Eight new seagrass beds were discovered along the coastline of Hainan Island in South China Sea with an area of 203.64ha. The leaf N content of all seagrasses was above the median value, indicative of N limitation, with their C:N ratio recorded significantly lower than the limiting criteria. This suggested that N is not limiting but in replete status. Further, the lower C content observed in the seagrass leaves was accompanied by higher nutrient concentration. The mean seagrass biomass C was 0.23±0.16MgCha−1, while the average sediment organic carbon (SOC) stock was 7.02±3.57MgCha−1. The entire SOC stock of the newly discovered seagrass beds was 1306.45 Mg C, and the overall SOC stock of seagrass bed at Hainan Island was 40858.5 Mg C. These seagrass beds are under constant threats from sea reclamation, nutrient input, aquaculture activities for oyster and snail farming, and fishing activities.

Climate change with human direct pressures represent significant threats to the resilience of shoreline habitats like mangroves. A rapid, whole-of-system assessment strategy is needed to evaluate such threats, better linking innovative remote sensing with essential on-ground evaluations. Using the Shoreline Video Assessment Method, we surveyed around 190km of the mostly mangrove-fringed (78%) coastline of Kien Giang Province, Vietnam. The aim was to identify anthropogenic drivers of degradation, establishing baseline for specific rehabilitation and protection strategies. Fish traps occupy at least 87% of shoreline mangroves, around which there were abundant human activities – like fishing, crabbing, farming, plus collecting firewood and foliage. Such livelihoods were associated with remnant, fringing mangrove that were largely degraded and threatened by erosion retreat, herbivory, and excessive cutting. Our assessment quantified associated threats to shoreline stability, along with previous rehabilitation intervention measures. The method offers key opportunities for effective conservation and management of vulnerable shoreline habitats.

Underwater man-made noise is recognized as a major global pollutant in the 21st Century, and its reduction has been included in national and international regulations. Despite the fact that many studies have pointed out the ecological impact of noise on marine organisms, few studies have investigated - in a field context - the behavioral response to boat noise in fish. In the present study we measure how Sciaena umbra reacts to boat noise. We found that boat noise: i) increased duration of flight reactions and number of individuals performing them, ii) increased the frequency of hiding behaviors, and iii) did not elicit a change in fish activity level and sound emission. Flights and hiding behavior, usually related to predation risk, were not uniform between individuals and showed a quick recovery after noise exposure. On the basis of these results, potential metabolic, physiological and behavioral consequences are discussed and management recommendations are proposed.

Six percent of the world's coral reefs occur around the Arabian Peninsula, providing a valuable ecological, economic and scientific resource for the nations bordering its shores. We provide the first region-wide assessment of the current status and historical trends in coral reef research, focusing on research in the Red Sea, Arabian Sea, and Arabian Gulf. In total, 633 regional reef publications have been produced since the 1930s, covering a wide variety of themes and taxa. Our results show a great deal of commonality in regional reef research, but also highlight important differences in research among the various seas as well as knowledge gaps that represent opportunities for future research. A regionally-integrated approach to future research is essential. There is a growing need for large-scale research to guide management of reefs and their stressors, as these operate at much larger scales than the national borders within which most research currently occurs.

Micro- and macroplastic accumulation threatens estuaries worldwide because of the often dense human populations, diverse plastic inputs and high potential for plastic degradation and storage in these ecosystems. Nonetheless, our understanding of plastic sources and sinks remains limited. We designed conceptual models of the local and estuary-wide transport of plastics. We identify processes affecting the position of plastics in the water column; processes related to the mixing of fresh and salt water; and processes resulting from the influences of wind, topography, and organism–plastic interactions. The models identify gaps in the spatial context of plastic–organisms interactions, the chemical behavior of plastics in estuaries, effects of wind on plastic suspension–deposition cycles, and the relative importance of processes affecting the position in the water column. When interpreted in the context of current understanding, sinks with high management potential can be identified. However, source–sink patterns vary among estuary types and with local scale processes.

Marine mammals are ecologically and culturally important species, and various countries have specific legislation to protect the welfare of individual marine mammals and the conservation of their populations. Anthropogenic noise represents a particular challenge for conservation and management. There is a large and growing body of research to support the conclusion that anthropogenic noise can affect marine mammal behavior, energetics, and physiology. The legal, policy, and management issues surrounding marine mammals and noise are similarly complex. Our objective is twofold. First, we discuss how policy and legal frameworks in Canada have some important differences from other jurisdictions covered in previous reviews, and provide a useful general case study. Secondly, we highlight some priority research areas that will improve marine mammal conservation and management. Our examples focus on the research needed to meet stated conservation objectives for marine mammal species in waters under Canadian jurisdiction.

Rottnest Island, Western Australia, receives >500,000visitorsy−1, who are mainly attracted by the Island’s natural values. Marine debris is a threat to both these natural values and to Island wildlife, and is consequently an important issue for managers. Engaging with volunteers, we quantified marine debris at 16 beach sites around the Island. The highest loads occurred on the SW coast and primarily comprised items originating from fishing activities. Sites on the NE coast, where >95% of the Island’s accommodation is located, supported the highest abundance of items deposited in situ (e.g. bottles and cigarette butts). We conclude that marine debris management may require a range of strategies to address the different primary sources. Raising awareness through education and intervention may be highly effective at popular beaches on the NE coast, but broader liaison with commercial and recreational fishers will be necessary to address the issue at the Island scale.

The annual flow and stock of marine debris in the Sea of Korea was estimated by summarizing previous survey results and integrating them with other relevant information to underpin the national marine debris management plan. The annual inflow of marine debris was estimated to be 91,195tons [32,825tons (36% of the total) from sources on land and 58,370tons (64%) from ocean sources]. As of the end of 2012, the total stock of marine debris on all South Korean coasts (12,029tons), the seabed (137,761tons), and in the water column (2451tons) was estimated to be 152,241tons. In 2012, 42,595tons of marine debris was collected from coasts, seabeds, and the water column. This is a very rare case study that estimated the amount of marine debris at a national level, the results of which provide essential information for the development of efficient marine debris management policies.

This study refers to the performance of Phase I Toxicity Identification Evaluation (TIE) procedures to identify the contaminants (i.e. organic compounds, metals and ammonia) exerting toxicity in marine sediments from the Pasaia harbor (Oiartzun estuary, northern Spain). The effectiveness of the manipulations to reduce toxicity was proved with the marine amphipod survival test (whole-sediment) and the sea urchin embryo-larval assay (elutriates).By means of TIEs it was concluded that organic compounds were the major contaminants exerting toxicity, although toxic effects by metals was also demonstrated. Additionally, the combination of Phase I treatments allowed to investigate the toxicity changes associated to the mobility of contaminants during dredging activities. Therefore, the performance of TIE procedures as another line of evidence in the decision-making process is recommended. They show a great potential to be implemented at different steps of the characterization and management of dredged harbor sediments.

Compiles information on materials-handling equipment and techniques that have been implemented throughout the US and Europe. Summarizes the types of debris, material and contaminants found at Superfund and other hazardous waste sites and the equipment and general procedures used to perform site remediation, restoration and/or cleanup.