It was thought that the Southern Ocean was relatively free of microplastic contamination; however, recent studies and citizen science projects in the Southern Ocean have reported microplastics in deep-sea sediments and surface waters. Here we reviewed available information on microplastics (including macroplastics as a source of microplastics) in the Southern Ocean. We estimated primary microplastic concentrations from personal care products and laundry, and identified potential sources and routes of transmission into the region. Estimates showed the levels of microplastic pollution released into the region from ships and scientific research stations were likely to be negligible at the scale of the Southern Ocean, but may be significant on a local scale. This was demonstrated by the detection of the first microplastics in shallow benthic sediments close to a number of research stations on King George Island. Furthermore, our predictions of primary microplastic concentrations from local sources were five orders of magnitude lower than levels reported in published sampling surveys (assuming an even dispersal at the ocean surface). Sea surface transfer from lower latitudes may contribute, at an as yet unknown level, to Southern Ocean plastic concentrations. Acknowledging the lack of data describing microplastic origins, concentrations, distribution and impacts in the Southern Ocean, we highlight the urgent need for research, and call for routine, standardised monitoring in the Antarctic marine system.
- Despite being globally widespread in coastal regions, the impacts of light pollution on intertidal ecosystems has received little attention. Intertidal species exhibit many night-time-dependent ecological strategies, including feeding, reproduction, orientation and predator avoidance, which are likely negatively affected by shifting light regimes, as has been observed in terrestrial and aquatic taxa.
- Coastal lighting may shape intertidal communities through its influence on the nocturnal foraging activity of dogwhelks (Nucella lapillus), a widespread predatory mollusc that structures biodiversity in temperate rocky shores. In the laboratory, we investigated whether the basal and foraging activity of this predator was affected by exposure to night-time lighting both in the presence and absence of olfactory predator cues (Carcinus maenas, common shore crab).
- Assessments of dogwhelks’ behavioural responses to night-time white LED lighting were performed on individuals that had been acclimated to night-time white LED lighting conditions for 16 days and individuals that had not previously been exposed to artificial light at night.
- Dogwhelks acclimated to night-time lighting exhibited natural refuge-seeking behaviour less often compared to control animals, but were more likely to respond to and handle prey irrespective of whether olfactory predator cues were present. These responses suggest night-time lighting likely increased the energetic demand of dogwhelks through stress, encouraging foraging whenever food was available, regardless of potential danger. Contrastingly, whelks not acclimated under night-time lighting were more likely to respond to the presence of prey under artificial light at night when olfactory predator cues were present, indicating an opportunistic shift towards the use of visual instead of olfactory cues in risk evaluation.
- These results demonstrate that artificial night-time lighting influences the behaviour of intertidal fauna such that the balance of interspecific interactions involved in community structuring may be affected.
After many years of Common Fisheries Policies in the European Union, 88% of stocks are still being fished beyond their Maximum Sustainable Yield. While several Member States and the European Commission are moving toward Individual Transferable Quotas as a solution, France has declared its opposition to such marketization of fishing access rights and a national law has classified fisheries resources as a collective heritage. This paper discusses the evolution of the French system, principally its distribution of access rights by the Producer Organizations instead of the market. However, the Producer Organizations, which are more linked to the industrial fleet organizations, have not always modified their sharing formulae to include small-scale fisheries, resulting in a demand for more transparency and equity.
Atlantic Canadian fisheries policy exhibits a tension between competing objectives of economic efficiency, and of well-being and equity within coastal communities and small-scale fisheries. The struggle between different actors over these objectives has generated distinct forms of neoliberalism in different regions and fishing fleets. In the lobster fishery, the right to fish has been concentrated since limited-entry licensing policy was introduced in the 1980s. This paper examines actors and events at two scales, including Lobster Fishing Area (LFA) 34 Advisory Committee meetings involving fishermen, representatives of Fisheries and Oceans Canada (DFO), and other stakeholders, and broader scale strategies of the Canadian Independent Fish Harvesters Federation (CIFHF). A Foucauldian perspective aids in understanding how fisheries governance is the product of struggles between the power and agency of individual fishermen, fishing organizations, processing companies, the DFO, the Minister of Fisheries and the courts. While many theorists view fisheries through the lens of the “tragedy of the commons”, alternative tragedies are developing in Atlantic Canadian fisheries. These include rising levels of debt, reduced earnings, vulnerability to financial volatility, loss of fishing rights within communities, and too much processor control.
Recent marine climate change research has largely focused on the response of individual species to environmental changes including warming and acidification. The response of communities, driven by the direct effects of ocean change on individual species as well the cascade of indirect effects, has received far less study. We used several rocky intertidal species including crabs, whelks, juvenile abalone, and mussels to determine how feeding, growth, and interactions between species could be shifted by changing ocean conditions. Our 10 wk experiment revealed many complex outcomes which highlight the unpredictability of community-level responses. Contrary to our predictions, the largest impact of elevated CO2 was reduced crab feeding and survival, with a pH drop of 0.3 units. Surprisingly, whelks showed no response to higher temperatures or CO2 levels, while abalone shells grew 40% less under high CO2 conditions. Massive non-consumptive effects of crabs on whelks showed how important indirect effects can be in determining climate change responses. Predictions of species outcomes that account solely for physiological responses to climate change do not consider the potentially large role of indirect effects due to species interactions. For strongly linked species (e.g. predator-prey or competitor relationships), the indirect effects of climate change are much less known than direct effects, but may be far more powerful in reshaping future marine communities.
Non-indigenous green crabs (Carcinus maenas) are emerging as important predators of autogenic engineers like American oysters (Crassostrea virginica) throughout the eastern seaboard of Canada and the United States. To document the spreading distribution of green crabs, we carried out surveys in seven sites of Prince Edward Island during three fall seasons. To assess the potential impact of green crabs on oyster mortality in relation to predator and prey size, we conducted multiple predator-prey manipulations in the field and laboratory. The surveys confirmed an ongoing green crab spread into new productive oyster habitats while rapidly increasing in numbers in areas where crabs had established already. The experiments measured mortality rates on four sizes of oysters exposed to three sizes of crab, and lasted 3–5 days. The outcomes of experiments conducted in Vexar® bags, laboratory tanks and field cages were consistent and were heavily dependent on both crab size and oyster size: while little predation occurred on large oysters, large and medium green crabs preyed heavily on small sizes. Oysters reached a refuge within the 35–55 mm shell length range; below that range, oysters suffered high mortality due to green crab predation and thus require management measures to enhance their survival. These results are most directly applicable to aquaculture operations and restoration initiatives but have implications for oyster sustainability.
The Dogger Bank is a subtidal hill in the North Sea that is a candidate Special Area of Conservation under the EU Habitats Directive in UK waters. Historical records indicate that the Bank has been subject to human exploitation from before the 16th century but conservation objectives have been developed using recent survey data. This has the potential to significantly underestimate the alteration this ecosystem has experienced, making the Dogger Bank an example of shifting baseline syndrome in protected area management. We compile quantitative and qualitative descriptions from historical records of change in catch rates, fishing effort, price and fish size to show that there have been prolonged declines in abundance of fish on the Bank since the early 19th century. Use of present day data to inform conservation has led to unambitious recovery targets. Historical data, we argue, are an essential input to conservation decision making.
At present, there is no specific legal basis for the development and utilisation of marine renewable energy, nor legal protection for the developers in China. The consequence is that the Chinese Government is unable to provide institutional support for the substantive development of marine renewable energy, resulting in slow development of China's marine energy industry. This paper provides an institutional framework for the establishment of relevant laws in China and legislative proposals in legal perspective, for the better development of marine renewable energy. The Chinese Government should optimise the administrative management system, strengthen financial regulation such as tax and emphasise sustainable development.
The coastal regions of inland seas are particularly vulnerable to Hg pollution. An important carrier of toxic Hg in the marine environment is suspended matter originating from multiple sources. The present study was conducted in the Gulf of Gdańsk and its adjoining land in the years 2011–2013. The results indicated that the HgSPM (Hg bound with suspended particulate matter) concentrations varied horizontally and vertically and were dependent on the water dynamics and the composition of organic matter. Conditions favourable for the accumulation of matter and adsorption of reactive gaseous mercury led to increasing HgSPM levels, which are especially hazardous in the case of semi-enclosed areas such as estuaries. These conditions also increase the Hg loads into the trophic chain through suspension feeders. Moreover, the HgSPM concentration was significantly affected by seasonal phenomena (mainly coastal erosion) and the quantity and quality of primary production (phytoplankton blooms, mainly Mesodinium rubrum).
Environmental DNA (eDNA) can be a powerful method for assessing the presence and the distribution of aquatic species. We used this tool in order to detect and quantify eDNA from the elusive species Octopus vulgaris, using qPCRs (SybrGreen protocol). We designed species-specific primers, and set up an experimental aquarium approach to validate the new molecular tool in different controlled conditions. Field validation was conducted from sea water samples taken from 8 locations within an octopus fishery area in the Cantabrian Sea during February–March 2016. A significant positive correlation between the total biomass (g of O. vulgaris within thanks) and the amount of O. vulgaris eDNA detected (p-value = 0.01261) was found in aquarium experiments. The species was also detected by PCR in 7 of the 8 water samples taken at sea, and successfully quantified by qPCR in 5 samples. This preliminary study and innovative method opens very promising perspectives for developing quick and cheap tools for the assessment of O. vulgaris distribution and abundance in the sea. The method could help in a close future for quantifying unseen and elusive marine species, thus contributing to establish sustainable fisheries.