Phytoplankton form the basis of the marine food web and are responsible for approximately half of global carbon dioxide (CO2) fixation (∼ 50 Pg of carbon per year). Thus, these microscopic, photosynthetic organisms are vital in controlling the atmospheric CO2 concentration and Earth’s climate. Phytoplankton are dependent on sunlight and their CO2-fixation activity is therefore restricted to the upper, sunlit surface ocean (that is, the euphotic zone). CO2 usually does not limit phytoplankton growth due to its high concentration in seawater. However, the vast majority of oceanic surface waters are depleted in inorganic nitrogen, phosphorus, iron and/or silica; nutrients that limit primary production in the ocean (Figure 1). Phytoplankton growth is mainly supported by either the recycling of nutrients or by reintroduction of nutrients from deeper waters by mixing. A small percentage of primary production, though, is fueled by ‘external’ or ‘new’ nutrients and it is these nutrients that determine the amount of carbon that can be sequestered long term in the deep ocean. For most nutrients such as phosphorus, iron, and silica, the external supply is limited to atmospheric deposition and/or coastal and riverine inputs, whereas their main sink is the sedimentation of particulate matter. Nitrogen, however, has an additional, biological source, the fixation of N2 gas, as well as biological sinks via the processes of denitrification and anammox. Despite the comparatively small contributions to the overall turnover of nutrients in the ocean, it is these biological processes that determine the ocean’s capacity to sequester CO2 from the atmosphere on time scales of ocean circulation (∼ 1000 years). This primer will highlight shifts in the traditional paradigms of nutrient limitation in the ocean, with a focus on the uniqueness of the nitrogen cycling and its biological sources and sinks.
Ecosystems store vast quantities of wealth, but difficulties measuring wealth held in ecosystems prevent its inclusion in accounting systems. Ecosystem-based management endeavors to manage ecosystems holistically. However, ecosystem-based management lacks headline indicators to evaluate performance. We unify the inclusive wealth and ecosystem-based management paradigms, allowing apples-to-apples comparisons between the wealth of the ecosystem and other forms of wealth, while providing a headline performance index for evaluating the performance of ecosystem-based management. We project that the Baltic Sea fishery ecosystem yields increasing stores of wealth over the next 50 y under the ecosystem-based management-inspired multispecies maximum sustainable yield management beginning in 2017, whereas the previous single-species management generally results in declining wealth.
Shark-diving is part of a rapidly growing industry focused on marine wildlife tourism. Our study aimed to provide an estimate of the economic value of shark-diving tourism across Australia by comprehensively surveying the whale shark (Rhincodon typus), white shark (Carcharodon carcharias), grey nurse shark (Carcharias taurus), and reef shark (mostly Carcharhinus amblyrhynchos and Triaenodon obesus) diving industries using a standardised approach. A socio-economic survey targeted tourist divers between March 2013 and June 2014 and collected information on expenditures related to diving, accommodation, transport, living costs, and other related activities during divers’ trips. A total of 711 tourist surveys were completed across the four industries, with the total annual direct expenditure by shark divers in Australia estimated conservatively at $25.5 M. Additional expenditure provided by the white-shark and whale-shark-diving industries totalled $8.1 and $12.5 M for the Port Lincoln and Ningaloo Reef regions respectively. International tourists diving with white sharks also expended another $0.9 M in airfares and other activities while in Australia. These additional revenues show that the economic value of this type of tourism do not flow solely to the industry, but are also spread across the region where it is hosted. This highlights the need to ensure a sustainable dive-tourism industry through adequate management of both shark-diver interactions and biological management of the species on which it is based. Our study also provides standardised estimates which allow for future comparison of the scale of other wildlife tourism industries (not limited to sharks) within or among countries.
The surface oil burns conducted by the U.S. Coast Guard from April to July 2010 during the Deepwater Horizon disaster in the Gulf of Mexico were simulated by small scale burns to characterize the pollutants, determine emission factors, and gather particulate matter for subsequent toxicity testing. A representative crude oil was burned in ocean-salinity seawater, and emissions were collected from the plume by means of a crane-suspended sampling platform. Emissions included particulate matter, aromatic hydrocarbons, polychlorinated dibenzodioxins/dibenzofurans, elements, and others, the sum of which accounted for over 92% by mass of the combustion products. The unburned oil mass was 29% of the original crude oil mass, significantly higher than typically reported. Analysis of alkanes, elements, and PAHs in the floating residual oil and water accounted for over 51% of the gathered mass. These emission factors, along with toxicity data, will be important toward examining impacts of future spill burning operations.
Millions of marine ornamental fishes are traded every year. Today, over half of the known nearly 4000 coral reef fish species are in trade with poor or no monitoring and demand is increasing. This study investigates their trade into and through Switzerland by analyzing import documents for live animals. In 2009, 151 import declarations with attached species lists for marine ornamental fishes from non-EU countries totaled 28 356 specimens. The 62% of the fishes remaining in Switzerland, comprised 440 marine species from 45 families, the rest transited to EU and non-EU countries. Despite the recognized large trade volume for the European region, due to bilateral agreements, no data is collected for imports from the EU. However, inferred data shows that more than 200 000 marine ornamental fishes could be imported into Switzerland every year and an unknown quantity re-exported. As biggest import region, it is therefore safe to assume, that the European region is importing at least as many marine ornamental fishes as the US. There is no adequate data-collecting system known to be in place in any country for monitoring this trade. The EU Trade Control and Expert System (TRACES) to monitor animal diseases could be adjusted to gather compulsory information for the EU and Switzerland. More than half of the species imported into Switzerland are not assessed by the IUCN and therefore marked as ‘not evaluated’ on the Red List. Overall, 70% of all known coral reef fish species have not been evaluated. If coral reef fishes are threatened or endangered due to large, possibly unsustainable numbers traded, it may be rational to monitor the trade in these species through the Convention on International Trade of Endangered Species (CITES).
Even in the presence of environmental safeguards, catastrophic accidents related to anthropogenic activities occur that can result in both immediate and chronic impacts on local biota. However, due to the unplanned nature of catastrophes, studies aimed to identify the effects of these accidents on an ecosystem and its inhabitants often have imperfect study designs that are reactive rather than proactive, resulting in methodological and analytical challenges. On 20 April 2010, following an explosion on the Deepwater Horizon oil rig, a well blowout occurred on the seafloor approximately 80 km off the Louisiana coast in the Gulf of Mexico. This blowout resulted in the largest marine oil spill in United States history, which impacted critical migratory stopover and overwintering habitat for many seabird and shorebird species, including species of high conservation concern such as the piping plover (Charadrius melodus). Here, we assessed the potential longer-term demographic impacts of the Deepwater Horizon oil spill on piping plovers in a capture-mark-recapture framework. We examined whether a series of demographic processes, including probabilities of remaining at a specific wintering site, over-winter and annual apparent survival, winter stopover duration, and abundance varied among oiled and unoiled habitats. We found that the perceived amount of oiling on land, in water, and on individual birds, as well as numerous demographic processes, were spatially or temporally variable. However, we found little support that piping plover demography was negatively influenced by the magnitude of oil observed at an impacted area, or that demographic rates substantially varied between reference and oil impacted areas. Nor did we find that piping plovers that were observed to be oiled had lower survival probabilities following the DWH oil spill relative to non-oiled individuals from the same winter population. Although we did not find that the Deepwater Horizon oil spill substantially influenced piping plovers, our methods provide an analytical framework to more appropriately address both the near or long-term impacts of an anthropogenic disturbance on a species.
During the last decade a number of Large Marine Protected Areas (LMPAs) – marine protected areas that exceed a minimum size threshold and are often in offshore or open ocean waters – have been designated in an effort to meet marine conservation objectives. Research on the human dimensions of LMPAs is limited, though comprehensive policy analysis requires an understanding of the full range of social, cultural and economic benefits associated with LMPA designation. This paper addresses this need by employing a stated preference choice experiment survey of U.S. west coast households to examine public preferences for different protected area designs sited off the U.S. west coast. Using data from over 3000 randomly selected households in California, Oregon, and Washington we estimate choice models and calculate economic values for a suite of LMPAs that vary in size and in the types of restrictions within area boundaries. Results show that the LMPA size yielding the highest value is ~15.6% of the west coast Federal waters. Results also underscore the importance of restriction type, as there are considerably different threshold sizes above which diminishing returns and negative economic values are derived from no-access reserves, no-take, and multiple-use designations. While the value of any specific configuration can be estimated using the model, results offer insight on optimal use designations from a public perspective for small (< 2.5% of west coast Federal waters), medium (2.5%–~10%) and large (> 10%) LMPAs sited off the U.S. west coast.
Increasing numbers of people are living in and using coastal areas. Combined with the presence of pervasive coastal threats, such as flooding and erosion, this is having widespread impacts on coastal populations, infrastructure and ecosystems. For the right adaptive strategies to be adopted, and planning decisions to be made, rigorous evaluation of the available options is required. This evaluation hinges on the availability and use of suitable datasets. For knowledge to be derived from coastal datasets, such data needs to be combined and analysed in an effective manner. This paper reviews a wide range of literature relating to data-driven approaches to coastal risk evaluation, revealing how limitations have been imposed on many of these methods, due to restrictions in computing power and access to data. The rapidly emerging field of ‘Big Data’ can help overcome many of these hurdles. ‘Big Data’ involves powerful computer infrastructures, enabling storage, processing and real-time analysis of large volumes and varieties of data, in a fast and reliable manner. Through consideration of examples of how ‘Big Data’ technologies are being applied to fields related to coastal risk, it becomes apparent that geospatial Big Data solutions hold clear potential to improve the process of risk based decision making on the coast. ‘Big Data’ does not provide a stand-alone solution to the issues and gaps outlined in this paper, yet these technological methods hold the potential to optimise data-driven approaches, enabling robust risk profiles to be generated for coastal regions.
Most larger water bodies worldwide are used for navigation, and the intensity of commercial and recreational navigation is expected to further increase. Navigation profoundly affects aquatic ecosystems. To facilitate navigation, rivers are trained and developed, and the direct effects of navigation include chemical and biological impacts (e.g., inputs of toxic substances and dispersal of non-native species, respectively). Furthermore, propagating ships create hydrodynamic alterations, often simply summarized as waves. Although ship-induced waves are recognized as influential stressors, knowledge on their effects is poorly synthesized. We present here a review on the effects of ship-induced waves on the structure, function and services of aquatic ecosystems based on more than 200 peer reviewed publications and technical reports. Ship-induced waves act at multiple organizational levels and different spatial and temporal scales. All the abiotic and biotic components of aquatic ecosystems are affected, from the sediment and nutrient budget to the planktonic, benthic and fish communities. We highlight how the effects of ship-induced waves cascade through ecosystems and how different effects interact and feed back into the ecosystem finally leading to altered ecosystem services and human health effects. Based on this synthesis of wave effects, we discuss strategies for mitigation. This may help to develop scientifically based and target-oriented management plans for navigational waters that optimize abiotic and biotic integrity and their ecosystem services and uses.
The excessive combustion of fossil fuels for energy provision have altered natural planetary functions, resulting in adverse biophysical and societal implications. Such implications have prompted many governments globally to advocate for the adoption of renewable energy systems in order to reduce GHG emissions. While renewable energy technologies such as solar and biogases have been thoroughly researched and deployed, tidal current turbines (TCTs) that harness kinetic energy from the lateral movement of the tides are a comparatively emerging renewable energy technology, and thus has received relatively less attention with respect to their potential to supplement the renewable energy transition. This paper examines the physics behind tidal movements and cycles, and the technological operation of TCTs. Environmental impacts and economic barriers are analyzed. Best practices of MSP from world leading nations are examined, along with current deploy-andmonitor-consenting regimes of TCT test facilities. An optimal TCT design is suggested based on a synthesis of information from proceeding sections. Finally, an analysis of the implementation of TCTs in Canada, China, and Norway is presented, the results of which demonstrate that harnessing the accessible and sustainably extractable resource of each nation can result in an aggregate installed capacity of 9076 MW through the deployment of 7564 TCTs at a cost of $5,740,964,430, thereby creating 14,467 jobs. This would produce 29,829,711 MW h/yr of electricity sold at approximately 22 cents/kWh, eliminating a total of 14,914,855,258 kg of CO2e, approximately 0.1%. of the projected global electricity demand for 2016.
Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.
Plastic waste that ends up in the oceans as marine litter is a tangible and urgent environmental pressure reaching even the most remote parts of the global oceans. It impacts marine life from plankton to whales and turtles to albatrosses. Public awareness on how the modern lifestyle and the use of plastics in all sectors of society has influenced the marine ecosystems in the last decades is growing, and an emerging discourse about countermeasures of all types can be seen in policies enacted by authorities in national, regional, and international policy arenas. Different coastal areas have launched Regional Action Plans (RAP) on marine litter that provide structured measures that need to be taken and general advice adapted to the respective region. However, the scale of the problem is not only global in dimension, it also cuts across all sectors in society, and until the use of materials in society becomes sustainable, plastic waste will continues to flow into the seas. This report focuses on how marine plastic litter affects Small Island Developing States (SIDS) because these are considered to be more directly vulnerable to environmental changes, including marine litter, than other countries.
This report was commissioned by the Swedish Agency for Marine and Water management and written by analysts at the Swedish Institute for the Marine Environment (affiliated with the University of Gothenburg, Lund University, and Chalmers University of Technology). In this report, it is documented how marine plastic litter reaches even the most remote parts of the oceans, such as some of the small island states, and how SIDS are especially vulnerable to environmental impacts such as climate change and marine litter. The origin and composition of marine plastic litter and its environmental and economic impacts are described. Finally, measures are discussed that can be launched to mitigate the problem, both from state agencies and private corporations. Here, measures from existing RAPs on marine litter are reviewed and examples of private initiatives are mentioned. Further, the corresponding legal framework is given and side effects of marine litter measures on the Sustainable Development Goals of the UN are debated.
Anthropogenic noise is a pollutant of international concern, with mounting evidence of disturbance and impacts on animal behaviour and physiology. However, empirical studies measuring survival consequences are rare. We use a field experiment to investigate how repeated motorboat-noise playback affects parental behaviour and offspring survival in the spiny chromis (Acanthochromis polyacanthus), a brooding coral reef fish. Repeated observations were made for 12 days at 38 natural nests with broods of young. Exposure to motorboat-noise playback compared to ambient-sound playback increased defensive acts, and reduced both feeding and offspring interactions by brood-guarding males. Anthropogenic noise did not affect the growth of developing offspring, but reduced the likelihood of offspring survival; while offspring survived at all 19 nests exposed to ambient-sound playback, six of the 19 nests exposed to motorboat-noise playback suffered complete brood mortality. Our study, providing field-based experimental evidence of the consequences of anthropogenic noise, suggests potential fitness consequences of this global pollutant.
Despite the environmental risks posed by microplastic pollution, there are presently few standardized protocols for monitoring these materials within marine and coastal habitats. We provide a robust comparison of methods for sampling microplastics on sandy beaches using pellets as a model and attempt to define a framework for reliable standing stock estimation. We performed multiple comparisons to determine: (1) the optimal size of sampling equipment, (2) the depth to which samples should be obtained, (3) the optimal sample resolution for cross-shore transects, and (4) the number of transects required to yield reproducible along-shore estimates across the entire sections of a beach. Results affirmed that the use of a manual auger with a 20-cm diameter yielded the best compromise between reproducibility (i.e., standard deviation) and sampling/processing time. Secondly, we suggest that sediments should be profiled to a depth of at least 1 m to fully assess the depth distribution of pellets. Thirdly, although sample resolution did not have major consequence for overall density estimates, using 7-m intervals provides an optimal balance between precision (SD) and effort (total sampling time). Finally, and perhaps most importantly, comparing the minimum detectable difference yielded by different numbers of transects along a given section of beach suggests that estimating absolute particle density is probably unviable for most systems and that monitoring might be better accomplished through hierarchical or time series sampling efforts. Overall, while our study provides practical information that can improve sampling efforts, the heterogeneous nature of microplastic pollution poses a major conundrum to reproducible monitoring and management of this significant and growing problem.
Scuba diving tourism has the potential to be a sustainable source of income for developing countries. Around the world, tourists pay significant amounts of money to see coral reefs or iconic, large animals such as sharks and manta rays. Scuba diving tourism is broadening and becoming increasingly popular, a novel type of scuba diving which little is known about, is muck diving. Muck diving focuses on finding rare, cryptic species that are seldom seen on coral reefs. This study investigates the value of muck diving, its participant and employee demographics and potential threats to the industry. Results indicate that muck dive tourism is worth more than USD$ 150 million annually in Indonesia and the Philippines combined. It employs over 2200 people and attracts more than 100,000 divers per year. Divers participating in muck dive tourism are experienced, well-educated, have high incomes, and are willing to pay for the protection of species crucial to the industry. Overcrowding of dive sites, pollution and conflicts with fishermen are reported as potential threats to the industry, but limited knowledge on these impacts warrants further research. This study shows that muck dive tourism is a sustainable form of nature based tourism in developing countries, particularly in areas where little or no potential for traditional coral reef scuba diving exists.
Although aquatic mammals are elusive subjects, long-term studies of cetaceans have revealed remarkable life-history traits, including long life spans, bisexual philopatry, prolonged maternal care, and even menopause. Long-term cetacean research, defined here as studies lasting ≥ 10 years, has also helped shape our understanding of large multilevel societies, fission–fusion dynamics, cultural processes, complex sociality, and cognition. Yet relative to their terrestrial counterparts, little is known about many cetacean societies, especially pelagic species; similarly, collection of biological samples (such as blood, feces, urine) from live subjects is rarely possible. Cetaceans have been severely impacted by human activities, from commercial whaling to fisheries bycatch, prey depletion, habitat loss, and chemical and noise pollution. Longitudinal research, defined as measuring the same individuals repeatedly over time, can provide vital information necessary for devising viable solutions for mitigating these impacts and promoting sustainable practices. This review evaluates key findings gleaned from continuous and systematic longitudinal studies of free-living cetaceans. We present examples for each topic, though our condensed review cannot be comprehensive. Given their adaptations to the marine environment, slow life histories, and complex societies, continued investment in long-term research is vital for both understanding and protecting this taxonomic group.
The objective of this paper is to present a method that qualifies the degree of visibility of an offshore wind farm from an observer located along the coast. In many cases, the deployment of an offshore wind farm leads to public opposition. This entails the need for the development of appropriate methods that might present in the most intelligible way the impacts of an offshore wind farm. Amongst many factors to take into account, the visual impact of such farms is surely a factor to take into account. We introduce a visual operator that integrates several parameters that mainly depend on the distance of the wind farm to the coast. We apply a measure that evaluates the horizon surface impact modulated by the number of distinguishable turbines and an aesthetic index based on turbine alignments. The whole method is implemented on top of Geographical Information System (GIS) and provides a decision-aid mechanism oriented to decision-makers. The whole approach is experimented in the context of a wind farm in North West France.
The establishment of Marine Protected Areas (MPAs) is seen as a chosen strategy in managing marine resources in Southeast Asia (SEA). The region has some of the most extensive coastline and diverse coral reef ecosystems that remain highly threatened. The need to protect these areas is definite, but establishment of a MPA often involves conflicts with its stakeholders that highly depend on the ecosystem. This paper reviews 32 studies that evaluated the MPA strategy implemented in various SEA countries since the 1980's to the present. The objective of this paper is to determine the effectiveness of the MPA strategy within the context of SEA. Biological, socioeconomic and governance indicators provided by The World Conservation Union (IUCN) were used in this paper as measures of MPA effectiveness. It was found that the MPA strategy may be ideally suited for some areas but may also be inappropriate for others. The three indicators are highly related to each other in determining a MPA success. An integrated study of these three aspects is believed to provide greater knowledge for future implementation of MPAs.
In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced a new policy interpretation for the Endangered Species Act. According to the Act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range. The 1973 law does not define “significant portion of its range,” leading to concerns that interpretations of “significant” by federal agencies and the courts could be inconsistent. The 2014 policy seeks to provide consistency by establishing that a portion of the range should be considered significant if the associated individuals’ “removal would cause the entire species to become endangered or threatened.” Here, we review quantitative techniques to assess whether a portion of a species’ range is significant according to the new guidance. Our assessments are based on the “3R” criteria – Redundancy (i.e., buffering from catastrophe), Resiliency (i.e., ability to withstand stochasticity), and Representation (i.e., ability to evolve) – that the Fish and Wildlife Service uses to determine if a species merits listing. We identify data needs for each quantitative technique and indicate which methods might be implemented given the data limitations typical of rare species. We also identify proxies that may be used with limited data. To assess potential data availability, we evaluate seven example species by assessing the data in their Species Status Assessments, which document all the information used during a listing decision. Our evaluation suggests that resiliency assessments will likely be most constrained by limited data. While we reviewed quantitative techniques for the US Endangered Species Act, other countries have legislation requiring identification of significant areas that could benefit from this research.
Coastal populations and tourism are growing worldwide. Consequently outdoor recreational activity is increasing and diversifying. While Marine Protected Areas (MPAs) are valuable for mitigating anthropogenic impacts, recreational uses are rarely monitored and studied, resulting in a lack of knowledge on users' practices, motivation and impacts. Based on boat counts and interview data collected in New Caledonia, we i) explored factors affecting user practices and motivations, ii) constructed fine-scale pressure indices covering activities and associated behaviors, and iii) assessed the relationships between user practices and site selection. User practices were found to depend on protection status, boat type and user characteristics. Pressure indices were higher within no-take MPAs, except for fishing. We found significant relationships between user practices and settings characteristics. In the context of increasing recreational uses, these results highlight options for managing such uses through settings management without jeopardizing the social acceptance of MPAs or the attainment of conservation goals.