2006), while a net accumulation of DIC up to 190 mmol L À1 was observed in the high-discharge period (December 2006). d 13 C DIC values were generally lower than expected for the mixing of the river water and seawater DIC, due to the 13 C-depleted DIC inputs from the riverside mangroves. The concentration of mangrove-derived DIC in the estuarine waters was estimated by the proposed models to be as much as 856 mmol L À1 , and was higher during the low-discharge period. This suggested that the mangroves exported much higher levels of DIC to the estuaries than indicated by the net accumulation of DIC. Our results confirm that mangroves function as an effective CO 2 pump that takes CO 2 from the atmosphere and releases it into estuarine waters. This study illustrates that d 13 C DIC is a sensitive and quantitative indicator for DIC emission to the sea from coastal wetlands including mangroves.

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The effects of emergence stress and morphological constraints on the distribution and growth of 3 subtropical seagrass species, Cymodocea rotundata, C. serrulata and Thalassia hemprichii, were examined in a series of transplantation experiments and a laboratory desiccation experiment. C. rotundata and T. hemprichii occur in both the intertidal and subtidal zones off Ishigaki Island, southwest Japan, whereas C. serrulata is found only in the subtidal zone. Within the same species, intertidal shoots for both C. robundata and T. hemprichii are significantly smaller than subtidal shoots. A subtidal-to-intertidal transplantation experiment was conducted on 3 occasions: July and September 2001 and January 2002. In July and September, when the intertidal sites were exposed to air for a shorter period, shoot densities of the transplanted 3 species did not decrease. In contrast, the shoot densities of all 3 transplanted species decreased significantly in February, when the exposure to air was longer. The survival of C. serrulata (2% of the initial density) was much lower than that of C. rotundata (48%) and T. hemprichii (48%). In subtidal-to-intertidal transplants, the size of C. rotundata and T. hemprichii leaves decreased, approaching that of intertidal shoots, indicating high morphological plasticity. In situ observations revealed that transplanted seagrasses with large leaves were exposed to air for longer than were intertidal controls. In the desiccation experiment, T. hemprichii leaves had higher water contents than those of C. rotundata and C. serrulata. The morphological traits of C. rotundata and T. hemprichii and their ability to change shoot size appear to be related to the better survival of these species in the intertidal area as compared to C. serrulata. This is consistent with the observed variation in the species distribution in the intertidal zone.

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