Fish traps are extensively used in tropical and subtropical reef fisheries. Despite this, there is a significant lack of extensive and consecutive research concerning the basic aspects of trap fishing. We herein compile the available information from the main coral and rocky reef fish trap fisheries, and compared their main aspects (i.e., mesh size, CPUE, catch composition, ghost fishing, and management) to assess the dynamics of these fisheries and their environmental impact. The analysis revealed that most fish stocks showed declining trends, with only few species under heavy management being capable of withstanding high fishing pressure. In other fisheries, due to fishing down the web, miscellaneous reef fish comprised the bulk of the catch, while the proportion of high-value landed species was insignificant. Gear restrictions remain the most common management method in trap fisheries; however, even the minimum mesh size has not been ubiquitously enforced, while due to great variability of targeted fish species, use of a uniform mesh size is highly unlikely. Other management tools, such as, restrictions in effort, size, and species, temporal and spatial closures were also widely used, but effective only when well enforced and interconnected. Rates of trap loss widely differed as well as the reported rates of ghost fishing mortality. In most cases, incorporation of escape panels resulted in almost complete elimination of ghost fishing. However, further research is required concerning these issues.
Despite an exponential increase in available data on marine plastic debris globally, information on levels and trends of plastic pollution and especially microplastics in the Arctic remains scarce. The few available peer-reviewed scientific works, however, point to a ubiquitous distribution of plastic particles in all environmental compartments, including sea ice. Here, we review the current state of knowledge on the sources, distribution, transport pathways and fate of meso- and microplastics with a focus on the European Arctic and discuss observed and projected impacts on biota and ecosystems.
The primary objective of this study is to develop a new weather routing system for vessel navigation in coastal and marginal seas based on the A-star algorithm. The cost function inherent in the original A-star algorithm is modified to account for oceanic and atmospheric conditions around the vessel of interest. Three options are introduced to search for optimal paths with the shortest travel distance, shortest travel time, and minimal fuel consumption. An avoidance algorithm for unsafe conditions is further incorporated to exempt any arbitrary area from the navigation solution. Furthermore, a compact ocean circulation model based on the Regional Ocean Modeling System executable on typical laptop PCs is configured for a vessel-borne weather routing system; the system is successfully applied to evaluate the optimal vessel paths in the Seto Inland Sea, where high-frequency tidal currents modified by complex topography make it essential to alter the vessel's speed.
The effectiveness of mussel caging for active microplastics (MPs) biomonitoring was investigated for the first time by comparing abundance and characteristics (shape, size, color and type of polymers) of MPs ingested by caged depurated blue mussels with those ingested by native mussels collected at the same sites and with those found in their surrounding environment (surface water and sediments). Mussels were exposed along a pollution gradient originating from a wastewater treatment plant discharge and near an abandoned coastal landfill. After 6 weeks of deployment, the majority (93%) of clean transplanted mussels had ingested MPs with a mean number of items ranging from 0.61 to 1.67 items/g. The occurrence, abundance and properties of MPs ingested by caged mussels were similar to those found in native mussels. Among the debris items detected in caged and native mussels, fragments were the most predominant type, consistent with the MPs found in their surrounding environment. MPs sizes were very similar whether in the water, sediments and both caged and native mussels, with a dominance of items <150 μm. Although some polymers were under-represented or totally absent in the caged mussels compared to overlying seawater or surrounding sediment, there was a good overlap in polymer types proportion being found between caged mussels and sediments (Morisita's index of similarity = 0.93) or seawater (0.86). Polystyrene dominated all samples in all the different matrices. Our study suggests that blue mussels caging may be a promising tool for MPs biomonitoring making monitoring more reliable with an accurate assessment of the biological effects of MPs over a predetermined exposure period. However, further methodological improvements should be considered to define a uniform protocol for blue mussels caging to allow spatial and temporal microplastics active biomonitoring.
Most fisheries management systems rely on a set of regulatory measures to achieve desired objectives. Controls on catch and effort are usually supplemented with gear restrictions, minimum landing sizes, and in the framework of the new common fisheries policy, limitation of discards and by-catch. However, the increasing use of spatial management measures such as conservation areas or spatial and temporal area closures faces new challenges for fishery managers. Here we present an integrated spatial framework to identify areas in which undersized commercial species are more abundant. Once these areas are identified they could be avoided by fishers, minimizing the fishing impact over the immature fraction of the stocks. In particular we applied this methodology to two species of megrim, Lepidorhombus whiffiagonis and L. boscii, in North Atlantic Iberian waters (ICES Divisions 8c and 9a), analyzing fishery-independent data provided by bottom-trawl surveys and environmental data through Bayesian spatial models. Results show that species exhibit species-specific spatial patterns, and we identified sensitive areas that could be used for conservation purposes. We discuss integrating technical measures together (e.g. Minimum Conservation Reference Size and spatial closures) could be a more effective approach for fishery management and this case study could be extended to other species.
We highlight the potential benefits of adopting Ecosystem-based Fishery Management (EBFM). We compare the EBFM implementation with the more traditional single-stock approach. We show the contribution of the portfolio theory to the EBFM, which can be achieved by selecting an optimal portfolio to maximise the average revenues and minimise the variance. We use this approach to construct two frontiers: the ecosystem efficient frontier, which considers stock interactions (the variance-covariance matrix), and the stock efficient frontier, only considering individual stock variances.
We also define two risk gaps. The first gap shows the reduction in the standard deviation per unit of revenue that the fleet could have achieved if they had decided to use the optimal portfolio of the stock frontier instead of the historical portfolio. The second gap reflects the reduction in the standard deviation per unit of revenue when the management moves from the stock frontier to the ecosystem frontier portfolio.
This approach is adapted to the Basque inshore fleet. According to our results, taking the single-stock approach as the benchmark, the EBFM would obtain the same historical revenue while reducing the risk by 23%. Alternatively, allowing the same level of risk, it could achieve a 21% increase in revenues.
Coastal and estuarine ecosystems, such as mangroves, tidal marshes and seagrass meadows, provide a range of ecosystem services, but have seen extensive degradation and decline. Effective protection and rehabilitation of coastal ecosystems requires an understanding of how efforts may improve associated ecosystem services. In this study, we present a spatially-explicit angler catch function to predict boat-based recreational catch as a function of ecosystem and angler characteristics. We developed a choice model to investigate where recreational anglers launch their boats and fish in southeast Australia. By linking the recreational catch models with a choice model, we were able to quantify welfare gains of ecosystem rehabilitation. We found welfare gains across fishing locations varied widely due to heterogeneous coverage of seagrass. The welfare gains of different fishing locations ranged from near-zero in areas of low seagrass coverage, to AU $19.18 (10% increase in seagrass area) and to AU $85.55 (30% increase) per trip in location of high seagrass coverage. Given two million fishing trips occurring per year in Port Phillip Bay, and one million in Western Port, the aggregated welfare gain could scale up to AU $6.2 million with a 10% increase in seagrass coverage, and AU $22 million per annum with a 30% increase in seagrass. We also calculated the welfare loss associated with total loss of seagrass ecosystem in each fishing location to represent the current value, which varied significantly, ranging from near-zero in some locations to AU $87.47 per trip in other location. Over the past several decades, the bay-wide seagrass ecosystem has dropped by 36.7% in Western Port, resulting in potential welfare loss of an estimated AU $ 86.7 million per annum. Our analyses provide insightful spatial policy implications for coastal and marine ecosystem rehabilitation in the region.
The aim of the present study was to risk screen 45 jellyfish species (30 hydromedusae, 14 scyphomedusae, one cubomedusa) for their potential invasiveness in the Mediterranean Sea to aid managers in making informed decisions on targeting appropriate species for management. Using the Aquatic Species Invasiveness Screening Kit (AS-ISK), calibrated basic and climate-change threshold assessment scores of 6.5 and 12.5, respectively, were identified for distinguishing reliably between species that pose ‘low-to-medium’ and ‘high’ risk of becoming invasive in the risk assessment area. Using these thresholds, 16 species were classified as high risk, 23 as medium risk and six as low risk under current climate conditions. Whereas, under future climate conditions, 13, 30 and two species, respectively, were classified as high, medium and low risk, respectively. Upside-down jellyfish Cassiopea andromeda, Australian spotted jellyfish Phyllorhiza punctata, sea nettle Chrysaora quinquecirrha and Rhopilema nomadica were the highest-scoring species, with the maximum increase in risk score under predicted climate change conditions being achieved by C. andromeda.
This paper examines the potential for improved environmental performance of smallholder aquaculture production through ‘beyond-farm’ governance. Smallholder aquaculture farmers face a range of systemic environmental risks related to disease and water quality that extend beyond the boundary of their farms. Yet most governance arrangements aimed at mitigating risks, such as certification, finance and insurance, are focused on the farm-level rather than the wider landscape within which farming takes place. In this paper we propose an integrated approach to area-based management of aquaculture risks that integrates collective action, risk assurance and transfer, and inclusive value chains. In doing so, we set a new research agenda for the integrated governance of mitigating production risks and producer vulnerability in global food production.
Marine biodiversity is under extreme pressure from anthropogenic activity globally, leading to calls to protect at least 10% of the world’s oceans within marine protected areas (MPAs) and other effective area-based conservation measures. Fulfilling such commitments, however, requires a detailed understanding of the distribution of potentially detrimental human activities, and their predicted impacts. One such approach that is being increasingly used to strengthen our understanding of human impacts is cumulative impact mapping; as it can help identify economic sectors with the greatest potential impact on species and ecosystems in order to prioritize conservation management strategies, providing clear direction for intervention. In this paper, we present the first local cumulative utilization impact mapping exercise for the Bioko-Corisco-Continental area of Equatorial Guinea’s Exclusive Economic Zone – situated in the Gulf of Guinea, one of the most important and least studied marine regions in the Eastern Central Atlantic. This study examines the potential impact of ten direct anthropogenic activities on a suite of key marine megafauna species and reveals that the most suitable habitats for these species, located on the continental shelf, are subject to the highest threat scores. However, in some coastal areas, the persistence of highly suitable habitat subject to lower threat scores suggests that there are still several strategic areas that are less impacted by human activity that may be suitable sites for protected area expansion. Highlighting both the areas with potentially the highest impact, and those with lower impact levels, as well as particularly damaging activities can inform the direction of future conservation initiatives in the region.
Current policy and management for marine water quality in the Great Barrier Reef (GBR) in north-eastern Australia primarily focusses on sediment, nutrients and pesticides derived from diffuse source pollution related to agricultural land uses. In addition, contaminants of emerging concern (CECs) are known to be present in the marine environments of the GBR and the adjacent Torres Strait (TS). Current and projected agricultural, urban and industrial developments are likely to increase the sources and diversity of CECs being released into these marine ecosystems. In this review, we evaluate the sources, presence and potential effects of six different categories of CECs known to be present, or likely to be present, in the GBR and TS marine ecosystems. Specifically, we summarize available monitoring, source and effect information for antifouling paints; coal dust and particles; heavy/trace metals and metalloids; marine debris and microplastics; pharmaceuticals and personal care products (PPCPs); and petroleum hydrocarbons. Our study highlights the lack of (available) monitoring data for most of these CECs, and recommends: (i) the inclusion of all relevant environmental data into integrated databases for building marine baselines for the GBR and TS regions, and (ii) the implementation of local, targeted monitoring programs informed by predictive methods for risk prioritization. Further, our spatial representation of the known and likely sources of these CECs will contribute to future ecological risk assessments of CECs to the GBR and TS marine environments, including risks relative to those identified for sediment, nutrients and pesticides.
As ocean acidification (OA) sensor technology develops and improves, in situ deployment of such sensors is becoming more widespread. However, the scientific value of these data depends on the development and application of best practices for calibration, validation, and quality assurance as well as on further development and optimization of the measurement technologies themselves. Here, we summarize the results of a 2-day workshop on OA sensor best practices held in February 2018, in Victoria, British Columbia, Canada, drawing on the collective experience and perspectives of the participants. The workshop on in situ Sensors for OA Research was organized around three basic questions: 1) What are the factors limiting the precision, accuracy and reliability of sensor data? 2) What can we do to facilitate the quality assurance/quality control (QA/QC) process and optimize the utility of these data? and 3) What sort of data or metadata are needed for these data to be most useful to future users? A synthesis of the discussion of these questions among workshop participants and conclusions drawn is presented in this paper.
The increasing perception that public communication in science and technology is an important tool to create a knowledge society is encouraging numerous public engagement activities. However, too little is known about scientists’ opinions of and attitudes towards the public with whom they interact during these activities, especially in southern European countries such as Spain. If we want to establish an effective dialogue between science and society, we need to be aware of the opinions and perceptions that both parties have of each other. In this study, we address this issue by focusing on 1022 responses to a survey conducted among scientists in Spain to discover their views of the public, and we then compare these responses with data from other national surveys on the public’s understanding of science. The results show that approximately 75% of Spanish scientists think that the general public has a serious lack of knowledge and understanding of scientific reasoning, although scientists do recognize that science interests the public (73%). Scientists believe that the public values the scientific profession to a lesser extent than suggested by public surveys: on a scale of 1–5, survey respondents rate their valuation of the scientific profession at 4.22, whereas scientists rate the public's valuation of the profession at 3.12, on average. Significant differences were detected between scientists’ perceptions of how citizens are informed about science and what citizens report in surveys. The challenge for the future is to narrow this gap in order to help scientists gain a better understanding of the public and their interests and to make public engagement activities more effective.
A wetland is a complex ecosystem with high biodiversity; in some situations, the productivity of a wetland is comparable to those of a rain forest or coral reef. The stability of wetlands is under threat due to human activities. The study area of the work described here was Palo Laziale (Province of Rome), a characteristic Mediterranean woodland and wetland area in central Italy. Agricultural activities and urbanisation have considerably reduced this habitat. The first evidence of stress on the area’s tree species was detected at the end of 1995, and this stress has gradually resulted in the complete collapse of the woodland habitat, with the deaths of more than 4000 individual trees. Physicochemical data, 87Sr/86Sr isotope data and saturation indices have been used to explore the trends in the characteristics of the aquifer over 15 years. We compared geochemical data from 2002 with new data collected in 2010 and 2016, which confirmed the brackish nature of the aquifer. The similarity of the 2010 and 2016 datasets and a comparison of those datasets with the 2002 dataset show that the system is resilient—it strongly buffers modifications without presenting any major alterations in function. The results demonstrate that the application of a hydrogeochemical approach emphasises the strong relationship between the level of wetland exposure and the nature of the wetland area at the monitoring scale applied.
A new method consisting of enrichment factor (EF) determination, nonmetric multidimensional scaling (NMS), and the geographic information system (GIS) technique was firstly developed to identify anthropogenic heavy metal sources in marine sediments of Hong Kong. Firstly, the EF was determined to differentiate between heavy metals originating from human and natural sources. Subsequently, NMS was applied to identify various source patterns of heavy metals, and the NMS score was calculated and spatially interpolated using GIS technology to evaluate the spatial influences of anthropogenic impacts in different areas. The concentrations of heavy metals in sediments of Hong Kong substantially exceeded their background values, demonstrating anthropogenic pollution. Two different types of human sources could be identified via NMS, one representing the industrial pollution discharges in the period from the 1960s to the 1980s before pollution control was introduced and one representing sewage discharge before the Tolo Harbour Action Plan in the mid-1980s.
Multi-scale social-ecological systems (SES) approaches to conservation and commons management are needed to address the complex challenges of the Anthropocene. Although SES approaches to monitoring and evaluation are advocated in global science and policy arenas, real-world applications remain scarce. Here, we describe the first operationalization and implementation of Ostrom’s influential SES framework for monitoring practice across multiple countries. Designed to inform management aimed at sustaining coral reefs and the people that depend on them, we developed our SES monitoring framework through a transdisciplinary process involving academics and practitioners with expertise in social and ecological sciences. We describe the SES monitroing framework, including how it operationalizes key insights from the SES and program evaluation literatures, and demonstrate how insights from its implementation in more than 85 communities in four countries (Fiji, Indonesia, Kenya and Madagascar) are informing decision-making at multiple levels. Responding to repeated calls for guidance on applying SES approaches to monitoring and management practice, we outline the key steps of the transdisciplinary development of the framework and lessons learnt. Therefore, our work contributes to bridging the gap between SES science and commons management practice through not only providing an SES monitoring framework that can be readily applied to coral reefs and other commons, but also through demonstrating how to operationalize SES approaches for real-world monitoring and management practice.
This study examined the carriage of antibiotic resistance in bacteria isolated from Food-related Marine Macroplastic Litter (FRMMPL) around the coastline of Northern Ireland. FRMMPL was collected from 18 coastal sites during November/December 2018 and the bacteria from the surface of the plastic examined for their susceptibility to 10 common human antibiotics. Ten bacterial genera and 13 species were identified from the plastic materials. Bacteria isolated from plastic material were most resistant to the beta-lactam antibiotics (ampicillin, ceftazidime and cefpodoxime) (98.1% resistant) and least resistant to the tetracycline group, minocycline (16.1% resistant). This study is significant as it highlights a new potential route of dispersal of such antibiotic-resistance in the environment, which may act as carriers of such bacteria by introducing them into new marine ecosystems, as well as potential pathways having impacts on animal and human health, until their final interaction with the human foodchain.
This paper investigates the livelihood situation of small-scale coastal fisherfolk in the Western Region of Ghana. This paper is one of the first studies focusing on coastal spatial mobility strategies to improve living standards adopted by fisherfolk in sub-Saharan Africa. It examines how fisherfolk livelihoods have been affected by the extraction and production of oil. The study further explores the various livelihood strategies deployed by fisherfolk to avoid decrease fish catch. A mixed- methods approach made up of 400 fisherfolk households survey and 42 interviews with stakeholders in the fisheries and the petroleum industries were conducted. The study shows that fisherfolk in the Western Region of Ghana are under high socioeconomic vulnerability because of decreased fish catch and declining coastal livelihoods. The spatial restriction of fishers’ mobility offshore, the destruction and confiscation of fishing gear, the presence of seaweed in the ocean, and the lack of land opportunities are some of the key petroleum-induced stressors on fisheries livelihoods. The various in situ marine-based adaptation strategies deployed by fisherfolk, especially illegal light fishing and fishing around oil rigs, are unsustainable and are counterproductive in the rebuilding of depleted marine fish stocks.
Sandstone reefs may be considered a unique geomorphologic feature within the subtropical Southwestern Atlantic Ocean region; however, biodiversity on these reefs has received little to no attention. Herein, we recorded the fish assemblage and benthic cover of sandstone reefs between 23 and 29 m depth in Southern Brazil and evidenced potential threats to habitat health. Video analysis and underwater censuses recorded 30 fish species. The unexpected high biomass of Epinephelus marginatus indicated that sandstone reefs may contain suitable habitats for the recovery of this endangered species. A rich benthic coverage including bryozoans, algae, hydrozoans, sponges, and octocorals increased local habitat structural complexity. However, a wide diversity of tangled fishing gear and broken sandstone slabs suggested that a valuable feature from Southern Brazil seascape is being lost by cumulative fishing impacts. An extensive mapping of sandstone reefs is urgently needed for better delineation of marine protected areas network in Southeast and Southern Brazil.
In the process of marine resource development and marine environmental protection, the government supervises the production behavior of enterprises; enterprises accept government supervision; and non-profit organizations supervise the process. On this basis, a conceptual model of the relationship between government, enterprises, and non-profit organizations is established, and the internal mechanism governing their interactions is analyzed. Using game theory, a simulation model of government, enterprises, and non-profit organizations is constructed, and a Nash equilibrium solution and strategy selection analysis are carried out. The correlation between the game participants and strategy selection is simulated and analyzed with MATLAB 7 software. Lastly, relevant countermeasures and suggestions are put forward to engender effective supervision by government departments, continuous environmental development and effective environmental protection of enterprises, and effective supervision by non-profit organizations. Studying the regulatory strategies of the government, enterprises, and non-profit organizations can provide a foundation for marine resource development and marine environmental protection policy in accordance with the current situation.