To examine down-estuary effects and how differences in food webs along a salinity gradient might influence mercury (Hg) biomagnification, we conducted a study from 2010 to 2015 in an estuary with a known biological hotspot at its headwaters. Over 907 samples of biota, representing 92 different taxa of fish and invertebrates, seston and sediments were collected from the upper, middle and lower reach for Hg determination and for stable nitrogen and carbon isotope analyses. Trophic magnification slopes (TMS; log Hg versus δ15N), as a measure of biomagnification efficiency, ranged from 0.23 to 0.241 but did not differ statistically among reaches. Hg concentrations were consistently highest, ranging as high as 4.9 mg/kg in top predatory fish, in the upper-reach of the estuary where basal Hg entering the food web was also highest, as evidenced by methylmercury concentrations in suspension feeders. Top predatory fish at the mouth of the estuary contained relatively low [THg], likely due to lower basal Hg. This was nonetheless surprising given the potential for down-estuary biotransport.
The science-policy nexus has long puzzled scholars and managers working across diverse public policy areas, including environment. The rise of science-based management, especially in an era of big data, assumes science can improve environmental policy. At the same time, increasing attention to stakeholder engagement provides avenues for non-scientists to participate in collaborative environmental management, which might displace science in decision-making processes. Prior research points to a variety of factors thought to affect the degree to which science is used in collaborative partnerships. Drawing on such research, we examine the use of science across 9 collaborative partnerships structured and resourced from the top-down by a state government agency. All of these partnerships are working in the U.S.’s second largest estuary, the Puget Sound in Washington State. Data from partnership meeting minutes indicates that science is scarcely discussed in executive committee meetings, but is more commonly discussed in technical committee meetings. We thus might expect that the ecosystem management plans produced by these technical committees would be closely informed by science. Results indicate these plans include few citations to peer-reviewed scientific studies, but they do draw consistently on scientific information from grey literature including scientific and technical reports from federal and state agencies. These results raise important questions about government efforts to foster the use of science in collaborative partnerships, including the benefits and drawbacks of using grey literature rather than scientific articles directly, the interaction of science with other forms of knowledge, and local actors’ capacity to understand and access science.
Aquaculture is supporting demand and surpassing wild-caught seafood. Yet, most fed aquaculture species (finfish and crustacea) rely on wild-captured forage fish for essential fatty acids and micronutrients, an important but limited resource. As the fastest growing food sector in the world, fed aquaculture demand will eventually surpass ecological supply of forage fish, but when and how best to avoid this ecological boundary is unclear. Using global production data, feed use trends, and human consumption patterns, we show how combined actions of fisheries reform, reduced feed use by non-carnivorous aquaculture and agricultural species, and greater consistent inclusion of fish by-products in China-based production can circumvent forage fish limits by mid-century. However, we also demonstrate that the efficacies of such actions are diminished if global diets shift to more seafood-heavy (that is, pescatarian) diets and are further constrained by possible ecosystem-based fisheries regulations in the future. Long-term, nutrient-equivalent alternative feed sources are essential for more rapid and certain aquaculture sustainability.
The aim of this research was to propose and evaluate a methodological approach to integration and spatial data analysis in order to generate information towards a participatory site selection for bivalve marine aquaculture in the Baía Sul, Florianópolis, Santa Catarina, Brazil. For this purpose, the Baía Sul was investigated considering an ecosystem approach for aquaculture leading to an assessment of its potential for marine aquaculture. The planning of the aquaculture parks was made through a participatory process to incorporate both environmental carrying capacity and social carrying capacity. Experts and modellers developed a GIS model to assess the potential for marine aquaculture in Baía Sul. Continuous (unclassified) maps were used to provide spatial information about the variation of the potential for marine aquaculture in the Baía Sul. The maps were used to plan 53 aquaculture parks over the Baía Sul. The site selection of the parks was made in six public hearings attended by 403 stakeholders from 38 institutions representing different sectors with diverse interests in coastal zone. The results showed that although the Baía Sul is suitable for the growth of bivalve molluscs, some hydrodynamic characteristics and the influence of urbanization constitute a sanitary risk for the activity. Experts, modellers and stakeholders had a different perception about the importance of criteria in the aquaculture parks site selection. While the experts and modellers considered the environmental criteria as the most important aspect to locate the aquaculture parks, the stakeholders took into account mainly the logistics. The final result of the aquaculture parks location, approved by the Brazilian Ministry of Fisheries and Aquaculture (MPA), adopted the site selection by the stakeholders, providing aquaculture parks in areas with sanitary risk for the bivalve cultivation. The main advantage of the adopted assessment strategy was to identify the divergence between experts, modellers and the stakeholders and the distance that still exist between scientist and decision makers in Brazil.
This study examines the use of water-use fees in California’s bidding-based power markets to balance freshwater conservation and reduction of the marine ecosystem impact of coastal once-through-cooled power plants. An hourly power dispatch is simulated using the state’s 2014 demand and generation capacity data. Fees on ocean water withdrawals of $5–120/acre-ft are simulated in three scenarios that test the grid’s ability to simultaneously mitigate its impact on marine ecosystems, conserve freshwater, and incentivize recycled water use. Although fees modeled represent a small share of generator fuel costs, results show that they trigger declines in ocean water withdrawals of up to 11% that are almost always cost-effective if accounting for effects on system-wide fuel costs and CO2 emissions. An appropriately designed fee-structure reduces ocean water withdrawals by 9% without increasing freshwater consumption elsewhere. Wholesale electricity price increases of 5–10% are concentrated in Northern California, and marine ecosystem benefits are partly offset by increases in NOx and SO2 emissions inland. Overall, this study finds that water-use fees could be an effective strategy for reducing the marine ecosystem impacts of California’s power sector, particularly because they can also address short term fluctuations in freshwater scarcity. Keywords: Energy-water nexus, once-through cooling, scarce water, environmental pricing, energy policy, electricity dispatch, power systems.
Sea-level rise (SLR) is predicted to elevate water depths above coral reefs and to increase coastal wave exposure as ecological degradation limits vertical reef growth, but projections lack data on interactions between local rates of reef growth and sea level rise. Here we calculate the vertical growth potential of more than 200 tropical western Atlantic and Indian Ocean reefs, and compare these against recent and projected rates of SLR under different Representative Concentration Pathway (RCP) scenarios. Although many reefs retain accretion rates close to recent SLR trends, few will have the capacity to track SLR projections under RCP4.5 scenarios without sustained ecological recovery, and under RCP8.5 scenarios most reefs are predicted to experience mean water depth increases of more than 0.5 m by 2100. Coral cover strongly predicts reef capacity to track SLR, but threshold cover levels that will be necessary to prevent submergence are well above those observed on most reefs. Urgent action is thus needed to mitigate climate, sea-level and future ecological changes in order to limit the magnitude of future reef submergence.
Coastal wetlands are some of the most valuable ecosystems on Earth because they provide many ecological services for coastal security. However, these wetlands are seriously threatened by accelerated climate change and intensive anthropogenic activities. To understand the impacts of land reclamation on landscape change of coastal wetlands and the long-term effects of disturbances of coastal wetlands on their sustainable management, we used time-series Landsat imagery with an object-oriented classification and Digital Shoreline Analysis System to map wetland changes within a reclaimed area in the Pudong District (PD), in Shanghai, China. Our analysis indicated that from 1989 to 2013, 19,793.4 ha of coastal wetlands have been changed to inland wetlands enclosed by a seawall and dike since 1989, thereby cutting off the exchange of sediment and water flux between the wetlands and the coastal ocean. Subsequently, under the increasing threats of anthropogenic activities, the wetland ecosystem collapsed sharply, in a transformation chain of inland wetland (fresh swamp), artificial wetland (agriculture and aquaculture wetland), and non-wetland (urban land). Under this explosive utilization following coastal reclamation, only 8.9% of natural wetlands remain in the reclaimed area, which has experienced an average annual wetland loss rate of 3.8% over the past 24 years. More than 80% of the wetlands have been developed for agricultural, industrial, and urban land uses, leading to an enormous loss of associated ecological services—benefits arising from the ecological functions provided by wetland ecosystems, thereby undermining the coastal protection these wetlands provided. Nevertheless, considerable regeneration of wetlands occurred because of their inherent resilience. This paper addresses the importance of maintaining a balance between economic growth and coastal ecological protection for sustainable management. It proposes a strategy for how ecosystem-based land planning and ecological engineering should be applied to ensure the effective and sustainable management of living shorelines so that the benefits of healthy ecological functions accrue to coastal ecosystems.
The ocean is the next frontier for many conservation and development activities. Growth in marine protected areas, fisheries management, the blue economy, and marine spatial planning initiatives are occurring both within and beyond national jurisdictions. This mounting activity has coincided with increasing concerns about sustainability and international attention to ocean governance. Yet, despite growing concerns about exclusionary decision-making processes and social injustices, there remains inadequate attention to issues of social justice and inclusion in ocean science, management, governance and funding. In a rapidly changing and progressively busier ocean, we need to learn from past mistakes and identify ways to navigate a just and inclusive path towards sustainability. Proactive attention to inclusive decision-making and social justice is needed across key ocean policy realms including marine conservation, fisheries management, marine spatial planning, the blue economy, climate adaptation and global ocean governance for both ethical and instrumental reasons. This discussion paper aims to stimulate greater engagement with these critical topics. It is a call to action for ocean-focused researchers, policy-makers, managers, practitioners, and funders.
This study aimed to determine the main anthropogenic pressures and the effectiveness of management practices in marine protected areas (MPAs) (Rocas Atoll and Fernando de Noronha Archipelago, South Atlantic). The MPAs exhibited high management effectiveness over the last 25 years due to the control of local pressures (i.e., fishing and tourism). However, the increase in regional and global pressures, such as invasive species, marine debris, and climate change stressors (sea-level rise, extreme events, range shifts of species, warming, and ocean acidification), are environmental risks that need to be considered during conservation. Strategies for large scale marine spatial planning, as well as proposals for an integrated management of MPAs (including coral reef islands and seamounts) by the articulation of a network, which reduces regional human pressures and improves ocean governance were discussed. This study provided insights into the challenges faced in the management of MPAs in a rapidly changing ocean.
Although the importance of Maritime Spatial Planning (MSP) as a concept is know acknowledged and the legal framework is in place, the task of applying it remains a delicate one. One of the keys to success is having pertinent data. Knowing how maritime uses unfold in a spatio-temporal context, and what conflicting or synergistic interactions exist between activities, is crucial. However, this information is especially hard to obtain in a marine environment. As a result this information has often been identified as the missing layer in information systems developed by maritime stakeholders. Since 2002, the Automatic Identification System (AIS) has been undergoing a major development. Allowing for real time geo-tracking and identification for equipped vessels, the data that issues from AIS data promises to map and describe certain marine human activities.
After recapitulating the main characteristics of AIS and the data it provides, this article proposes to evaluate how AIS is currently used in MSP at a European level, and to concisely present a series of methods and results obtained within the framework of several operational research projects. The objective is to illustrate how the AIS data processing and analysis can produce adequate information for MSP: maritime traffic density, shipping lanes and navigation flows, hierarchical network of maritime routes, alleged fishing zones, spatio-temporal interactions between activities (potential conflicting uses or synergies). The conclusion looks in particular at the legal questions concerning the use of AIS.