Biodiversity offsets are increasingly used in policy frameworks to regulate the environmental impacts of development including projects located in marine environments. Scientific knowledge gaps and other practical challenges have necessitated flexibility concerning the manner in which key offsetting principles are implemented in policy frameworks relevant to such environments. The potential trade-off of such flexibility is that consequent marine offsetting practice may not be compatible with the ultimate objective of no net loss of biodiversity. Here we present a systematic review of marine and coastal development projects in Australia, examining how offsetting is being implemented in practice. Forty-two (42) projects were assessed, predominantly located in Queensland and Western Australia and associated with the development and operation of ports. We find that application of key biodiversity offsetting principles (e.g. ecological equivalence) was frequently incomplete or absent. For approximately 50% of reviewed projects we were unable to identify public information concerning how offsetting requirements were established. The current environmental outcomes of marine biodiversity offsetting in Australia are unclear but there are indications that it is unlikely to achieve no net loss of biodiversity.
In addition to being an academic endeavour, the practical purpose of conducting age and growth studies on fishes is to provide biological data to stock assessment scientists and fisheries managers so they may better understand population demographics and manage exploitation rates. Age and size data are used to build growth models, which are a critical component of stock assessments. Though age determination of elasmobranchs in the northeast Pacific Ocean (NEP) began in the 1930s, the field has evolved substantially in recent years, allowing scientists to incorporate age data into assessments for more species than ever before. Owing to the highly diverse biology of this group of fishes, each species has its own set of challenges with regard to age determination. Age determination methods typically rely on semicalcified hard structures that form regular growth patterns; however, the structure selected and preparation method used is often species specific. New staining techniques have improved the ability to assess age and improve ageing precision for some species, and advances in microchemical methods have allowed for independent means of estimating age and validating age determination accuracy. Here we describe current age determination methods for NEP elasmobranchs. While the library of available techniques is increasing, there are still some NEP species for which reliable ageing methods have yet to be defined; we discuss these challenges and potential avenues of future research. Finally, we conclude by describing how age estimates are used in growth models and subsequently in stock assessments of selected NEP elasmobranchs.
The ability of mangrove ecosystem to accumulate carbon from air, water and soil as sinker carbon is very important to reduce carbon emission in coastal ecosystem. Carbon sink represent role of mangrove ecosystem to sequestrate carbon emission is developed by a system of mangrove zone and demonstrative activities system. These paper purposes to develop system of carbon conservation in mangrove ecosystem to apply REDD program and demonstrative activities. The research methods used Komiyama equation tCer analysis and demonstrative activities formulation.
The research results showed that the carbon percentage of mangrove species between 35.97%–53.98% with Bruguiera gymnorrhiza (52.54%) and Rhizophora apiculata (52.38%) as the biggest carbon sinker of mangrove species. The carbon of mangrove ecosystem were 79.2 tonC/ha −242.2 tonC/ha, with the economic value between 396.2 US$/ha (price 5 U$/tonC) −4360.4 US$/ha, (price 18 US$). The best choice of demostrative activites in REDD framework to reduce the degradation of mangrove ecosystem was the fish pond. And the best carbon sequestration of mangrove species were Bruguiera praviflora, Rhizophora mucronta, Bruguiera sexangula, Rhizophora apiculata and Bruguiera gymnorrhiza (first mangrove zone).
Sandy beach ecosystems have various ecocentric and anthropocentric values. These values are under multiple, increasing pressures from diverse human activities and, in particular, from the consequences of climate-change. The conservation of these values requires evidence-based policy formulation and management strategies that address societal goals such as those set by the United Nations (2012). Here, we use these goals, pressures, knowledge gaps and our combined judgement to nominate important policy- and management-orientated research questions. These are grouped under five broad topics: natural condition; protecting ecosystem health; conservation of biodiversity; sustaining ecosystem goods and services; and climate change. The last is particularly important since it threatens both services to society and the ecological integrity of beach ecosystems at great spatial and temporal scales. Further, humans are likely to respond to climate change in the urban coastal zone with large-scale engineering projects (e.g., nourishment, seawalls) which will have substantial ecological effects. The resolution of these questions should inform evidence-based policies and strategies to manage the pressures faced by ocean beaches.
Maximising the long term average catch of single stock fisheries as prescribed by the globally-legislated MSY objective is unlikely to ensure ecosystem, economic, social and governance sustainability unless an effort is made to explicitly include these considerations. We investigated how objectives to be maximised can be combined with sustainability constraints aiming specifically at one or more of these four sustainability pillars. The study was conducted as a three-year interactive process involving 290 participating science, industry, NGO and management representatives from six different European regions. Economic considerations and inclusive governance were generally preferred as the key objectives to be maximised in complex fisheries, recognising that ecosystem, social and governance constraints are also key aspects of sustainability in all regions. Relative preferences differed between regions and cases but were similar across a series of workshops, different levels of information provided and the form of elicitation methods used as long as major shifts in context or stakeholder composition did not occur. Maximising inclusiveness in governance, particularly the inclusiveness of affected stakeholders, was highly preferred by participants across the project. This suggests that advice incorporating flexibility in the interpretation of objectives to leave room for meaningful inclusiveness in decision-making processes is likely to be a prerequisite for stakeholder buy-in to management decisions.
The recent years have witnessed a rise in interest in the ocean economy. To cover a more sustainable dimension, terms such as ‘blue economy’ and ‘blue growth’ have been coined, and are increasingly used in international contexts and academic literature. However, there are no generally accepted definitions of these ‘blue’ concepts. In particular, it is not clear what connotation of sustainability and what role of natural environment is linked to these terms. The objective of this study is to retrace the meaning of the concepts of blue economy and blue growth and include them in a coherent environmental accounting framework. Starting from the System of Environmental-Economic Accounting of the United Nations, a set of assumptions is proposed to link blue economy/growth and ecosystem services, including the creation of an adjusted measure of value added, while considering the depletion and degradation of the environment and the value of non-market benefits provided by the ecosystem. Finally, an example of this approach in the case of the Mediterranean Sea is presented.
This paper explores the economic and biological effects of exploiter and species interactions in a multiplayer, multispecies fishery. To this end, a partial ecosystem model for three key pelagic species in the Northeast Atlantic (Norwegian spring-spawning herring, mackerel and blue whiting) is developed and coupled with an economic model describing harvesting behavior of three major exploiters. We explore the effects on the fishery under assumptions on plausible interaction parameters between the harvested species and the type of management adopted by the exploiting countries. Single-species management is modeled by using three single-species models of the pelagic complex. Net present value is increased by over 20% when applying multispecies management in the cooperative case. Under non-cooperation there is always overfishing of all species compared to the global optimum, resulting in depletion of the mackerel stock and an almost 50% loss in net present value attainable from the aggregate fishery. Interestingly, under non-cooperation the effect of exploiters applying either single-species or multispecies management is rather small on the health of the stocks and on economic benefits.
Mortality from collisions with vessels is one of the main human causes of death for large whales. Ship strikes are rarely witnessed and the distribution of strike risk and estimates of mortality remain uncertain at best. We estimated ship strike mortality for blue humpback and fin whales in U.S. West Coast waters using a novel application of a naval encounter model. Mortality estimates from the model were far higher than current minimum estimates derived from stranding records and are closer to extrapolations adjusted for detection probabilities of dead whales. Our most conservative model estimated mortality to be 7.8x, 2.0x and 2.7x the U.S. recommended limit for blue, humpback and fin whales, respectively, suggesting that death from vessel collisions may be a significant impediment to population growth and recovery. Comparing across the study area, the majority of strike mortality occurs in waters off California, from Bodega Bay south and tends to be concentrated in a band approximately 24 Nm (44.5 km) offshore and in designated shipping lanes leading to and from major ports. While some mortality risk exists across nearly all West Coast waters, 74%, 82% and 65% of blue, humpback and fin whale mortality, respectively, occurs in just 10% of the study area, suggesting conservation efforts can be very effective if focused in these waters. Risk is highest in the shipping lanes off San Francisco and Long Beach, but only a fraction of total estimated mortality occurs in these proportionally small areas, making any conservation efforts exclusively within these areas insufficient to address overall strike mortality. We recommend combining shipping lane modifications and re-locations, ship speed reductions and creation of ‘Areas to be Avoided’ by vessels in ecologically important locations to address this significant source of whale mortality.
In developing regions, coastal communities are particularly dependent on small-scale fisheries for food security and income. However, information on the scale and impacts of small-scale fisheries on coastal marine ecosystems are frequently lacking. Large marine vertebrates (marine mammals, sea turtles and chondrichthyans) are often among the first species to experience declines due to fisheries. This paper reviews the interactions between small-scale fisheries and vulnerable marine megafauna in the southwestern Indian Ocean. We highlight an urgent need for proper documentation, monitoring and assessment at the regional level of small-scale fisheries and the megafauna affected by them to inform evidence-based fisheries management. Catch and landings data are generally of poor quality and resolution with compositional data, where available, mostly anecdotal or heavily biased towards easily identifiable species. There is also limited understanding of fisheries effort, most of which relies on metrics unsuitable for proper assessment. Management strategies (where they exist) are often created without strong evidence bases or understanding of the reliance of fishers on resources. Consequently, it is not possible to effectively assess the current status and ensure the sustainability of these species groups; with indications of overexploitation in several areas. To address these issues, a regionally collaborative approach between government and non-governmental organisations, independent researchers and institutions, and small-scale fisheries stakeholders is required. In combination with good governance practices, appropriate and effective, evidence-based management can be formulated to sustain these resources, the marine ecosystems they are intrinsically linked to and the livelihoods of coastal communities that are tied to them.
Postsettlement spillover from marine protected areas (MPAs) can support adjacent fished populations and has been subject of many scientific studies. The larval subsidy effect, on the contrary, is more challenging to study and less demonstrated, although it, arguably, provides key benefits for fisheries. We modeled and predicted the spatial distribution of fish spawning biomass and fecundity across a temperate insular MPA network (Azores archipelago, Northeast Atlantic) and identified potential single- and multispecies reproductive habitats (RHs) in shallow reefs. Reproductive strategies or skewed sex ratios influenced spatial patterns of potential spawning biomass and fecundity. Predicted multispecies RHs covered 5%–20% of the studied reef habitat. Given their potentially high reproductive output, we argue that such sites should be considered in marine conservation planning to increase chances of achieving fisheries and conservation benefits. Spatial patterns of the reproductive output may function as surrogates for larval subsidy when limited or no larval connectivity information is available and also may assist in identifying potential larval sources and priority sites for conservation.
This paper reviews literature on aesthetics and describes the development of vista and landscape aesthetics models. Spatially explicit variables were chosen to represent physical characteristics of natural landscapes that are important to aesthetic preferences. A vista aesthetics model evaluates the aesthetics of natural landscapes viewed from distances of more than 1000 m, and a landscape aesthetics model evaluates the aesthetic value of wetlands and forests within 1000 m from the viewer. Each of the model variables is quantified using spatially explicit metrics on a pixel-specific basis within EcoAIM™, a geographic information system (GIS)–based ecosystem services (ES) decision analysis support tool. Pixel values are “binned” into ranked categories, and weights are assigned to select variables to represent stakeholder preferences. The final aesthetic score is the weighted sum of all variables and is assigned ranked values from 1 to 10. Ranked aesthetic values are displayed on maps by patch type and integrated within EcoAIM. The response of the aesthetic scoring in the models was tested by comparing current conditions in a discrete area of the facility with a Development scenario in the same area. The Development scenario consisted of two 6-story buildings and a trail replacing natural areas. The results of the vista aesthetic model indicate that the viewshed area variable had the greatest effect on the aesthetics overall score. Results from the landscape aesthetics model indicate a 10% increase in overall aesthetics value, attributed to the increase in landscape diversity. The models are sensitive to the weights assigned to certain variables by the user, and these weights should be set to reflect regional landscape characteristics as well as stakeholder preferences. This demonstration project shows that natural landscape aesthetics can be evaluated as part of a nonmonetary assessment of ES, and a scenario-building exercise provides end users with a tradeoff analysis in support of natural resource management decisions.
This study presents a comprehensive methodology that addresses climate change–induced coastal erosion at the regional scale O (100 km). The use of climate data with high space-time resolution enabled the reconstruction of the shoreline response to cross-shore forcing both historically and throughout the twenty-first century. Cross section–based equilibrium models were combined to assess beach erosion induced by local waves, storm surge, astronomical tide and mean sea-level rise. The approach incorporates the potential impacts that tidal inlets could have on the long-term evolution of adjacent beaches as sink terms in the beaches’ budget. The methodology provides probabilistic estimates of coastline recession while accounting for sea level rise uncertainty, both of which are essential aspects for establishing adaptation priorities and efficient fund allocation. The outlined assessment was undertaken on 57 sandy beaches along a 345 km coastline stretch in Asturias, a region in the northwest of Spain open to the Atlantic.
Ocean acidification and changing sea surface temperatures stand to affect the interactions of corals and their Symbiodinium symbionts with regard to the inorganic carbon used for photosynthesis. However, there have been few investigations on the availability of dissolved inorganic carbon (DIC) for algal symbionts in hospite. This study compared the DIC-associated photosynthetic kinetic parameters of three Caribbean corals and their freshly isolated symbionts, as well as components of the DIC concentrating systems of both corals and symbionts. Species level differences were found in the extent of inorganic carbon saturation among the coral taxa studied. Only Orbicella faveolata was photosynthesizing at maximum rates under current seawater conditions, while Porites astreoides and Siderastrea radians were at or below half DIC saturation. O. faveolata also had significantly more external carbonic anhydrase activity, indicating that this species could produce more CO2 at the coral surface than P. astreoides or S. radians. In contrast and despite differences in Symbiodinium type, the symbionts of all the corals had a similar, very low DIC half saturation constant for photosynthesis and high levels of internal carbonic anhydrase activity, showing that they live in a carbon scarce environment and invest a great deal of energy in concentrating carbon at the site of photosynthesis. Considering the diffusional dynamics of the system and the relationship of host to symbiont kinetic parameters, the most likely cause of this scarcity is host regulation of DIC delivery to the symbionts.
Despite the deep sea being the largest habitat on Earth, there are just 77 population genetic studies of invertebrates (115 species) inhabiting non-chemosynthetic ecosystems on the deep-sea floor (below 200 m depth). We review and synthesize the results of these papers. Studies reveal levels of genetic diversity comparable to shallow-water species. Generally, populations at similar depths were well connected over 100s–1,000s km, but studies that sampled across depth ranges reveal population structure at much smaller scales (100s–1,000s m) consistent with isolation by adaptation across environmental gradients, or the existence of physical barriers to connectivity with depth. Few studies were ocean-wide (under 4%), and 48% were Atlantic-focused. There is strong emphasis on megafauna and commercial species with research into meiofauna, “ecosystem engineers” and other ecologically important species lacking. Only nine papers account for ~50% of the planet's surface (depths below 3,500 m). Just two species were studied below 5,000 m, a quarter of Earth's seafloor. Most studies used single-locus mitochondrial genes revealing a common pattern of non-neutrality, consistent with demographic instability or selective sweeps; similar to deep-sea hydrothermal vent fauna. The absence of a clear difference between vent and non-vent could signify that demographic instability is common in the deep sea, or that selective sweeps render single-locus mitochondrial studies demographically uninformative. The number of population genetics studies to date is miniscule in relation to the size of the deep sea. The paucity of studies constrains meta-analyses where broad inferences about deep-sea ecology could be made.
Coastal shoreline hardening is intensifying due to human population growth and sea level rise. Prior studies have emphasized shoreline-hardening effects on faunal abundance and diversity; few have examined effects on faunal biomass and size structure or described effects specific to different functional groups. We evaluated the biomass and size structure of mobile fish and crustacean assemblages within two nearshore zones (waters extending 3 and 16 m from shore) adjacent to natural (native wetland; beach) and hardened (bulkhead; riprap) shorelines. Within 3 m from shore, the total fish/crustacean biomass was greatest at hardened shorelines, driven by greater water depth that facilitated access to planktivore (e.g., bay anchovy) and benthivore-piscivore (e.g., white perch) species. Small-bodied littoral-demersal species (e.g., Fundulus spp.) had greatest biomass at wetlands. By contrast, total biomass was comparable among shoreline types within 16 m from shore, suggesting the effect of shoreline hardening on fish biomass is largely within extreme nearshore areas immediately at the land/water interface. Shoreline type utilization was mediated by body size across all functional groups: small individuals (≤60 mm) were most abundant at wetlands and beaches, while large individuals (>100 mm) were most abundant at hardened shorelines. Taxonomic diversity analysis indicated natural shoreline types had more diverse assemblages, especially within 3 m from shore, although relationships with shoreline type were weak and sensitive to the inclusion/exclusion of crustaceans. Our study illustrates how shoreline hardening effects on fish/crustacean assemblages are mediated by functional group, body size, and distance from shore, with important applications for management.
Blue whale sound production has been thought to occur by Helmholtz resonance via air flowing from the lungs into the upper respiratory spaces. This implies that the frequency of blue whale vocalizations might be directly proportional to the size of their sound-producing organs. Here we present a sound production mechanism where the fundamental and overtone frequencies of blue whale B calls can be well modeled using a series of short-duration (<1 s) wavelets. We propose that the likely source of these wavelets are pneumatic pulses caused by opening and closing of respiratory valves during air recirculation between the lungs and laryngeal sac. This vocal production model is similar to those proposed for humpback whales, where valve open/closure and vocal fold oscillation is passively driven by airflow between the lungs and upper respiratory spaces, and implies call frequencies could be actively changed by the animal to center fundamental tones at different frequency bands during the call series.
Scuba diving and snorkeling with manta rays (M. birostris, M. alfredi) at sites in Hawaii, USA, have become popular, with upward of 30 tour boats and 300 participants daily. This article examined whether conflicts are occurring within and between these activities and if so, what types of conflict are prevalent and how would participants respond (support restrictions, sanction others). Data from surveys of 444 participants following evening trips to view manta rays showed that 79% of snorkelers experienced in-group conflict with other snorkelers, and 53% of scuba divers reported conflict with other divers. Most conflicts were interpersonal (physical interactions among individuals interfering with experiences). Conflict behaviors included bumping into people (up to 92%), not being aware (up to 73%), and blinding people with underwater flashlights (up to 56%). There were fewer out-group conflicts between different activities (snorkelers vs. scuba divers) and minimal social values conflicts (negative preconceptions, no physical interactions among individuals). Participants supported limiting numbers of snorkelers, scuba divers, and boats, and providing education on how to behave with others. Those experiencing conflicts were more supportive of these strategies and more likely to directly sanction participants causing conflicts, but were not more likely to indirectly sanction managers and operators.
Research on enclosure has often examined the phenomenon as a process and outcome of state, neoliberal, and hybrid territorial practices with detrimental impacts for those affected. The proliferation of increasingly complex environmental governance regimes and new enclosures, such as those now seen in the oceans, challenge these readings, however. Using the case of U.S. marine spatial planning (MSP), this article reexamines enclosure through the lens of assemblage. A comprehensive new approach to oceans governance based on spatial data and collaborative decision making, MSP appears to follow past governance programs toward a broad-scale rationalization and enclosure of U.S. waters. Yet this appearance might only be superficial. As an assemblage, U.S. MSP—and its shifting actors, associations, and practices—holds the potential to both close and open the seas for oceans communities, environments, and other actors. Planning actors use three practices to stabilize U.S. MSP for governance and enclosure: narrativizing MSP, creating a geospatial framework to underlie planning, and engaging stakeholders. These practices, however, simultaneously provide opportunities for communities and environments to intervene in U.S. MSP toward alternative outcomes. Rather than a closed seas, U.S. MSP presents opportunities for enclosure to happen differently or not at all, producing alternative outcomes for coastal and oceans communities, environments, and governance.
The effect of various anthropogenic sources of noise (e.g. sonar, seismic surveys) on the behaviour of marine mammals is sometimes quantified as a dose–response relationship, where the probability of an animal behaviourally ‘responding’ (e.g. avoiding the source) increases with ‘dose’ (or received level of noise). To do this, however, requires a definition of a ‘significant’ response (avoidance), which can be difficult to quantify. There is also the potential that the animal ‘avoids’ not only the source of noise but also the vessel operating the source, complicating the relationship. The proximity of the source is an important variable to consider in the response, yet difficult to account for given that received level and proximity are highly correlated. This study used the behavioural response of humpback whales to noise from two different air gun arrays (20 and 140 cubic inch air gun array) to determine whether a dose–response relationship existed. To do this, a measure of avoidance of the source was developed, and the magnitude (rather than probability) of this response was tested against dose. The proximity to the source, and the vessel itself, was included within the one-analysis model. Humpback whales were more likely to avoid the air gun arrays (but not the controls) within 3 km of the source at levels over 140 re. 1 µPa2 s−1, meaning that both the proximity and the received level were important factors and the relationship between dose (received level) and response is not a simple one.
The microbial contribution to ecological resilience is still largely overlooked in coral reef ecology. Coral-associated bacteria serve a wide variety of functional roles with reference to the coral host, and thus, the composition of the overall microbiome community can strongly influence coral health and survival. Here, we synthesize the findings of recent studies (n = 45) that evaluated the impacts of the top three stressors facing coral reefs (climate change, water pollution and overfishing) on coral microbiome community structure and diversity. Contrary to the species losses that are typical of many ecological communities under stress, here we show that microbial richness tends to be higher rather than lower for stressed corals (i.e., in ~60% of cases), regardless of the stressor. Microbial responses to stress were taxonomically consistent across stressors, with specific taxa typically increasing in abundance (e.g., Vibrionales, Flavobacteriales, Rhodobacterales, Alteromonadales, Rhizobiales, Rhodospirillales, and Desulfovibrionales) and others declining (e.g., Oceanosprillales). Emerging evidence also suggests that stress may increase the microbial beta diversity amongst coral colonies, potentially reflecting a reduced ability of the coral host to regulate its microbiome. Moving forward, studies will need to discern the implications of stress-induced shifts in microbiome diversity for the coral hosts and may be able to use microbiome community structure to identify resilient corals. The evidence we present here supports the hypothesis that microbial communities play important roles in ecological resilience, and we encourage a focus on the microbial contributions to resilience for future research.