Toxic chemicals within and adsorbed to microplastics (0.05–5 mm) have the potential to biomagnify in food webs. However, microplastic concentrations in highly productive, coastal habitats are not well understood. Therefore, we quantified the presence of microplastics in a benthic community and surrounding environment of a remote marine reserve on the open coast of California, USA. Concentrations of microplastic particles in seawater were 36.59 plastics/L and in sediments were 0.227 ± 0.135 plastics/g. Densities of microplastics on the surfaces of two morphologically distinct species of macroalgae were 2.34 ± 2.19 plastics/g (Pelvetiopsis limitata) and 8.65 ± 6.44 plastics/g (Endocladia muricata). Densities were highest in the herbivorous snail, Tegula funebralis, at 9.91 ± 6.31 plastics/g, potentially due to bioaccumulation. This study highlights the need for further investigations of the prevalence and potential harm of microplastics in benthic communities at remote locations as well as human population centers.
Functional ecosystems depend on biotic and abiotic connections among different environmental realms, including terrestrial, freshwater, and marine habitats. Accounting for such connections is increasingly recognized as critical for conservation of ecosystems, especially given growing understanding of the way in which anthropogenic landscape disturbances can degrade both freshwater and marine habitats. This need may be paramount in conservation planning for tropical island ecosystems, as habitats across realms are often in close proximity, and because endemic organisms utilize multiple habitats to complete life histories. In this study, we used Marxan analysis to develop conservation planning scenarios across the five largest islands of Hawaii, in one instance accounting for and in another excluding habitat connectivity between inland and coastal habitats. Native vegetation, perennial streams, and areas of biological significance along the coast were used as conservation targets in analysis. Cost, or the amount of effort required for conservation, was estimated using an index that integrated degree and intensity of anthropogenic landscape disturbances. Our results showed that when connectivity is accounted for among terrestrial, freshwater, and marine habitats, areas identified as having high conservation value are substantially different compared to results when connectivity across realms is not considered. We also showed that the trade-off of planning conservation across realms was minimal and that cross-realm planning had the unexpected benefit of selecting areas with less habitat degradation, suggesting less effort for conservation. Our cross-realm planning approach considers biophysical interactions and complexity within and across ecosystems, as well as anthropogenic factors that may influence habitats outside of their physical boundaries, and we recommend implementing similar approaches to achieve integrated conservation efforts.
The use of mangroves as a travel and tourism destination has not received much attention, but provides a high-value, low impact use of these important ecosystems. This work quantifies and maps the distribution of mangrove visitation at global scales using keyword searches on user-generated content of the popular travel website, TripAdvisor. It further explores the use of user-generated content to uncover information about facilities, activities and wildlife in mangrove tourism locations world-wide. Some 3945 mangrove “attractions” are identified in 93 countries and territories. Boating is the most widespread activity, recorded in 82% of English-language sites. Birdlife is recorded by visitors in 28% of sites, with manatees/dugongs and crocodiles/alligators also widely reported. It is likely that mangrove tourism attracts tens to hundreds of millions of visitors annually and is a multi-billion dollar industry.
Renewable energy and sustainable food production are high on the international agenda, as is the prospect of expanding activity northwards to Arctic waters. In this article, we review core elements of the marine governance systems for aquaculture facilities and offshore wind farms in Norway and Scotland. Management of these sectors through strategic planning, marine spatial planning and licensing systems furthers rule of law values such as stability and predictability, making investment less risky. The review illustrates how the governance systems also facilitate flexibility and adaptability, balancing predictability considerations against the need to adapt management to natural and economic changes and innovative technologies, or even effective multi-use. This article discusses what endeavours have been made to strike a balance between predictability and adaptability in these sectors in Norway and Scotland. This study of marine management regimes in the Arctic and northern parts of the Temperate Northern Atlantic, and the values underpinning these regimes, provides lessons for the future of the Arctic.
The presence and effects of plastic debris is increasingly investigated. The majority of studies focuses on microplastics (MPs), but few reports suggest that plastic fragments in the <100 nm size range, referred to as nanoplastics (NPs), may also be formed in the aquatic environment and further to humans. This paper provides a review on routes of human exposure and potential effects of MPs and NPs to human health. MPs/NPs could potentially induce: physical damages through particles itself, and biological stress through MPs/NPs alone or leaching of additives (inorganic and organic). Future research should evaluate trophic transfer of MPs/NPs with their associated chemicals through the marine food web.
There is a controversy in the literature on marine protected areas (MPAs) over the way their outcomes are portrayed in terms of winners and losers. On the one hand, many analysts have portrayed MPAs as win-win solutions, resulting in both increased biodiversity and improved livelihoods. On the other hand, some analysts have argued that win-win outcomes are mythical, and in practice, MPAs invariably result in trade-offs between ecological and economic objectives. This study seeks to test which of these two hypotheses fits the Cabo de Palos Islas Hormigas marine protected area (CPH-MPA) in southeast Spain. However, it does so not by analysing directly the tension between the two objectives of ecological and economic goals, but by analysing the tensions between four groups of stakeholders—fishers, divers, community residents, and administrators—which map on to the tension between the two goals. The study is based on 111 interviews of key informants conducted in 2013–2014 to discover the perceptions of stakeholders on the issue of who are the winners and who are the losers as a result of the MPA. The main findings of this study on the CPH-MPA are that winning and losing are very complex and ambiguous categories; that there is no objective way of determining who are winners or losers; that the situation of winners and losers is due to human intervention rather than a natural and inevitable process; that win-win outcomes are implausible because trade-offs between wins and losses are inevitable; and that political authorities have to decide who will be the winners and who will be the losers.
Coastal human ecology (CHE) is a mixture of different theoretical and thematic approaches straddling between the humanities and social and natural sciences which studies human and coastal/marine interactions at the local-scale and through intense fieldwork. Topics of interest include human coastal adaptations past and present; the historical ecology of fisheries and future implications; local forms of marine governance and economic systems; local food security and livelihoods, and indigenous/local ecological knowledge systems among many research themes. In this paper, I explore different strands of CHE in the study of tribal, artisanal, and small-scale industrial fisheries from the mid-90s onward that can contribute to the foundational knowledge necessary for designing and implementing successful coastal fisheries management and conservation programs. Marine conservation has often failed due to a lack of understanding of the fine grained marine human-environmental interactions at the local scale. In this context, I also examine developing and future research directions in CHE, and discuss their potential contribution for filling the gap in existing approaches to actionable scholarship in marine conservation. The strength of many CHE approaches lies in their potential for bridging humanism and natural science, and thus CHE approaches are well equipped to address many of the challenges faced by marine conservation practitioners today.
The aspirations for natural capital and ecosystem service approaches to support environmental decision-making have not been fully realised in terms of their actual application in policy and management contexts. Application of the natural capital approach requires a range of methods, which as yet have not been fully tested in the context of decision making for the marine environment. It is unlikely that existing methodologies, which were developed for terrestrial systems and are based on land cover assessment approaches, will ever be feasible in the marine context at the national scale. Land cover approaches are also fundamentally insufficient for the marine environment because they do not take account of the water column, the significant interconnections between spatially disparate components, or the highly dynamic nature of the marine ecosystem, for example the high spatial mobility of many species. Data gaps have been a significant impediment to progress, so alternative methods that use proxies for quality information as well as the opportunities for remote sensing should be explored further. Greater effort to develop methodologies specifically for the marine environment is required, which should be interdisciplinary and cross-sectoral, coherent across policy areas, and applicable across a range of contexts.
The most recently revised CFP Regulation, adopted in 2013, includes a number of significant changes with the aim to make fisheries more in tune with concept of the ecosystem approach and to avoid unsustainable exploitation of marine biological resources, including fish, as a natural resource. As part of that the CFP Regulation introduced the landing obligation, an obligation to land all catches as opposed to previous praxis where fisheries have been relying on a system of discarding fish and other marine biological resources in order to optimize their catch. One aim with the landing obligation is to push for new adaptive fishing methods and in a way to implement an ecosystem approach since the fishing strategies are meant to be adjusted to ecosystem factors. To be effective, the system for controlling implementation must be adjusted to take different aspects of the ecosystem approach into account. The paper presents some reflections on the required balance between adaptive approaches connected to the ecosystem approach and the strictness established by principles of rule of law in relation to the so called EU CFP landing obligation. It is concluded that the best way to create a control system adjusted to these factors seems to be by giving more influence to the industry itself. Involving those concerned at all levels, and thus applying all aspects of the regulatory governance under an ecosystem approach, would create an effective adaptive system where the rule of law is also safe-guarded.
Worldwide, as wild-caught commercial fisheries plateau and human demands for protein increase, marine aquaculture is expanding. Much marine aquaculture is inherently adaptable to changing climatic and chemical conditions. Nevertheless, siting of marine aquaculture operations is subject to competing environmental, economic, and social demands upon and priorities for ocean space, while some forms of marine aquaculture can also impose other externalities on marine systems, such as pollution from wastes (nutrients) and antibiotics, consumption of wild fish as food, and introduction of non-native or genetically modified species. As a result, governmental policy decisions to promote both marine aquaculture that can adapt to a changing ocean and adaptive governance for that aquaculture can become contested, requiring attention to their social legitimacy.
This article explores how the law can promote the adaptability of marine aquaculture to climate change and ocean acidification—adaptive marine aquaculture—while still preserving key rule-of-law values, such as public participation and accountability. Perhaps most obviously, law can establish substantive requirements for marine aquaculture that minimize its impacts, promoting marine resilience overall. However, to foster truly adaptive marine aquaculture, including adaptive governance institutions, coastal nations should also procedurally reform their marine spatial planning efforts to legally connect the procedures for aquaculture permitting, marine spatial planning (MSP), and adaptive management. The goals for such connections, moreover, should be to mandate new forums for public participation and creative collaboration, promote experimentation with accountability that leads to increased knowledge, and foster the emergence of adaptive governance regarding the use of marine space.
The history of commercial exploitation of fish stocks is replete with instances of over-exploitation and stock collapse. Particularly in situations where little is known about a species or a particular fish stock, unregulated expansion into new fisheries may effectively wipe out a species or stock before its existence is even formally recognised or understood. Globally, there has been a strong interest in ensuring that such a fate does not befall any fish stocks that either exist in or may migrate in future into the high seas portion of the Central Arctic Ocean. The Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean establishes a framework for the acquisition of science upon which precautionary, ecosystem-based management measures can be based, if and when they become necessary in the future. This article examines the role of international law in facilitating both the adoption of the Agreement and the adaptive management of fisheries in the high seas portion of the Central Arctic Ocean. It will be shown that the Agreement provides the initial framework for precautionary, ecosystem-based, adaptive and environmentally sound decision making regarding potential future fisheries in the Central Arctic Ocean.
The deep ocean below 200 m water depth is the least observed, but largest habitat on our planet by volume and area. Over 150 years of exploration has revealed that this dynamic system provides critical climate regulation, houses a wealth of energy, mineral, and biological resources, and represents a vast repository of biological diversity. A long history of deep-ocean exploration and observation led to the initial concept for the Deep-Ocean Observing Strategy (DOOS), under the auspices of the Global Ocean Observing System (GOOS). Here we discuss the scientific need for globally integrated deep-ocean observing, its status, and the key scientific questions and societal mandates driving observing requirements over the next decade. We consider the Essential Ocean Variables (EOVs) needed to address deep-ocean challenges within the physical, biogeochemical, and biological/ecosystem sciences according to the Framework for Ocean Observing (FOO), and map these onto scientific questions. Opportunities for new and expanded synergies among deep-ocean stakeholders are discussed, including academic-industry partnerships with the oil and gas, mining, cable and fishing industries, the ocean exploration and mapping community, and biodiversity conservation initiatives. Future deep-ocean observing will benefit from the greater integration across traditional disciplines and sectors, achieved through demonstration projects and facilitated reuse and repurposing of existing deep-sea data efforts. We highlight examples of existing and emerging deep-sea methods and technologies, noting key challenges associated with data volume, preservation, standardization, and accessibility. Emerging technologies relevant to deep-ocean sustainability and the blue economy include novel genomics approaches, imaging technologies, and ultra-deep hydrographic measurements. Capacity building will be necessary to integrate capabilities into programs and projects at a global scale. Progress can be facilitated by Open Science and Findable, Accessible, Interoperable, Reusable (FAIR) data principles and converge on agreed to data standards, practices, vocabularies, and registries. We envision expansion of the deep-ocean observing community to embrace the participation of academia, industry, NGOs, national governments, international governmental organizations, and the public at large in order to unlock critical knowledge contained in the deep ocean over coming decades, and to realize the mutual benefits of thoughtful deep-ocean observing for all elements of a sustainable ocean.
Penguins face a wide range of threats. Most observed population changes have been negative and have happened over the last 60 years. Today, populations of 11 penguin species are decreasing. Here we present a review that synthesizes details of threats faced by the world’s 18 species of penguins. We discuss alterations to their environment at both breeding sites on land and at sea where they forage. The major drivers of change appear to be climate, and food web alterations by marine fisheries. In addition, we also consider other critical and/or emerging threats, namely human disturbance near nesting sites, pollution due to oil, plastics and chemicals such as mercury and persistent organic compounds. Finally, we assess the importance of emerging pathogens and diseases on the health of penguins. We suggest that in the context of climate change, habitat degradation, introduced exotic species and resource competition with fisheries, successful conservation outcomes will require new and unprecedented levels of science and advocacy. Successful conservation stories of penguin species across their geographical range have occurred where there has been concerted effort across local, national and international boundaries to implement effective conservation planning.
Traditional ecological research has focused on taxonomic units to better understand the role of organisms in marine ecosystems. This approach has significantly contributed to our understanding of how species interact with each other and with the physical environment and has led to relevant site-specific conservation strategies. However, this taxonomic-based approach can limit a mechanistic understanding of how environmental change affects marine megafauna, here defined as large fishes (e.g., shark, tuna, and billfishes), sea turtles, marine mammals, and seabirds. Alternatively, an approach based on traits, i.e., measurable behavioral, physiological, or morphological characteristics of organisms, can shed new light on the processes influencing structure and functions of biological communities. Here we review 33 traits that are measurable and comparable among marine megafauna. The variability of these traits within the organisms considered controls functions mainly related to nutrient storage and transport, trophic-dynamic regulations of populations, and community shaping. To estimate the contributions of marine megafauna to ecosystem functions and services, traits can be quantified categorically or over a continuous scale, but the latter is preferred to make comparisons across groups. We argue that the most relevant traits to comparatively study marine megafauna groups are body size, body mass, dietary preference, feeding strategy, metabolic rate, and dispersal capacity. These traits can be used in combination with information on population abundances to predict how changes in the environment can affect community structure, ecosystem functioning, and ecosystem services.
Underwater photogrammetry has been increasingly used to study and monitor the three-dimensional characteristics of marine habitats, despite a lack of knowledge on the quality and reliability of the reconstructions. More particularly, little attention has been paid to exploring and estimating the relative contribution of multiple acquisition parameters on the model resolution (distance between neighbor vertices), accuracy (closeness to true positions/measures) and precision (variability of positions/measures). On the other hand, some studies used expensive or cumbersome camera systems that can restrict the number of users of this technology for the monitoring of marine habitats. This study aimed at developing a simple and cost-effective protocol able to produce accurate and reproducible high-resolution models. Precisely, the effect of the camera system, flying elevation, camera orientation and number of images on the resolution and accuracy of marine habitat reconstructions was tested through two experiments. A first experiment allowed for testing all combinations of acquisition parameters through the building of 192 models of the same 36 m2study site. The flying elevation and camera system strongly affected the model resolution, while the photo density mostly affected bundle adjustment accuracy and total processing time. The camera orientation, in turn, mostly affected the reprojection error. The best combination of parameters was used in a second experiment to assess the accuracy and precision of the resulting reconstructions. The average model resolution was 3.4 mm, and despite a decreasing precision in the positioning of markers with distance to the model center (0.33, 0.27, and 1.2 mm/m Standard Deviation (SD) in X, Y, Z, respectively), the measures were very accurate and precise: 0.08% error ± 0.06 SD for bar lengths, 0.36% ± 0.51 SD for a rock model area and 0.92% ± 0.54 SD for its volume. The 3D geometry of the rock only differed by 1.2 mm ± 0.8 SD from the ultra-high resolution in-air reference. These results suggest that this simple and cost-effective protocol produces accurate and reproducible models that are suitable for the study and monitoring of marine habitats at a small reef scale.
Blue carbon is the organic carbon in oceanic and coastal ecosystems that is captured on centennial to millennial timescales. Maintaining and increasing blue carbon is an integral component of strategies to mitigate global warming. Marine vegetated ecosystems (especially seagrass meadows, mangrove forests, and tidal marshes) are blue carbon hotspots and their degradation and loss worldwide have reduced organic carbon stocks and increased CO2 emissions. Carbon markets, and conservation and restoration schemes aimed at enhancing blue carbon sequestration and avoiding greenhouse gas emissions, will be aided by knowing the provenance and fate of blue carbon. We review and critique current methods and the potential of nascent methods to track the provenance and fate of organic carbon, including: bulk isotopes, compound-specific isotopes, biomarkers, molecular properties, and environmental DNA (eDNA). We find that most studies to date have used bulk isotopes to determine provenance, but this approach often cannot distinguish the contribution of different primary producers to organic carbon in depositional marine environments. Based on our assessment, we recommend application of multiple complementary methods. In particular, the use of carbon and nitrogen isotopes of lipids along with eDNA have a great potential to identify the source and quantify the contribution of different primary producers to sedimentary organic carbon in marine ecosystems. Despite the promising potential of these new techniques, further research is needed to validate them. This critical overview can inform future research to help underpin methodologies for the implementation of blue carbon focused climate change mitigation schemes.
In highly social top predators, group living is an ecological strategy that enhances individual fitness, primarily through increased foraging success. Additive mortality events across multiple social groups in populations may affect the social structure, and therefore the fitness, of surviving individuals. This hypothesis was examined in a killer whale (Orcinus orca) population that experienced a 7-y period of severe additive mortality due to lethal interactions with illegal fishing vessels. Using both social and demographic analyses conducted on a unique long-term dataset encompassing periods before, during, and after this event, results indicated a decrease in both the number and the mean strength of associations of surviving individuals during the additive mortality period. A positive significant correlation between association strength and apparent survival suggested that the fitness of surviving individuals was impacted by the additive mortality event. After this event, individuals responded to the loss of relatives in their social groups by associating with a greater number of other social groups, likely to maintain a functional group size that maximized their foraging success. However, these associations were loose; individuals did not reassociate in highly stable social groups, and their survival remained low years after the mortality event. These findings demonstrate how the disruption of social structure in killer whales may lead to prolonged negative effects of demographic stress beyond an additive mortality event. More importantly, this study shows that sociality has a key role in the resilience of populations to human-induced mortality; this has major implications for the conservation of highly social and long-lived species.
Structurally complex habitat is declining across temperate marine environments. This trend has been attributed to changes in land use and increasing coastal development, which are activities likely to continue with governments supporting ongoing economic growth within the marine realm. This can compromise biodiversity, and biodiversity offsetting is increasingly being heralded as a means to reduce the conflict between development and conservation. Offset schemes are often evaluated against targets of ‘ecological equivalence’ or ‘like-for-like’ but these terms can be difficult to define and quantify. Although targets of equivalence have been generally shown to be feasible in terrestrial environments, the complex and dynamic nature of the marine and coastal realms present difficulties when aiming for strict equivalence targets as measures of success. Here, we investigated four intertidal biogenic reef habitats formed by the tube worm Sabellaria alveolata within, and in proximity to, Swansea Bay (Wales, UK). The aim was to identify measurable biodiversity components for S. alveolata reef habitat, and to investigate the natural spatio-temporal variation in these components, to determine whether a target of equivalence was feasible. We also looked to identify the most important drivers of species assemblages within the reefs. Results showed that biodiversity both S. alveolata formation and tube aperture condition showed a significant interaction between site and season, with community composition varying significantly by site only. Site was found to explain the highest variation in community composition, followed by substrate type, and geographical position. These results highlight how widely coastal habitats can vary, in both space and time, and therefore calls into question a strict target of ecological equivalence when planning biodiversity offsets in coastal environments.
The hypothesis that carnivorous consumers associated with the seabed are more likely to ingest marine debris was tested based on stomach content analysis of fish(Trichiurus lepturus and species of Ariidae) and cetaceans (Sotalia guianensis and Pontoporia blainvillei). Among 596 stomach contents, only 22 (3.7%) contained debris. The debris was flexible plastic, nylon yard, paper, latex, styrofoam and cigarettefilter. The proportion of stomach contents with debris varied among species: P. blainvillei (pelagic demersal consumer) presented the highest frequency of ingestion(15.7%), while T. lepturus (pelagic consumer), S. guianensis (pelagic consumer) and Ariidae (demersal consumer) presented similar frequencies (1.3–1.8%). Therefore, a feeding site in the water column does not predict the probability of debris ingestion. Concerning these species, this probability seems to be more associated with prey-capture strategies (or feeding behavior), regardless of debris availability in the environment.