Understanding how changes in biodiversity affects ecosystem functioning is imperative in allowing Ecosystem-Based Management (EBM), especially when addressing global change and environmental degradation. Research into the link between biodiversity and ecosystem functioning (BEF) has indeed increased considerably over the past decades. BEF research has focussed on terrestrial ecosystems and aquatic ecosystems have received considerably less attention. Due to differences in phylogenetic diversity, ecological processes and reported BEF relationships, however, it may at least be questionable whether BEF relationships are exchangeable between these ecosystems (i.e. terrestrial and aquatic). The aim of the present paper was therefore to pinpoint key areas and bottlenecks in establishing BEF relationships for aquatic ecosystems (freshwater, transitional, and marine). To this end, the available literature with special emphasis on the last 10 years was assessed to evaluate: i) reported mechanisms and shapes of aquatic BEF relationships; ii) to what extent BEF relations are interchangeable or ecosystem-specific; and iii) contemporary gaps and needs in aquatic BEF research. Based on our analysis, it may be concluded that despite considerable progress in BEF research over the past decades, several bottlenecks still need to be tackled, namely incorporating the multitude of functions supported by ecosystems, functional distinctiveness of rare species, multitrophic interactions and spatial-temporal scales, before BEF relationships can be used in ecosystem-based management.
The following titles are freely-available, or include a link to a preprint or postprint.
Deepwater exploration has been developed for more than 40 years since 1975; generally, its exploration history can be divided into the beginning stage (1975–1984), the early stage (1985–1995) and the rapid development stage (1996-now). Currently, deepwater areas have become the hotspot of global oil and gas exploration, and they are also one of the most important fields of oil and gas increase in reserves and production all over the world. In 40 years, global deepwater oil and gas discoveries are mainly distributed along five deepwater basin groups which are characterized by “three vertical and two horizontal” groups: (1) In deepwater basins of the Atlantic Ocean, giant discoveries of oil are mainly concentrated in Brazil, West Africa and the Gulf of Mexico, and significant discoveries of natural gas are mainly on the west coast of Norway in the northern part of the Atlantic Ocean; (2) In deepwater basins of the East African continental margin, a group of giant gas fields has been found in the Rovuma Basin and Tanzania Basin; (3) In deepwater basins of the West Pacific Ocean, giant discoveries of oil and gas are mainly concentrated in the South China Sea and Southeast Asian waters; (4) The deepwater basins of the Neo-Tethys Region are rich in gas, and the most important gas discoveries are mainly distributed in the northwest shelf of Australia and the eastern Mediterranean; and (5) In deepwater basins around the Arctic Pole, major discoveries of oil and gas have been only found in deepwater areas of the Barents sea. Global deepwater oil resources are mainly concentrated in the middle and south sections of the Atlantic Ocean. Deepwater gas resources are relatively widely spread and mainly distributed in the northern part of Atlantic Ocean deepwater basins, the deepwater basins of East Africa, the deepwater basins of the Neo-Tethys region and the deepwater basins around the Arctic Pole. There will be six domains for future oil-gas exploration of global deepwater basins which are characterized by “two old and four new” domains; specifically, “two old” domains referring to the Atlantic offshore deepwater basins and offshore deepwater basins of the Neo-Tethys structural domain, where the exploration degree is relatively high, and the potential is still great. While the “four new” domains stand for pre-salt and ultra deepwater basin formations, offshore deepwater basins surrounding the North Pole area and West Pacific offshore deepwater basins and the new fields will be the main fields of deepwater oil and gas exploration in the future.
Aquaculture is a major contributor to global food production, but has attracted considerable controversy. Disagreements over the social and ecological impacts of aquaculture (positive and negative) have hindered further expansion of aquaculture production, particularly in wealthy democratic countries. This article presents findings from a series of workshops bringing international aquaculture scholars together from the natural and social sciences to examine and compare social-ecological challenges facing aquaculture development in five nations: Canada, the Faroe Islands, Iceland, Norway, and Sweden. This multinational comparison provides unique insights into common and particular challenges in aquaculture governance – a dimension that is missing in current literature about the industry. A political ecology framework from the environmental social sciences is used to examine how natural and human phenomena interact to shape these challenges and frame the conflicts that often result. The analysis reveals a wide range of social-ecological factors limiting aquaculture expansion in the five countries, including access to suitable environments, interactions with other sectors, and policy and regulatory gaps – not only with respect to aquaculture, but also on related issues such as marine spatial planning and the involvement of indigenous peoples in decision-making. The findings provide preliminary guidance for future policy development and comparative aquaculture research.
Homes exposed to sea level rise (SLR) sell for approximately 7% less than observably equivalent unexposed properties equidistant from the beach. This discount has grown over time and is driven by sophisticated buyers and communities worried about global warming. Consistent with causal identification of long-horizon SLR costs, we find no relation between SLR exposure and rental rates and a 4% discount among properties not projected to be flooded for almost a century. Our findings contribute to the literature on the pricing of long-run risky cash flows and provide insights for optimal climate change policy.
Catch share programs can have far-reaching effects on coastal communities and the people that rely on fishing income, including crew members. Analysis of management actions affecting crew wages and well-being is often limited due to a dearth of available data. We examine crew-related outcomes during the first six years of the West Coast Groundfish Trawl Catch Share Program using two unique datasets – a mandatory economic survey and a voluntary social science study. We find that impacts on crew compensation differ from other catch share programs due to prior conditions of the fishery and also vary by the target species within the program. The median number of crew positions per vessel increased slightly, annual crew days decreased, and crew wage as a percentage of revenue was nearly unchanged, even with the introduction of new costs. Median daily crew compensation increased from $514 per day to $776 after implementation of catch shares and annual compensation increased from $33 thousand to $39 thousand. Many crew members expressed a lack of support for the program and job satisfaction did not rise with increased wages and fewer days at sea, indicating that job satisfaction is likely influenced by more than compensation and effort.
The West Coast Groundfish Trawl Catch Share Program was designed to achieve multiple economic goals and objectives, including increasing net benefits, profitability, flexibility, and utilization of harvest allocations. In this article, we leverage seven years of comprehensive cost and earnings data to evaluate progress towards these goals with a focus on harvesters. Our assessment shows that five years post-implementation, net benefits to the nation have doubled, and indicators of productivity and profitability have increased. The fleet that targets Pacific whiting has seen the largest gains, due in part to increases in total allowable catch and the elimination of the race-to-fish. However, increased revenues have not been realized to the degree that was expected for harvesters targeting non-whiting groundfish, partly due to lower than predicted consolidation and relatively low quota utilization. Economic outcomes indicate that tradeoffs exist between certain objectives of the program, specifically between achieving full utilization and flexibility for harvesters. Results are discussed in the context of the design and evaluation of catch share programs for diverse, multispecies fisheries.
Rising seas, more frequent storms and other climate-driven coastal hazards necessitate adaptation planning measures to protect people and property. To date, coastal vulnerability assessments have prioritized the most exposed areas of coastline, but there is a gap between recognized climate science and the feasibility or suitability considerations relevant for implementing coastal adaptation strategies—including legal, policy, financial, or engineered approaches—to address coastal threats. This paper sets forth a methodology for bridging the gap between climate science, law and coastal adaptation policies. This methodology seeks to connect spatial analysis methods with attributes of coastal adaptation strategies that make them inherently place-based—ranging from engineered solutions, to legal strategies and financial tools—to determine where they are legally feasible and suitable. Both spatial and non-spatial limiting and enabling conditions of coastal adaptation policies drive these determinations. The methodology integrates a spatial framework using feasibility statements derived by 1) coupling these conditions and features with spatial information (e.g., zoning, land use/land cover, geomorphologic features), and 2) identifying suitability conditions through synthesizing policy considerations for each coastal adaptation strategy.
The inherent complexity of planning at sea, called maritime spatial planning (MSP), requires a planning approach where science (data and evidence) and stakeholders (their engagement and involvement) are integrated throughout the planning process. An increasing number of innovative planning support systems (PSS) in terrestrial planning incorporate scientific models and data into multi-player digital game platforms with an element of role-play. However, maritime PSS are still early in their innovation curve, and the use and usefulness of existing tools still needs to be demonstrated. Therefore, the authors investigate the serious game, MSP Challenge 2050, for its potential use as an innovative maritime PSS and present the results of three case studies on participant learning in sessions of game events held in Newfoundland, Venice, and Copenhagen. This paper focusses on the added values of MSP Challenge 2050, specifically at the individual, group, and outcome levels, through the promotion of the knowledge co-creation cycle. During the three game events, data was collected through participant surveys. Additionally, participants of the Newfoundland event were audiovisually recorded to perform an interaction analysis. Results from survey answers and the interaction analysis provide evidence that MSP Challenge 2050 succeeds at the promotion of group and individual learning by translating complex information to players and creating a forum wherein participants can share their thoughts and perspectives all the while (co-) creating new types of knowledge. Overall, MSP Challenge and serious games in general represent promising tools that can be used to facilitate the MSP process.
The resilience and recovery dynamics of deep-sea habitats impacted by bottom trawling are poorly known. This paper reports on a fishing impact recovery comparison based on four towed camera surveys over a 15-year period (2001–2015) on a group of small seamounts on the Chatham Rise, east of New Zealand, on which pre-disturbance benthic communities are dominated by thicket-forming scleractinian corals. The six seamounts studied encompass a range of trawl histories, including one with high and persistent levels of trawling throughout the survey period, two with intermittent and intermediate levels of trawling, two which were low/untrawled, and one, ‘Morgue’, which was closed to trawling in 2001, having been heavily trawled up to that point. Still photographs from all surveys were analyzed for the identification and abundance of all visible benthic fauna with effort made to ensure consistency of data among surveys. Because increases in image resolution and quality over time resulted in a persistent trend of increasing abundances, analyses were concentrated on comparisons among seamounts within surveys and how these relationships changed with time. The abundance, species richness, and diversity of benthic communities were higher on low/untrawled seamounts than on those that had been trawled. Multivariate community structure showed similar patterns at each survey point, the low/untrawled seamounts being strongly dissimilar to the persistently trawled seamount, with the others ranged between these extremes, broadly in accordance with their cumulative trawl histories. Community structure on the persistently trawled seamount was less variable than on the other seamounts throughout the study period, possibly because of regular ‘re-setting’ of the community by disturbance from trawling. Although there was some variability in results between whole seamount and summit sector analyses, in general communities on Morgue remained similar to those on the persistently trawled seamount, showing little indication of steps toward recovery to its pre-disturbance state following its closure. These results indicate low resilience of benthic communities on the seamounts to the effects of bottom trawling.
Identifying critical aggregation sites and behavioral patterns of imperiled species contributes to filling knowledge gaps essential for their conservation. Manta rays present a prominent example of such species, the populations of which are declining globally due to directed fishery, by-catch, and other anthropogenic stressors. Our goal was to explore manta ray aggregation sites in the Philippines in order to determine the factors governing the mantas’ visits – a knowledge gap essential to understand manta ecology, facilitate ecosystem-based fishery management, and promote sustainable manta-based ecotourism. Diving surveys, environmental conditions assessment, and autonomous cameras were employed to study manta behavior and visit patterns to a cleaning station cluster on a commonly fished seamount, visited by both Mobula birostris and Mobula alfredi. Our findings reveal several environmental conditions (e.g., sea state, moon illumination, and flow) that serve as predictors of manta presence/absence at the site. We suggest that these conditions affect both the behavior of the manta’s food (i.e., the spatial distribution of plankton) and the cleaning effectiveness of the cleaner wrasse, which consequently influence manta activity. The findings suggest a trade-off between cleaning and foraging: i.e., mantas tend to visit the cleaning stations when environmental conditions are less favorable for foraging but suitable for effective cleaning; while being absent from the cleaning stations when environmental conditions form plankton aggregations, ideal for efficient feeding. This study sheds light on manta behavior and habitat use on dynamic, small spatio-temporal scales (i.e., hundreds of meters to a few kilometers, hours to days). The acquired data may be applied in the planning of marine protected areas and in fishery management (e.g., to reduce the chances of manta bycatch by limiting fishing activities to periods of manta absence) as well as contribute to enhancing sustainable exploitation, such as ecotourism, by increasing the chances of diving encounters with manta rays.
Ecosystem services (ESs) may be both non-market and market based. Both may provide important input to societal welfare. Using natural resources, or converting nature in the development of market based ES may impact the access to non-market or more conservationist ES, and vice versa. How does the general public trade-off between these two types of ES? We use two valuation studies in Northern Norway to identify the public’s preferences for marine industries versus other marine use and non-use values. One study assesses willingness to pay to protect cold-water corals, a relatively abundant, and to some degree, protected resource off the coast of Norway. The other study elicits people’s willingness to pay for stricter regulations of industrial activity in the coastal zone, providing more coastal area for recreational activities. Both studies show strong conservation preferences, and willingness to forego blue industrial growth. However, these preferences are heterogeneous across socio-economic characteristics, and, interestingly, educational level is the characteristic that most distinctly separates the population into various preference groups.
Nutrient subsidies across ecotone boundaries can enhance productivity in the recipient ecosystem, especially if the nutrients are transferred from a nutrient rich to an oligotrophic ecosystem. This study demonstrates that seabird nutrients from islands are assimilated by endosymbionts in corals on fringing reefs and enhance growth of a dominant reef-building species, Acropora formosa. Nitrogen stable isotope ratios (δ15N) of zooxanthellae were enriched in corals near seabird colonies and decreased linearly with distance from land, suggesting that ornithogenic nutrients were assimilated in corals. In a one-year reciprocal transplant experiment, A. formosa fragments grew up to four times faster near the seabird site than conspecifics grown without the influence of seabird nutrients. The corals influenced by elevated ornithogenic nutrients were located within a marine protected area with abundant herbivorous fish populations, which kept nuisance macroalgae to negligible levels despite high nutrient concentrations. In this pristine setting, seabird nutrients provide a beneficial nutrient subsidy that increases growth of the ecologically important branching corals. The findings highlight the importance of catchment–to–reef management, not only for ameliorating negative impacts from land but also to maintain beneficial nutrient subsidies, in this case seabird guano.
Thermal-stress events associated with climate change cause coral bleaching and mortality that threatens coral reefs globally. Yet coral bleaching patterns vary spatially and temporally. Here we synthesize field observations of coral bleaching at 3351 sites in 81 countries from 1998 to 2017 and use a suite of environmental covariates and temperature metrics to analyze bleaching patterns. Coral bleaching was most common in localities experiencing high intensity and high frequency thermal-stress anomalies. However, coral bleaching was significantly less common in localities with a high variance in sea-surface temperature (SST) anomalies. Geographically, the highest probability of coral bleaching occurred at tropical mid-latitude sites (15–20 degrees north and south of the Equator), despite similar thermal stress levels at equatorial sites. In the last decade, the onset of coral bleaching has occurred at significantly higher SSTs (∼0.5 °C) than in the previous decade, suggesting that thermally susceptible genotypes may have declined and/or adapted such that the remaining coral populations now have a higher thermal threshold for bleaching.
Catch share management was implemented in the bottom trawl sector of the West Coast Groundfish fishery in 2011 to address a range of issues including high bycatch and discard rates. The catch share program was designed to remove the incentives to discard through full catch accounting, tradeable quotas, increased flexibility in fishing, and penalties for catch overages. We assess the effectiveness of the program in meeting its environmental objectives by comparing discard weights, proportions, and variability from 2004–2010 with 2011–2016. We analyzed these metrics for species managed using quota, including historically overfished stocks, as well as for non-quota species caught in the fishery. Discard amounts decreased over time for all species and declined to historic lows after the implementation of the program, remaining low through 2016 with much less inter-annual variability. Mean annual discards of two highly-targeted quota species, sablefish and Dover sole, showed the greatest decreases, falling by 97 and 86%, respectively. The discard proportion of overfished quota species fell by 50% on average. The unanticipated decline in discards of non-quota species as well as the decreased variability in discard amounts for all species indicate that the incentives produced by catch share management provided additional ecosystem benefits.
Diatoms are silicifying phytoplankton contributing about one quarter to primary production on Earth. Ocean acidification (OA) could alter the competitiveness of diatoms relative to other taxa and/or lead to shifts among diatom species. In spring 2016, we set up a plankton community experiment at the coast of Gran Canaria (Canary Islands, Spain) to investigate the response of subtropical diatom assemblages to elevated seawater pCO2. Therefore, natural plankton communities were enclosed for 32 days in in situ mesocosms (∼8 m3volume) with a pCO2 gradient ranging from 380 to 1140 μatm. Halfway through the study we added nutrients to all mesocosms (N, P, Si) to simulate injections through eddy-induced upwelling which frequently occurs in the region. We found that the total diatom biomass remained unaffected during oligotrophic conditions but was significantly positively affected by high CO2 after nutrient enrichment. The average cell volume and carbon content of the diatom community increased with CO2. CO2 effects on diatom biomass and species composition were weak during oligotrophic conditions but became quite strong above ∼620 μatm after the nutrient enrichment. We hypothesize that the proliferation of diatoms under high CO2 may have been caused by a fertilization effect on photosynthesis in combination with reduced grazing pressure. Our results suggest that OA in the subtropics may strengthen the competitiveness of (large) diatoms and cause changes in diatom community composition, mostly under conditions when nutrients are injected into oligotrophic systems.
Ocean climate drivers and phytoplankton life strategies interact in a complex dynamic to produce harmful algal blooms (HABs). This study aims to integrate historical biological data collected during “red tide” events along the Ecuadorian coast between 1997 and 2017 in relation to five ocean variables derived from satellite remote sensing data to explain the seasonal drivers of coastal processes associated with HABs dynamics. Seasonality of the occurrence of HABs was assessed in relation to oceanographic variables by applying multiple correspondence analysis (MCA) to the Ecuadorian central coast (Zone 1) and at the outer and inner Gulf of Guayaquil (Zone 2). Sixty-seven HABs events were registered between 1997 and 2017. From a total of 40 species of phytoplankton identified, 28 were identified as non-toxic and the remaining 12 are well known to produce toxins. Dinoflagellates were the taxonomic group most highly associated with potential HABs events along the entire Ecuadorian coast. HABs appear to be constrained by the Humboldt coastal upwelling, high precipitation, and associated coastal runoff, with higher biomass abundance in the Gulf of Guayaquil than in the central coast. Results from the MCA reveal that in the central Ecuadorian coast (oligotrophic system), toxic HABs occurred with low abundance of dinoflagellates, while in the Gulf of Guayaquil (eutrophic system), toxic HABs corresponded to a high abundance of dinoflagellates. In both cases, high values were found for sea surface temperature, precipitation, and irradiance—characteristic of wet seasons or El Niño years. Non-toxic HABs occurred with a high abundance of dinoflagellates, ciliates, and centric diatoms, corresponding to colder waters and low levels of precipitation and irradiance. These findings confirm that dinoflagellates display several strategies that enhance their productive capacity when ocean conditions are warmer, allowing them to produce toxins at high or at low concentrations. Considering that the Gulf of Guayaquil is essential to tourism, the shrimp industry, fisheries, and international shipping, these findings strongly suggest the need to establish an ecosystem health research program to monitor HABs and the development of a preventive policy for tourism and public health in Ecuador.
Some of the major challenges in seagrass restoration on exposed open coasts are the choice of transplant design that is optimal for coastlines periodically exposed to high water motion, and understanding the survival and dynamics of the transplanted areas on a long time-scale over many years. To contribute to a better understanding of these challenges, we describe here part of a large-scale seagrass restoration program conducted in a Marine Park in Portugal. The goal of this study was to infer if it was possible to recover seagrass habitat in this region, in order to restore its ecosystem functions. To infer which methods would produce better long term persistence to recover seagrass habitat, three factors were assessed: donor seagrass species, transplant season, source location. Monitoring was done three times a year for 8 years, in which areas and densities of the planted units were measured, to assess survival and growth. The best results were obtained with the species Zostera marina transplanted during spring and summer as compared to Zostera noltii and Cymodocea nodosa. Long-term persistence of established (well rooted) transplants was mainly affected by extreme winter storms but there was evidence of fish grazing effects also. Our results indicate that persistence assessments should be done in the long term, as all transplants were successful (survived and grew initially) in the short term, but were not resistant in the long term after a winter with exceptionally strong storms. The interesting observation that only the largest (11 m2) transplanted plot of Z. marina persisted over a long time, increasing to 103 m2 in 8 years, overcoming storms and grazing, raised the hypothesis that for a successful shift to a vegetated state it might be necessary to overpass a minimum critical size or tipping point. This hypothesis was therefore tested with replicates from two donor populations and results showed effects of size and donor population, as only the larger planting units (PUs) from one donor population persisted and expanded. It is recommended that in future habitat restoration efforts large PUs are considered.
Ocean data assimilation is increasingly recognized as crucial for the accuracy of real-time ocean prediction systems and historical re-analyses. The current status of ocean data assimilation in support of the operational demands of analysis, forecasting and reanalysis is reviewed, focusing on methods currently adopted in operational and real-time prediction systems. Significant challenges associated with the most commonly employed approaches are identified and discussed. Overarching issues faced by ocean data assimilation are also addressed, and important future directions in response to scientific advances, evolving and forthcoming ocean observing systems and the needs of stakeholders and downstream applications are discussed.
Indicators are effective tools for summarizing and communicating key aspects of ecosystem state and have a long record of use in marine pollution and fisheries management. The application of biodiversity indicators to assess the status of species, habitats, and functional diversity in marine conservation and policy, however, is still developing and multiple indicator roles and features are emerging. For example, some operational biodiversity indicators trigger management action when a threshold is reached, while others play an interpretive, or surveillance, role in informing management. Links between biodiversity indicators and the pressures affecting them are frequently unclear as links can be obscured by environmental change, data limitations, food web dynamics, or the cumulative effects of multiple pressures. In practice, the application of biodiversity indicators to meet marine conservation policy and management demands is developing rapidly in the management realm, with a lag before academic publication detailing indicator development. Making best use of biodiversity indicators depends on sharing and synthesizing cutting-edge knowledge and experience. Using lessons learned from the application of biodiversity indicators in policy and management from around the globe, we define the concept of ‘biodiversity indicators,’ explore barriers to their use and potential solutions, and outline strategies for their effective communication to decision-makers.
Coral reef managers currently face the challenge of mitigating global stressors by enhancing local ecological resilience in a changing climate. Effective herbivore management is one tool that managers can use in order to maintain resilience in the midst of severe and frequent bleaching events. One recommended approach is to establish networks of herbivore management areas (HMAs), which prohibit the take of herbivorous reef fishes. However, there is a need to develop design principles to guide planning and implementation of these HMAs as a resilience-building tool. We refine available guidance from fully protected marine protected area (MPA) networks and developed a set of 11 biophysical design principles specifically for HMAs. We then provide a case study of how to apply these principles using the main Hawaiian Islands. We address site-specific considerations in terms of protecting habitats, including ecologically critical areas, incorporating connectivity, and addressing climate and local threats. This synthesis integrates core marine spatial planning concepts with resilience-based management and provides actionable guidance on the design of HMAs. When combined with social considerations, these principles will support spatial planning in Hawai‘i and could guide the future design of HMA networks globally.