These Mapping and estimation of seagrass total above-ground carbon (STAGC) using satellite-based techniques are required to fast-track the achievement of the 2020 agenda on Sustainable Development Goals (SDG) 14th. This attainment is possible as seagrass habitats provide a critical coastal ecosystem for storing blue carbon stock, sediment accumulation, fisheries production and stabilisation of coastal environment. However, seagrasses are generally declining across the globe due to anthropogenic disturbance, resulting in a prolonged growth rate of seagrasses that varies according to the species compositions. Therefore, this study aims at mapping and estimation of seagrass total above-ground carbon (STAGC) using Landsat ETM+ in the coastline of Penang. These satellite images were calibrated with Bottom Reflected Index (BRI) and Depth Invariant Index (DII) to compare the estimate of the STAGC for more accuracy. The leaving radiances of the seagrass were correlated with the corresponding in-situ measurements to predict seagrass carbon. This established relationship with BRI image shown a healthy correlation with STAGB (R2 = 0.992, p ≤ 0.001). Whereas the STAGB versus DII relationship has less accuracy (R2 = 0.955, p ≤ 0.01), adjusted R2 = 0.980 and 0.978 were recorded for both BRI and DII STAGC estimate using the logistic model. Therefore, careful management of blue carbon stock is essential, as this study shall contribute to achieving targets 14.2 and 14.5 of SDG 14th by the United Nations.
Renewed interest in the estimation of spatial and temporal variation in fish traits, such as body size, is a result of computing advances and the development of spatially-explicit management frameworks. However, many attempts to quantify spatial structure or the distribution of traits utilize a priori approaches, which involve pre-designated geographic regions and thus cannot detect unanticipated spatial patterns. We developed a new, model-based method that uses the first derivative of the spatial smoothing term of a generalized additive model to identify spatial zones of variation in fish length-at-age. We use simulation testing to evaluate the method across a variety of synthetic, stratified age and length datasets, and then apply it to survey data for Northeast Pacific sablefish (Anoplopoma fimbria). Simulation testing illustrates the robustness of the method across a variety of scenarios related to spatially or temporally stratified length-at-age data, including strict boundaries, overlapping zones and changes at the extreme of the range. Results indicate that length-at-age for Northeast Pacific sablefish increases with latitude, which is consistent with previous work from the western United States. Model-detected spatial breakpoints corresponded to major oceanographic features, including the northern end of the Southern California Bight and the bifurcation of the North Pacific Current. This method has the potential to improve detection of large-scale patterns in fish growth, and aid in the development of spatiotemporally structured population dynamics models to inform ecosystem-based fisheries management.
The health of the ocean, central to human well-being, has now reached a critical point. Most fish stocks are overexploited, climate change and increased dissolved carbon dioxide are changing ocean chemistry and disrupting species throughout food webs, and the fundamental capacity of the ocean to regulate the climate has been altered. However, key technical, organizational, and conceptual scientific barriers have prevented the identification of policy levers for sustainability and transformative action. Here, we recommend key strategies to address these challenges, including (1) stronger integration of sciences and (2) ocean-observing systems, (3) improved science-policy interfaces, (4) new partnerships supported by (5) a new ocean-climate finance system, and (6) improved ocean literacy and education to modify social norms and behaviors. Adopting these strategies could help establish ocean science as a key foundation of broader sustainability transformations.
Herbivory is an important process in the general structuring of coral reef benthic communities. However, evidence of its ability to control coral reef benthic cyanobacterial mats, which have recently proliferated on reefs worldwide, remains ambivalent. Here, we report that the French Angelfish (Pomacanthus paru), Striped Parrotfish (Scarus iseri), Rock Beauty (Holacanthus tricolor), Ocean Surgeonfish (Acanthurus bahianus), Blue Parrotfish (Scarus coeruleus), and Atlantic Blue Tang (Acanthurus coeruleus) consume benthic cyanobacterial mats on coral reefs in Bonaire, Netherlands. We documented the foraging patterns of P. paru and S. iseri, and found that benthic cyanobacterial mats comprised 36.7% ± 5.8% and 15.0% ± 1.53% (mean ± standard error) of the total bites taken by P. paru and S. iseri respectively. This magnitude of consumption suggests that grazing by reef fishes may represent a potentially important, but previously undocumented, top-down control on benthic cyanobacterial mats on Caribbean reefs.
Conservation management of marine biodiversity depends on biomonitoring of marine habitats, but current approaches are resource‐intensive and require different approaches for different organisms. Environmental DNA (eDNA) extracted from water samples is an efficient and versatile approach to detecting aquatic animals. In the ocean, eDNA composition reflects local fauna at fine spatial scales, but little is known about the effectiveness of eDNA‐based monitoring of marine communities at larger scales. We investigated the potential of eDNA to characterize and distinguish marine communities at large spatial scales by comparing vertebrate species composition among marine habitats in Qatar, the Arabian Gulf (also known as the Persian Gulf), based on eDNA metabarcoding of seawater samples. We conducted species accumulation analyses to estimate how much of the vertebrate diversity we detected. We obtained eDNA sequences from a diverse assemblage of marine vertebrates, spanning 191 taxa in 73 families. These included rare and endangered species and covered 36% of the bony fish genera previously recorded in the gulf. Sites of similar habitat type were also similar in eDNA composition. The species accumulation analyses showed that the number of sample replicates was insufficient for some sampling sites but suggested that a few hundred eDNA samples could potentially capture >90% of the marine vertebrate diversity in the study area. Our results confirm that seawater samples contain habitat‐characteristic molecular signatures and that eDNA monitoring can efficiently cover vertebrate diversity at scales relevant to national and regional conservation and management.
The present study highlights the importance of intertidal seagrass beds as nursery areas for coral reef fish juveniles along four sites (Mtsoubatsou, Sohoa, Boueni, Ngouja) on the western coast of Mayotte Island. The results collected by underwater visual census from November 2012 to January 2013 showed that mean total fish density between adults and juveniles varied significantly at each site, with juveniles always being more abundant in seagrass beds than adults. Of the total fish assemblages sampled in seagrass beds, 73% were juveniles and few adults of large species were observed. Overall, our study highlights the important functional role of intertidal seagrass beds for fish assemblages, as they are the primary habitat for the juveniles of many fish species on Mayotte reefs. Seagrass beds, however, are very vulnerable ecosystems and are decreasing worldwide. Therefore it is of primary importance to protect seagrass beds within the Indo-Pacific.
Since the start of commercial plastics production in the 1940s, global production has rapidly accelerated, doubling approximately every 11 years. Despite this increase and clear evidence of plastics loss into the oceans, including a substantial standing stock, previous research has not detected a temporal trend in plastic particle concentration in the surface ocean. Using a generalized additive statistical model, we examined the longest dataset available on floating plastic debris collected using plankton nets in the western North Atlantic from 1986 through 2015. There was a significant increasing temporal trend in plastic particle concentration that tracked cumulative global plastics production. We estimated an increase of 506,000 tonnes of floating plastic in the ocean in 2010 alone, or 0.2% of global production. Our results suggest that, while loss of plastic particles from the surface ocean undoubtedly occurs, the input exceeds the collective losses.
Marine parks were established to protect the diverse marine ecosystem in Malaysia, and over the years, the islands have attracted an increasing number of tourists. These marine park islands have become not only one of the top ecotourism destinations in Malaysia but an important contributor to the socio-economic growth of the nation. Nonetheless, it is a constant challenge to maintain the marine parks’ natural charm due to negative tourism impacts. Humans’ consumption behaviour has been identified as a driver of climate change. Given that humans’ contribution to the problem is closely related to sustainable behaviour, this study focuses on tourists’ behaviour. With the growing awareness on global environmental challenges, environmental knowledge has often been prescribed as one of the main precursors of tourists’ behaviour, yet few studies have attempted to assess this factor from different dimensions. This paper examines tourists’ environmental knowledge from a multidimensional aspect of factual, conceptual and procedural dimensions to determine its role in influencing attitude and responsible environmental behaviour. A face-to-face survey was conducted among 85 domestic and international marine park tourists, and data were analysed using PLS-SEM method. This preliminary study revealed that environmental knowledge is formatively represented by factual, conceptual and procedural dimensions. Furthermore, results confirmed the linear relationships between knowledge, attitude and behaviour with knowledge as a strong predictor of attitude that leads to higher pro-environmental behaviours, hence highlighting the importance of promoting environmental knowledge among marine park tourists who drives pro-environmental attitude and responsible behaviour to achieve a sustainable ecotourism development.
Globally, conflicts between marine nature conservation and fishery interests are common and increasing, and there is often a glaring lack of dialogue between stakeholders representing these two interests. There is a need for a stronger and enforced coordination between fishing and conservation authorities when establishing marine protected areas for conservation purposes. We propose that an appropriate instrument for such coordination is a broad ecosystem-based marine spatial planning procedure, representing neither nature conservation nor fishery. Strategic environmental assessment for plans and programmes and environmental impact assessment for projects are commonly used tools for assessing the environmental impacts of different human activities, but are seldom used for evaluating the environmental effects of capture fisheries. The diversity of fisheries and the drastic effects of some fisheries on the environment are strong arguments for introducing these procedures as valuable supplements to existing fisheries assessment and management tools and able to provide relevant environmental information for an overall marine spatial planning process. Marine protected areas for nature conservation and for protection of fisheries have different objectives. Therefore, the legal procedure when establishing marine protected areas should depend on whether they are established for nature conservation purposes or as a fisheries resource management tool. Fishing in a marine protected area for conservation purpose should be regulated according to conservation law. Also, we argue that marine protected areas for conservation purposes, in the highest protection category, should primarily be established as fully protected marine national parks and marine reserves.
Despite general and wide-ranging negative effects of coral reef degradation on reef communities, hope might exist for reef-associated predators that use nursery habitats. When reef structural complexity is lost, refuge density declines and prey vulnerability increases. Here, we explore whether the presence of nursery habitats can promote high predator productivity on degraded reefs by mitigating the costs of increased vulnerability in early life, whilst allowing for the benefits of increased food availability in adulthood. We apply size-based ecosystem models of coral reefs with high and low structural complexity to predict fish biomass and productivity in the presence and absence of mangrove nurseries. Our scenarios allow us to elucidate the interacting effects of refuge availability and ontogenetic habitat shifts for fisheries productivity. We find that low complexity, degraded reefs with nurseries can support fisheries productivity that is equal to or greater than that in complex reefs that lack nurseries. We compare and validate model predictions with field data from Belize. Our results should inform reef fisheries management strategies and protected areas now and into the future.
Mass mortality events (MMEs) are a key concern for the management of marine ecosystems. Specific stages and species are at risk and the causes may be single or cumulative pressure from a range of sources including pollutants, anthropogenic climate change or natural variability. Identifying risk and quantifying effects of plausible scenarios including MMEs are key to stakeholders and a quest for scientists. MMEs affect the whole ecosystem, but are traditionally only studied in relation to specific species, disregarding ecological feedbacks. Here we use an end-to-end ecosystem model adapted to the Nordic and Barents seas to evaluate the species-specific and ecological impacts for 50 years following an MME. MMEs were modeled as 10, 50, or 90% reduced recruitment for cod, herring and haddock, individually or in combination. The MME scenarios were compared to a base case model run that includes the current fishing mortality. All species showed declines in population biomass following an MME, increasing in duration and severity with increasing mortality. Cod biomass rebounded to the base case level within 3–13 years post the MME independent of scenario, while neither haddock nor herring fully rebounded to base case levels within the considered time horizon. Haddock responded much more variably to the mortality scenarios than cod or herring, with some scenarios yielding much higher levels of biomass than the base case. Herring responded negatively to all scenarios, leading to lower herring biomass and a steeper decline of the species than seen in the base case due to persistent harvest pressure. Corresponding responses showed that the demersal guild biomass increased substantially, while the pelagic guild biomass declined. Few effects were observed on the other guilds, including the top predators. Ecosystem effects as measured by ecological indicators were greatest after 5 years, but persisted through the entire model run. Fishery indicators showed the same features, but the responses were stronger than for the ecosystem indicators. Taken together this indicates long-term, ecological response to MMEs that can be described as regime shifts, highlighting the importance of using ecosystem models when evaluating effects of MMEs.
Existing marine bioregions covering the Pacific Ocean are conceptualised at spatial scales that are too broad for national marine spatial planning. Here, we developed the first combined oceanic and coastal marine bioregionalisation at national scales, delineating 262 deep-water and 103 reef-associated bioregions across the southwest Pacific. The deep-water bioregions were informed by thirty biophysical environmental variables. For reef-associated environments, records for 806 taxa at 7369 sites were used to predict the probability of observing taxa based on environmental variables. Both deep-water and reef-associated bioregions were defined with cluster analysis applied to the environmental variables and predicted species observation probabilities, respectively to classify areas with high taxonomic similarity. Local experts further refined the delineation of the bioregions at national scales for four countries. This work provides marine bioregions that enable the design of ecologically representative national systems of marine protected areas within offshore and inshore environments in the Pacific.
Elasmobranchs, extremely charismatic and threatened animals, still are an important economic source for fishers in many parts of the world, providing significant income through trade. Even though Greek seas host at least 67 elasmobranch species, our knowledge about their biology and ecology is to a large extent unknown. In the present study the integration of conventional (legislation, official data from fisheries landings and fish market value and import/export data) and unconventional (social media) sources of data, accompanied with the use of genetics, aim at outlining the elasmobranch fisheries and trade in Greece and identifying “weak spots” that sabotage their conservation. Results revealed that: (a) about 60% of the 68 specimens collected in fish markets were mislabelled, with that being very common for Prionace glauca and Mustelus spp., (b) Illegal fishing is a reality, c) Greece represents one of the top-three European Union southern countries in terms of elasmobranch market size, (d) Aegean Sea and especially its Northern part (Thermaikos Gulf and Thracian Sea) contributed to more than half of the M. mustelus Greek fisheries landings and (e) wholesale prices of elasmobranchs have remained stable during the last decade. Mislabelling and illegal trade of elasmobranchs are common ground in Greece. This context stems from incoherent and complex fisheries legislative framework due to institutional decoupling, discrepancies in the collection and analysis of fisheries-related data, thus substantially reducing the efficiency of the fisheries management in Greek seas.
Coupled wave – 3D-hydrodynamics model runs are performed to investigate thermal discharge release to coastal areas by means of including nearshore effects of wave-current dynamics. The study area comprises the vicinity of a power plant at Cerano, in South Italy, where cooling industrial waters are released to the sea. The implemented model is calibrated by using temperature measurements and sensitivity analyses are carried out for various relevant drivers and input parameters. Afterwards, the effect of thermal discharge is investigated through distinct hypothetical scenarios for a combination of metocean conditions and operational features of the power plant (modifying water discharge and temperature at its outlet). The model results of this representative array of conditions are intercompared and evaluated on the basis of heat dispersion rate and areas of influence, providing with useful insights on the numerical simulation of the process and the potential effects for the specific coastal area.
Payments for Ecosystem Services (PES) have emerged as a popular conservation tool, yet evaluation among different PES programs strategies remains piecemeal. We prospectively compare cost-effectiveness of general PES, collective payments for ecosystem services (CPES) and the transition from PES to Land Purchases or Easements (LPE). We analyze the economic cost using statistics data and literature data, and analyze the transaction cost with the ordinal variable. We develop the Emergy Analysis method with the InVEST Habitat Quality model, and utilize it to analyze and map the ecological effectiveness. This paper gives an example to assessing the cost-effectiveness of different PES programs. Based on the analysis, LPE strategy led to improved ecological effectiveness, lower cost and greater cost-effectiveness. The collective PES has lower cost than general PES. However, they demonstrate equal ecological effectiveness. Based on these outcomes, we analyze the factors that influence PES programs’ cost-effectiveness, including collective or group, market-based mechanism, economic incentive, transaction cost, contract scale etc. We conclude that minimal number of intermediaries, community/collective support and involvement constitute the key factors in improving the cost-effectiveness of ecological programs. However, we acknowledge the need for further studies on the subject.
Coral reef fishes are about 10% of commercial fishes worldwide. Their pollution is close to human’s health. Antibiotics are one group of emerging organic pollutants in the marine environment. However, little data is available on the bioaccumulation and dietary risks of antibiotics in coral reef fish from the South China Sea (SCS) or any other parts of the global coral reef environment. In this study, we examined 19 antibiotics in 18 species of coral reef fish collected from coastal and offshore regions in the SCS. The results revealed that 17 antibiotics were detected in the fishes. Their average concentrations ranged from 1.3×10-5 to 7.9×10-1 ng/g ww, which were at the lower end of the global range about antibiotic levels in fish. The average total antibiotic concentrations (∑19ABs) were significantly higher in the offshore fish (1.2 ng/g ww) than in the coastal fish (0.16 ng/g ww). Different fish species or the protection of mucus produced by coastal fish at severe environmental stress may cause the differences. Fluoroquinolones (FQs) accounted for 89% and 74% of the average ∑19ABs in the offshore and coastal fish, respectively. It may relate to their relative high aqueous solubility and adsorption ability to particles. The log BAFs (bioaccumulation factors) of the antibiotics ranged from -0.34 to 4.12. Norfloxacin, dehydrated erythromycin (DETM), and roxithromycin were bioaccumulative in some offshore fish samples with their log BAFs higher than 3.7. The results of trophic magnification factors (TMFs) demonstrated that DETM underwent significant trophic dilution while enoxacin underwent trophic magnification in the food web of coral reef fishes. The estimated daily intakes of antibiotics via fish consumption by China residents ranged from 2.0×10-4 to 2.7 ng/kg weight body/day, which was 3 to 8 orders of magnitude lower than the respective acceptable daily intakes.
This article explores the possible interplay between the envisioned agreement on biodiversity beyond national jurisdiction (“the envisioned BBNJ Agreement”) and the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean (“the CAO Fisheries Agreement”). After summarizing the main provisions of the CAO Fisheries Agreement and the emerging elements of the envisioned BBNJ Agreement, the article considers ways in which the two agreements could be implemented consistently. However, a number of challenging questions remain, raising the specter of friction between the two regimes. The article concludes by calling on the negotiators of the envisioned BBNJ Agreement to consider these questions carefully, in the hope that the two Agreements can work together to ensure effective stewardship of the high seas portion of the Central Arctic Ocean.
In the ocean, plastic debris containing chemical additives is fragmented into smaller pieces that can be ingested by a wide range of organisms, potentially exposing them to additives. However, the levels of additives retained in marine plastic fragments have rarely been assessed. In this study, 141 plastic fragments from a beach in Kauai were analyzed piece-by-piece for 12 compounds, including UV stabilizers and brominated flame retardants. UV stabilizers (UV-326, UV-328, UV-327, and BP-12) were found in 13% of “small” fragments (4–7 mm) with levels of up to 315 μg/g and in 33% of “large” fragments (15–80 mm) with levels of up to 1130 μg/g. This observation suggests that exhaustive leaching of additives does not occur during fragmentation and that significant levels of additives, comparable to those of the original products, can be retained in fragments of marine plastic, indicating their importance as a vector of chemical additive exposure.
This paper evaluates two stakeholder participatory workshops (local communities and tourism stakeholder) to support the development of a management plan for South Ari Atoll Marine Protected Area (SAMPA), Maldives. SAMPA is the largest MPA in the country declared by Maldives to preserve one of the largest whale shark aggregations in the world. However, to date it exists with no management plan to date. The objective of the workshops was to consult with stakeholders on a range of potential regulatory and governance mechanisms proposed for the MPA that can be included in a potential management plan. The paper finds that the two stakeholder workshops had, both functional and dysfunctional aspects that influenced the potential design of a management plan for SAMPA. Overall, the workshops represented a clear opportunity for collective learning and collaboration that fostered dialogue and deliberation. However, important and influential stakeholders were under-represented at the workshops. Furthermore, a reluctance of government to demonstrate how the outcomes of the workshop would be integrated in its decision-making left many participants feeling sceptical about the fairness, equity and effectiveness of the processes that would follow. With no management plan to date, this paper proposes that any future stakeholder process in SAMPA should be underpinned by well informed governance and regulatory options that have the support and commitment of the government which can ensure SAMPA's ecosystem services are sustained to benefit long-term human well-being.
Enrichment of the oceans with CO2 may be beneficial for some marine phytoplankton, including harmful algae. Numerous laboratory experiments provided valuable insights into the effects of elevated pCO2 on the growth and physiology of harmful algal species, including the production of phycotoxins. Experiments close to natural conditions are the next step to improve predictions, as they consider the complex interplay between biotic and abiotic factors that can confound the direct effects of ocean acidification. We therefore investigated the effect of ocean acidification on the occurrence and abundance of phycotoxins in bulk plankton samples during a long-term mesocosm experiment in the Gullmar Fjord, Sweden, an area frequently experiencing harmful algal blooms. During the experimental period, a total of seven phycotoxin-producing harmful algal genera were identified in the fjord, and in accordance, six toxin classes were detected. However, within the mesocosms, only domoic acid and the corresponding producer Pseudo-nitzschia spp. was observed. Despite high variation within treatments, significantly higher particulate domoic acid contents were measured in the mesocosms with elevated pCO2. Higher particulate domoic acid contents were additionally associated with macronutrient limitation. The risks associated with potentially higher phycotoxin levels in the future ocean warrants attention and should be considered in prospective monitoring strategies for coastal marine waters.