One of the more challenging tasks in Marine Spatial Planning (MSP) is identifying critical areas for management and conservation of fish stocks. However, this objective is difficult to achieve in data-poor situations with different sources of uncertainty. In the present study we propose a combination of hierarchical Bayesian spatial models and remotely sensed estimates of environmental variables to be used as flexible and reliable statistical tools to identify and map fish species richness and abundance hot-spots. Results show higher species aggregates in areas with higher sea floor rugosity and habitat complexity, and identify clear richness hot-spots. Our findings identify sensitive habitats through essential and easy-to-use interpretation tools, such as predictive maps, which can contribute to improving management and operability of the studied data-poor situations.
About half of the world's oil supply, a fifth of coal supply and a tenth of natural gas supply are traded by ship. Accordingly, any significant shift in the size and shape of the global energy system has important consequences for shipping, which underpins international trade and supports economic development. The Paris Agreement requires an acceleration of the drive towards energy system decarbonisation. Yet, the International Maritime Organisation's understanding of the future is more in line with the high-carbon scenarios analysed here. This paper is a first comprehensive and global assessment of implications of fundamental changes to global and regional energy systems for international shipping, under-researched in energy scenarios consistent with deep decarbonisation. It concludes that, despite uncertainties (particularly with negative emission technologies), fossil fuel trade by the middle of the century will almost certainly be significantly lower under low-carbon than under high-carbon scenarios, and (for oil and coal) lower than in 2012. As to bioenergy and captured carbon dioxide, while their supply is expected to increase during a low-carbon transition, worldwide shipped trade in these commodities will not necessarily grow, based on the analysis in this paper. In other words, if the low-carbon futures envisioned in the Paris Agreement materialise, energy-related shipping will likely decline (by a quarter for oil and by 50% for coal in the median < 2 °C scenarios by 2050), with significant ramifications for policies and regulation in the shipping sector and international trade.
Scientific evidence suggests that rising levels of anthropogenic underwater sound (“ocean noise”) produced by industrial activities are causing a range of injuries to marine animals—in particular, whales. These developments have forced states and development proponents into acknowledging ocean noise as a threat to marine economic activity. This paper delivers a Gramsci-inspired critique of the modernizations of ocean noise regulation being wrought by science, state and politics. Gramsci was acutely interested in the dynamic and social nature of scientific research, and his writings affirm science's powers and ambitions. At the same time, he was keen to observe how science participates in the process he called hegemony. Using examples drawn from Canada's West Coast, I suggest that capital is engaging ocean noise not only as a regulatory problem issuing from legal duties and legitimacy concerns, but opportunities linked to the commercialization of ocean science.
Understanding how climate change and other environmental stressors will affect species is a fundamental concern of modern ecology. Indeed, numerous studies have documented how climate stressors affect species distributions and population persistence. However, relatively few studies have investigated how multiple climate stressors might affect species. In this study, we investigate the impacts of how two climate change factors affect an important foundation species. Specifically, we tested how ocean acidification from dissolution of CO 2and increased sea surface temperatures affect multiple characteristics of juvenile eastern oysters (Crassostrea virginica). We found strong impacts of each stressor, but no interaction between the two. Simulated warming to mimic heat stressed summers reduced oyster growth, survival, and filtration rates. Additionally, we found that CO 2-induced acidification reduced strength of oyster shells, which could potentially facilitate crab predation. As past studies have detected few impacts of these stressors on adult oysters, these results indicate that early life stages of calcareous marine organisms may be more susceptible to effects of ocean acidification and global warming. Overall, these data show that predicted changes in temperature and CO 2 can differentially influence direct effects on individual species, which could have important implications for the nature of their trophic interactions.
In this article, we examine the problem of coral reef destruction and discuss various stakeholders who suffer losses from the destruction. We then postulate a stakeholder versus threats matrix and outline an algorithm where public authorities can streamline policy based on expected losses. We also formulate, using local data, divergence between public good and individual benefits and examine the agent behaviour under monitoring. Our examples, using previous estimations on net benefits, give guidelines on how to form public policy and management strategies.
The interests, responsibilities and opportunities of states to provide infrastructure and resource management are not limited to their land territory but extend to marine areas as well. So far, although the theoretical structure of a Marine Administration System (MAS) is based on the management needs of the various countries, the marine terms have not been clearly defined. In order to define an MAS that meets the spatial marine requirements, the specific characteristics of the marine environment have to be identified and integrated in a management system. Most publications that address the Marine Cadastre (MC) concept acknowledge the three-dimensional (3D) character of marine spaces and support the need for MC to function as a multipurpose instrument. The Land Administration Domain Model (LADM) conceptual standard ISO 19152 has been referenced in scholarly and professional works to have explicit relevance to 3D cadastres in exposed land and built environments. However, to date, very little has been done in any of those works to explicitly and comprehensively apply LADM to specific jurisdictional MAS or MC, although the standard purports to be applicable to those areas. Since so far the most comprehensive MC modeling approach is the S-121 Maritime Limits and Boundaries (MLB) Standard, which refers to LADM, this paper proposes several modifications including, among others, the introduction of class marine resources into the model, the integration of data on legal spaces and physical features through external classes, as well as the division of law and administrative sources. Within this context, this paper distinctly presents both appropriate modifications and applications of the IHO S-121 standard to the particular marine and maritime administrative needs of both Greece and the Republic of Trinidad and Tobago.
The oceans are changing more rapidly than ever before. Unprecedented climatic variability is interacting with unmistakable long-term trends, all against a backdrop of intensifying human activities. What remains unclear, however, is how to evaluate whether conditions have changed sufficiently to provoke major responses of species, habitats, and communities. We developed a framework based on multimodel inference to define ecosystem-based thresholds for human and environmental pressures in the California Current marine ecosystem. To demonstrate how to apply the framework, we explored two decades of data using gradient forest and generalized additive model analyses, screening for nonlinearities and potential threshold responses of ecosystem states (n = 9) across environmental (n = 6) and human (n = 10) pressures. These analyses identified the existence of threshold responses of five ecosystem states to four environmental and two human pressures. Both methods agreed on threshold relationships in two cases: (1) the winter copepod anomaly and habitat modification, and (2) sea lion pup production and the summer mode of the Pacific Decadal Oscillation (PDO). Considered collectively, however, these alternative analytical approaches imply that as many as five of the nine ecosystem states may exhibit threshold changes in response to negative PDO values in the summer (copepods, scavengers, groundfish, and marine mammals). This result is consistent with the idea that the influence of the PDO extends across multiple trophic levels, but extends current knowledge by defining the nonlinear nature of these responses. This research provides a new way to interpret changes in the intensities of human and environmental pressures as they relate to the ecological integrity of the California Current ecosystem. These insights can be used to make more informed assessments of when and under what conditions intervention, preparation, and mitigation may enhance progress toward ecosystem-based management goals.
The evolution of cetaceans is one of the best examples of macroevolution documented from the fossil record. While ecological transitions dominate each phase of cetacean history, this context is rarely stated explicitly. The first major ecological phase involves a transition from riverine and deltaic environments to marine ones, concomitant with dramatic evolutionary transformations documented in their early fossil record. The second major phase involves ecological shifts associated with evolutionary innovations: echolocation (facilitating hunting prey at depth) and filter-feeding (enhancing foraging efficiency on small prey). This latter phase involves body size shifts, attributable to changes in foraging depth and environmental forcing, as well as re-invasions of freshwater systems on continental basins by multiple lineages. Modern phenomena driving cetacean ecology, such as trophic dynamics and arms races, have an evolutionary basis that remains mostly unexamined. The fossil record of cetaceans provides an historical basis for understanding current ecological mechanisms and consequences, especially as global climate change rapidly alters ocean and river ecosystems at rates and scales comparable to those over geologic time.
This paper reviews the use of acoustic telemetry as a tool for addressing issues in fisheries management, and serves as the lead to the special Feature Issue of Ecological Applications titled Acoustic Telemetry and Fisheries Management. Specifically, we provide an overview of the ways in which acoustic telemetry can be used to inform issues central to the ecology, conservation, and management of exploited and/or imperiled fish species. Despite great strides in this area in recent years, there are comparatively few examples where data have been applied directly to influence fisheries management and policy. We review the literature on this issue, identify the strengths and weaknesses of work done to date, and highlight knowledge gaps and difficulties in applying empirical fish telemetry studies to fisheries policy and practice. We then highlight the key areas of management and policy addressed, as well as the challenges that needed to be overcome to do this. We conclude with a set of recommendations about how researchers can, in consultation with stock assessment scientists and managers, formulate testable scientific questions to address and design future studies to generate data that can be used in a meaningful way by fisheries management and conservation practitioners. We also urge the involvement of relevant stakeholders (managers, fishers, conservation societies, etc.) early on in the process (i.e., in the co-creation of research projects), so that all priority questions and issues can be addressed effectively.
Identifying the most sensitive indicators to changes in fishing pressure is important for accurately detecting impacts. Biomass is thought to be more sensitive than abundance and length, while the wariness of fishes is emerging as a new metric. Periodically harvested closures (PHCs) that involve the opening and closing of an area to fishing are the most common form of fisheries management in the western Pacific. The opening of PHCs to fishing provides a unique opportunity to compare the sensitivity of metrics, such as abundance, length, biomass and wariness, to changes in fishing pressure. Diver-operated stereo video (stereo-DOV) provides data on fish behavior (using a proxy for wariness, minimum approach distance) simultaneous to abundance and length estimates. We assessed the impact of PHC protection and harvesting on the abundance, length, biomass, and wariness of target species using stereo-DOVs. This allowed a comparison of the sensitivity of these metrics to changes in fishing pressure across four PHCs in Fiji, where spearfishing and fish drives are common. Before PHCs were opened to fishing they consistently decreased the wariness of targeted species but were less likely to increase abundance, length, or biomass. Pulse harvesting of PHCs resulted in a rapid increase in the wariness of fishes but inconsistent impacts across the other metrics. Our results suggest that fish wariness is the most sensitive indicator of fishing pressure, followed by biomass, length, and abundance. The collection of behavioral data simultaneously with abundance, length, and biomass estimates using stereo-DOVs offers a cost-effective indicator of protection or rapid increases in fishing pressure. Stereo-DOVs can rapidly provide large amounts of behavioral data from monitoring programs historically focused on estimating abundance and length of fishes, which is not feasible with visual methods.
In several Pacific Island countries and territories (PICTs), rapid population growth and inadequate management of coastal fish habitats and stocks is causing a gap to emerge between the amount of fish recommended for good nutrition and sustainable harvests from coastal fisheries. The effects of ocean warming and acidification on coral reefs, and the effects of climate change on mangrove and seagrass habitats, are expected to widen this gap. To optimise the contributions of small-scale fisheries to food security in PICTs, adaptations are needed to minimise and fill the gap. Key measures to minimise the gap include community-based approaches to: manage catchment vegetation to reduce sedimentation; maintain the structural complexity of fish habitats; allow landward migration of mangroves as sea level rises; sustain recruitment and production of demersal fish by managing ‘source’ populations; and diversify fishing methods to increase catches of species favoured by climate change. The main adaptions to help fill the gap in fish supply include: transferring some fishing effort from coral reefs to tuna and other large pelagic fish by scaling-up the use of nearshore fish aggregating devices; developing fisheries for small pelagic species; and extending the shelf life of catches by improving post-harvest methods. Modelling the effects of climate change on the distribution of yellowfin tuna, skipjack tuna, wahoo and mahi mahi, indicates that these species are likely to remain abundant enough to implement these adaptations in most PICTs until 2050. We conclude by outlining the policies needed to support the recommended adaptations.
Effective management of coastal and marine resources requires knowledge of how community sensitivity varies spatially. With this in mind, we developed a benthic sensitivity index (SI), based on the distribution and abundance of five ecological groups that can be used to assess community tolerance to organic enrichment and other disturbances. The index, projected as a high-resolution map, ranks communities from those dominated by sensitive and ecologically important species (i.e. low SI values) to those composed mainly of tolerant and/or opportunistic species (i.e., high SI values). Applying our model to a multiple-use case study in southeast Brazil, we were able to show considerable variability in the sensitivity of communities across the study area that was relatively stable over time. This allowed us to evaluate the possible direct (i.e., spatially overlapping) and indirect effects (i.e., cumulative changes to the physical environment) of a range of activities on sensitive and ecologically diverse benthic communities. Our approach and the resulting high-resolution maps hold promise for a range of spatial planning applications, including the development of coastal infrastructure, assessments of the representativeness of marine protected areas and other activities such as the selection of appropriate locations for dredge spoil dumping. Overall, we present a novel and transparent way of extrapolating limited survey data to provide spatial and temporal information on the sensitivity of benthic communities in multiple-use coastal and marine areas.
Shark fin has long been one of the most highly demanded 'luxury seafood' in the Chinese market. From the latest available data (1998–2013), 130 countries/territories around the world were recorded as exporting shark fin to Hong Kong. Spain, Taiwan, Indonesia, UAE, Singapore and Japan made up over 50% of all of Hong Kong's shark fin imports. Comparison of Hong Kong's import data with the exporting countries/territories' FAO declarations indicates that some countries/territories are potentially consistently underreporting shark fin exports. Since 2009 Vietnam had overtaken China as the most important destination of Hong Kong's shark fin re-exports, a change that warrants further investigation. Ocean transportation was also identified as the most important transportation mode for shark fin imports into and re-exports from Hong Kong. Given the importance of Hong Kong and based on findings from this study, suggestions are made for the Hong Kong Government to tighten controls to reduce illegal trades, and eliminate loopholes so that a more comprehensive statistical representation of the shark fin trade may be captured for future analysis.
The biodiversity of East to Southeast (E–SE) Asian waters is rapidly declining because of anthropogenic effects ranging from local environmental pressures to global warming. To improve marine biodiversity, the Aichi Biodiversity Targets were adopted in 2010. The recommendation of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA), encourages application of the ecologically or biologically significant area (EBSA) process to identify areas for conservation. However, there are few examples of the use of EBSA criteria to evaluate entire oceans. In this article, seven criteria are numerically evaluated to identify important marine areas (EBSA candidates) in the E–SE Asia region. The discussion includes 1) the possibility of EBSA criteria quantification throughout the E–SE Asia oceans and the suitability of the indices selected; 2) optimal integration methods for criteria, and the relationships between the criteria and data robustness and completeness; and; 3) a comparison of the EBSA candidates identified and existing registered areas for the purpose of conservation, such as marine protected areas (MPAs). Most of the EBSA criteria could be quantitatively evaluated throughout the Asia-Pacific region. However, three criteria in particular showed a substantial lack of data. Our methodological comparison showed that complementarity analysis performed better than summation because it considered criteria that were evaluated only in limited areas. Most of the difference between present-day registered areas and our results for EBSAs resulted from a lack of data and differences in philosophy for the selection of indices.
The Topical Collection on Invasive Species includes 50 articles addressing many tenets of marine invasion ecology. The collection covers important topics relating to propagule pressure associated with transport vectors, species characteristics, attributes of recipient ecosystems, invasion genetics, biotic interactions, testing of invasion hypotheses, invasion dynamics and spread, and impacts of nonindigenous species. This article summarizes some of the collection’s highlights.
The oceans appear ideal for biodiversity — they have unlimited water, a large area, are well connected, have less extreme temperatures than on land, and contain more phyla and classes than land and fresh waters. Yet only 16% of all named species on Earth are marine. Species richness decreases with depth in the ocean, reflecting wider geographic ranges of deep sea than coastal species. Here, we assess how many marine species are named and estimated to exist, paying particular regard to whether discoveries of deep-sea organisms, microbes and parasites will change the proportion of terrestrial to marine species. We then review what factors have led to species diversification, and how this knowledge informs conservation priorities. The implications of this understanding for marine conservation are that the species most vulnerable to extinction will be large and endemic. Unfortunately, these species are also the most threatened by human impacts. Such threats now extend globally, and thus the only refuges for these species will be large, permanent, fully protected marine reserves.
Using long-term data from government, non-government, academic, and industry sources, we developed species distribution models (SDMs) to predict priority areas in which to target and enhance blue whale Balaenoptera musculus and northern bottlenose whale Hyperoodon ampullatus monitoring efforts in eastern Canada. Priority areas for blue whales were located primarily on the Scotian Shelf and along the south shelf break in waters off Newfoundland. Priority areas for northern bottlenose whales were identified primarily in areas along the edges of the eastern Scotian Shelf and the Newfoundland and Labrador Shelves, in submarine canyons, and deep basins. The SDM results and the tools presented in this study indicate that there are few conservation areas in eastern Canada that currently protect whales at risk, and that priority areas for blue and northern bottlenose whales overlap with regions where noise-producing activities (shipping and seismic exploration) occur. This study also highlighted large gaps in the cetacean data related to human activities (e.g. seismic survey lines are outdated and recent information from the past 5 to 10 yr is not available). The SDM approach developed in this study can be used as an iterative, adaptive process by including updated data as it becomes available, further refining and validating the SDM results and thereby improve our understanding of the distribution of cetaceans and noise-producing activities in eastern Canada.
Wrasse (Labridae) fisheries have increased markedly in Norway since 2010. Wrasse are being used as cleaner fish in salmonid aquaculture to control sea-lice infestations. However, fundamental knowledge on the demography and abundance of the targeted wrasse populations in Norwegian waters is lacking, and the consequences of harvesting at the current intensity have not been assessed. Here, we compared catch per unit effort (CPUE), size, age and sex ratio of goldsinny wrasse (Ctenolabrus rupestris) and corkwing wrasse (Symphodus melops) between marine protected areas (MPAs) and control areas open for fishing at four localities on the Skagerrak coast in Southern Norway. The CPUE of goldsinny larger than the minimum size limit was 33–65% higher within MPAs, while for corkwing three of four MPAs had higher CPUE with the relative difference between MPAs and control areas ranging from −16% to 92%. Moreover, corkwing, but not goldsinny, was significantly older and larger within MPAs than in control areas. Sex ratios did not differ between MPAs and control areas for either species. Our study suggests that despite its short history, the wrasse fisheries have considerable impacts on the target populations and, further, that small MPAs hold promise as a management tool for maintaining natural population sizes and size structure. Goldsinny, being a smaller-sized species, also seems to benefit from the traditional minimum size limit management tool, which applies outside MPAs.
The coastal seagrass meadows in the Townsville region of the Great Barrier Reef are crucial seagrass foraging habitat for endangered dugong populations. Deteriorating coastal water quality and in situ light levels reduce the extent of these meadows, particularly in years with significant terrestrial runoff from the nearby Burdekin River catchment. However, uncertainty surrounds the impact of variable seagrass abundance on dugong carrying capacity. Here, I demonstrate that a power-law relationship with exponent value of − 1 (R2 ~ 0.87) links mortality data with predicted changes in annual above ground seagrass biomass. This relationship indicates that the dugong carrying capacity of the region is tightly coupled to the biomass of seagrass available for metabolism. Thus, mortality rates increase precipitously following large flood events with a response lag of < 12-months. The management implications of this result are discussed in terms of climate scenarios that indicate an increased future likelihood of extreme flood events.
Artificial reefs (ARs) are the most common man-made constructions adopted to prevent coastal erosion from wave actions and currents. Despite their worldwide application in coastal management and the documented chemical and physical alterations on surrounding seabeds that they may cause, few studies have been carried out on their impact upon meiofauna. The aim of this survey was to evaluate the potential effects of ARs on the seabed using various meiofaunal descriptors such as the structure of the entire assemblage and of rare taxa, the richness, the diversity indices and the Nematode:Copepod (Ne:Co) ratio. We investigated meiofaunal assemblages of some exposed areas on the Adriatic coast that are protected by ARs and subject to different levels of anthropogenic impact. This last issue was fundamental to examining possible interactions between AR presence and riverine discharges. The results of this study showed that the most efficient meiofaunal descriptors were diversity indices and the Ne:Co ratio, and suggested that the existence of ARs along with uncontrolled riverine discharges may increase anthropogenic impacts upon coastlines. This point is crucial for the conservation and monitoring of beaches because coastal management should be focused on preventing not only coastal erosion, but also possible impacts on marine ecosystem and human health.