Plastic pollution is a major anthropogenic contaminant effecting the marine environment and is often associated with high human population densities and industrial activities. The microplastic (63 to 5000 μm) burden of beach sediment and surf-zone water was investigated at selected sites along the entire length of the South African coastline. It was predicted that samples collected in areas of high population density, would contain a higher microplastic burden than those along coasts that demonstrate very low population densities. With the exception of water column microplastics within Richard's Bay Harbour (413.3 ± 77.53 particles·m− 3) and Durban Harbour (1200 ± 133.2 particles·m− 3), there were no significant spatial differences in microplastic loads. This supports the theory that harbours act as a source of microplastics for the surrounding marine environment. Additionally, the absence of any spatial variation highlights the possible long range distribution of microplastic pollutants by large scale ocean currents.
Microplastics in the world's oceans are a global concern due to the potential threat they pose to marine organisms. This study investigated microplastic abundance, distribution and composition in the Atlantic Ocean on a transect from the Bay of Biscay to Cape Town, South Africa. Microplastics were sampled from sub-surface waters using the underway system of the RV Polarstern. Potential microplastics were isolated from samples and FT-IR spectroscopy was used to identify polymer types. Of the particles analysed, 63% were rayon and 37% were synthetic polymers. The majority of microplastics were identified as polyesters (49%) and blends of polyamide or acrylic/polyester (43%). Overall, fibres (94%) were predominant. Average microplastic abundance in the Atlantic Ocean was 1.15 ± 1.45 particles m− 3. Of the 76 samples, 14 were from the Benguela upwelling and there was no statistically significant difference in microplastic abundance between upwelled and non-upwelled sites.
Microplastic particles smaller than 5 mm in size are of increasing concern, especially in aquatic environments, such as the ocean. Primary source is microbeads (<1 mm) used in cosmetics and cleaning agents and fiber fragments from washing of clothes, and secondary source such as broken down plastic litter and debris. These particles are mostly made from polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyesters. They are ingested by diverse marine fauna, including zooplanktons, mussel, oyster, shrimp, fish etc. and can enter human food chains via several pathways. Strategy for control of microplastics pollution should primarily focus on source reduction and subsequently on the development of cost-effective clean up and remediation technologies. Recent research results on biodegradation of plastics have revealed a potential for microbial biodegradation and bioremediation of plastic pollutants, such as PE, PS and PET under appropriate conditions.
Dust and Sand Storms (DSS) originating in deserts in arid and semi-arid regions are events raising global public concern. An important component of atmospheric aerosols, dust aerosols play a key role in climatic and environmental changes at the regional and the global scale. Deserts and semi-deserts are the main source of dust and sand, but regions that undergo vegetation deterioration and desertification due to climate change and human activities also contribute significantly to DSS. Dust aerosols are mainly composed of dust particles with an average diameter of 2 mm, which can be transported over thousands of kilometers. Dust aerosols influence the radiation budget of the earthatmosphere system by scattering solar short-wave radiation and absorbing surface long-wave radiation. They can also change albedo and rainfall patterns because they can act as cloud condensation nuclei (CCN) or ice nuclei (IN). Dust deposition is an important source of both marine nutrients and contaminants. Dust aerosols that enter marine ecosystems after long-distance transport influence phytoplankton biomass in the oceans, and thus global climate by altering the amount of CO2 absorbed by phytoplankton. In addition, the carbonates carried by dust aerosols are an important source of carbon for the alkaline carbon pool, which can buffer atmospheric acidity and increase the alkalinity of seawater. DSS have both positive and negative impacts on human society: they can exert adverse impacts on human’s living environment, but can also contribute to the mitigation of global warming and the reduction of atmospheric acidity.
Juveniles of blue shark Prionace glauca caught in pelagic longlines targeting tuna and swordfish in the Atlantic Ocean and the Mediterranean Sea were found entangled with plastic straps around their gill region. The plastic debris were identified as strapping bands and caused several degrees of injuries on the dorsal musculature and pectoral fins. They were also obstructing the gill slits probably causing breathing issues. These records were uploaded in the web site seawatchers.org, and highlight the potential of citizen science in revealing the occurrence of such problems which could help to measure the effects of plastic debris on marine life.
Understanding the mental constructs underlying people's social responses, decisions and behaviors is crucial to defining the governance challenges faced in dealing with marine anthropogenic litter. Using interactive governance theory, this study provides qualitative insights into how a small group of Arab-Israeli artisanal fishermen perceive marine litter and its impact (system to be governed) in the context of the socio-institutional structures (governing system) which manage waste and aim to protect the surrounding environment. It demonstrates that, until the relationships between local people and the various governing institutions are transformed, there is little hope for citizen cooperation in reducing marine litter long-term in the case-study site. More generally, underlying narratives and politics playing out at a local level need to be understood in order to identify which interventions are likely to be effective and which are not. An intervention checklist to assess the potential effectiveness of a marine litter intervention is proposed.
Coastal litter is a source of environmental, economic and health-related problems in many parts of the world, but local responses are not necessarily related to the severity of the impacts. In particular, it is unclear how environmental perception of community members and government bodies relate to active engagement on coastal pollution. The present study analyses the coastal litter situation and evaluates the willingness of citizens to engage at four sites (three regions of mainland Chile, and Easter Island; henceforth Rapa Nui) that feature differences in culture, economy sectors and landscape characteristics. Data on coastal litter were obtained from citizen science campaigns and assessments of large litter accumulations on beaches and rocky shores. The willingness to engage was evaluated qualitatively, considering municipal planning documents and the perception of residents on coastal litter and general waste management. We found very large quantities of litter in northern Chile, posing a hazard to marine wildlife and human health, and moderate quantities in the other regions. The region with the most severe case of coastal pollution does not feature the highest engagement, possibly a result of underlying factors such as an unsustainable economy and few possibilities for the population to connect with the natural environment. On mainland Chile, municipal engagement is low to moderate while on Rapa Nui there exist integrated waste-management strategies that address coastal pollution. Inhabitants of Rapa Nui seem to have a better conduct in the coastal environment (picking up litter, littering less), and show more engagement in waste-reduction strategies (recycling, volunteering for beach clean-ups). We suggest that the unique cultural history of the island, a landscape that allows meaningful interaction with nature and an economy based on sustainable tourism and high international visibility facilitates engagement on environmental issues. We advise managers to consider respective underlying variables, to create environments that allow contact with nature (e.g. public access to parks), and to encourage bottom-up initiatives, preferably by local actors (e.g. by promoting already engaged individuals or organisations).
A passive acoustic telemetry survey was conducted to determine occurrence patterns of commercially important fishes on a steep reef slope along a marine protected area (MPA) in the southern Philippines, where the outer reef edge is often set as an offshore MPA boundary. Based on 4–61 days of tracking data from 21 detected individuals of five species (Lutjanus argentimaculatus, Lutjanus monostigma, Lethrinus atkinsoni, Lethrinus obsoletus, and Siganus guttatus; 20.7–69.2 cm fork length) caught near the reef slope of the MPA, S. guttatus occurred most frequently on the reef flat of the MPA, whereas all individuals of the four lutjanid and lethrinid species were primarily (99.4–100%) detected near the reef slope, and nine individuals (56.3% of these four species) of three of these species (not L. obsoletus) most likely used the shallow (≤10 m) and deep (≥20 m) layers, and thus, middle layers of the slope. These findings indicate that commercially important lutjanid and lethrinid species predominantly and vertically used the areas near the reef slope, suggesting the importance of fully including reef slopes in MPAs to enhance their effectiveness for the conservation of such fishes.
The recovery of whale species at risk requires the implementation of protection measures designed to mitigate the risks posed by various stressors. In the St. Lawrence Estuary (Canada), several whale species are threatened by navigation activities in various ways. Since 2013, seasonal voluntary ship strike mitigation measures, including a speed reduction area (SRA) and a no-go area, were implemented annually and largely adopted by the maritime industry to reduce the risks of lethal collisions with four species of baleen whales. While the endangered St. Lawrence beluga population is unlikely to be subject to collisions with large merchant ships, it is known to be negatively affected by vessel-generated underwater noise. To assess how these protection measures modify the beluga’s soundscape throughout their critical habitat, we implemented an underwater acoustic module within an existing agent-based model (3MTSim) of ship-whale movements and interactions in the St. Lawrence Estuary. We ran multiple simulations for two scenarios 1) without and 2) with the protection measures to compare the level of noise received by belugas before and after 2013. Overall, the simulations showed a statistically-significant 1.6% decrease in the total amount of noise received by belugas in their critical habitat following the implementation of the protection measures. Although slowing down ships reduces instantaneous radiated noise, it also increases the total amount of acoustic energy released in the environment by extending the time spent in the SRA. Accordingly, our simulations showed a 2.4% increase in the cumulative noise from shipping received by beluga in the SRA. Conversely, belugas located in the Upper Estuary, mostly females and calves, i.e., the most valuable individuals experienced a 5.4% reduction in the cumulative received level of shipping noise. Although refinements are required to improve the modelling of noise sources and propagation for finer scale projections in this complex nearshore environment, this agent-based modelling paradigm of 3MTSim proved informative for underwater acoustic impact assessments.
Destructive fishing is a significant area of focus for fisheries management. It is at odds with a sustainable fisheries management policy. Key examples of destructive fishing include blast fishing, cyanide fishing, illegal netting, and bottom trawling. It is characterized by indiscriminate killing, stunning, and/or waste of marine life. These methods are attractive to fishermen due to the high initial value of catches, however, the value of catch rapidly depletes as the habitat and surrounding eco-system is damaged or destroyed. For many South-East Asian (SEA) countries the loss of fisheries resource has been a sensitive topic that has been largely ignored. The traditional paradigm towards combating this problem has been to only consider the use of marine-based enforcement strategies. However, even under optimum conditions, current marine based enforcement strategies are ineffective, ineffiecient, and wasteful; failing to distrupt the majority of blast fishermen. This paper considers three major aspects of blast fishing; the problem, the strategies used to eradicate it, and the motivations of the fishers. This study utilizes a database of over 850,000 blast records collected by detectors in Hong Kong, Malaysia, and Phillipines since 2006. Analysis shows three different groups of blast fishermen as well as an increase in the size of explosive charges over time, the latter compensateing for the reduction in fish stocks. Futhurmore interviews with blast fishermen reaafirm the different groups. Potential solutions based on providing fishermen and their family with alternative livelihoods, education, and associated actions are suggested. Progress of any eradication method implemented can be monitored through the continued collection of bacground blast data from areas. The results can also regularly indicate the effectiveness of the efforts made to stop blast fishing.
Coralline algae provide important ecosystem services but are susceptible to the impacts of ocean acidification. However, the mechanisms are uncertain, and the magnitude is species specific. Here, we assess whether species-specific responses to ocean acidification of coralline algae are related to differences in pH at the site of calcification within the calcifying fluid/medium (pHcf) using δ11B as a proxy. Declines in δ11B for all three species are consistent with shifts in δ11B expected if B(OH)4− was incorporated during precipitation. In particular, the δ11B ratio in Amphiroa anceps was too low to allow for reasonable pHcf values if B(OH)3 rather than B(OH)4− was directly incorporated from the calcifying fluid. This points towards δ11B being a reliable proxy for pHcf for coralline algal calcite and that if B(OH)3 is present in detectable proportions, it can be attributed to secondary postincorporation transformation of B(OH)4−. We thus show that pHcf is elevated during calcification and that the extent is species specific. The net calcification of two species of coralline algae (Sporolithon durum, and Amphiroa anceps) declined under elevated CO2, as did their pHcf. Neogoniolithon sp. had the highest pHcf, and most constant calcification rates, with the decrease in pHcf being ¼ that of seawater pH in the treatments, demonstrating a control of coralline algae on carbonate chemistry at their site of calcification. The discovery that coralline algae upregulate pHcf under ocean acidification is physiologically important and should be included in future models involving calcification.
The effects of oil spills on marine biological systems are of great concern, especially in regions with high biological production of harvested resources such as in the Northeastern Atlantic. The scientific studies of the impact of oil spills on fish stocks tend to ignore that spatial patterns of natural mortality may influence the magnitude of the impact over time. Here, we first illustrate how spatial variation in natural mortality may affect the population impact by considering a thought experiment. Second, we consider an empirically based example of Northeast Arctic cod to extend the concept to a realistic setting. Finally, we present a scenario-based investigation of how the degree of spatial variation in natural mortality affects the impact over a gradient of oil spill sizes. Including the effects of spatial variations in natural mortality tends to widen the impact distribution, hence increasing the probability of both high and low impact events.
The survival of federally protected North Atlantic right whales (Eubalaena glacialis) requires an immediate reduction in the risk of entanglement in commercial fishing gear. This paper argues that at least a 30% reduction in risk is needed to meaningfully contribute to the conservation of right whales. The argument follows from risk estimates calculated using time and space intersections of right whales and fishing gear in Canadian waters. Almost all the risk occurs during July, August and September (12%, 50%, 37% respectively) and the groundfish fishery contributed the greatest proportion (86%) of annual risk. Given that efforts in the USA to reduce entanglement risk through modified fishing gear have been unsuccessful to date, we address the alternative option of restricting certain fishing gear at times and locations where entanglement risk is elevated. There are many options that Canada could employ to achieve the above risk reduction and our results clearly point to the most effective and efficient action being seasonally restricted fishing in two relatively small regions; the Grand Manan Basin and the Roseway Basin. Fully a third (34%±4%) of the annual risk is associated with these two basins, though fishery catch estimates in the basins are relatively small and declining.
According to the European Union Habitats and Birds Directives, EU Member States must extend the Natura 2000 network to marine ecosystems, through the designation of Marine Protected Areas (MPAs). However, the initial status of cetacean and seabird communities across European waters is often poorly understood. It is assumed that an MPA is justified where at least 1% of the “national population” of a species is present during at least part of its biological cycle. The aim of the present work was to use model-based cetacean and seabird distribution to assess the networks of existing Natura 2000 sites and offshore proposed areas of biological interest. The habitat models used here were Generalised Additive Models computed from aerial surveys observational data collected during the winter 2011–2012 and the summer 2012 across the English Channel, Bay of Biscay and north-western Mediterranean Sea. Based on these models, a ratio between species relative abundance predicted within each MPA and the total relative abundance predicted over the French Atlantic or Mediterranean marine regions was computed and compared to the 1% threshold. This assessment was conducted for winter and summer independently, providing information for assessing the relevance of individual MPAs and MPA networks at a seasonal scale. Our results showed that the existing network designed for coastal seabird species was relevant in both marine regions. In contrast, a clear shortfall was identified for offshore seabird species in the Atlantic region and for cetaceans in both regions. Moreover, the size of MPAs appeared to be a crucial feature, with larger MPAs being relevant for more species. Finally, we showed that the proposed large offshore areas of interest would constitute a highly relevant network for all offshore species, with e.g. up to 61% of the Globicephalinae population in the Atlantic French waters being present within these areas.
Systematic conservation planning, a widely used approach to identify priority lands and waters, uses efficient, defensible, and transparent methods aimed at conserving biodiversity and ecological systems. Limited financial resources and competing land uses can be major impediments to conservation; therefore, diverse stakeholders must participate in the planning process to address broad-scale threats and challenges of the twenty-first century. While a broad extent is needed to identify core areas and corridors for fish and wildlife populations, a fine scale resolution is needed to manage for multiple, interconnected ecosystems. Here, we developed a conservation plan using a systematic approach to promote landscape-level conservation within the extent of the South Atlantic Landscape Conservation Cooperative. Our objective was to identify the highest ranked 30% of lands and waters within the South Atlantic deemed necessary to conserve ecological and cultural integrity for the ten primary ecosystems of the southeastern United States. These environments varied from terrestrial, freshwater aquatic, and marine. The planning process was driven by indicators of ecosystem integrity at a 4-ha resolution. We used the program Zonation and 28 indicators to optimize the identification of lands and waters to meet the stated objective. A novel part of our study was the prioritization of multiple ecosystems, and we discuss the advantages and disadvantages of this approach. The evaluation of indicator representation within prioritizations was a useful method to show where improvements could be made; some indicators dictated hotspots, some had a limited extent and were well represented, and others had a limited effect. Overall, we demonstrate that a broad-scale (408,276 km2 of terrestrial and 411,239 km2 of marine environments) conservation plan can be realized at a fine-scale resolution, which will allow implementation of the regional plan at a local level relevant to decision-making.
The growing demand for new destinations, for new experiences, for different realities and cultures, the need for contact with authentic heritage, and the will to participate in the co-creation of experiences are marking the development of tourism for the future. The evolution of knowledge and demand in Tourism research, direct us on a new path of knowledge, a meeting between the strong presence of tourism in coastal areas and the still fragile tourism in rural areas. The aim of this paper is to present a coastal tourism development model in rural areas. The model was created based on key elements of tourism, tourism in rural areas and tourism in coastal areas, focusing on their relationship, complementarity and sustainability. The model intends to be innovative in creating a differentiated tourism market, based on new dimensions of knowledge on Tourism.
Marine protected areas (MPAs) are being successful in the management of fishing resources and conservation of biodiversity in many parts of the world. The assessment of the management effectiveness provides examples to improve the management of these areas. Thus, this study assessed the management effectiveness of 11 MPAs with reef environments in the coast of Brazil, in the period of 10 years (2005, 2010, and 2015), through the method of Rapid Assessment and Priorization of Protected Area Management (RAPPAM). The questionnaire was also used to address the pressure (activities that affect the MPA in the last 5 years) and threats (activities that can potentially affect the MPA in the next 5 years. From the 11 MPAs assessed, the highest values of pressures and threats were obtained for two areas in the year of 2005 and four areas in 2015 (above 35%). The mean management effectiveness between 2005 and 2015 increased from 55.6% (±8.2) in 2005 to 60% (±11.5) in 2015. However, even with this increase, the mean effectiveness of some MPAs is still below the limit considered ideal for satisfactory management (<40%), and the number of MPAs with good management (>60%) has not changed over time.
Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline, and shoaling of intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin. The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching “atlantification” of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows.
Data from real-time sensor networks along the Great Barrier Reef (GBR) over the 2015–2016 austral summer showed that reef water temperatures exceeded empirical coral bleaching thresholds at a number of sites. Temperatures in the southern GBR were within historically normal limits with temperatures below the empirical bleaching threshold. The central GBR just reached the empirical bleaching threshold while, in the north, Lizard Island recorded four consecutive days above the bleaching threshold. Thursday Island in the far northern GBR experienced 10 days above the bleaching threshold. The in situ data predicted only slight bleaching in the southern GBR, moderate bleaching in the central GBR, widespread bleaching in the north and severe bleaching in the far north, which compares well with the initial survey data. Peak temperatures occurred later in the year in the north (mid-March 2016) than in the south (early February 2015) with temperatures remaining above the long-term mean well into the austral autumn. Comparison against satellite sea surface temperature data highlighted issues of cloud cover with data only being available for 30–40% of days over the summer. While the agreement with the in situ data was good, the satellite data missed fine-scale events and under-estimated the event at Thursday Island.
The blue economy can be a driver for Europe's welfare and prosperity. That was the message of the Blue Growth Strategy adopted by the Commission in 2012. Since then, the Commission has undertaken a series of steps to translate it into actions. It has launched initiatives in many policy areas related to Europe's oceans, seas and coasts, facilitating the cooperation between maritime business and public authorities across borders and sectors, and stakeholders to ensure the sustainability of the marine environment.