Increasing exploration and industrial exploitation of the vast and fragile deep-ocean environment for a wide range of resources (e.g., oil, gas, fisheries, new molecules, and soon, minerals) raises global concerns about potential ecological impacts (1–3). Multiple impacts on deep-sea ecosystems (>200 m below sea level; ∼65% of the Earth's surface is covered by deep ocean) caused by human activities may act synergistically and span extensive areas. Cumulative impacts could eventually cause regime shifts and alter deep-ocean life-support services, such as the biological pump or nutrient recycling (2, 4, 5). Although international law and national legislation largely ignore the deep sea's critical role in the functioning and buffering of planetary systems, there are promising developments in support of deep-sea protection at the United Nations and the International Seabed Authority (ISA). We propose a strategy that builds from existing infrastructures to address research and monitoring needs to inform governments and regulators.
The Philippines has a long history of protecting marine resources and limiting resource extraction and has been a world leader in marine protected areas (MPA) establishment, with over 1800 MPAs (Cabral et al. 2014). Understanding the success or failure of MPAs depends on evaluating both the biological and social aspects of the MPA. However, there has been limited research into the social goals of MPAs. This study helps fill the critical research gap by examining the social goals of Philippines MPAs using a mixed method approach. In 2012, household socio-economic surveys were administered to residents via a questionnaire (N = 599) in three MPA communities in the Province of Misamis Oriental, Philippines. Tubajon MPA a local community initiated MPA (bottom-up MPA), Agutayan MPA a government initiated MPA (top-down MPA), and Duka Bay MPA a privately managed MPA (private MPA) and one non-MPA community: Tagoloan. Quantitative data from questionnaires were used to analyze and statistically test similarities and differences in respondent’s perceptions and attitudes of MPA performance both biologically and socially, involvement in decision making, problems with MPAs, and overall impacts of the MPA on their livelihood in each of three MPAs. Additionally, qualitative data was gathered via transcribed, semi-structured interviews (N = 30) with various local government unit officers, barangay captains (elected village leaders), Deputized Fish Wardens, and resort managers in each of the three MPA communities, to further understand MPA performance. Significant differences in perceptions were found between MPAs sites. Duka Bay (private MPA) respondents had more negative perceptions of the impact of the MPA on their livelihood, decreased fish catch since the MPA, and less government involvement. While in Agutayan (top-down MPA) and Tubajon (bottom-up MPA) respondents had significantly more positive views regarding the MPA’s impact on their livelihood and improved health of their coral reef. All MPA sites were found to have limited involvement in decision-making except in Tagoloan (non-MPA site). Tagoloan (non-MPA site) was found to have a significantly higher percentage of respondents involved in making decisions including marine resource decision-making. Significant differences in perceptions were found between fisherfolk and non-fisherfolk, where non-fisherfolk perceived more biological improvements and increased social benefits (i.e. increased tourists). Negative attitudes from fisherfolk need to be addressed in all MPA sites because it has been found to be detrimental to the success of MPAs. Qualitative data revealed problems with enforcement and corruption of some MPA managers, but many informants commented on how the MPA has been beneficial regarding increased fish abundance and diversity, improved coral health, and the presence of more tourists in their community. Future management strategies for MPAs need to consider the conservation objectives, location, and social situation of the MPA (i.e. highly dependent fishing communities). Recommendations for all sites are the development of livelihoods alternative to fishing, holding of open forums and discussions to encourage communication between managers, local government units, and stakeholders to help maintain support, compliance, and a sense of empowerment for community members.
Coastal ecosystems, which provide numerous essential ecological functions for fish, are threatened by the proliferation of green macroalgae that significantly modify habitat conditions in intertidal areas. Understanding the influence of green tides on the nursery function of these ecosystems is essential to determine their potential effects on fish recruitment success. In this study, the influence of green tides on juvenile fish was examined in an intertidal sandy beach area, the Bay of Saint-Brieuc (Northwestern France), during two annual cycles of green tides with varying levels of intensity. The responses of three nursery-dependent fish species, the pelagic Sprattus sprattus (L.), the demersal Dicentrarchus labrax (L.) and the benthic Pleuronectes platessa L., were analysed to determine the effects of green tides according to species-specific habitat niche and behaviour. The responses to this perturbation were investigated based on habitat selection and a comparison of individual performance between a control and an impacted site. Several indices on different integrative scales were examined to evaluate these responses (antioxidant defence capacity, muscle total lipid, morphometric condition and growth). Based on these analyses, green tides affect juvenile fish differently according to macroalgal density and species-specific tolerance, which is linked to their capacity to move and to their distribution in the water column. A decreasing gradient of sensitivity was observed from benthic to demersal and pelagic fish species. At low densities of green macroalgae, the three species stayed at the impacted site and the growth of plaice was reduced. At medium macroalgal densities, plaice disappeared from the impacted site and the growth of sea bass and the muscle total lipid content of sprat were reduced. Finally, when high macroalgal densities were reached, none of the studied species were captured at the impacted site. Hence, sites affected by green tides are less favourable nursery grounds for all the studied species, with species-specific effects related to macroalgal density.
Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus) were exposed to control pCO2 (532 μatm, pH 8.06) and high pCO2 (1503 μatm, pH 7.66) conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.
Sediments are found in the epilithic algal matrix (EAM) of all coral reefs and play important roles in ecological processes. Although we have some understanding of patterns of EAM sediments across individual reefs, our knowledge of patterns across broader spatial scales is limited. We used an underwater vacuum sampler to quantify patterns in two of the most ecologically relevant factors of EAM sediments across the Great Barrier Reef: total load and grain size distribution. We compare these patterns with rates of sediment production and reworking by parrotfishes to gain insights into the potential contribution of parrotfishes to EAM sediments. Inner-shelf reef EAMs had the highest sediment loads with a mean of 864.1 g m-2, compared to 126.8 g m-2 and 287.4 g m-2 on mid- and outer-shelf reefs, respectively. High sediment loads were expected on inner-shelf reefs due to their proximity to the mainland, however, terrigenous siliceous sediments only accounted for 13–24% of total mass. On inner-shelf reef crests parrotfishes would take three months to produce the equivalent mass of sediment found in the EAM. On the outer-shelf it would take just three days, suggesting that inner-shelf EAMs are characterised by low rates of sediment turnover. By contrast, on-reef sediment production by parrotfishes is high on outer-shelf crests. However, exposure to oceanic swells means that much of this production is likely to be lost. Hydrodynamic activity also appears to structure sediment patterns at within-reef scales, with coarser sediments (> 250 μm) typifying exposed reef crest EAMs, and finer sediments (< 250 μm) typifying sheltered back-reef EAMs. As both the load and grain size of EAM sediments mediate a number of important ecological processes on coral reefs, the observed sediment gradients are likely to play a key role in the structure and function of the associated coral reef communities.
The objective of this study is to assess the performance of fishery buybacks so as to determine the conditions under which positive socio-economic outcomes can occur during the process of fisheries adjustments. We do this by conducting a desk top review and supplementing the literature with targeted interviews with experts who have direct knowledge or experience with the implementation of buybacks. We focus on four case studies: Australia, the United States, British Columbia (Canada), and Norway. The outcome of each buyback was assessed in terms of the extent to which it achieved its capacity, economic, ecological, and social objectives. Our results indicate that buybacks can be successful in achieving specific programme objectives, such as reducing fishing capacity and increasing economic profits, at least in the short term. However, none of the buybacks evaluated were a resounding success due to the presence of latent permits or licences, effort creep, and continued reinvestment in the fishery. Enabling conditions for positive social outcomes included a strong economy, accountable leadership, and social assistance programmes tailored to local fishing communities. This study is useful in informing future buyback programmes’ design and implementation.
The social cost of carbon (SCC) is a central concept for understanding and implementing climate change policies. This term represents the economic cost caused by an additional ton of carbon dioxide emissions or its equivalent. The present study presents updated estimates based on a revised DICE model (Dynamic Integrated model of Climate and the Economy). The study estimates that the SCC is $31 per ton of CO2 in 2010 US$ for the current period (2015). For the central case, the real SCC grows at 3% per year over the period to 2050. The paper also compares the estimates with those from other sources.
Large marine protected areas (MPAs) have recently been established throughout the world at an unprecedented pace, yet the value of these reserves for mobile species conservation remains unclear. Reef shark populations continue to decline even within some of the largest MPAs, fueling unresolved debates over the ability of protected areas to aid mobile species that transit beyond MPA boundaries. We assessed the capacity of a large MPA to conserve grey reef sharks - a Near Threatened species with a widespread distribution and poorly understood offshore movement patterns - using a combination of conventional tags, satellite tags, and an emerging vessel tracking technology. We found that the 54,000 km2 U.S. Palmyra Atoll National Wildlife Refuge in the central Pacific Ocean provides substantial protection for grey reef sharks, as two-thirds of satellite-tracked sharks remained within MPA boundaries for the entire study duration. Additionally, our analysis of > 0.5 million satellite detections of commercial fishing vessels identified virtually no fishing effort within the refuge and significant effort beyond the MPA perimeter, suggesting that large MPAs can effectively benefit reef sharks and other mobile species if properly enforced. However, our results also highlight limitations of place-based conservation as some of these reef-associated sharks moved surprising distances into pelagic waters (up to 926 km from Palmyra Atoll, 810 km beyond MPA boundaries). Small-scale fishermen operating beyond MPA boundaries (up to 366 km from Palmyra) captured 2% of sharks that were initially tagged at Palmyra, indicating that large MPAs provide substantial, though incomplete, protection for reef sharks.
The international scientific community is increasingly recognizing the role of natural systems in climate-change mitigation. While forests have historically been the primary focus of such efforts, coastal wetlands – particularly seagrasses, tidal marshes, and mangroves – are now considered important and effective long-term carbon sinks. However, some members of the coastal and marine policy and management community have been interested in expanding climate mitigation strategies to include other components within coastal and marine systems, such as coral reefs, phytoplankton, kelp forests, and marine fauna. We analyze the scientific evidence regarding whether these marine ecosystems and ecosystem components are viable long-term carbon sinks and whether they can be managed for climate mitigation. Our findings could assist decision makers and conservation practitioners in identifying which components of coastal and marine ecosystems should be prioritized in current climate mitigation strategies and policies.
Submarine canyons are major geomorphic features of continental margins around the world. Several recent multidisciplinary projects focused on the study of canyons have considerably increased our understanding of their ecological role, the goods, and services they provide to human populations, and the impacts that human activities have on their overall ecological condition. Pressures from human activities include fishing, dumping of land-based mine tailings, and oil and gas extraction. Moreover, hydrodynamic processes of canyons enhance the down-canyon transport of litter. The effects of climate change may modify the intensity of currents. This potential hydrographic change is predicted to impact the structure and functioning of canyon communities as well as affect nutrient supply to the deep-ocean ecosystem. This review not only identifies the ecological status of canyons, and current and future issues for canyon conservation, but also highlights the need for a better understanding of anthropogenic impacts on canyon ecosystems and proposes other research required to inform management measures to protect canyon ecosystems.