Shark depredation, where a shark consumes a hooked fish before it can be retrieved to the fishing vessel, can occur in recreational fisheries. This may cause higher mortality rates in target fish species, injuries to sharks from fishing gear and negatively impact the recreational fishing experience. This study quantified spatial variation and frequency of shark depredation in a recreational fishery in the Ningaloo Marine Park and Exmouth Gulf, Western Australia, by surveying 248 fishing boats at west coast boat ramps and 155 boats at Exmouth Gulf boat ramps from July 2015 to May 2016. Shark depredation occurred on 38.7% of fishing trips from west coast boat ramps and 41.9% of trips from Exmouth Gulf boat ramps. The mean (±95% CI) shark depredation rate per trip was 13.7 ± 3.3% for demersal fishing (n = 185) and 11.8 ± 6.8% for trolling (n = 63) for west coast boat ramps, compared to 11.5 ± 2.8% (n = 128) and 7.2 ± 8.4% (n = 27) for Exmouth Gulf ramps. Depredation rates varied spatially, with higher depredation in areas which received greater fishing pressure. A novel application of Tweedie generalised additive mixed models indicated that depth, the number of other boats fishing within 5 km and survey period influenced depredation rates for fishing trips from west coast boat ramps. For the Exmouth Gulf ramps, fishing pressure and decreasing latitude positively affected the number of fish depredated. These results highlight the important influence of spatial variation in fishing pressure. The occurrence of higher depredation rates in areas which receive greater fishing pressure may indicate the formation of a behavioural association in the depredating sharks. This study is the first quantitative assessment of shark depredation in an Australian recreational fishery, and provides important insights that can assist recreational fishers and managers in reducing depredation
Ocean acidification (OA), the gradual decline in ocean pH and [ ] caused by rising levels of atmospheric CO2, poses a significant threat to coral reef ecosystems, depressing rates of calcium carbonate (CaCO3) production, and enhancing rates of bioerosion and dissolution. As ocean pH and [ ] decline globally, there is increasing emphasis on managing local stressors that can exacerbate the vulnerability of coral reefs to the effects of OA. We show that sustained, nutrient rich, lower pH submarine groundwater discharging onto nearshore coral reefs off west Maui lowers the pH of seawater and exposes corals to nitrate concentrations 50 times higher than ambient. Rates of coral calcification are substantially decreased, and rates of bioerosion are orders of magnitude higher than those observed in coral cores collected in the Pacific under equivalent low pH conditions but living in oligotrophic waters. Heavier coral nitrogen isotope (δ15N) values pinpoint not only site-specific eutrophication, but also a sewage nitrogen source enriched in 15N. Our results show that eutrophication of reef seawater by land-based sources of pollution can magnify the effects of OA through nutrient driven-bioerosion. These conditions could contribute to the collapse of coastal coral reef ecosystems sooner than current projections predict based only on ocean acidification.
Plain Language Summary
We show that sustained, nutrient rich, lower pH submarine groundwater discharging onto nearshore coral reefs off west Maui lowers the pH of seawater and exposes corals to nitrate concentrations 50 times higher than ambient. Rates of coral calcification are substantially decreased, and rates of bioerosion are orders of magnitude higher than those observed in coral cores collected in the Pacific. With many of Maui's coral reefs in significant decline reducing any stressors at a local scale is important to sustaining future coral reef ecosystems and planning for resiliency.
Tidal response to sea-level rise (SLR) varies in different coastal systems. To provide a generic pattern of tidal response to SLR, a systematic investigation was conducted using numerical techniques applied to idealized and realistic estuaries, with model results cross-checked by analytical solutions. Our results reveal that the response of tidal range to SLR is nonlinear, spatially heterogeneous, and highly affected by the length and bathymetry of an estuary and weakly affected by the estuary convergence with an exception of strong convergence. Contrary to the common assumption that SLR leads to a weakened bottom friction, resulting in increased tidal amplitude, we demonstrate that tidal range is likely to decrease in short estuaries and in estuaries with a narrow channel and large low-lying shallow areas.
To minimize the impacts of climate change on human wellbeing, governments, development agencies, and civil society organizations have made substantial investments in improving people’s capacity to adapt to change. Yet to date, these investments have tended to focus on a very narrow understanding of adaptive capacity. Here, we propose an approach to build adaptive capacity across five domains: the assets that people can draw upon in times of need; the flexibility to change strategies; the ability to organize and act collectively; learning to recognize and respond to change; and the agency to determine whether to change or not.
Plastics and spilled oil pose a critical threat to marine life and human health. As a result of wind forcing and wave motions, theoretical and laboratory studies predict very strong velocity variation with depth over the upper few centimeters of the water column, an observational blind spot in the real ocean. Here we present the first-ever ocean measurements of the current vector profile defined to within 1 cm of the free surface. In our illustrative example, the current magnitude averaged over the upper 1 cm of the ocean is shown to be nearly four times the average over the upper 10 m, even for mild forcing. Our findings indicate that this shear will rapidly separate pieces of marine debris which vary in size or buoyancy, making consideration of these dynamics essential to an improved understanding of the pathways along which marine plastics and oil are transported.
Coastal oceans are increasingly eutrophic, warm and acidic through the addition of anthropogenic nitrogen and carbon, respectively. Among the most sensitive taxa to these changes are scleractinian corals, which engineer the most biodiverse ecosystems on Earth. Corals’ sensitivity is a consequence of their evolutionary investment in symbiosis with the dinoflagellate alga, Symbiodinium. Together, the coral holobiont has dominated oligotrophic tropical marine habitats. However, warming destabilizes this association and reduces coral fitness. It has been theorized that, when reefs become warm and eutrophic, mutualistic Symbiodinium sequester more resources for their own growth, thus parasitizing their hosts of nutrition. Here, we tested the hypothesis that sub-bleaching temperature and excess nitrogen promotes symbiont parasitism by measuring respiration (costs) and the assimilation and translocation of both carbon (energy) and nitrogen (growth; both benefits) within Orbicella faveolata hosting one of two Symbiodinium phylotypes using a dual stable isotope tracer incubation at ambient (26 °C) and sub-bleaching (31 °C) temperatures under elevated nitrate. Warming to 31 °C reduced holobiont net primary productivity (NPP) by 60% due to increased respiration which decreased host %carbon by 15% with no apparent cost to the symbiont. Concurrently, Symbiodinium carbon and nitrogen assimilation increased by 14 and 32%, respectively while increasing their mitotic index by 15%, whereas hosts did not gain a proportional increase in translocated photosynthates. We conclude that the disparity in benefits and costs to both partners is evidence of symbiont parasitism in the coral symbiosis and has major implications for the resilience of coral reefs under threat of global change.
A brief history of marine fisheries is presented which emphasizes the expansion of industrial fleets in the 20th century, and their inherent lack of sustainability. In contrast, small scale fisheries, i.e. artisanal, subsistence and recreational fisheries could become part of a blue economy, given that care is taken to reduce incentives for building up fishing effort. However, they usually receive little attention from policy makers, as reflected by the almost complete absence from the catch data submitted by member countries to the FAO. While industrial fisheries tend to lack the features that would make them compatible with a blue economy, small-scale fisheries possess most of these features, and thus may represent the future of sustainable fisheries.
The vast and complex coast of the Magellan Region of extreme southern Chile possesses a diversity of habitats including fjords, deep channels, and extensive kelp forests, with a unique mix of temperate and sub-Antarctic species. The Cape Horn and Diego Ramírez archipelagos are the most southerly locations in the Americas, with the southernmost kelp forests, and some of the least explored places on earth. The giant kelp Macrocystis pyrifera plays a key role in structuring the ecological communities of the entire region, with the large brown seaweed Lessonia spp. forming dense understories. Kelp densities were highest around Cape Horn, followed by Diego Ramírez, and lowest within the fjord region of Francisco Coloane Marine Park (mean canopy densities of 2.51 kg m-2, 2.29 kg m-2, and 2.14 kg m-2, respectively). There were clear differences in marine communities among these sub-regions, with the lowest diversity in the fjords. We observed 18 species of nearshore fishes, with average species richness nearly 50% higher at Diego Ramírez compared with Cape Horn and Francisco Coloane. The number of individual fishes was nearly 10 times higher at Diego Ramírez and 4 times higher at Cape Horn compared with the fjords. Dropcam surveys of mesophotic depths (53–105 m) identified 30 taxa from 25 families, 15 classes, and 7 phyla. While much of these deeper habitats consisted of soft sediment and cobble, in rocky habitats, echinoderms, mollusks, bryozoans, and sponges were common. The southern hagfish (Myxine australis) was the most frequently encountered of the deep-sea fishes (50% of deployments), and while the Fueguian sprat (Sprattus fuegensis) was the most abundant fish species, its distribution was patchy. The Cape Horn and Diego Ramírez archipelagos represent some of the last intact sub-Antarctic ecosystems remaining and a recently declared large protected area will help ensure the health of this unique region.
Ocean acidification (OA) leads to significant changes in seawater carbon chemistry, broadly affects marine organisms, and considered as a global threat to the fitness of marine ecosystems. Due to the crucial role of copepods in marine food webs of transferring energy from primary producers to higher trophic levels, numerous studies have been conducted to examine the impacts of OA on biological traits of copepods such as growth and reproduction. Under OA stress, the copepods demonstrated species-specific and stage-dependent responses. Notably, different populations of the same copepod species demonstrated different sensitivities to the increased pCO2. In copepods, the deleterious effects of OA are also reinforced by other naturally occurring co-stressors (e.g., thermal stress, food deprivation, and metal pollution). Given that most OA stress studies have focused on the effects of short-term exposure (shorter than a single generation), experiments using adults might have underestimated the damaging effects of OA and the long-term multigenerational exposure to multiple stressors (e.g., increased pCO2 and food shortage) will be required. Particularly, omics-based technologies (e.g., genomics, proteomics, and metabolomics) will be helpful to better understand the underlying processes behind biological responses (e.g., survival, development, and offspring production) at the mechanistic level which will improve our predictions of the responses of copepods to climate change stressors including OA.
2017 was the warmest year on record for the global ocean according to an updated Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP, CAS; http://english. iap.cas.cn/) ocean analysis. The oceans in the upper 2000 m were 1.51 × 1022 J warmer than the second warmest year of 2015 and 19.19×1022 J above the 1981–2010 climatological reference period (Fig. 1). For comparison, total electricity generation in China in 2016 was 0.00216 × 1022 J, which is 699 times smaller than the increase in ocean heat in 2017.
In 1997, the United Nations Environment’s Caribbean Environment Program (UNEP-CEP) convened a meeting of 50 MPA managers from which CaMPAM was born. Since then, CaMPAM has adaptively evolved into a comprehensive regional program that aims at strengthening Caribbean marine protected areas at the site and national level through a variety of mechanisms. CaMPAM’s original focus was to provide training, information sharing, and communications. Shortly after, grants awarding for learning exchanges and for implementing small projects started. Partnerships were established with interested organizations. Some collaborators became mentors and served as instructors and activities' coordinators.These tools allowed the capacity building program to address the MPA changing needs. These needs have been captured through site visits, consultations with scientists and managers, surveys, evaluations of courses and the entre program, CaMPAM project reports, specific requests of donors, the intergovernmental meetings of UNEP-CEP’s Cartagena Convention’s Specially Protected Areas and Wildlife (SPAW) Protocol, etc. and have shaped the program. In the spirit of having a balance between the region’s needs and the role of CaMPAM as the SPAW MPA capacity building tool, in 2016 the UNEP-CEP commissioned the review of CaMPAM program in order to make it more relevant and useful. This paper co-autored by the CaMPAM founder, its coordinator, the main collaborator, and the expert commissioned to assess CaMPAM performance describes the activities implemented in 1997-2017 and the latest assessment of the program.
The protection of marine megafauna within Europe is rather fragmented. Developing conservation measures for highly mobile species presents definite challenges, particularly due to the many knowledge gaps. Recent studies have shown that these gaps can be filled in by Platforms of Opportunity (PO) which create low-cost approaches. However, the number of wildlife tour operators actively collecting PO data related to distribution and relative abundance of marine fauna remains limited. In this study, we investigated whether effort-corrected data on marine megafauna facilitated by a wildlife tour operator afforded robust long temporal data (2011-2015). Sightings data, collected in the wider Mount’s Bay area (southwest Cornwall, UK), along with a GPS application, were collected to accurately record survey effort. In addition, radial sighting distances and detection curves were computed to explore the robustness of the data. Density maps of marine megafauna indicated that encounters occurred throughout the area in all three seasons but the temporal distribution was significantly different with numbers peaking in autumn. Odontocetes were mostly recorded during autumn, basking shark (Cetorhinus maximus) and ocean sunfish (Mola mola) were more abundant during summer and leatherback turtles (Dermochelys coriacea) were recorded occasionally. Our data showed that this shallow coastal environment is particularly important as a nursing area for harbour porpoises (Phocoena phocoena). Risso’s dolphins (Grampus griseus) showed a high semi-residency pattern for adults with calves within one core-habitat. As such, the study provides important spatial and temporal baseline data that are essential for the protection of marine megafauna through the development of an ecological network of marine protected areas within UK waters. Although, data facilitated by wildlife operators have certain shortcomings we highlight that the protocols developed here secured efficient and precise data. Such collection protocols can be implemented on a larger scale, ultimately enhancing research monitoring efforts and marine ecosystem management.
Ecology and biodiversity research are underpinned by species richness patterns and their environmental drivers. However, a key topic in this discussion is the accuracy of these patterns which are greatly dependent on species detection probabilities. Due to variations in detection of species, true ecological patterns may be distorted. This is particularly true for subtidal macro-infaunal communities. We tested three hypothesized relationships between marine benthic macrofaunal diversity and depth using species richness per site estimated with a capture-recapture heterogeneity model that accounts for variable detection probabilities. These metrics were based on data from 42 replicated sites across the continental shelf of the Southern Benguela. Average detection probability decreased with greater depth but species richness increased along the same depth gradient. The conflation of these trends in observed diversity data resulted in a positively near-linear depth-diversity relationship, while accounting for variable species detection revealed a much stronger relationship. Ignoring species detection in ecosystems with imperfect detection could therefore distort species richness patterns, which has implications for ecological theory, management and conservation.
The Ministry of Tourism has created a 10-priority destination program in Indonesia. Pulau Seribu is one of the 10 destinations. Meanwhile, Bira Island is located in the Thousand Islands. To improve the performance of the Island, it is also necessary to increase the island of Bira. This mixed mode research, conducted for a year on the island of Bira to respond to the plans of the Ministry of Tourism. This study aims to discern Coastal Ecotourism in Bira Island, Indonesia. The results of data collection and tabulation show the existence of gap between the performances of the island at this time and expected. Ecotourism concept enhances CE performance on the island. In addition, the concept also creates jobs of women and anglers living along the coastline. Besides, environmental conservation efforts create marine ecotourism. Furthermore, their efforts also increase economic contribution to them and local governments. The economic improvement is accompanied by improved coastal environmental performance and improved performance of culinary and handicraft tourism.
Plastic waste can promote microbial colonization by pathogens implicated in outbreaks of disease in the ocean. We assessed the influence of plastic waste on disease risk in 124,000 reef-building corals from 159 reefs in the Asia-Pacific region. The likelihood of disease increases from 4% to 89% when corals are in contact with plastic. Structurally complex corals are eight times more likely to be affected by plastic, suggesting that microhabitats for reef-associated organisms and valuable fisheries will be disproportionately affected. Plastic levels on coral reefs correspond to estimates of terrestrial mismanaged plastic waste entering the ocean. We estimate that 11.1 billion plastic items are entangled on coral reefs across the Asia-Pacific and project this number to increase 40% by 2025. Plastic waste management is critical for reducing diseases that threaten ecosystem health and human livelihoods.
Corals and sponges create the most important biogenic habitats in the deep sea, and support ecosystems of incredible variety and biodiversity. In 2007, the United States National Oceanic and Atmospheric Administration (NOAA) published the first peer‐reviewed report on the State of Deep Coral Ecosystems of the United States (Lumsden et al. 2007). The 2017 report on the State of Deep‐Sea Coral and Sponge Ecosystems of the United States updates information on deep‐sea coral ecosystems and management efforts to protect them over the last decade, and presents a first summary of information on U.S. deep‐sea sponge ecosystems. It consists of an introduction, six regional chapters with accompanying on‐line resources, and six spotlight chapters that highlight advances on crosscutting themes.
We describe the structure and historic landings of the Punta Abreojos fishing cooperative (Baja California Sur, Mexico) for the period between 2001 and 2015 to understand the dynamics of an economically and ecologically successful coastal fishing community according to catches and the direct income of fishers. A total of 21 commercial species were classified into three major groups: cultural resources, target resources and complementary resources. The most important resource in terms of total biomass was Paralabrax nebulifer(58.4%), followed by Panulirus interruptus and P. inflatus (13.6%). Seriola lalandi, Atractoscion nobilis, Caulolatilus princeps, Paralichtys californicus and P. woolmani made up minor proportions of the total biomass contributing 7.0%, 5.7%, 3.4% and 3.2% respectively. Haliotis fulgens and H. corrugata represented just 1.1% of the total biomass caught. Lobsters were the most profitable source of direct income for fisherman (77.5%), followed by the green and pink abalone (10.4%), barred sand bass (5.6%), white seabass (2.7%), California and speckled flounder (1.2%), yellowtail (1%) and whitefish (0.4%). The rest of the catch was composed of six species of finfish that represented 4.1% of the total catch biomass and 0.4% of the revenues from fishing.
This work provides a first clear base-line description of the fisheries in Punta Abreojos which implements a management program that aims to ensure the wellbeing of the fishers and the fishery. The cooperative has been successful in maintaining catch at levels considered optimal to sustain revenues and continued annual landings. A management and cooperative structure that allows for adaptive change whilst maintaining revenues of the fishers is testament to the stewardship of the community and the participatory management upon which the community is built. For this reason, Punta Abreojos should be considered an example of a successful small-scale fishing cooperative that other, less successful fishing groups, can learn from.
Floating oil, plastics, and marine organisms are continually redistributed by ocean surface currents. Prediction of their resulting distribution on the surface is a fundamental, long-standing, and practically important problem. The dominant paradigm is dispersion within the dynamical context of a nondivergent flow: objects initially close together will on average spread apart but the area of surface patches of material does not change. Although this paradigm is likely valid at mesoscales, larger than 100 km in horizontal scale, recent theoretical studies of submesoscales (less than ∼10 km) predict strong surface convergences and downwelling associated with horizontal density fronts and cyclonic vortices. Here we show that such structures can dramatically concentrate floating material. More than half of an array of ∼200 surface drifters covering ∼20 × 20 km2 converged into a 60 × 60 m region within a week, a factor of more than 105 decrease in area, before slowly dispersing. As predicted, the convergence occurred at density fronts and with cyclonic vorticity. A zipperlike structure may play an important role. Cyclonic vorticity and vertical velocity reached 0.001 s−1 and 0.01 ms−1, respectively, which is much larger than usually inferred. This suggests a paradigm in which nearby objects form submesoscale clusters, and these clusters then spread apart. Together, these effects set both the overall extent and the finescale texture of a patch of floating material. Material concentrated at submesoscale convergences can create unique communities of organisms, amplify impacts of toxic material, and create opportunities to more efficiently recover such material.
Biodiversity compensation policy programs such as offsetting are increasingly being expanded to the marine realm. We reviewed the literature on biodiversity offsets and related compensatory policy to determine where marine offset policies occur. We also identified the most important differences between marine and terrestrial systems that are likely to have implications for how offsetting is conducted. We found that 77 nations had compensatory policies that enabled the use of offsets in the marine environment. Two important differences between marine and terrestrial offsets emerged: (1) biophysical differences, such as greater marine connectivity, lower likelihood of restoration success, and data paucity, and (2) social or governance differences, such as a lack of private ownership and a greater probability of leakage. We conclude that without better evaluation and innovation, it is premature to conclude that marine offsets can be effective. The lessons learned from the development of terrestrial offsets provide an opportunity to improve their application to marine ecosystems.
Marine Protected Areas (MPAs) have become recognized as important management tools for marine and coastal ecosystems in the last few decades. However, the theoretical underpinnings of MPA regimes have arguably not yet received sufficient attention. This paper attempts to remedy this by exploring how the Cultural Theory initiated by Dame Mary Douglas can provide a theoretical foundation for the current debates about the design of MPA regimes. It does so by firstly noting that the various types of MPA governance discussed in the literature correspond to the ways of organizing, perceiving and justifying social relations recognized in Cultural Theory. The article continues by setting out how Cultural Theory helps to explain when and why MPA regimes succeed or fail to reach their goals. In particular, the article highlights the practical importance of accommodating all ways of organizing and perceiving social relations in any MPA management plan. Finally, the paper suggests that further systematic, empirical work for assessing MPAs needs to be undertaken so as to corroborate the arguments advanced in this paper.