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.
This study was implemented in the context of the emerging concept of aesthetic ecosystem services (AES) of coastal protected dunes and forests. The main problem addressed was that many coastal management research case studies focusing on AES still rely on the objectivist paradigm, eliciting aesthetic values based on objective sets of criteria independent from human perception ‘here and now’. This doesn't use the knowledge accrued from several decades of psychophysical studies in landscape aesthetics using photographs as visual stimuli, due to the complexity of the psychophysical approach. The study bridges this major research gap by eliciting the preferences for and the attractiveness of coastal landscapes that are founded in the landscape's physical attributes. An innovative ‘quali-quantitative’ methodology was applied, combining both quantitative (paired comparison survey) and qualitative (semi-structured in-depth interviews) methods for valuation and interpretation of coastal AES. The main aim of the study was to test a ‘quali-quantitative’ methodology for the valuation of AES of protected coastal dunes and forests, using the Curonian Spit (Lithuania) as a case study. The key finding of the quantitative survey was that domestic summer visitors found the open landscapes of the Curonian Spit most attractive, especially 1) White mobile dunes; 2) White dunes with grey dunes in the background; 3) Grey dunes with white dunes in the background. The main result of the qualitative survey was that local stakeholders living on the Curonian Spit consider the concept of visual coherence as best explaining the aesthetic appeal of the dune and forest landscapes on the spit. The main associated policy recommendation to coastal management policymakers on the Curonian Spit, and in other protected coastal dune areas, is to pay more attention to AES along with the care for biodiversity conservation and for other tangible dune ecosystem services.
The life-histories of exploited fish species, such as Pacific salmon, are vulnerable to a wide variety of anthropogenic stressors including climate change, selective exploitation and competition with hatchery releases for finite foraging resources. However, these stressors may generate unexpected changes in life-histories due to developmental linkages when species complete their migratory life cycle in different habitats. We used multivariate time-series models to quantify changes in the prevalence of different life-history strategies of sockeye salmon from Bristol Bay, Alaska, over the past half-century—specifically, how they partition their lives between freshwater habitats and the ocean. Climate warming has decreased the time spent by salmon in their natal freshwater habitat, as climate-enhanced growth opportunities have enabled earlier migration to the ocean. Migration from freshwater at a younger age, and increasing competition from wild and hatchery-released salmon, have tended to delay maturation toward the salmon spending an additional year feeding in the ocean. Models evaluating the effects of size-selective fishing on these patterns had only small support. These stressors combine to reduce the size-at-age of fish vulnerable to commercial fisheries and have increasingly favoured a single-age class, potentially affecting the age class complexity that stabilizes this highly reliable resource.
Rocky intertidal habitats in urbanized settings, such as in southern California, USA, are heavily perturbed by human visitors (tidepoolers) through the deleterious activities of collecting, handling, and trampling. To protect rocky intertidal biota, certain locations have been designated as Marine Protected Areas (MPAs), yet MPA status can be ineffective when public knowledge of regulations is low and regulations do not protect flora and fauna from the impacts of handling and trampling. To help reduce detrimental activities of visitors, propagate environmentally-safe tidepooling behaviors, and increase public knowledge of MPA regulations, two outreach tools were instituted in southern California, USA: 1) an education program whereby trained educators are on-site, interacting with the public and educating visitors about MPA regulations, and 2) the ISOpod (Interactive Sealife Outreach pod) vehicle, a mobile tidepool exhibit parked near the site for visitors to observe organisms in a controlled setting and where MPA awareness is emphasized. To determine if these tools were effective in reducing deleterious activities, visitors were discretely observed at two sites, counted, and placed into behavior categories under four scenarios based on combinations of the presence and absence of both the ISOpod and educators. A questionnaire was conducted at one site to determine if MPA regulation and conservation knowledge increased with public interaction with outreach programs. The ISOpod and, in part, educators were effective in reducing the frequency of individuals engaged in detrimental activities. This occurred despite high MPA awareness of visitors, which was further increased by public interaction with the ISOpod. Results from this study suggest that outreach programs focused on conservation education can be effective options to assist with protection of coastal ecosystems.
California's network of 124 marine protected areas (MPAs) is managed by state agencies with support from non-state partners. Partners include MPA Collaboratives, which were established through the California Collaborative Approach to provide a localized, comprehensive approach to ocean resource management by bringing together local experts and authorities in the areas of outreach and education, enforcement and compliance, and research and monitoring. Given their role in MPA management in California, there is a need to understand the contributions that MPA Collaboratives are making to MPA management activities. In this case study, Blue Earth Consultants, a Division of ERG, conducted a valuation of in-kind contributions made by non-state members of one Collaborative, the Orange County Marine Protected Area Council (OCMPAC), to MPA management activities in Orange County. We performed research and worked collaboratively with OCMPAC to develop a definition of in-kind contributions and a contribution reporting framework that asked respondents to report contributions by type (Labor Services; Goods, Equipment, and Supplies; Travel; Facilities; and Other) as well as by category (Outreach, Education, and Compliance Building; Research and Monitoring; Partnership Coordination and Fundraising Support; and Other). We distributed the reporting framework to each member organization of OCMPAC and performed data analysis to quantify the total values of the contributions they reported. We found that non-state members of OCMPAC contributed support worth over US $4 million to Orange County MPA management during a two-year time frame between 2013 and 2015. In both years, the contribution type with the greatest value was Labor Services, and the category with the greatest value was Outreach, Education, and Compliance Building. Member organizations also noted that their future contributions to OCMPAC, particularly volunteer hours and pro bono work, may be vulnerable to changes in funding, staff time, and organizational priorities. To help ensuring ongoing support for MPA management, OCMPAC and member organizations would benefit from dedicated staff time for MPA-related work, coordinating OCMPAC activities, and education and science programs, among other needs. The approach developed for this case study provides a replicable methodology for quantifying the value of in-kind contributions made through local partnerships to the management of natural resources in California and beyond.
In this paper, a multidisciplinary performance analysis model of a small intelligent ocean exploration underwater vehicle is established, which involves six disciplines such as the hull form, structure, propulsion, energy, maneuverability and general arrangement. Based on the radial basis function based high dimensional model, a design optimization is performed by using the concurrent subspace design method, which yields a set of design variables to address design requirements (weight, diving depth, and range). The construction of the corresponding approximate computational model is analyzed in detail. Performances of the vehicle before and after optimization are also compared. The results shows that the optimization lead to an decrease of vehicle weight as much as 27%., and the sea test results show that the designed underwater vehicle satisfies the design requirements of weight, diving depth and range, moreover, the navigation performance is improved significantly, which proves the effectiveness of the design method.
Shoreline litter is one of the most widespread pollution problems today. Since shorelines represent very sensitive and large geographical areas, any organized cleanup event requires considerable manpower in order to be successful. This case study illustrates how Vancouver Aquarium and World Wildlife Foundation recruited, organized, and retained tens of thousands of volunteers in order to build a shoreline cleanup movement across Canada.
A suite of recent international commitments and aspirational targets related to ocean conservation and sustainable fisheries management suggest growing consensus among states regarding the urgency of action. Yet, securing adequate financial resources to achieve these goals will be a crucial hurdle for many countries and will depend on financing mechanisms that go beyond traditional official development assistance (ODA) and philanthropy. An expanding and diversifying universe of financing mechanisms, however, risks generating confusion, incoherence, and uneven outcomes. This Special Issue on “Funding for ocean conservation and sustainable fisheries” was conceived to gain insights into current and emerging trends in the rapidly evolving world of ‘blue’ finance. While one emphasis of the Special Issue is on ODA and philanthropy, additional contributions also cover new and emerging financing mechanisms. Throughout the Special Issue, authors reflect on important gaps, future perspectives and prospects for greater impact. Two relevant topics for the Special Issue, for which dedicated manuscripts are not available, are also briefly addressed: China's growing role as a provider of development finance and a shift to overtly transactional use of aid by the current US administration.
Gear restrictions are an important management tool in small-scale tropical fisheries, improving sustainability and building resilience to climate change. Yet to identify the management challenges and complete footprint of individual gears, a broader systems approach is required that integrates ecological, economic and social sciences. Here we apply this approach to artisanal fish fences, intensively used across three oceans, to identify a previously underrecognized gear requiring urgent management attention. A longitudinal case study shows increased effort matched with large declines in catch success and corresponding reef fish abundance. We find fish fences to disrupt vital ecological connectivity, exploit > 500 species with high juvenile removal, and directly damage seagrass ecosystems with cascading impacts on connected coral reefs and mangroves. As semi-permanent structures in otherwise open-access fisheries, they create social conflict by assuming unofficial and unregulated property rights, while their unique high-investment-low-effort nature removes traditional economic and social barriers to overfishing.
In the present study, we surveyed the distribution and diversity of fungal assemblages associated with 10 species of marine animals from Antarctica. The collections yielded 83 taxa from 27 distinct genera, which were identified using molecular biology methods. The most abundant taxa were Cladosporium sp. 1, Debaryomyces hansenii, Glaciozyma martinii, Metschnikowia australis, Pseudogymnoascus destructans, Thelebolus cf. globosus, Pseudogymnoascus pannorum, Tolypocladium tundrense, Metschnikowia australis, and different Penicillium species. The diversity, richness, and dominance of fungal assemblages ranged among the host; however, in general, the fungal community, which was composed of endemic and cold-adapted cosmopolitan taxa distributed across the different sites of Antarctic Peninsula, displayed high diversity, richness, and dominance indices. Our results contribute to knowledge about fungal diversity in the marine environment across the Antarctic Peninsula and their phylogenetic relationships with species that occur in other cold, temperate, and tropical regions of the World. Additionally, despite their extreme habitats, marine Antarctic animals shelter cryptic and complex fungal assemblages represented by endemic and cosmopolitan cold-adapted taxa, which may represent interesting models to study different symbiotic associations between fungi and their animal hosts in the extreme conditions of Antarctica.
Knowledge on microplastic (MP) ingestion by cetaceans is difficult to obtain. We infer the potential for MP uptake by cetaceans from the occurrence of MP in prey species. First, we reviewed information on whale prey species, focussing on common minke (Balaenoptera acutorostrata) and sei whale (B. borealis), for which the most comprehensive quantitative datasets exist. Second, evidence of MP ingestion by their prey species was reviewed. We found common minke whales forageopportunistically on fish from various families: Ammodytidae, Clupeidae, Gadidae, Engraulidae and Osmeridae. Sei whales mostly feed on copepods, Engraulidae, Clupeidae and Scombridae. High levels of MP contamination are reported for Scombridae in the Atlantic and Engraulidae in the Northwest Pacific Ocean. Copepods exhibit low levels of MP ingestion in the Northeast Pacific Ocean. Species-specific prey preferences and feeding strategies imply different cetaceans have varied potential for MP uptake, even if they feed in similar geographic areas.
The natural capital of the vast deep ocean is significant yet not well quantified. The ecosystem services provided by the deep sea provide a wide range of benefits to humanity. Proposed deep-sea economic activities such as fishing, deep-sea mining and bioprospecting therefore need to be assessed in this context. In addition to quantifying the economic benefits and costs of such activities on their own, their potential impact on the deep-sea natural capital also needs to be considered.
This article describes such a natural capital approach, identifies relevant ecosystem services and looks at how a range of proposed commercial activities could be assessed in this context. It suggests a methodology for such analysis and suggests an approach to a sustainable blue deep-sea economy that is consistent with environmental precaution. It will close with suggestions of how potential risks can best be handled.
The article aims to show that modern environmental economics based on natural capital can provide a useful framework for deciding future deep-sea efforts.
Using the production and trade data of marine shellfish extracted from the database of FishStatJ, this study aims to i) measure development level (DL) of the marine shellfish industry (MSI) in 10 major producing countries by the TOPSIS model; ii) classify the MSI into different classes in term of the results from the above measurement; and iii) identify, by the variation coefficient, how DL of the MSI in the 10 countries was changing during the period of 1997–2016.
The results of the TOSIS analysis indicate that, by the relative closeness and the number of turning points, the 10 countries can be divided into three types, i.e., with no change (China and Thailand); with little change and in a gradual way (Japan, Canada, France, Spain and Italy); and with a dramatical change (USA, Chile and South Korea). In term of the mean of relative closeness, the 10 countries can be divided into four classes, i.e., excellent (class I), good (class II), weak (class III), and poor (class IV), with China being in class I, USA, Japan and Canada in class II, France, Chile, Spain and South Korea in class III, and Italy and Thailand in class IV.
The results of the variation coefficient analysis suggest that the difference in DL of the 10 countries’ MSI increased over the past 20 years. In particular, the difference among the developing countries increased significantly, while those between the developed countries shrank slightly.
Marine biogenic habitats—habitats created by living organisms—provide essential ecosystem functions and services, such as physical structuring, nutrient cycling, biodiversity support, and increases in primary, secondary, and tertiary production. With the growing trend toward ecosystem approaches to marine conservation and fisheries management, there is greater emphasis on rigorously designed habitat monitoring programs. However, such programs are challenging to design for data‐limited habitats for which underlying ecosystem processes are poorly understood. To provide guidance in this area, we reviewed approaches to benthic assessments across well‐studied marine biogenic habitats and identified common themes related to indicator selection, sampling methods, and survey design. Biogenic habitat monitoring efforts largely focus on the characteristics, distribution, and ecological function of foundation species, but may target other habitat‐forming organisms, especially when community shifts are observed or expected, as well as proxies of habitat status, such as indicator species. Broad‐scale methods cover large spatial areas and are typically used to examine the spatial configuration of habitats, whereas fine‐scale methods tend to be laborious and thus restricted to small survey areas, but provide high‐resolution data. Recent, emerging methods enhance the capabilities of surveying large areas at high spatial resolution and improve data processing efficiency, bridging the gap between broad‐ and fine‐scale methods. Although sampling design selection may be limited by habitat characteristics and available resources, it is critically important to ensure appropriate matching of ecological, observational, and analytical scales. Drawing on these common themes, we propose a structured, iterative approach to designing monitoring programs for marine biogenic habitats that allows for rigorous data collection to inform management strategies, even when data and resource limitations are present. A practical application of this approach is illustrated using glass sponge reefs—a recently discovered and data‐limited habitat type—as a case study.