With rapid urbanization in the coastal zone and increasing habitat losses, it is imperative to understand how urban development affects coastal biodiversity and ecosystem service provision. Furthermore, it is important to understand how habitat fragments can best be incorporated into broader land use planning and coastal management, in order to maximize the environmental benefits they provide. In this study, we characterized the trade-offs between (a) urban development and individual mangrove environmental indicators (habitat quality and ecosystem services), and (b) between different environmental indicators in the tropical nation of Singapore. A range of biological, biophysical, and cultural indicators, including carbon, charcoal production, support for offshore fisheries, recreation, and habitat quality for a threatened species were quantified using field-based, remote sensing, and expert survey methods. The shape of the trade-off Pareto frontiers was analyzed to assess the sensitivity of environmental indicators for development. When traded off individually with urban development, four out of five environmental indicators were insensitive to development, meaning that relatively minor degradation of the indicator occurred while development was below a certain threshold, although indicator loss accelerated once this threshold was reached. Most of the pairwise relationships between the five environmental indicators were synergistic; only carbon storage and charcoal production, and charcoal production and recreational accessibility showed trade-offs. Trade-off analysis and land use optimization using Pareto frontiers could be a useful decision-support tool for understanding how changes in land use and coastal management will impact the ability of ecosystems to provide environmental benefits.
The use of a one-dimensional interdisciplinary numerical model of the coastal ocean as a tool contributing to the formulation of ecosystem-based management (EBM) is explored. The focus is on the definition of an experimental design based on ensemble simulations, integrating variability linked to scenarios (characterised by changes in the system forcing) and to the concurrent variation of selected, and poorly constrained, model parameters. The modelling system used was previously specifically designed for the use in “data-rich” areas, so that horizontal dynamics can be resolved by a diagnostic approach and external inputs can be parameterised by nudging schemes properly calibrated. Ensembles determined by changes in the simulated environmental (physical and biogeochemical) dynamics, under joint forcing and parameterisation variations, highlight the uncertainties associated to the application of specific scenarios that are relevant to EBM, providing an assessment of the reliability of the predicted changes. The work has been carried out by implementing the coupled modelling system BFM-POM1D in an area of Gulf of Trieste (northern Adriatic Sea), considered homogeneous from the point of view of hydrological properties, and forcing it by changing climatic (warming) and anthropogenic (reduction of the land-based nutrient input) pressure. Model parameters affected by considerable uncertainties (due to the lack of relevant observations) were varied jointly with the scenarios of change. The resulting large set of ensemble simulations provided a general estimation of the model uncertainties related to the joint variation of pressures and model parameters. The information of the model result variability aimed at conveying efficiently and comprehensibly the information on the uncertainties/reliability of the model results to non-technical EBM planners and stakeholders, in order to have the model-based information effectively contributing to EBM.
Many marine mammal predators, particularly pinnipeds, have increased in abundance in recent decades, generating new challenges for balancing human uses with recovery goals via ecosystem-based management. We used a spatio-temporal bioenergetics model of the Northeast Pacific Ocean to quantify how predation by three species of pinnipeds and killer whales (Orcinus orca) on Chinook salmon (Oncorhynchus tshawytscha) has changed since the 1970s along the west coast of North America, and compare these estimates to salmon fisheries. We find that from 1975 to 2015, biomass of Chinook salmon consumed by pinnipeds and killer whales increased from 6,100 to 15,200 metric tons (from 5 to 31.5 million individual salmon). Though there is variation across the regions in our model, overall, killer whales consume the largest biomass of Chinook salmon, but harbor seals (Phoca vitulina) consume the largest number of individuals. The decrease in adult Chinook salmon harvest from 1975–2015 was 16,400 to 9,600 metric tons. Thus, Chinook salmon removals (harvest + consumption) increased in the past 40 years despite catch reductions by fisheries, due to consumption by recovering pinnipeds and endangered killer whales. Long-term management strategies for Chinook salmon will need to consider potential conflicts between rebounding predators or endangered predators and prey.
Wild stocks of Pacific salmonids have experienced sharp declines in abundance over the past century. Consequently, billions of fish are released each year for enhancing abundance and sustaining fisheries. However, the beneficial role of this widely used management practice is highly debated since fitness decrease of hatchery-origin fish in the wild has been documented. Artificial selection in hatcheries has often been invoked as the most likely explanation for reduced fitness, and most studies to date have focused on finding signatures of hatchery-induced selection at the DNA level. We tested an alternative hypothesis, that captive rearing induces epigenetic reprogramming, by comparing genome-wide patterns of methylation and variation at the DNA level in hatchery-reared coho salmon (Oncorhynchus kisutch) with those of their wild counterparts in two geographically distant rivers. We found a highly significant proportion of epigenetic variation explained by the rearing environment that was as high as the one explained by the river of origin. The differentially methylated regions show enrichment for biological functions that may affect the capacity of hatchery-born smolts to migrate successfully in the ocean. Shared epigenetic variation between hatchery-reared salmon provides evidence for parallel epigenetic modifications induced by hatchery rearing in the absence of genetic differentiation between hatchery and natural-origin fish for each river. This study highlights epigenetic modifications induced by captive rearing as a potential explanatory mechanism for reduced fitness in hatchery-reared salmon.
Marine plastic debris is a global environmental problem. Surveys have shown that <5 mm plastic particles, known as microplastics, are significantly more abundant in surface seawater and on shorelines than larger plastic particles are. Nevertheless, quantification of microplastics in the environment is hampered by a lack of adequate high-throughput methods for distinguishing and quantifying smaller size fractions (<1 mm), and this has probably resulted in an underestimation of actual microplastic concentrations. Here we present a protocol that allows high-throughput detection and automated quantification of small microplastic particles (20–1000 μm) using the dye Nile red, fluorescence microscopy, and image analysis software. This protocol has proven to be highly effective in the quantification of small polyethylene, polypropylene, polystyrene, and nylon-6 particles, which frequently occur in the water column. Our preliminary results from sea surface tows show a power-law increase in small microplastics (i.e., <1 mm) with a decreasing particle size. Hence, our data help to resolve speculation about the “apparent” loss of this fraction from surface waters. We consider that this method presents a step change in the ability to detect small microplastics by substituting the subjectivity of human visual sorting with a sensitive and semiautomated procedure.
Coral reefs are among Earth’s best-studied ecosystems, yet the degree to which large predators influence the ecology of coral reefs remains an open and contentious question. Recent studies indicate the consumptive effects of large reef predators are too diffuse to elicit trophic cascades. Here, we provide evidence that such predators can produce non-consumptive (fear) effects that flow through herbivores to shape the distribution of seaweed on a coral reef. This trophic cascade emerged because reef topography, tidal oscillations, and shark hunting behaviour interact to create predictable “hot spots” of fear on the reef where herbivores withhold feeding and seaweeds gain a spatial refuge. Thus, in risky habitats, sharks can exert strong ecological impacts even though they are trophic generalists that rarely feed. These findings contextualize the debate over whether predators influence coral reef structure and function and move us to ask not if, but under what specific conditions, they generate trophic cascades.
Kei Islands located inside the coral triangle. Therefore, the biodiversity level on the sea in this area is considered high. United nation has proposed for water that included in the coral triangle has to apply marine protected area (MPA) to preserve the area. The main problem is most of the community especially in Kei Islands have depended on the sea as their sources of the economy even fisheries commodity like fish play a large part on the inflation rate and other prosperity indicators likes school and housing. Also, Kei Islands practice on form local wisdom for owning areal of the sea which calls "petuanan laut" by certain of villages or group of villages in one area. This study aimed to map the cluster of catching fisheries area based on the quantity of fish supply on a local market in Kei Islands and measure each cluster on their support and perspective on Marine Protected Area (MPA). We conducted a focus group discussion and collecting additional data by questionnaires with descriptive and quantitative analysis with logistic regression. The implication of this study can provide a clear view of coastal communities view on MPA program also to identify an area that has marine resources, human resources, and equipment to provide government an empirical view on catching fisheries in Kei Islands to issued better policy to develop fishing industry in Kei Islands.
Reef-building corals have essential roles in reef ecosystems but are highly susceptible to disturbances. Increasing anthropogenic disturbances are eroding coral community resilience, leading to declining reef ecosystem function and status globally. Successful reproduction and recruitment are essential for restoring coral populations but recruitment-limitation can constrain recovery. We supplied ~400,000 Acropora tenuis larvae in fine-mesh enclosures on each of four larval-enhancement plots, comprising natural reef substrata and ten settlement tiles, on degraded reef areas in the northwestern Philippines. Initial mean total settlement on tiles in larval-enhancement plots was high (255.3 ± 68.6), whereas no larvae settled in natural control plots. Recruit survivorship began stabilising after five months, with juveniles becoming visible by eye at nine months. After three years a mean of 2.3 m−2 colonies survived within each larval-enhancement plot. Most colonies grew rapidly (16.1 ± 0.7 cm mean diameter) and spawned successfully at three years, thereby quickly re-establishing a breeding population. In contrast, natural recruitment failed to produce any new visible A. tenuis colonies. These results demonstrate that mass larval settlement can rapidly enhance recruitment and coral recovery on degraded reef areas, and provides an important option for active reef restoration where larval supply and recruitment success are limiting.
Brazil currently ranks as the 11th producer and 1st importer of shark meat around the world. Data available from the FAO software FishStatJ along with data from regional sources, such as governmental bulletins, scientific papers, gray literature and internet were revisited to identify the main issues surrounding pelagic shark fisheries, trade and consumption in the largest country in South America. Among the main findings, it was noted that Brazil has not properly collected fishery statistics since 2007, that many species of threatened sharks are freely landed and traded even though it is prohibited by local legislation and/or international recommendations (regional fisheries management organizations). The blue shark (Prionace glauca) is the most frequently recorded shark in the official bulletins and is currently a locally targeted species. Additionally, the significant imports of this species from 23 other countries that also provide fins for Asia has drawn attention in recent decades. Regarding consumption, shark is considered to be low-value seafood compared to more common fish, such as groupers and snappers, and most Brazilians actually do not know that they are eating sharks. At present, the proportion of threatened elasmobranchs (in which sharks are included) in Brazil (33%, of 145 species) exceeds the global rate identified for the group (25%), and, until the present moment, no measure related to the management of species has been implemented. As advice, Brazil urgently needs to restructure its fishery information collection systems, management strategies and to tighten sanitary and labeling regulations for the marketing of fish.
Understanding cumulative effects of multiple threats is key to guiding effective management to conserve endangered species. The critically endangered, Southern Resident killer whale population of the northeastern Pacific Ocean provides a data-rich case to explore anthropogenic threats on population viability. Primary threats include: limitation of preferred prey, Chinook salmon; anthropogenic noise and disturbance, which reduce foraging efficiency; and high levels of stored contaminants, including PCBs. We constructed a population viability analysis to explore possible demographic trajectories and the relative importance of anthropogenic stressors. The population is fragile, with no growth projected under current conditions, and decline expected if new or increased threats are imposed. Improvements in fecundity and calf survival are needed to reach a conservation objective of 2.3% annual population growth. Prey limitation is the most important factor affecting population growth. However, to meet recovery targets through prey management alone, Chinook abundance would have to be sustained near the highest levels since the 1970s. The most optimistic mitigation of noise and contaminants would make the difference between a declining and increasing population, but would be insufficient to reach recovery targets. Reducing acoustic disturbance by 50% combined with increasing Chinook by 15% would allow the population to reach 2.3% growth.
The Arabian Seas Region plays an important role in the global landings and trade of sharks and rays. The United Arab Emirates (UAE) and Yemen, two countries with stark socio-economic differences, serve as major regional trade hubs for shark and ray products and four countries (Oman, Pakistan, UAE and Yemen) supply nearly 11% of dried fin exports to Hong Kong. Yet, little information is available on the characteristics of this trade and the fisheries contributing to it. Here, we review the fisheries characteristics, trade, utilization and distribution chain of sharks and rays in 15 countries of the Arabian Seas Region based on published and grey literature, landing surveys, field observations and interviews with fishermen and traders. Although regional shark fisheries remain mostly artisanal, reported shark and ray landings represent 28% of the regional total fish production, reaching 56,074 mt in 2012 (7.3% of total world catches), with Iran, Oman, Pakistan and Yemen ranking as the primary catchers. Utilization and distribution patterns are complex, vary between landing sites and countries, and remain unmonitored. Based on widespread over-exploitation of most teleost fisheries, current exploitation levels for most sharks and rays are potentially unsustainable. The situation is exacerbated by limited research and political will to support policy development, the incomplete nature of fisheries data, as well as insufficient regulations and enforcement. A better understanding of shark and ray fisheries will be key for regulating trade, promoting conservation and developing management initiatives to secure food security, livelihoods and biodiversity conservation in the region.
The present study investigated the impacts of treated effluent discharge on physicochemical and biological properties of coastal waters from three pharmaceuticals situated along the coast of Visakhapatnam (SW Bay of Bengal). Seawater samples were collected (during the months of December 2013, March 2014 and April 2014) from different sampling locations (Chippada (CHP), Tikkavanipalem (TKP) and Nakkapalli (NKP)) at 0- and 30-m depths within 2-km radius (0.5 km = inner, 1 km = middle and 2 km = outer sampling circles) from the marine outfall points. Physicochemical and biological parameters, which differed significantly within the stations, were likely to be influenced by strong seasonality rather than local discharge. Dissolved oxygen variability was tightly coupled with both physical and biological processes. Phytoplankton cell density and total chlorophyll (TChla) concentrations were significantly correlated with dissolved inorganic nutrient concentrations. CHP (December) represented a diatom bloom condition where the highest concentrations of diatom cells, total chlorophyll (TChla), dissolved oxygen coupled with lower zooplankton abundance and low nutrient levels were noticed. The centric diatom, Chaetoceros sp. (> 50%) dominated the phytoplankton community. TKP (March) represented a post-diatom bloom phase with the dominance of Pseudo-nitzschia seriata; zooplankton abundance and nutrient concentrations were minimum. Conversely, NKP (April) represented a warm well-stratified heterotrophic period with maximum zooplankton and minimum phytoplankton density. Dinoflagellate abundance increased at this station. Relatively higher water temperature, salinity, inorganic nutrients coupled with very low concentrations of dissolved oxygen, TChla and pH were observed at this station. Copepods dominated the zooplankton communities in all stations and showed their highest abundance in the innermost sampling circles. Treated effluent discharge did not seem to have any significant impact at these discharge points.
Laterally bent dorsal fins are rarely observed in free-ranging populations of cetaceans, contrary to captivity, where most killer whale Orcinus orca adult males have laterally collapsed fins. This topic has been poorly explored, and data/information on its occurrence and possible causes are limited. The present study: (i) undertakes a review of the available information on bent dorsal fins in free-ranging cetaceans, and updates it with new records, (ii) reports on the proportion of bent fins in different study populations, and (iii) discusses possible causes. An empirical approach based on bibliographic research and compilation of 52 new records collected worldwide resulted in a total of 17 species of cetaceans displaying bent dorsal fins. The species with the highest number of records (64%) and from most locations was O. orca. On average, individuals with bent dorsal fins represent < 1% of their populations, with the exception of false killer whales Pseudorca crassidens and O. orca. While line injuries associated with fisheries interactions may be the main cause for P. crassidens, and the vulnerability to health issues caused by the evolutionary enlargement of the fin may be the cause for O. orca adult males, factors contributing to this abnormality for other species are still unclear. The occurrence of bent dorsals could be influenced by a set of variables rather than by a single factor but, irrespective of the cause, it is suggested that it does not directly affect the animals' survivorship. While still rare in nature, this incident is more common (at least 101 known cases) and widespread (geographically and in species diversity) than hypothesized, and is not confined only to animals in captive environments. Investigation into the occurrence of bent fins may be an interesting avenue of research.
The European Union requires that major legislative actions undergo an impact assessment (IA), but this methodology is often not adapted to policy measures in complex situations, as the coexistence of marine protected areas and small scale fisheries.
The appropriateness of the IA methodology currently in use is tested on the example of a small scale fishery in a protected area in the German coast in the Baltic Sea (Fehmarn island). The impact of the fisheries management measures is first assessed using the available data and the results are then checked with the local fishermen and a producer organization representative using a focus group. Given the discrepancies identified in the focus group, additional methodologies are explored.
By performing a literature review and a workshop with scientists, fishermen representatives, environmental organizations and managers, inputs from political science (the “wicked problem” approach) and philosophy of science (the NUSAP matrix) are applied to cope with the context of high uncertainty driven by poor ecological, economic and social data.
This case study brings the opportunity to identify challenges as the assessment of biodiversity and potentially conflictive differences in national policy objectives under different EU policies (including the Common Fisheries Policy), in a way that goes beyond the contribution of other commonly used management tools as impact assessment and spatial planning. The usefulness of the approach resides both in a better identification of impacts on small scale fisheries and the unveiling of hidden governance conflicts that prevent the fulfilment of the objectives of policy measures.
Marine management has typically prioritised natural science methodological traditions as an evidence base for decision-making; yet better integration of social science methods are increasingly shown to provide a more comprehensive picture to base management decisions. Specifically, perceptions-based assessments are gaining support, as they can provide efficient and holistic evaluation regarding management issues. This study focuses on coral reefs because they are particularly threatened ecosystems, due to their ecological complexity, socio-economic importance, and the range of environmental drivers that impact them. Research has largely concentrated on assessing proximate threats to coral reefs. Less attention has been given to distal drivers, such as socio-economic and governance factors. A common understanding of threats related to coral reef degradation is critical for integrated management that takes account of peoples’ concerns. This study compares perceptions of drivers of reef health among stakeholders (n = 110) across different sectors and governance levels, in four Caribbean countries. Interview data identified 37 proximate and 136 distal drivers, categorised into 27 themes. Five sub-groups of themes connecting proximate and distal drivers were identified. Perceptions of two of these narratives, relating to ‘fishing and socioeconomic issues’ and ‘reef management and coastal development’, differed among respondents from different countries and sectors respectively. However, the findings highlight a shared perception of many themes, with 18 of the 27 (67%) mentioned by > 25% of respondents. This paper highlights the application of perceptions data for marine management, demonstrating how knowledge of proximate and distal drivers can be applied to identify important issues at different context-specific scales.
In this work, an extended overview of the marine renewable energy in the Mediterranean Sea is provided as regards current status, potential problems, challenges, and perspectives of development. An integrated and holistic approach is necessary for the economic viability and sustainability of marine renewable energy projects; this approach comprises three different frameworks, not always aligned, i.e., geotechnical/engineering, socio-economic, and environmental/ecological frameworks. In this context, the geomorphological, climatological, socio-economic, and environmental/ecological particularities of the Mediterranean basin are discussed, as they constitute key issues of the spatial context in which marine renewable energy projects are to be implemented. General guidelines for the sustainable development of marine renewable energy in the Mediterranean are also provided.
A new methodology based in the use of fishers’ knowledge and cost-effective tools to obtain information about marine recreational fisheries (MRF) is presented. The squid and cuttlefish fishery of the Ría of Vigo (NW Spain) was selected because it is managed in a data-poor environment. In-depth interviews (57) were conducted with fishers, collecting ecological and socio-economic information. A cartography of fishing grounds based on their knowledge was obtained, while the intensity of effort and catches was mapped by the monitoring of two vessels with low-cost GPS data loggers. The 102 shore anglers and 248 recreational boats catch 8 t/year of European squid Loligo vulgaris and 11 t/year of common cuttlefish Sepia officinalis (11% of total catches on these species in the area). Shore anglers fish from 11 ports, while boat fishers use 14 fishing grounds (covering 30 km2). Most of the catches (86%) are landed by boats, and their CPUE is higher in the outer part of the Ría of Vigo. The use of fishers’ knowledge and cost-effective monitoring is encouraged to obtain information for the management of MRF. Given the economic contribution of MRF (260,000 €/year in direct expenses), this activity should be considered in the regulations.
Trade regulations may be useful for conserving marine species that are suffering from overexploitation. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has emerged as an instrument to help tighten fisheries management. However, the impacts of CITES regulations have not been examined for the trade in fully marine fishes. This study used seahorses (Hippocampus spp.), the first fully marine fishes listed in CITES Appendix II since treaty inception, as a case study. Drawing on Customs data from Taiwan and Hong Kong SAR (which cover pre-CITES periods), iterative-segmented regressions were applied to investigate changes in seahorse trade corresponding to CITES interventions. Principal component analyses were conducted to understand characteristics of seahorse source countries, and a gravity model of trade was applied to identify predictors of seahorse trade volumes. This study found that the total weight of seahorses in documented trade decreased significantly after CITES implementation, recorded trade became concentrated in fewer countries, and prices increased. Seahorse source countries were found having more fishers, demersal fish catch and general trade with China, compared to other range states. However, countries that reported no exports, unchanged export volumes or declining volumes after CITES were similar. In addition, volumes traded between two countries were found significantly higher when the two countries were closer together or when the source country had a lower per capita GDP or higher demersal catch. This study can help guide targeted actions to maximize CITES effectiveness for marine species.
The ocean is increasingly facing direct and indirect threats from multiple human activities that alter marine ecosystems worldwide. Mitigating these threats requires a global shift in the way people perceive and interact with the marine environment. Marine public perceptions research has emerged as a useful tool to understand public awareness and attitudes towards the sea. This study compares available surveys of public perceptions of marine threats and protection involving >32,000 respondents across 21 countries. Results indicate that 70% of respondents believe the marine environment is under threat from human activities, and 45% believe the threat is high or very high. Yet when asked about the ocean's health, only 15% thought it was poor or threatened. Respondents consistently ranked pollution issues as the highest threat, followed by fishing, habitat alteration and climate change. With respect to ocean protection, 73% of respondents support marine protected areas in their region. Most respondents overestimated the area of ocean currently protected, and would like to see much larger areas protected in the future. Overall, a clear picture emerged of the perceived threats and support for protection which can inform marine managers, policy makers, conservation practitioners and educators to improve marine management and conservation programs.
Previous research on offshore wind farm (OWF) siting has been dominated by studies centred on energy resources and profitability, human activities and acceptance. Recently, studies on environmental impacts of OWFs have emerged. Few studies have been carried out to discuss the issues comprehensively. This study develops a set of comprehensive OWF siting criteria; including the profitability, social, security and environmental considerations. It solicits expert opinions from academia and industry through an international Delphi method. Contrary to the typical consensus seeking in Delphi studies, it focuses on understanding the dissensus through a comprehensive discussion. We find that profitability and social considerations are the most commonly agreed siting criteria among the experts whereas environmental and security criteria receive less agreement. As OWFs move further offshore, we are concerned about the understanding of the associated environmental impacts, and how energy and marine policy affect the marine spatial planning and consenting process. Research must get ahead of the developments to provide a better understanding of the potential impacts and to guide the consenting and monitoring processes.