RESUMO
Inshore marine habitats experience considerable anthropogenic pressure, as this is where many adverse effects of human activities concentrate. In the rapidly-changing seascape of the Anthropocene, Hong Kong waters at the heart of world's fastest developing coastal region can serve as a preview-window into coastal seas of the future, with ever-growing anthropogenic footprint. Here, we quantify how large-scale coastal infrastructure projects can affect obligatory inshore cetaceans, bringing about population-level consequences that may compromise their long-term demographic viability. As a case in point, we look at the construction of world's longest sea crossing system and broad-scale demographic, social and spatial responses it has caused in a shallow-water delphinid, the Indo-Pacific humpback dolphin (Sousa chinensis). Soon after the infrastructure project began, dolphins markedly altered their home range near construction sites such that these waters no longer functioned as dolphin core areas despite the apparent presence of prey, indicating that anthropogenic impacts outweighed foraging benefits. The contraction of key habitats has in turn led individuals to interact over spatially more constricted area, reshaping their group dynamics and social network. Although there was no apparent decline in dolphin numbers that could be detected with mark-recapture estimates, adult survival rates decreased drastically from 0.960 to 0.904, the lowest estimate for these animals anywhere across the region to date, notably below the previously estimated demographic threshold of their long-term persistence (0.955). It is apparent that during an advanced stage of this coastal infrastructure project, dolphins were under a major anthropogenic pressure that, if sustained, could be detrimental to their long-term persistence as a viable demographic unit. As effective conservation of species and habitats depends on informed management decisions, this study offers a valuable lesson in environmental risk assessment, underscoring the implications of human-induced rapid environmental change on obligatory inshore delphinids-sentinels of coastal habitats that are increasingly degraded in fast-changing coastal seas.
Assuntos
Golfinhos , Animais , Humanos , Hong Kong , Cetáceos , Dinâmica Populacional , Comportamento de Retorno ao Território Vital , EcossistemaRESUMO
Despite the ubiquity of coastal infrastructure, it is unclear what factors drive its placement, particularly for water access infrastructure (WAI) that facilitates entry to coastal ecosystems such as docks, piers, and boat landings. The placement of WAI has both ecological and social dimensions, and certain segments of coastal populations may have differential access to water. In this study, we used an environmental justice framework to assess how public and private WAI in South Carolina, USA are distributed with respect to race and income. Using publicly available data from State agencies and the US Census Bureau, we mapped the distribution of these structures across the 301 km of the South Carolina coast. Using spatially explicit analyses with high resolution, we found that census block groups (CBGs) with lower income are more likely to contain public WAI, but racial composition has no effect. Private docks showed the opposite trends, as the abundance of docks is significantly, positively correlated with CBGs that have greater percentages of White residents, while income has no effect. We contend that the racially unequal distribution of docks is likely a consequence of the legacy of Black land loss, especially of waterfront property, throughout the coastal southeast during the past half-century. Knowledge of racially uneven distribution of WAI can guide public policy to rectify this imbalance and support advocacy organizations working to promote public water access. Our work also points to the importance of considering race in ecological research, as the spatial distribution of coastal infrastructure directly affects ecosystems through the structures themselves and regulates which groups access water and what activities they can engage in at those sites.
Assuntos
Ecossistema , Navios , Sudeste dos Estados UnidosRESUMO
Over time, considerable changes in the earth's climate have always occurred due to a wide variety of natural processes. During the last century, these natural changes have all been accelerated by global warming, which has been driven by human activities. Climate change leads to wide variations in environmental variables such as temperature, relative humidity, carbon dioxide, etc. These changes could adversely affect the performance, serviceability, and safety of infrastructure assets. The challenge, therefore, is to not only understand the effect of extreme events and their links to climate change, but also to obtain data that could be used for assessing long-term gradual effects affecting infrastructure assets. In this paper is presented a climate indicators database that was collected and provided in an excel format. This database could be used for assessing the durability, vulnerability, and cost-effectiveness of adaptation measures for coastal infrastructure assets. The database contains information for specific coastal locations placed in five European countries: Caxias (Portugal), Saint Nazaire (France), Vigo (Spain), Brighton (UK), Dublin and Cork (Ireland). The database includes atmospheric, and oceanic indicators, as well as and the flow of rivers. It covers a time series of up to 2100 with various representative concentration pathways and climate models.
RESUMO
The American slipper limpet Crepidula fornicata is an invasive, non-native species (INNS) abundant along the European coast. Its further distribution may be facilitated by activities such as dredging and spoil disposal, and the aim of this study was to assess whether C. fornicata is able to survive sediment burial. The slipper limpet was found attached to hard substratum in intertidal areas, but it was absent at a nearby subtidal dredge spoil site. In laboratory experiments 22% of C. fornicata emerged when buried under a 2â¯cm sediment-layer; only half of them survived. When buried under ≥6â¯cm none re-surfaced or survived. The results provided evidence that C. fornicata is poorly adapted to adjust its vertical position in sediment and is killed by sudden burial underneath 2 to 6â¯cm of sediment. The combined laboratory experiments and field surveys suggested that C. fornicata has limited scope to survive the dredge spoil disposal process.