Snapper and grouper are important fisheries resources, with high commercial value and an important role in the livelihoods and food security of many local communities worldwide. However, the status of many snapper and grouper fisheries is unknown, particularly in the cases of small-scale fisheries in developing countries. The main goals of this work are to provide an overview of the current status and trends of these resources and to find alternative sources of information that could be used to determine the status of snapper and grouper fisheries, as well as other data-limited fisheries. Several complementary approaches were explored, including determination of the status of snapper and grouper fisheries based on FAO assessment criteria, analysis of landings time-series trends, and investigation of whether other variables could be used as proxies for fishery status. About half of these fisheries were classified as overexploited, 30% as non-fully exploited and 19% as fully exploited. The FAO landings data indicated that the number of overexploited fisheries has been increasing over the years and that the majority of these fisheries are in transition between the fully exploited and overexploited statuses. The Human Development Index emerged as a potential proxy for the status of the biomass. The multinomial modeling approach explained about 44% of the variability observed in the biomass stock status classification data and indicated a high level of correspondence between original and estimated status, which makes this approach very attractive for application to other data-limited fisheries.
The increasing use of tracking devices, such as the Vessel Monitoring System (VMS) and the Automatic Identification System (AIS), have allowed, in the last decade, detailed spatial and temporal analyses of fishing footprints and of their effects on environments and resources. Nevertheless, tracking devices usually allow monitoring of the largest length classes composing different fleets, whereas fishing vessels below a regulatory threshold (i.e., 15 m in length-over-all) are not mandatorily equipped with these tools. This issue is critical, since 36% of the vessels in the European Union (EU) fleets belong to these “hidden” length classes. In this study, a model [namely, a cascaded multilayer perceptron network (CMPN)] is devised to predict the annual fishing footprints of vessels without tracking devices. This model uses information about fleet structures, environmental characteristics, human activities, and fishing effort patterns of vessels equipped with tracking devices. Furthermore, the model is able to take into account the interactions between different components of the fleets (e.g., fleet segments), which are characterized by different operating ranges and compete for the same marine space. The model shows good predictive performance and allows the extension of spatial analyses of fishing footprints to the relevant, although still unexplored, fleet segments.
Marine reserves are an important management tool for conserving local biodiversity and protecting fragile ecosystems such as seagrass that provide significant ecological functions and services to people and the marine environment. With humans placing ever-growing pressure on seagrass habitats, marine reserves also provide an important reference from which changes to seagrass and their ecological assemblages may be assessed. After eight years of protection of seagrass beds (Posidonia australis) in no-take marine reserves (Sanctuary Zones) within the Jervis Bay Marine Park (New South Wales, Australia; zoned in 2002), we aimed to assess what changes may have occurred and assess continuing change through time in fish assemblages within these seagrass meadows. Using baited remote underwater videos (BRUVs), we sampled seagrass fish assemblages at three locations in no-take zones and five locations in fished zones three times from 2010 to 2013. Overall, we observed a total of 2615 individuals from 40 fish species drawn from 24 families. We detected no differences in total fish abundance, diversity, or assemblage composition between management zones, although we observed a significant increase in Haletta semifasciata, a locally targeted fish species, in no-take marine reserves compared with fished areas. Fish assemblages in seagrass varied greatly amongst times and locations. Several species varied in relative abundance greatly over months and years, whilst others had consistently greater relative abundances at specific locations. We discuss the potential utility of marine reserves covering seagrass habitats and the value of baseline data from which future changes to seagrass fish populations may be measured.
Marine protected areas (MPAs) have emerged as a valuable tool in biodiversity conservation and fisheries management. However, the effective use of MPAs depends upon the successful integration of social and ecological information. We investigated relationships between the social system structure of coastal communities alongside biological data describing the status and trends in fish communities around Yap, Micronesia. Traditional marine tenure made Yap an ideal place to investigate the underlying principles of social-ecological systems, as communities own and manage spatially-defined coastal resources. Analysis of social survey data revealed three social regimes, which were linked to corresponding gradients of ecological outcomes. Communities with decentralized decision-making and a preference for communal forms of fishing had the greatest ecological outcomes, while communities lacking any form of leadership were linked to poor ecological outcomes. Interestingly, communities with strong top-down leadership were shown to have variable ecological outcomes, depending on the presence of key groups or individuals. We last investigated whether social perception could successfully predict the status of fish assemblages within non-managed reefs. Several biological metrics of fish assemblages within non-managed areas were significantly predicted by a gradient of human access, suggesting social perception could not predict the growing human footprint over the study period. These findings highlight the potentially overlooked role that community-oriented decision-making structures and fishing methods could play in successful conservation efforts, and the limitations of perception data. Policies that promote communal marine resource use offer a novel approach to improve fisheries management and promote social-ecological resilience.
An assessment of quantity, composition and seasonal variation of fishing-related plastic debris was conducted in six beaches along the Kerala coast of India during 2017–2018. Plastic items were the most dominant type of waste constituting 73.8% by number and 59.9% by weight. In the total debris recorded, 5540 pieces (36%) weighing 198.4 kg (39.8%) were fishing related trash. On an average 14.4 ± 12 fishing related items/100 m2, corresponding to mean weight of 0.55 ± 0.7 kg/100 m2 was recorded from these beaches. Results indicated that the fishing-related plastic items were concentrated four times more in the beaches with higher fishing intensity, as compared to the other beaches. Also, the concentration of fishing-related plastic was recorded higher in the post-monsoon season compared to the lowest during monsoon, which was significant with p-value < 0.05. The results emphasize the role of fishing activities in the generation of marine litter.
Following the Editorial addressing the BALMAS project, we open the ballast water management special issue for the Adriatic Sea by providing background information on non-indigenous species and the mechanisms (vectors) of transport. Problems allocating introduction mechanisms for various species with certainty are described; in general, key introduction mechanisms are shipping, with ballast water and biofouling as dominant vectors, and aquaculture activities. The dominant mechanisms for introduction may differ through time, between regions and across species. We highlight ballast water as the focus of an international convention to prevent future introductions, reviewing management options and suggesting future research needs. This assessment is not restricted in application to the Adriatic Sea, but is applicable to other coastal waters. Results of such future work may contribute to the experience building phase planned by the International Maritime Organization for a harmonised implementation of the Ballast Water Management Convention.
The fossil record provides valuable data for improving our understanding of both past and future reef resilience and vulnerability to environmental change. The spatial and temporal pattern of the initiation of the Holocene Great Barrier Reef presents a case study of reef response to rapid sea-level rise. Past studies have been limited by the lack of well-dated and closely spaced reef core transects and have not closely examined the composition of the reef-building communities through time. This study presents 80 new high precision U-Th and 5 radiocarbon ages from twelve new cores located along three transects across different geomorphic and hydrodynamic settings of One Tree Reef, southern Great Barrier Reef, to document three distinct stages of Holocene reef development in unprecedented detail. Temporal constraints on changing paleoecological assemblages of coral, coralline algae and associated biota revealed three distinct phases of reef development, consisting of: 1) a fast, shallow and clear-water reef initiation from 8.3 until 8 ka; 2) a shift to slower, deeper and more turbid-water reef growth from 8-7 ka; and 3) a return to shallow and rapid branching coral growth in clear-water conditions as the reef “catches up” to sea-level. A minimum lag prior to reef initiation of 700 years was identified, which differs in length depending on reef environment and Pleistocene substrate height. In this new model, reef growth initiated on the topographically lower leeward margin and patch reef, prior to the start of windward margin development, contrary to the traditional reef growth model. While there was a shift to conditions less favorable for reef growth at 8 ka, this did not prevent the slow accretion of more sediment-tolerant coral communities. The majority of the reef reached sea level by ~6 ka. This new conceptual model of Holocene reef growth provides new constraints on changes in paleoenvironment that controlled reef community composition and growth trajectories through sea-level rise following inundation.
Microplastics (MPs, particles <5 mm) represent an emerging global environmental concern, having been detected in multiple aquatic species. However, very little is known about the presence of MPs in higher trophic level species, including cetaceans. We worked with community based monitors and Inuvialuit hunters from Tuktoyaktuk (Northwest Territories, Canada) to sample seven beluga whales (Delphinapterus leucas) in 2017 and 2018. Microplastics were detected in the gastrointestinal tracts in every whale. We estimate that each whale contained 18 to 147 MPs in their GI tract (average of 97 ± 42 per individual). FTIR-spectroscopy revealed over eight plastic polymer types, with nearly half being polyester. Fibres made up 49% of MPs. The diversity of MP shapes and polymeric identities in beluga points to a complex source scenario, and ultimately raises questions regarding the significance and long-term exposure of this pollutant in this ecologically and culturally valuable species.
Microplastics (MP) pollution has received increased attention over the last few years. However, while the number of studies documentating the ingestion of microplastics by fish has increased, fewer studies have addressed the toxicological effects derived from the ingestion of these small items in wild conditions. Here, MP contamination and effect biomarkers were investigated in three commercially important fish species from North East Atlantic Ocean. From the 150 analysed fish (50 per species), 49 % had MP. In fish from the 3 species, MP in the gastrointestinal tract, gills and dorsal muscle were found. Fish with MP had significantly (p ≤ 0.05) higher lipid peroxidation levels in the brain, gills and dorsal muscle, and increased brain acetylcholinesterase activity than fish where no MP were found. These results suggest lipid oxidative damage in gills and muscle, and neurotoxicity through lipid oxidative damage and acetylcholinesterase induction in relation to MP and/or MP-associated chemicals exposure. From the 150 fish analysed, 32 % had MP in dorsal muscle, with a total mean (± SD) of 0.054 ± 0.099 MP items/g. Based on this mean and on EFSA recommendation for fish consumption by adults or the general population, human consumers of Dicentrachus labrax, Trachurus trachurus, Scomber colias may intake 842 MP items/year from fish consumption only. Based on the mean of MP in fish muscle and data (EUMOFA, NOAA) of fish consumption per capita in selected European and American countries, the estimated intake of microplastics through fish consumption ranged from 518 to 3078 MP items/year/capita. Considering that fish consumption is only one of the routes of human exposure to microplastics, this study and others in the literature emphasize the need for more research, risk assessment and adoption of measures to minimize human exposure to these particles. Thus, microplastics pollution and its effects should be further investigated and addressed according to the WHO ‘One Health’ approach.
Significant quantities of plastic debris pollute nearly all the world’s ecosystems, where it persists for decades and poses a considerable threat to flora and fauna. Much of the focus has been on the marine environment, with little information on the hazard posed by debris accumulating on beaches and adjacent vegetated areas. Here we investigate the potential for beach debris to disrupt terrestrial species and ecosystems on two remote islands. The significant quantities of debris on the beaches, and throughout the coastal vegetation, create a significant barrier which strawberry hermit crabs (Coenobita perlatus) encounter during their daily activities. Around 61,000 (2.447 crabs/m2) and 508,000 crabs (1.117 crabs/m2) are estimated to become entrapped in debris and die each year on Henderson Island and the Cocos (Keeling) Islands, respectively. Globally, there is an urgent need to establish a clear link between debris interactions and population persistence, as loss of biodiversity contributes to ecosystem degradation. Our findings show accumulating debris on these islands has the potential to seriously impact hermit crab populations. This is important for countless other islands worldwide where crabs and debris overlap, as crabs play a crucial role in the maintenance of tropical ecosystems.
Using simple models, coupled with parameters extracted from published studies, the annual inputs of macro and micro plastics to the Scottish Atlantic Coast and the Scottish North Sea Coast regions are estimated. Two estimates of land-based sources are used, scaled by catchment area population size. The oceanic supply of floating plastic is estimated for wind-driven and general circulation sources. Minimum, typical and maximum values are computed to examine the magnitude of uncertainties. Direct inputs from fishing and the flux of macroplastic onto the seabed are also included. The modelled estimates reveal the importance of local litter sources to Scottish coastal regions, and hence local management actions can be effective. Estimates provide a scale against which removal efforts may be compared, and provide input data for future more complex modelling. Recommendations for research to improve the preliminary estimates are provided. Methods presented here may be useful elsewhere.
The scientific literature on marine and coastal climate change has proliferated in recent decades. Translating and communicating this evidence in a timely, and accessible manner, is critical to support adaptation, but little is being done to summarise the latest science for decision makers. For Small Island Developing States (SIDS), which are highly vulnerable to marine and coastal climate change impacts, there is an urgent need to make the latest science readily available to inform national policy, leverage climate funding and highlight their vulnerability for international reports and climate negotiations. Climate change report cards are a proven successful way of presenting climate change information in an easily accessible and informative manner. Here we compare the development of marine climate change report cards for Caribbean and Pacific Commonwealth SIDS as a means of translating the latest science for decision makers. Regional engagement, priority issues and lessons learnt in these regions are compared, and future opportunities identified.
This study explored public perceptions of the marine environment in three coastal communities in Greece and further investigated intentions to adopt behaviors that contribute to marine conservation. We used the Theory of Planned Behavior (TPB) to study the psychological determinants of behavioral intentions. The findings indicated that respondents have positive attitudes, moderate knowledge of marine issues, and they value the marine environment for the multiple ecosystem services that it provides. Litter and pollution from industry were considered as the most important marine threats, followed by fishing and farming. Participants suggested that informing the public and giving prominence to environmental education can contribute to marine conservation efforts. They felt that research centers and scientific community were more competent than governmental authorities and the private sector concerning the management and protection of the marine environment. Intention to adopt environmental behaviors was influenced by normative considerations, attitudes toward marine biodiversity and perceived behavioral control beliefs. The results may: 1) help inform policymakers to improve marine resource management towards a more sustainable relationship between people and the sea; 2) support the development of marine strategies that fit the social preferences, needs, and priorities to increase the likelihood of public support; and 3) support marine spatial planning efforts to uncover the intrinsic complexity of societal interactions with the marine environment. The findings further support policymakers that wish to promote behavior change through communication strategies that deliver environmental messages that focus on enhancing normative considerations, behavioral control beliefs, and corresponding attitudes.
Commercial fisheries yield essential foods, sustain cultural practices, and provide widespread employment around the globe. Commercially harvested species face a myriad of anthropogenic threats including degraded habitats, changing climate, overharvest, and pollution. Microplastics are pollutants of increasing concern, which are pervasive in the environment and can harbor or adsorb pollutants from surrounding waters. Aquatic organisms, including commercial species, encounter and ingest microplastics, but there is a paucity of data about those caught and cultured in North America. Additional research is needed to determine prevalence, physiological effects, and population‐level implications of microplastics in commercial species from Canada, the United States, and Mexico. Investigations into possible human health effects of microplastic exposure from seafood are also greatly needed. This synthesis summarizes current knowledge, identifies data gaps, and provides future research directions for addressing microplastics effects in commercially valuable North American fishery species.
Microplastics are an ecological stressor with implications for ecosystem and human health when present in seafood. We quantified microplastic types, concentrations, anatomical burdens, geographic distribution, and temporal differences in Pacific oysters (Crassostrea gigas) and Pacific razor clams (Siliqua patula) from 15 Oregon coast, U.S.A. sites. Microplastics were present in organisms from all sites. On average, whole oysters and razor clams contained 10.95 ± 0.77 and 8.84 ± 0.45 microplastic pieces per individual, or 0.35 ± 0.04 pieces g−1 tissue and 0.16 ± 0.02 pieces g−1 tissue, respectively. Contamination was quantified but not subtracted. Over 99% of microplastics were fibers. Material type was determined using Fourier‐transform infrared spectroscopy. Spring samples contained more microplastics than summer samples in oysters but not razor clams. Our study is the first to document microplastics in Pacific razor clams and provides important coast‐wide data to compare microplastic burden across species, seasons, and sites.
The exploration of gradients of development stages of coral reef ecosystems is a subject poorly studied, especially when they exhibit multiple degrees of geomorphological or structural development or both. The objective of the present work was to study the gradient of functional and structural maturity of the Mexican Caribbean coral reefs (CM). Here we analyzed three geomorphological zones that cover a gradient of 400 km in length in order to obtain coral reefs with different geomorphologies. Thirteen reefs were selected, for which 12 ecosystem development attributes and five topological indices were analyzed. The development attributes of coral reefs were estimated from trophic models constructed using Ecopath with Ecosim (EwE), while the topological indices were calculated from the predator-prey matrix obtained from each EwE model. Through a partial redundancy analysis (RDA) seven of the 12 development attributes (ascendency, overhead, development capacity, net primary production, ascendency/development capacity, overhead/development capacity and richness of functional group) were selected due their low or null collinearity. Using the developmental attributes selected in a non-metric multidimensional scaling (stress: 0.1) and analysis of similarities (r global: 0.828 and p: 0.001), we found a gradient of maturity that increases from north to south, i.e., northern coral reefs (e.g. Puerto Morelos) are less mature than southern coral reefs (e.g. Mahahual). On other hand, through a non-parametric ANOVA and a partial redundancy analysis (first axis: F-ratio = 62.054, p = 0.012; second axis: F-ratio = 1.591, p = 0.014; 100% of the total variance explained by the first two canonical axes) we detected that topological indices respond to development stages, in this way the control flow increases with the maturity while the intermediation, number of connections and number of interactions depredator-prey are inverse to maturity; therefore, topological indices can be used to describe development stages. The determination of a gradient of maturity in MC coral reefs should be considered in management and conservation policies, therefore different strategies must be implemented in ecosystems, because resilience and ecosystem response depend on them.
This paper reviews literature relating to Marine Protected Areas (MPAs) and human well-being. It finds that explicit studies on human well-being from MPAs are limited and empirical studies quantifying these relationships are rare. Most MPA papers, including those examining MPA effectiveness, focus on just a few aspects of well-being in the context of a sub-set of stakeholders, and consider only a single type of MPA. They mostly focus on conventional objective measures that are not comprehensive or systematically selected. This review argues for a systematic and integrative framework to ensure future MPA assessments are equipped to capture MPAs’ contributions to human well-being more adequately and comprehensively. Such a framework can also allow for cross-MPA comparisons that can capture differences in well-being across different types of MPAs, and information gained can be useful for MPA practitioners and policy makers, particularly in reaching current global targets, such as the CBD, Aichi Target 11.
Marine Protected Areas (MPAs) are effective resource management and conservation measures, but their success is often hindered by non-compliant activities such as poaching. Understanding the risk factors and spatial patterns of poaching is therefore crucial for efficient law enforcement. Here, we conducted explanatory and predictive modelling of poaching from recreational fishers within no-take zones of Australia's Great Barrier Reef Marine Park (GBRMP) using Boosted Regression Trees (BRT). Combining patrol effort data, observed distribution of reported incidents, and spatially-explicit environmental and human risk factors, we modeled the occurrence probability of poaching incidents and mapped poaching risk at fine-scale. Our results: (i) show that fishing attractiveness, accessibility and fishing capacity play a major role in shaping the spatial patterns of poaching; (ii) revealed key interactions among these factors as well as tipping points beyond which poaching risk increased or decreased markedly; and (iii) highlight gaps in patrol effort that could be filled for improved resource allocation. The approach developed through this study provide a novel way to quantify the relative influence of multiple interacting factors in shaping poaching risk, and hold promises for replication across a broad range of marine or terrestrial settings.
Seafloor Geomorphology as Benthic Habitat: GeoHab Atlas of Seafloor Geomorphic Features and Benthic Habitats, Second Edition, provides an updated synthesis of seabed geomorphology and benthic habitats. This new edition includes new case studies from all geographic areas and habitats that were not included in the previous edition, including the Arctic, Asia, Africa and South America. Using multibeam sonar, the benthic ecology of submarine features, such as fjords, sand banks, coral reefs, seamounts, canyons, mud volcanoes and spreading ridges is revealed in unprecedented detail. This timely release offers new understanding for researchers in Marine Biodiversity, environmental managers, ecologists, and more.