Subtropical reefs are biogeographic transition zones, providing critical habitat for a range of tropical, subtropical and temperate biota, including many endemic species. To date, limited research has been conducted on assessing the level of SCUBA diving risks to subtropical benthic habitats. This study surveyed 407 SCUBA divers to determine the types and rates of contact presenting the greatest risk to benthic taxa. Data were aggregated to give the total number of severe contacts for each diver. Site-level analysis based on 95% confidence level showed that severe impacts were more probable as reef complexity increased vertically. A general linear regression model was used to assess the level of risk to habitat based on the contact type and benthic percentage cover. SCUBA tank, camera, diver's knee and untethered equipment created the greatest proportion of severe impacts to benthic taxa. As benthic percentage cover increased for Scleractinia, Echinodermata, Ascidiacea, Porifera, susceptibility and vulnerability to severe impacts also increased. Abrasions, breaks, compression and mucus release were common forms of impact. Risk assessment findings suggest that subtropical benthic taxa are highly susceptible to SCUBA diver impacts. Targeted risk reduction is required in future management strategies.
This paper considers fisheries bycatch reduction within the least-cost biodiversity impact mitigation hierarchy. It introduces conservatory offsets that are implemented earlier in the biodiversity impact mitigation hierarchy than conventional compensatory offsets used as instruments of last resort. The paper illustrates implementation in an on-going sea turtle conservation programme by the International Seafood Sustainability Foundation.
Indonesia's marine ecosystems form a fundamental part of the world's natural heritage, representing a global maxima of marine biodiversity and supporting the world's second largest production of seafood. Seagrasses are a key part of that support. In the absence of empirical data we present evidence from expert opinions as to the state of Indonesia's seagrass ecosystems, their support for ecosystem services, with a focus on fisheries, and the damaging activities that threaten their existence. We further draw on expert opinion to elicit potential solutions to prevent further loss. Seagrasses and the ecosystem services they support across the Indonesian archipelago are in a critical state of decline. Declining seagrass health is the result of shifting environmental conditions due largely to coastal development, land reclamation, and deforestation, as well as seaweed farming, overfishing and garbage dumping. In particular, we also describe the declining state of the fisheries resources that seagrass meadows support. The perilous state of Indonesia's seagrasses will compromise their resilience to climate change and result in a loss of their high ecosystem service value. Community supported management initiatives provide one mechanism for seagrass protection. Exemplars highlight the need for increased local level autonomy for the management of marine resources, opening up opportunities for incentive type conservation schemes.
“Dark times lie ahead of us and there will be a time when we must choose between what is easy and what is right”—the sad case of Vaquita, the Trump administration and the removal of protections for whales and dolphins
Improving and conserving marine ecosystems to maintain and promote their sustainability and to enhance or protect biodiversity and ecosystems’ services and functions is clearly a necessity. The importance of biodiversity in supporting ecosystem services and functioning has been established; thus, the worldwide creation of marine protected areas (MPAs), the goals of which vary with location, design, management, and compliance enforcement has been increasing. This paper explores the opinions regarding the creation of MPAs in Italy, people’s willingness to pay (WTP) for the conservation of marine biodiversity and ecosystem services, and maintenance of MPAs. The results indicate that most people would be willing to pay an entrance fee to MPAs, that is, depending of the valuation scenario proposed the mean WTP for a visit ranged from about €5 to €21 per person, and preferred environmental organizations as the most trustworthy organization type to manage the MPAs.
Warming weather conditions in the Arctic are already resulting in changes in both sea ice extent and thickness. The resulting extended ‘open water’ season has many implications for vessel traffic and marine life. For example, an increase in vessel traffic due to ice-free waters will most likely lead to an increased risk of impact on cetaceans through increased noise pollution, strike risk for some cetacean species, and the possibility of exposure to chemical pollutants. The objective of this study was to pre-empt a predicted increase in vessels by investigating and exploring possible management scenarios, with the aim of mitigating negative impacts on locally important species such as bowhead and beluga whales. Utilizing insights gained from established vessel management schemes in more southerly regions, this paper evaluates the current suite of tools being implemented and their appropriateness for implementation in a more extreme Arctic environment.
Designated large-scale marine protected areas (LSMPAs, 100,000 or more square kilometers) constitute over two-thirds of the approximately 6.6% of the ocean and approximately 14.5% of the exclusive economic zones within marine protected areas. Although LSMPAs have received support among scientists and conservation bodies for wilderness protection, regional ecological connectivity, and improving resilience to climate change, there are also concerns. We identified 10 common criticisms of LSMPAs along three themes: (1) placement, governance, and management; (2) political expediency; and (3) social–ecological value and cost. Through critical evaluation of scientific evidence, we discuss the value, achievements, challenges, and potential of LSMPAs in these arenas. We conclude that although some criticisms are valid and need addressing, none pertain exclusively to LSMPAs, and many involve challenges ubiquitous in management. We argue that LSMPAs are an important component of a diversified management portfolio that tempers potential losses, hedges against uncertainty, and enhances the probability of achieving sustainably managed oceans.
Deep-sea fish species are targeted globally by bottom trawling. The species captured are often characterized by longevity, low fecundity and slow growth making them vulnerable to overfishing. In addition, bottom trawling is known to remove vast amounts of non-target species, including habitat forming deep-sea corals and sponges. Therefore, bottom trawling poses a serious risk to deep-sea ecosystems, but the true extent of deep-sea fishery catches through history remains unknown. Here, we present catches for global bottom trawling fisheries between years 1950–2015. This study gives new insight into the history of bottom trawled deep-sea fisheries through its use of FAO capture data combined with reconstructed catch data provided by the Sea Around Us- project, which are the only records containing bycatches, discards and unreported landings for deep-sea species. We illustrate the trends and shifts of the fishing nations and discuss the life-history and catch patterns of the most prominent target species over this time period. Our results show that the landings from deep-sea fisheries are miniscule, contributing less than 0.5% to global fisheries landings. The fisheries were found to be overall under-reported by as much as 42%, leading to the removal of an estimated 25 million tons of deep-sea fish. The highest catches were of Greenland halibut in the NE Atlantic, Longfin codling from the NW Pacific and Grenadiers and Orange roughy from the SW Pacific. The results also show a diversification through the years in the species caught and reported. This historical perspective reveals that the extent and amount of deep-sea fish removed from the deep ocean exceeds previous estimates. This has significant implications for management, conservation and policy, as the economic importance of global bottom trawling is trivial, but the environmental damage imposed by this practice, is not.
The many values that humans place on biodiversity are widely acknowledged but difficult to measure in practice. We address this problem by quantifying the contribution of marine‐related environmental stewardship, in the form of donations and volunteer hours, to the economy of coastal Massachusetts. Our conservative evaluation suggests that marine stewardship activities contributed at least $179 million to the state economy in 2014, a figure that exceeded revenues derived in that same year from commercial finfish operations ($105 million) and whale watching ($111 million), two acknowledged cornerstones of the regional economy. Almost imperceptibly, the coastal economy has been transformed from one dependent on commercial exchange to a diverse economy that includes, to a large measure, marine stewardship. Donations and volunteer efforts are useful indicators of environmental values that can be hard to quantify, and represent one measure of human determination to protect the planet.
This research presents a comprehensive Cumulative Effects Assessment (CEA) based on the Tools4MSP modelling framework tested for the Italian Adriatic Sea. The CEA incorporates five methodological advancements: (1) linear and non-linear ecosystem response to anthropogenic pressures/effects, (2) modelling of additive, dominant and antagonist stressor effects, (3) implementation of a convolution distance model for stressor dispersion modelling, (4) application of a CEA backsourcing (CEA-B) model to identify and quantify sources of anthropogenic pressures affecting environmental components, based on the convolution distance model and (5) a novel CEA impact chain visualization tool based on Sankey diagrams. Results from CEA in the Italian Adriatic Sea show that highest CEA scores are located in the Northern Adriatic Sea (Port of Trieste and Venice Lagoon inlets) while abrasion, marine litter and selective extraction are the most pronounced pressures within the 12 nm. Results from CEA-B application for two case studies evidence a clear distinction among local human impacts (trawling, small scale fishery) versus long-range diffusive human impacts (underwater noise and marine litter). Results were discussed for their geospatial outcomes, importance for transboundary effects assessment, conservation planning and future application potentials.
The use of lethal research methods on cetaceans has a long and complicated history in cetology (the scientific study of whales, dolphins and porpoises). In the current era, collecting data through the hunting of whales (sometimes referred to as scientific whaling) remains a source of considerable conflict in various fora, including scientific ones. Based on interviews and documents, this article explores how marine mammal scientists articulate the validity of particular practices and research at both the International Whaling Commission and in professional scientific societies. Drawing on cultural theory, the article explores scientists’ boundary work, describing the purity and pollution of particular whaling practices in different institutional contexts. Respondents on either side of the debate argued for the pure or polluted nature of various positions, often utilising particular idealised values of science: objectivity, honesty and openness regarding how conclusions were drawn. The nature of boundary work performed is then related to the institutional context within which it takes place. This article thus highlights how science’s role in environmental conflicts can be assessed through boundary work that denotes who can legitimately speak for science, on what topics and how science is stage-managed.
Seabirds and fisheries have been interacting from ancient times, sometimes with mutual benefits: Seabirds provided fishermen with visual cues of fish aggregations, and also fed upon food subsids generated by fishing activities. Yet fisheries and seabirds may also compete for the same resources, and their interactions can lead to additional seabird mortality through accidental bycatch and diminishing fishing efficiency, threatening vulnerable seabird populations. Understanding these complex relationships is essential for conservation strategies, also because it could enhance and ease discussion between stakeholders, towards a common vision for marine ecosystem management. As an aid in this process, we reviewed 510 scientific publications dedicated to seabirds–fisheries interactions, and compiled a methodological toolkit. Methods employed therein serve four main purposes: (i) Implementing distribution overlap analyses, to highlight areas of encounter between seabirds and fisheries (ii) Analysing movement and behavioural patterns using finer-scale information, to characterize interaction types (iii) Investigating individual-scale feeding ecology, to assess fisheries impacts at the scale of bird populations, and (iv) Quantifying the impacts of seabird–fishery interactions on seabird demography and population trends. This latter step allows determining thresholds and tipping points with respect to ecological sustainability. Overall, we stress that forthcoming studies should integrate those multiple approaches, in order to identify and promote best practices towards ecosystem-based fisheries management and ecologically sound marine spatial planning.
Health and economic benefits may accrue from marine and coastal recreation. In England, few national-level descriptive analyses exist which examine predictors of recreation in these environments. Data from seven waves (2009–2016) of a representative survey of the English population (n = 326,756) were analysed to investigate how many recreational visits were made annually to coastal environments in England, which activities were undertaken on these visits, and which demographic, motivational, temporal, and regional factors predict them. Inland environments are presented for comparison. Approximately 271 million recreational visits were made to coastal environments in England annually, the majority involving land-based activities such as walking. Separately, there were around 59 million instances of water-based recreation undertaken on recreational visits (e.g. swimming, water sports). Visits to the coast involving walking were undertaken by a wide spectrum of the population: compared to woodland walks, for instance, coastal walks were more likely to be made by females, older adults, and individuals from lower socioeconomic classifications, suggesting the coast may support reducing activity inequalities. Motivational and temporal variables showed distinct patterns between visits to coastal and inland comparator environments. Regional variations existed too with more visits to coastal environments made by people living in the south-west and north-east compared to London, where more visits were made to urban open spaces. The results provide a reference for current patterns of coastal recreation in England, and could be considered when making policy-level decisions with regard to coastal accessibility and marine plans. Implications for future public health and marine plans are discussed.
Coastal ecosystems have drastically declined in coverage and condition across the globe. To combat these losses, marine conservation has recently employed habitat restoration as a strategy to enhance depleted coastal ecosystems. For restoration to be a successful enterprise, however, it is necessary to identify and address potential knowledge gaps and review whether the field has tracked scientific advances regarding best practices. This enables managers, researchers, and practitioners alike to more readily establish restoration priorities and goals. We synthesized the peer-reviewed, published literature on habitat restoration research in salt marshes, oyster reefs, and seagrasses to address three questions related to restoration efforts: (i) How frequent is cross-sector authorship in coastal restoration research? (ii) What is the geographic distribution of coastal restoration research? and (iii) Are abiotic and biotic factors equally emphasized in the literature, and how does this vary with time? Our vote-count survey indicated that one-third of the journal-published studies listed authors from at least two sectors, and 6% listed authors from all three sectors. Across all habitat types, there was a dearth of studies from Africa, Asia, and South America. Finally, despite many experimental studies demonstrating that species interactions can greatly affect the recovery and persistence of coastal foundation species, only one-fourth of the studies we examined discussed their effects on restoration. Combined, our results reveal gaps and discrepancies in restoration research that should be addressed in order to further propel coastal restoration science.
The role of rising atmospheric CO2 in modulating estuarine carbonate system dynamics remains poorly characterized, likely due to myriad processes driving the complex chemistry in these habitats. We reconstructed the full carbonate system of an estuarine seagrass habitat for a summer period of 2.5 months utilizing a combination of time-series observations and mechanistic modeling, and quantified the roles of aerobic metabolism, mixing, and gas exchange in the observed dynamics. The anthropogenic CO2 burden in the habitat was estimated for the years 1765–2100 to quantify changes in observed high-frequency carbonate chemistry dynamics. The addition of anthropogenic CO2 alters the thermodynamic buffer factors (e.g., the Revelle factor) of the carbonate system, decreasing the seagrass habitat’s ability to buffer natural carbonate system fluctuations. As a result, the most harmful carbonate system indices for many estuarine organisms [minimum pHT, minimum Ωarag, and maximum pCO2(s.w.)] change up to 1.8×, 2.3×, and 1.5× more rapidly than the medians for each parameter, respectively. In this system, the relative benefits of the seagrass habitat in locally mitigating ocean acidification increase with the higher atmospheric CO2 levels predicted toward 2100. Presently, however, these mitigating effects are mixed due to intense diel cycling of CO2 driven by aerobic metabolism. This study provides estimates of how high-frequency pHT, Ωarag, and pCO2(s.w.) dynamics are altered by rising atmospheric CO2 in an estuarine habitat, and highlights nonlinear responses of coastal carbonate parameters to ocean acidification relevant for water quality management.
Understanding how invasive species affect key ecological interactions and ecosystem processes is imperative for the management of invasions. We evaluated the effects of invasive corals (Tubastraea spp.) on fish trophic interactions in an Atlantic coral reef. Remote underwater video cameras were used to examine fish foraging activity (bite rates and food preferences) on invasive cover levels. Using a model selection approach, we found that fish feeding rates declined with increased invasive cover. For Roving Herbivores (RH) and Sessile Invertivores (SI), an abrupt reduction of fish feeding rates corresponded with higher invasive cover, while feeding rates of Territorial Herbivores (TH) and Mobile Invertivores (MI) decreased linearly with cover increase. Additionally, some fish trophic groups, such as RH, SI and Omnivores (OM), had lower densities in reef sections with high invasive cover. These findings demonstrate that invasive corals negatively impact fish-benthic interactions, and could potentially alter existing trophic relationships in reef ecosystems.
As catches of economically valuable target fishes decline, indiscriminate fisheries are on the rise, where commercial and small-scale fishers retain and sell an increasing number of marine species. Some of these catches are destined for international markets and subject to international trade regulations. Many of these species are considered “data-poor” in that there are limited data on their biology, ecology, and exploitation, which poses a serious management challenge for sustainable fisheries and trade. Our research explores the relative pressure exerted by such indiscriminate fisheries on a data-poor marine fish genus—seahorses (Hippocampus spp.)—whose considerable international trade is regulated globally. Our focus is Thailand, a dominant fishing nation and the world‘s largest exporter of seahorses, where we gathered data by interviewing commercial and small-scale fishers and through port sampling of landed catch. We estimate that annual catches were more than threefold larger than previously documented, approximating 29 million individuals from all gears. Three fishing gears–two commercial (otter and pair trawl) and one small-scale (gillnet)–caught the most individuals. Results from port sampling and our vulnerability analysis confirmed that H. kelloggi, H. kuda, and H. trimaculatuswere the three species (of seven found in Thai waters) most susceptible to fishing. Small-scale gillnets captured the majority of specimens under length at maturity, largely due to catches of juvenile H. kuda and H. trimaculatus. This research indicates a role for vulnerability analysis to initiate precautionary management plans while more extensive studies can be conducted.
Microplastics (plastics <5 mm diameter) are at the forefront of current environmental pollution research, however, little is known about the degradation of microplastics through ingestion. Here, by exposing Antarctic krill (Euphausia superba) to microplastics under acute static renewal conditions, we present evidence of physical size alteration of microplastics ingested by a planktonic crustacean. Ingested microplastics (31.5 µm) are fragmented into pieces less than 1 µm in diameter. Previous feeding studies have shown spherical microplastics either; pass unaffected through an organism and are excreted, or are sufficiently small for translocation to occur. We identify a new pathway; microplastics are fragmented into sizes small enough to cross physical barriers, or are egested as a mixture of triturated particles. These findings suggest that current laboratory-based feeding studies may be oversimplifying interactions between zooplankton and microplastics but also introduces a new role of Antarctic krill, and potentially other species, in the biogeochemical cycling and fate of plastic.
Large pelagic fishes are assessed and managed by tuna Regional Fisheries Management Organizations (tRFMOs). These organizations have been criticized for not meeting conservation objectives, which may relate to aspects of governance and management. No previous studies have systematically evaluated why management performance differs among tRFMOs and among stocks within each tRFMO. In this study, we collected data on the nature of research, management, enforcement and socioeconomics of management systems in the five principal tRFMOs of the world's oceans. We quantified influences of economic and fishery‐related factors on these management characteristics and examined how these factors vary among tRFMOs. We found that tRFMOs with a greater number of member countries, a greater economic dependency on tuna resources, a lower mean per capita gross domestic product, a greater number of fishing vessels and smaller vessels were associated with less intensive research, management and enforcement in these tuna fisheries. We also quantified the influence of specific management attributes and of biological, economic and fishery‐related factors on the trends and current status of large pelagic fish stocks in these regions. The most important factors correlated with trends and current stock status were external to the management systems, and included stock size, age at maturity, ex‐vessel price and economic dependency of countries on tuna fisheries. To improve the overall status of large pelagic fish stocks in the global high seas, more intensive data collection, research and management are needed in certain areas, especially in the Indian Ocean, and for certain stocks, especially non‐target species.
This paper aims to highlight the risk of climate change on coupled marine human and natural systems and explore possible solutions to reduce such risk. Specifically, it explores some of the key responses of marine fish stocks and fisheries to climate change and their implications for human society. It highlights the importance of mitigating carbon emission and achieving the Paris Agreement in reducing climate risk on marine fish stocks and fisheries. Finally, it discusses potential opportunities for helping fisheries to reduce climate threats, through local adaptation. A research direction in fish biology and ecology is proposed that would help support the development of these potential solutions.