Primarily applied to land-based resources, academics have utilised the concept of commodity frontiers to understand the expansionary nature of capitalism, and the ways that existing hegemonies and systems of control and access of resources are challenged and altered. Following recent calls to expand this concept to marine spaces, this paper has used political ecology and in particular its focus on power and access to explore how capitalist expansion has impacted the means and methods of access to key resources in a small-scale marine fishing community in Ghana. The findings of the paper are based upon an eight-month field visit to Aboadze in the Western Region of Ghana, a traditional fishing community that is considered a ‘closing’ frontier, on account of recent research that suggests the small-pelagic fish stocks will collapse within a decade. The findings of the paper show that accessing fish and other necessary resources such as gear and capital has become increasingly difficult as stocks continue to dwindle, and those living in the case study community have to resort to unsustainable fishing methods in order to survive. The paper also finds that the vulnerability caused by decades of overfishing by foreign trawlers is felt disproportionately by certain members of the community, compounding existing vulnerabilities that arise through gender and class.
A cocktail of land-based sources of pollution threatens coral reef ecosystems, and addressing these has become a key management and policy challenge in the State of Hawaiʻi, other US territories, and globally. In West Maui, Hawaiʻi, nearly one quarter of all living corals were lost between 1995 and 2008. Onsite disposal systems (OSDS) for sewage leak contaminants into drinking water sources and nearshore waters. In recognition of this risk, the Hawaiʻi State Department of Health (DOH) is prioritizing areas for cesspool upgrades. Independently, we applied a decision analysis process to identify priority areas to address sewage pollution from OSDS in West Maui, with the objective of reducing nearshore coral reef exposure to pollution. The decision science approach is relevant to a broader context of coastal areas both statewide and worldwide which are struggling with identifying pollution mitigation actions on limited budgets.
The community of species, human institutions, and human activities at a given location have been shaped by historical conditions (both mean and variability) at that location. Anthropogenic climate change is now adding strong trends on top of existing natural variability. These trends elevate the frequency of “surprises”—conditions that are unexpected based on recent history. Here, we show that the frequency of surprising ocean temperatures has increased even faster than expected based on recent temperature trends. Using a simple model of human adaptation, we show that these surprises will increasingly challenge natural modes of adaptation that rely on historical experience. We also show that warming rates are likely to shift natural communities toward generalist species, reducing their productivity and diversity. Our work demonstrates increasing benefits for individuals and institutions from betting that trends will continue, but this strategy represents a radical shift that will be difficult for many to make.
The present study aims to provide a conceptual framework to help practitioners to improve the quality of recreational waters near estuary, which may be affected by untreated wastewater from Combined Sewer Overflows (CSOs). When CSOs are activated, the concentration of bacteria (e.g., Enterococci and E. coli) in estuary increases, thereby resulting in a potential health threat to swimmers. Here, the bacterial exposure is evaluated using physically-based stochastic model for contaminant transport, while human health risk is determined by Quantitative Microbial Risk Assessment (QMRA). Based on human health risk framework, we quantify the Carrying Capacity (CC) of the recreational water body. Such an indicator is defined as the number of swimming individuals that can be sustained in a beach resort with an acceptable risk threshold. The CC increases by dilution processes and by reduction of the source concentration, which in turn depends on the improvements in the sewage system. The presented approach can be a useful screening tool for policy-makers and other stakeholders, thereby providing a potential solution to the trade-off between economic development and the sustainable ecosystem in coastal areas.
Managing coastal areas under an Ecosystem Based Approach–Marine Spatial Planning framework acknowledges the complexity associated with the need to address multiple environmental and socioeconomic issues. The development of efficient management plans is critical to the implementation success of the framework; in this regard, unresolved challenges remain for measuring the effectiveness of planning plans and monitoring implementation progress. This paper describes the development of a Bayesian Belief Network as a prototype Decision Support Tool to assist coastal planning in the catchment areas of the Sydney Harbour, New South Wales, Australia. The model was co-designed with local managers, underpinned by the Drivers-Pressures-States-Impacts-Responses analytical framework to identify key coastal cause-effect relationships, and by the Recreational Opportunity Spectrum framework to account for significant recreational areas. The Bayesian Belief Network was structured on a conceptualisation of the relationships between key pressures affecting coastal management targets (biological areas and human activities) and their impacts on the state of the variables, with emphasis on the beach ecosystem. The socio-economic component of the model consists of predictive socio-economic modelling on preferred beach activities, the assessment of beach recreational settings, and a beach quality survey. Conditional probability tables were derived from local and regional databases. The model structure allows decision makers enhanced understanding of key interactions between management variables, assessment of management scenarios, and increased accountability of planning decisions. Future work on the prototype could expand the model to become a Bayesian Decision Network, through the integration of proposed management actions and their utilities, thereby helping managers identify optimal decisions.
Young men in coastal Tanzania are often blamed for damaging marine habitats by engaging in unsustainable and destructive fishing practices, including dynamite fishing, but their perceptions have not been sufficiently documented. While marine scientists, international environmental NGOs, and activists have called attention to the destructive fishing practices’ devastating impacts, insights into the contextual factors that motivate those who engage in dynamite fishing are limited. Additionally, risk perceptions and concerns regarding the environmental impact and dangers of dynamite fishing among the youth are also understudied. This paper provides ethnographic insights into the historical and contextual factors underlying dynamite fishing in rural coastal Mtwara. It draws on ethnographic data gathered through participant observation, focus group discussions and in-depth interviews with residents from two neighboring coastal villages – one located inside a marine protected area (MPA), and another located outside the MPA’s boundary. The paper first examines the views of elderly men and women to provide the historical context of dynamite fishing in coastal Mtwara. It then juxtaposes youth perceptions regarding marine conservation and dynamite fishing in the two villages, vis-à-vis ongoing efforts to curb destructive fishing practices and to enhance marine biodiversity and ecotourism in the region. Results of the study reveal that unresolved tensions between the MPA authorities and local fishers surrounding enforcement practices and unfulfilled gear-exchange-related promises, and allegations of poor governance, are important contextual factors in the persistence of dynamite fishing. The paper concludes by articulating possible remedial measures to mitigate the tensions between youth concerns about their livelihoods, and the goals of marine biodiversity conservation as a way forward in preventing dynamite fishing.
In world fisheries, incidental non target species mortality have turned in a permanent debate issue. Although many studies have dealt with these interactions from a descriptive overview, there is little information based on fishing operations data. One of the most important species that have awakened scientific concern are seabird, being southern Chile one of the areas with the highest levels in this kind of interactions. In order to improve our understanding on these relationships, we analyze records of fishing hauls of industrial trawlers off the coast of Chile between 39 and 57°S. The results showed that incidental seabird mortality appears to be affected mainly by the collisions with net monitoring systems (net-sonde cable), the duration of fishing hauls, the year period, and the fishing zones, these last related to the breeding period and areas of albatross colonies. We indirectly address a probable relationship between seabird mortality and fishing discards, and some hypothesis are proposed to explain the results. Finally, we demonstrated that longer fishing hauls are less efficient for fishing, beside to a high seabird mortality. Our findings suggest mitigation actions that would harmonize fishing activity with the ecosystem, in particular, for trawl fishing management and operations off far southern Chile.
Black consumer plastics are often contaminated with hazardous chemicals because of technological constraints on sorting dark plastic during recycling of municipal waste coupled with the convenience of waste electrical and electronic equipment (WEEE) as a secondary source of black plastic. In this study, samples of beached plastic litter (n = 524) from southwest England were categorised according to origin, appearance and colour (black versus non-black) before being analysed by x-ray fluorescence (XRF) spectrometry for elements that are characteristic of EEE. The small number of items of WEEE retrieved (n = 36) were largely restricted to wiring insulation and constructed of lead-stabilised polyvinyl chloride (PVC). Among the remaining samples, Br, Cd, Cr and Pb were commonly detected in all categories of black plastics (n = 264) with maximum concentrations of 43,400 mg kg−1, 2080 mg kg−1, 662 mg kg−1 and 23,800 mg kg−1, respectively. Moreover, concentrations of Br were significantly correlated with concentrations of the flame retardant synergist, Sb (n = 22), and 35 samples were potentially non-compliant with regard to limits defined by the Restriction of Hazardous Substances Directive. For plastics of other colours (n = 224), Br and Pb were detected in fewer samples and Br was co-associated with Sb in only two cases, with occasional high concentrations Cd, Cr and Pb largely attributed to the historical use of cadmium sulphide and lead chromate pigments. An avian physiologically-based extraction test applied to selected samples cut to mm-dimensions revealed bioaccessibilities ranging from <0.1% for Cr in a green fragment to about 2.4% (or about 580 mg kg−1) for Pb in black PVC. The recycling of WEEE into consumer, industrial and marine (e.g. fishing) plastics that are mainly coloured black appears to be an important vehicle for the introduction of hazardous chemicals into the environment and a source of their exposure to wildlife.
Plastic pollution is a major ecological catastrophe that endangers vulnerable species. Small plastic fragments and filaments enter the food web in the ocean threatening marine species health. Here microplastics between 0.5 and 5 mm were quantified from eight beaches of southwest Bay of Biscay (Spain) within Natura-2000 Special Protection Areas for birds. Sand samples were taken using a randomized quadrat-based protocol. Between 145 and 382 particles per kg of dry sand were found, which is relatively high in comparison with other European beaches. Microfibers were more abundant than microplastics. PERMANOVA revealed a significant effect of the beach location (inside versus outside the estuary). Open beaches contained a higher microplastic density than sheltered ones suggesting that many beached microplastics come from the ocean. Birds are at risk in the studied protected spaces as revealed from high concentrations of fibres in depositions of European shag and gulls.
This research reveals attitudes towards enclosure and privatisation of ocean space. The development of spatially distributed industries like marine renewables and aquaculture, the need for marine conservation, and the ongoing emphasis on spatial aspects of marine planning, have resulted in increasing encroachment into the marine environment. The study, situated in Scotland, investigates the attitudes of stakeholders who are affecting, or being affected by, these processes. The attitude analysis, done by Q methodology, highlights potentially conflicting priorities and processes. Five unique factors emerged. These are expressed as: free seas, the ‘greater good’, mitigating losses, local powers, and the status quo. The topography of views revealed demonstrates clear tensions between key players in Scotland's marine planning landscape, and calls into question the processes for effective collaborative working for sustainable and conflict-free development at sea. The paper concludes with an appeal for changes in rights to be accounted for in decision making processes, accompanied by better dissemination of information regarding rights at sea, governance and the future of the blue economy.
Estimates of connectivity are vital for understanding population dynamics and for the design of spatial management areas. However, this is still a major challenge in the marine environment because the relative contributions of factors influencing connectivity amongst subpopulations are difficult to assess. This study combined population genetics with hydrodynamic modelling (Regional Ocean Modeling System, ROMS) to assess spatial and temporal exchange of individuals among subpopulations of the New Zealand scallop, Pecten novaezelandiae, within the Coromandel fishery area open to commercial fishing. Significant genetic differentiation was revealed among subpopulations with variable levels of recruitment. Connectivity, as assessed by ROMS, was a significant explanatory variable of genetic differentiation when accounting for the spatial dependency between locations. Although additional research is needed before source-sink population dynamics can be confidently used in management, these results imply that higher yields could be available from this fishery at lower risk of over-exploitation if the fishing of each subpopulation could be tailored to its contribution to recruitment, perhaps using subpopulation catch limits. This study highlights inter-annual patterns of connectivity, the importance of combining different methods for a better prediction of population dynamics, and how such an approach may contribute to management of living marine resources.
The seascape context of coastal ecosystems plays a pivotal role in shaping patterns in fish recruitment, abundance, and diversity. It might also be a principal determinant in structuring the recruitment of fish assemblages to restored habitats, but the trajectories of these relationships require further testing. In this study, we surveyed fish assemblages from 14 restored oyster reefs and 14 control sites in the Noosa River, Queensland, Australia, that differed in the presence or absence of seagrass within 500 m, over four periods using baited cameras. Fish assemblages at oyster reefs differed from those at control sites, with higher species richness (1.4 times) and more individuals of taxa that are harvested by fishers (1.8 times). The presence or absence of seagrass nearby affected the abundance of a key harvestable fish species (yellowfin bream Acanthopagrus australis) on oyster reefs, but not the overall composition of fish assemblages, species richness, or the total abundance of harvestable fishes overall. These findings highlight the importance of considering species-specific patterns in seascape utilization when selecting restoration sites and setting restoration goals, and suggest that the effects of restoration on fish assemblages might be optimized by focusing efforts in prime positions in coastal seascapes.
In February and March 2017, a coastal El Niño caused extraordinary heavy rains and a rise in water temperatures along the coast of northern Peru. In this work, we document the impacts of this phenomenon on the artisanal fisheries and the scallop aquaculture sector, both of which represent important socio-economic activities for the province of Sechura. Despite the perceived absence of effective disaster management and rehabilitation policies, resource users opted for a wide range of different adaptation strategies and are currently striving towards recovery. One year after the event, the artisanal fisheries fleet has returned to operating almost on a normal scale, while the aquaculture sector is still drastically impacted, with many people continuing to work in different economic sectors and even in other regions of the country. Recovery of the social-ecological system of Sechura likely depends on the occurrence of scallop seed and the financial capacity of small-scale producers to reinitiate scallop cultures. Long-term consequences of this coastal El Niño are yet to be studied, though the need to develop trans-local and trans-sectoral management strategies for coping with disturbance events of this scale is emphasized.
Hydrological monitoring is essential to guide evidence-based decision making necessary for sustainable water resource management and governance. Limited hydrometric datasets and the pressure on long-term hydrological monitoring networks make it paramount to explore alternative methods for data collection. This is particularly the case for low-income countries, where data scarcity is more pronounced, and where conventional monitoring methods are expensive and logistically challenging. Citizen science in hydrological research has recently gained popularity and crowdsourced monitoring is a promising cost-effective approach for data collection. Citizen science also has the potential to enhance knowledge co-creation and science-based evidence that underpins the governance and management of water resources. This paper provides a comprehensive review on citizen science and crowdsourced data collection within the context of hydrology, based on a synthesis of 71 articles from 2001 to 2018. Application of citizen science in hydrology is increasing in number and breadth, generating a plethora of scientific data. Citizen science approaches differ in scale, scope and degree of citizen involvement. Most of the programs are found in North America and Europe. Participation mostly comprises a contributory citizen science model, which engages citizens in data collection. In order to leverage the full potential of citizen science in knowledge co-generation, future citizen science projects in hydrology could benefit from more co-created types of projects that establish strong ties between research and public engagement, thereby enhancing the long-term sustainability of monitoring networks.
Since the 1950s, industrial fisheries have expanded globally, as fishing vessels are required to travel further afield for fishing opportunities. Technological advancements and fishery subsidies have granted ever-increasing access to populations of sharks, tunas, billfishes, and other predators. Wilderness refuges, defined here as areas beyond the detectable range of human influence, are therefore increasingly rare. In order to achieve marine resources sustainability, large no-take marine protected areas (MPAs) with pelagic components are being implemented. However, such conservation efforts require knowledge of the critical habitats for predators, both across shallow reefs and the deeper ocean. Here, we fill this gap in knowledge across the Indo-Pacific by using 1,041 midwater baited videos to survey sharks and other pelagic predators such as rainbow runner (Elagatis bipinnulata), mahi-mahi (Coryphaena hippurus), and black marlin (Istiompax indica). We modeled three key predator community attributes: vertebrate species richness, mean maximum body size, and shark abundance as a function of geomorphology, environmental conditions, and human pressures. All attributes were primarily driven by geomorphology (35%−62% variance explained) and environmental conditions (14%−49%). While human pressures had no influence on species richness, both body size and shark abundance responded strongly to distance to human markets (12%−20%). Refuges were identified at more than 1,250 km from human markets for body size and for shark abundance. These refuges were identified as remote and shallow seabed features, such as seamounts, submerged banks, and reefs. Worryingly, hotpots of large individuals and of shark abundance are presently under-represented within no-take MPAs that aim to effectively protect marine predators, such as the British Indian Ocean Territory. Population recovery of predators is unlikely to occur without strategic placement and effective enforcement of large no-take MPAs in both coastal and remote locations.
Compliance is a key factor in ensuring success of marine conservation. We describe a community–academic partnership that seeks to reduce non-compliance of recreational fishers with Rockfish Conservation Areas (RCAs) around Galiano Island in British Columbia, Canada. Previous work showed mostly unintentional non-compliance by recreational fishers. From 2015 to 2018 we developed and implemented outreach and public education activities. We distributed information at community events, and installed 46 metal signs with maps of nearby RCAs at marinas, ferry terminals, and boat launches. During the summers of 2015, 2017, and 2018, we interviewed 86 recreational fishers to gauge their compliance with RCAs. Compared with a baseline in 2014, there was a reduction of 22% (from 25 to 3%) of people who unintentionally fished in RCAs with prohibited gears. In 2018, 67% of participants had seen our outreach materials. We used trail cameras overlooking RCAs to assess non-compliance in six locations on Galiano Island. Illegal fishing incidents within RCAs declined from 42% of days monitored in 2014 to 14% in 2018. Although our outreach efforts were limited in scale and scope, they appear to be making a difference. Our activities and findings can provide guidance for other regions seeking to improve compliance by recreational fishers.
In this study, a commercial CFD code, STARCCM+, is used to analyze the performance of a passive ocean plastic collector under rough sea conditions. The CFD code was first validated by comparing with data from a scaled model experiment conducted in the towing water tank in National Cheng Kung University, and it was proven to return accurate catch rate. Then thirty-eight test cases were setup to investigate the effects of four different parameters, namely, ocean current speed, wave height, wave length, and plastic density, on the plastic collector's catch rate, which is the percentage of incoming plastic debris intercepted by the plastic collector. It was found that the parameters of wave length and plastic density posed very little effect on catch rate. In contrast, the effects of the other two parameters were significant. Two important thresholds were found, and they were ocean current speed of 2.5 ms−1 and wave height of 0.4 m. The catch rate remained at high level until these thresholds were reached. The information found in this study is invaluable for the design of a practical passive ocean plastic collector.
Few studies assess the effects of recreational fishing in isolation from commercial fishing. We used meta-analysis to synthesise 4444 samples from 30 years (1987–2017) of fish surveys inside and outside a large network of highly protected reserves in the Ningaloo Marine Park, Western Australia, where the major fishing activity is recreational. Data were collected by different agencies, using varied survey designs and sampling methods. We contrasted the relative abundance and biomass of target and non-target fish groups between fished and reserve locations. We considered the influence of, and possible interactions between, seven additional variables: age and size of reserve, one of two reserve network configurations, reef habitat type, recreational fishing activity, shore-based fishing regulations and survey method. Taxa responded differently: the abundance and biomass inside reserves relative to outside was higher for targeted lethrinids, while other targeted (and non-targeted) fish groups were indistinguishable. Reef habitat was important for explaining lethrinid response to protection, and this factor interacted with reserve size, such that larger reserves were demonstrably more effective in the back reef and lagoon habitats. There was little evidence of changes in relative abundance and biomass of fishes with reserve age, or after rezoning and expansion of the reserve network. Our study demonstrates the complexities in quantifying fishing effects, highlighting some of the key factors and interactions that likely underlie the varied results in reserve assessments that should be considered in future reserve design and assessment.
There are several environmental and ecological effects of shipping. However, these are rarely assessed in total in the scientific literature. Thus, the aim of this study was to summarize the different impacts of water-based transport on aquatic and nearshore ecosystems and to identify knowledge gaps and areas for future research. The review identified several environmental and ecological consequences within the main impact categories of water discharges, physical impacts, and air emissions. However, although quantitative data on these consequences are generally scarce the shipping contribution to acidification by SOx- and NOx-emissions has been quantified to some extent. There are several knowledge gaps regarding the ecological consequences of, for example, the increasing amount of chemicals transported on water, the spread of non-indigenous species coupled with climate change, and physical impacts such as shipping noise and artificial light. The whole plethora of environmental consequences, as well as potential synergistic effects, should be seriously considered in transport planning.
As global fisheries management shifts towards ecosystem-based management, responsible organizations and governments must also address the socio-economic impacts of this shift. This study evaluates potential impacts of such management shift with a case study of Pulley Ridge (PR), an ecologically rich area in the Gulf of Mexico, on fishermen and economies of Florida's Gulf Coast. We developed an input-output model to estimate direct, backward-linkage, forward-linkage, and induced consumption effects of various management scenarios on the region's economy. We also solicited input on the proposed management changes from Florida saltwater fishing license holders using an online survey. Although gear restrictions may affect harvest of the region's two most lucrative fish types, snappers and groupers, the proposed changes would impact only a small fraction of the fishing industry and the regional economy. Results suggest economic impacts to affected counties and the overall Gulf Coast fishery from management changes would be limited, i.e., less than 3% reductions in income, taxes and employment. Nonetheless, almost 90% of survey respondents indicated the proposed management changes would affect their business either “Significantly” or “Very Significantly”. Results suggest developing broad based support for changes affecting the commercial fishing sector may require stakeholder negotiation along with convincing evidence that the proposed changes will improve regional fishery production in the near term.