Literature Library

Currently indexing 7642 titles

Toward a Harmonization for Using in situ Nutrient Sensors in the Marine Environment

Daniel A, Laës-Huon A, Barus C, Beaton AD, Blandfort D, Guigues N, Knockaert M, Muraron D, Salter I, E. Woodward MS, et al. Toward a Harmonization for Using in situ Nutrient Sensors in the Marine Environment. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00773/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Improved comparability of nutrient concentrations in seawater is required to enhance the quality and utility of measurements reported to global databases. Significant progress has been made over recent decades in improving the analysis and data quality for traditional laboratory measurements of nutrients. Similar efforts are required to establish high-quality data outputs from in situ nutrient sensors, which are rapidly becoming integral components of ocean observing systems. This paper suggests using the good practices routine established for laboratory reference methods to propose a harmonized set of deployment protocols and of quality control procedures for nutrient measurements obtained from in situsensors. These procedures are intended to establish a framework to standardize the technical and analytical controls carried out on the three main types of in situ nutrient sensors currently available (wet chemical analyzers, ultraviolet optical sensors, electrochemical sensors) for their deployments on all kinds of platform. The routine reference controls that can be applied to the sensors are listed for each step of sensor use: initial qualification under controlled conditions in the laboratory, preparation of the sensor before deployment, field deployment and finally the sensor recovery. The fundamental principles applied to the laboratory reference method are then reviewed in terms of the calibration protocol, instrumental interferences, environmental interferences, external controls, and method performance assessment. Data corrections (linearity, sensitivity, drifts, interferences and outliers) are finally identified along with the concepts and calculations for qualification for both real time and time delayed data. This paper emphasizes the necessity of future collaborations between research groups, reference-accredited laboratories, and technology developers, to maintain comparability of the concentrations reported for the various nutrient parameters measured by in situ sensors.

Assessing Knowledge Gaps and Management Needs to Cope With Barriers for Environmental, Economic, and Social Sustainability of Marine Recreational Fisheries: The Case of Spain

Pita P, Alós J, Antelo M, Artetxe I, Biton-Porsmoguer S, Carreño A, Cuadros A, Font T, Beiro J, García-Charton JA, et al. Assessing Knowledge Gaps and Management Needs to Cope With Barriers for Environmental, Economic, and Social Sustainability of Marine Recreational Fisheries: The Case of Spain. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/article/10.3389/fmars.2020.00023/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The European Parliament is concerned about the lack of information on the relevance of nine million Europeans engaged in marine recreational fishing (MRF), committing Member States to encourage environmental and socioeconomic sustainability of the sector. The objective of this paper is to provide recommendations to guide research actions and management policies, based on the case of Spain, a key country because its complex administrative regimen and the intensive use of its coasts, including 900,000 recreational fishers. A review of the state of the knowledge was performed to identify research gaps, while governance challenges were identified in an International Symposium on MRF. In the last two decades research on MRF was remarkable (139 publications). However, public investment in research (€2.44 million in the same period) should be improved to cover knowledge gaps on socioeconomic relevance, on impacts on vulnerable species and on implications of global warming. The license system should be standardized to allow estimation of effort, catch and expenditure. Social networks, mobile applications, fisher ecological knowledge, and citizen science programs could help to develop cost-effective research and management. Science-based, adaptive policies should improve the allocation of resources between MRF and other stakeholders, introducing co-management to reduce conflicts.

Harmful Algal Blooms: Identifying Effective Adaptive Actions Used in Fishery-Dependent Communities in Response to a Protracted Event

Moore KM, Allison EH, Dreyer SJ, Ekstrom JA, Jardine SL, Klinger T, Moore SK, Norman KC. Harmful Algal Blooms: Identifying Effective Adaptive Actions Used in Fishery-Dependent Communities in Response to a Protracted Event. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00803/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The “blob” of anomalously warm surface water that persisted in the North Pacific Ocean from 2013 to 2016 resulted in a massive harmful algal bloom (HAB) of Pseudo-nitzschia along the entire United States West Coast. The bloom produced record-breaking concentrations of domoic acid, a marine neurotoxin, that contaminated seafood and necessitated fisheries harvest closures beginning in May 2015. The subsequent closures were unprecedented in length and geographic extent, generating an economic shock for fishing communities. We sought to identify effective adaptive actions used in fishery-dependent communities in response to this event. Using survey data collected across 16 fishing communities following the 2015 HAB event, we empirically identified factors affecting an individual’s: (1) absolute magnitude of income loss, (2) likelihood of income loss recovery, and (3) severity of emotional stress. Our findings indicate that individuals who suffered greater absolute income losses were exposed to longer fisheries closures, more dependent on shellfish as a source of income, and employed in the fishing industry. Income diversification was an effective strategy for reducing and/or recovering HAB related income losses. Advertising was also found to be an effective income recovery strategy, but for fishers it was associated with increased emotional stress. If increasing the adaptive capacity of fishery-dependent coastal communities to HAB events is a policy goal, then costs to adaptive action such as emotional stress, limited access to alternate fisheries, new fishing gear, a lack of alternate job skills or access to job networks, and a lack of advertising know-how will need to be addressed.

Applications of Spatial Autocorrelation Analyses for Marine Aquaculture Siting

Jossart J, Theuerkauf SJ, Wickliffe LC, Jr. JAMorris. Applications of Spatial Autocorrelation Analyses for Marine Aquaculture Siting. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00806/ful
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Interest and growth in marine aquaculture are increasing around the world, and with it, advanced spatial planning approaches are needed to find suitable locations in an increasingly crowded ocean. Standard spatial planning approaches, such as a Multi-Criteria Decision Analysis (MCDA), may be challenging and time consuming to interpret in heavily utilized ocean spaces. Spatial autocorrelation, a statistical measure of spatial dependence, may be incorporated into the planning framework, which provides objectivity and assistance with the interpretation of spatial analysis results. Here, two case studies highlighting applications of spatial autocorrelation analyses in the northeast region of the United States of America are presented. The first case study demonstrates the use of a local indicator of spatial association analysis within a relative site suitability analysis – a variant of a MCDA – for siting a mussel longline farm. This case study statistically identified 17% of the area as highly suitable for a mussel longline farm, relative to other locations in the area of interest. The use of a clear, objective, and efficient analysis provides improved confidence for industry, coastal managers, and stakeholders planning marine aquaculture. The second case study presents an incremental spatial autocorrelation analysis with Moran’s I that is performed on modeled and remotely sensed oceanographic data sets (e.g., chlorophyll a, sea surface temperature, and current speed). The results are used to establish a maximum area threshold for each oceanographic variable within the online decision support tool, OceanReports, which performs an automated spatial analysis for a user-selected area (i.e., drawn polygon) of ocean space. These thresholds provide users guidance and summary statistics of relevant oceanographic information for aquaculture planning. These two case studies highlight practical uses and the value of spatial autocorrelation analyses to improve the siting process for marine aquaculture.

Estimating Mangrove Tree Biomass and Carbon Content: A Comparison of Forest Inventory Techniques and Drone Imagery

Jones AR, Segaran RRaja, Clarke KD, Waycott M, Goh WSH, Gillanders BM. Estimating Mangrove Tree Biomass and Carbon Content: A Comparison of Forest Inventory Techniques and Drone Imagery. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00784/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Mangroves provide many ecosystem services including a considerable capacity to sequester and store large amounts of carbon, both in the sediment and in the above-ground biomass. Assessment of mangrove above-ground carbon stock relies on accurate measurement of tree biomass, which traditionally involves collecting direct measurements from trees and relating these to biomass using allometric relationships. We investigated the potential to predict tree biomass using measurements derived from unmanned aerial vehicle (UAV), or drone, imagery. This approach has the potential to dramatically reduce time-consuming fieldwork, providing greater spatial survey coverage and return for effort, and may enable data to be collected in otherwise hazardous or inaccessible areas. We imaged an Avicennia marina (grey mangrove) stand using an RGB camera mounted on a UAV. The imaged trees were subsequently felled, enabling physical measurements to be taken for traditional biomass estimation techniques, as well as direct measurements of biomass and tissue carbon content. UAV image-based tree height measurements were highly accurate (R2 = 0.98). However, the variables that could be measured from the UAV imagery (tree height and canopy area) were poor predictors of tree biomass. Using the physical measurement data, we identified that trunk diameter is a key predictor of A. marina biomass. Unfortunately, trunk diameter cannot be directly measured from the UAV imagery, but it can be predicted (with some error) using models that incorporate other UAV image-based measurements, such as tree height and canopy area. However, reliance on second-order estimates of trunk diameter leads to increased uncertainty in the subsequent predictions of A. marina biomass, compared to using physical measurements of trunk diameter taken directly from the trees. Our study demonstrates that there is potential to use UAV-based imagery to measure mangrove A. marina tree structural characteristics and biomass. Further refinement of the relationship between UAV image-based measurements and tree diameter is needed to reduce error in biomass predictions. UAV image-based estimates can be made far more quickly and over extensive areas when compared to traditional data collection techniques and, with improved accuracy through further model-calibration, have the potential to be a powerful tool for mangrove biomass and carbon storage estimation.

Sea Surface Temperature Imagery Elucidates Spatiotemporal Nutrient Patterns for Offshore Kelp Aquaculture Siting in the Southern California Bight

Snyder JN, Bell TW, Siegel DA, Nidzieko NJ, Cavanaugh KC. Sea Surface Temperature Imagery Elucidates Spatiotemporal Nutrient Patterns for Offshore Kelp Aquaculture Siting in the Southern California Bight. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/article/10.3389/fmars.2020.00022/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Offshore aquaculture of giant kelp (Macrocystis pyrifera) has been proposed by the US Department of Energy for large scale biofuel production along the west coast of California. The Southern Californian Bight provides an ideal area for offshore kelp aquaculture as the upwelling and advection of cool, nutrient-rich waters supports the growth of vast native giant kelp populations. However, concentrations of nutrients vary greatly across space, can be limiting for kelp growth over seasonal to interannual time scales, and inputs of nutrients to surface waters may be subject to local circulation processes. Therefore, it is important to understand both the spatiotemporal variability of seawater nitrate concentrations and the appropriate scale of observation in order for offshore kelp aquaculture to be successful. Here, we use a combination of satellite sea surface temperature imagery, in situ measurements, and modeling to determine seawater nitrate fields across multiple spatial and temporal scales. We then combine this information with known giant kelp physiological traits to develop a kelp stress index (KSI) for the optimal siting of offshore kelp aquaculture over seasonal to decadal scales. Temperature to nitrate relationships were determined from in situ measurements using generalized additive models and validated with buoy data. Summer and winter relationships were significantly different, and satellite-derived products compared well to buoy validations. Surface nitrate patterns, as derived from satellite temperature products, reveal the spatial variability in nitrate concentrations, and indicate areas that that may cause nutrient stress seasonally and during the negative phase of the North Pacific Gyre Oscillation. As the spatial scale of the surface nitrate product decreased, the negative bias increased and fine scale spatial variability was lost. Similarly, the averaging of daily nitrate concentration determinations over longer time scales increased the negative bias. We found that daily, 1 km spatial resolution nitrate products were most sufficient for identifying localized upwelling and areas of consistently high surface nitrate concentrations, and that areas in the northern and western-most portions of the Southern California Bight are the most suitable for sustained offshore kelp aquaculture.

Gazing at the Crystal Ball: Predicting the Future of Marine Protected Areas Through Voluntary Commitments

Nocito ES, Brooks CM, Strong AL. Gazing at the Crystal Ball: Predicting the Future of Marine Protected Areas Through Voluntary Commitments. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00835/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The beginning of 2015 saw a new era within the United Nations: the era of the sustainable development goals (SDGs). Built off the previous Millennium Development Goals, this new set of goals included 17 target areas, including, for the first time, an explicit global goal related to the ocean. In June 2017, at the United Nations Headquarters in New York City, a high-level conference surrounding SDG 14: Life Under Water convened. One dimension of goal 14 calls for 10% of the ocean conserved by the year 2020, through sub-target 14.5. That 10% fulfillment is often thought of in terms of areal coverage via marine protected areas (MPAs). While many objectives were laid out for this conference, one of the most prominent objectives was to build on existing partnerships and foster new collaborations. One way to achieve this target was through the creation of the voluntary commitment program. This “Call for Action” came from heads of state and government, as well as high-level representatives from organizations and stakeholder groups. Under this “Call for Action,” 22 actions related to goal 14 were listed for stakeholders to partake in, including an appeal to create voluntary commitments surrounding the oceans. As of September 2017, 1,395 voluntary commitments had been registered through the voluntary commitment portal process, spanning across organizations and disciplines. Here, we analyze these commitments, specifically those related to the fifth sub-target of SDG 14. Commitments were further refined through spotlighting on those under 14.5 that focused on different forms of resilience. The resulting 133 separate codes covered over 12 distinct forms of resilience. Through analyzing commitments, we map out future plans and predict different forms of MPAs. This research shows collaboration and co-production of knowledge linking across the SDGs. This work can be seen as a stepping-stone to the fulfillment of 10% conservation by 2020.

The Azores: A Mid-Atlantic Hotspot for Marine Megafauna Research and Conservation

Afonso P, Fontes J, Giacomello E, Magalhães MC, Martins HR, Morato T, Neves V, Prieto R, Santos RS, Silva MA, et al. The Azores: A Mid-Atlantic Hotspot for Marine Megafauna Research and Conservation. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00826/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The increasing public perception that marine megafauna is under threat is an outstanding incentive to investigate their essential habitats (EMH), their responses to human and climate change pressures, and to better understand their largely unexplained behaviors and physiology. Yet, this poses serious challenges such as the elusiveness and remoteness of marine megafauna, the growing scrutiny and legal impositions on their study, and difficulties in disentangling environmental drivers from human disturbance. We argue that advancing our knowledge and conservation on marine megafauna can and should be capitalized in regions where exceptional access to multiple species (i.e., megafauna ‘hotspots’) combines with the adequate legal framework, sustainable practices, and research capacity. The wider Azores region, hosting EMHs of all key groups of vulnerable or endangered vertebrate marine megafauna, is a singular EMH hotspot on a migratory crossroads, linking eastern and western Atlantic margins and productive boreal waters to tropical seas. It benefits from a sustainable development model based on artisanal fisheries with zero or minor megafauna bycatch, and one of the largest marine protected area networks in the Atlantic covering coastal, oceanic and deepsea habitats. Developing this model can largely ensure the future integrity of this EMH hotspot while fostering cutting-edge science and technological development on megafauna behavior, biologging and increased ocean observation, with potential major impacts on the Blue Growth agenda. An action plan is proposed.

Contribution of Seagrass Blue Carbon Toward Carbon Neutral Policies in a Touristic and Environmentally-Friendly Island

Bedulli C, Lavery PS, Harvey M, Duarte CM, Serrano O. Contribution of Seagrass Blue Carbon Toward Carbon Neutral Policies in a Touristic and Environmentally-Friendly Island. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/article/10.3389/fmars.2020.00001/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Estimates of organic carbon (Corg) storage by seagrass meadows which consider inter-habitat variability are essential to understand their potential to sequester carbon dioxide (CO2) and derive robust global and regional estimates of blue carbon storage. In this study, we provide baseline estimates of seagrass extent, and soil Corg stocks and accumulation rates from different seagrass habitats at Rottnest Island (in Amphibolis spp., Posidonia spp., Halophila ovalis, and mixed Posidonia/Amphibolis spp. meadows). The Corg stocks in 0.5 m thick seagrass soil deposits, derived from 24 cores, were 5.1 ± 0.7 kg Corg m–2(mean ± SE, ranging from 0.05 to 12.9 kg Corg m–2), accumulating at 23.2 ± 3.2 g Corg m–2 year–1(ranging from 0.22 to 58.9 g Corg m–2 year–1) over the last decades. There were significant differences in Corg content (%) and stocks (mg Corg cm–3), stable carbon isotope composition of the soil organic matter (δ13C), and soil grain size among the seagrass meadows studied, highlighting that biotic and abiotic factors influence seagrass soil Corg storage. Mixed meadows of Posidonia/Amphibolis spp. and monospecific meadows of Posidonia spp. and Amphibolis spp. had the highest Corg stocks (ranging from 6.2 to 6.4 kg Corg m–2), while Halophila spp. meadows had the lowest Corg stocks (1.2 ± 0.6 kg Corg m–2). We estimated a total soil Corg stock of 48.1 ± 8.5 Gg Corg beneath the 755 ha of Rottnest Island’s seagrasses, and a Corg sequestration capacity of 0.81 ± 0.06 Gg Corg year–1, which is equivalent to the sequestration of ∼22% of the island’s current annual CO2 emissions. Our results contribute to the existing global dataset on seagrass soil Corg storage and show a significant potential of seagrass to sequester CO2, which are particularly relevant in the context of achieving carbon neutrality through conservation actions in environmentally-marketed, tourist destinations such as Rottnest Island.

Finding Crush: Environmental DNA Analysis as a Tool for Tracking the Green Sea Turtle Chelonia mydas in a Marine Estuary

Harper KJ, Goodwin KD, Harper LR, LaCasella EL, Frey A, Dutton PH. Finding Crush: Environmental DNA Analysis as a Tool for Tracking the Green Sea Turtle Chelonia mydas in a Marine Estuary. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00810/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Environmental DNA (eDNA) analysis is a rapid, non-invasive method for species detection and distribution assessment using DNA released into the surrounding environment by an organism. eDNA analysis is recognised as a powerful tool for detecting endangered or rare species in a range of ecosystems. Although the number of studies using eDNA analysis in marine systems is continually increasing, there appears to be no published studies investigating the use of eDNA analysis to detect sea turtles in natural conditions. We tested the efficacy of two primer pairs known to amplify DNA fragments of differing lengths (488 and 253 bp) from Chelonia mydas tissues for detecting C. mydas eDNA in water samples. The capture, extraction, and amplification of C. mydas eDNA from aquaria (Sea World, San Diego, CA, United States) and natural water (San Diego Bay, CA, United States) were successful using either primer set. The primer pair providing the shorter amplicon, LCMint2/H950g, demonstrated the ability to distinguish cross-reactive species by melt curve analysis and provided superior amplification metrics compared to the other primer set (LTCM2/HDCM2); although primer dimer was observed, warranting future design refinement. Results indicated that water samples taken from deeper depths might improve detection frequency, consistent with C. mydas behaviour. Overall, this pilot study suggests that with refinement of sampling methodology and further assay optimisation, eDNA analysis represents a promising tool to monitor C. mydas. Potential applications include rapid assessment across broad geographical areas to pinpoint promising locations for further evaluation with traditional methods.

Research Priorities for Achieving Healthy Marine Ecosystems and Human Communities in a Changing Climate

Friedman WR, Halpern BS, Mcleod E, Beck MW, Duarte CM, Kappel CV, Levine A, Sluka RD, Adler S, O’Hara CC, et al. Research Priorities for Achieving Healthy Marine Ecosystems and Human Communities in a Changing Climate. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/article/10.3389/fmars.2020.00005/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The health of coastal human communities and marine ecosystems are at risk from a host of anthropogenic stressors, in particular, climate change. Because ecological health and human well-being are inextricably connected, effective and positive responses to current risks require multidisciplinary solutions. Yet, the complexity of coupled social–ecological systems has left many potential solutions unidentified or insufficiently explored. The urgent need to achieve positive social and ecological outcomes across local and global scales necessitates rapid and targeted multidisciplinary research to identify solutions that have the greatest chance of promoting benefits for both people and nature. To address these challenges, we conducted a forecasting exercise with a diverse, multidisciplinary team to identify priority research questions needed to promote sustainable and just marine social–ecological systems now and into the future, within the context of climate change and population growth. In contrast to the traditional reactive cycle of science and management, we aimed to generate questions that focus on what we need to know, before we need to know it. Participants were presented with the question, “If we were managing oceans in 2050 and looking back, what research, primary or synthetic, would wish we had invested in today?” We first identified major social and ecological events over the past 60 years that shaped current human relationships with coasts and oceans. We then used a modified Delphi approach to identify nine priority research areas and 46 questions focused on increasing sustainability and well-being in marine social–ecological systems. The research areas we identified include relationships between ecological and human health, access to resources, equity, governance, economics, resilience, and technology. Most questions require increased collaboration across traditionally distinct disciplines and sectors for successful study and implementation. By identifying these questions, we hope to facilitate the discourse, research, and policies needed to rapidly promote healthy marine ecosystems and the human communities that depend upon them.

A Critical Examination of the Role of Marine Snow and Zooplankton Fecal Pellets in Removing Ocean Surface Microplastic

Kvale KF, Prowe AEFrieder, Oschlies A. A Critical Examination of the Role of Marine Snow and Zooplankton Fecal Pellets in Removing Ocean Surface Microplastic. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00808/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Numerical simulations and emissions estimates of plastic in and to the ocean consistently over-predict the surface inventory, particularly in the case of microplastic (MP), i.e., fragments less than 5 mm in length. Sequestration in the sediments has been both predicted and, to a limited extent, observed. It has been hypothesized that biology may be exporting a significant fraction of surface MP by way of marine snow aggregation and zooplankton fecal pellets. We apply previously published data on MP concentrations in the surface ocean to an earth system model of intermediate complexity to produce a first estimate of the potential global sequestration of MP by marine aggregates, including fecal pellets. We find a MP seafloor export potential of between 7.3E3 and 4.2E5 metric tons per year, or about 0.06–8.8% of estimated total annual plastic ocean pollution rates. We find that presently, aggregates alone would have the potential to remove most existing surface ocean MP to the seafloor within less than 2 years if pollution ceases. However, the observed accumulation of MP in the surface ocean, despite this high potential rate of removal, suggests that detrital export is an ineffective pathway for permanent MP removal. We theorize a prominent role of MP biological fouling and de-fouling in the rapid recycling of aggregate-associated MP in the upper ocean. We also present an estimate of how the potential detrital MP sink might change into the future, as climate change (and projected increasing MP pollution) alters the marine habitat. The polar regions, and the Arctic in particular, are projected to experience increasing removal rates as export production increases faster than MP pollution. Northern hemisphere subtropical gyres are projected to experience slowing removal rates as stratification and warming decrease export production, and MP pollution increases. However, significant uncertainty accompanies these results.

Editorial: New Challenges in Marine Pollution Monitoring

Bellas J, Hylland K, Burgeot T. Editorial: New Challenges in Marine Pollution Monitoring. Frontiers in Marine Science [Internet]. 2020 ;6. Available from: https://www.frontiersin.org/article/10.3389/fmars.2019.00820/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

There is abundant evidence that anthropogenic activities have polluted all compartments of the oceans, from the poles to the tropics, by different physical, chemical, and biological stressors. Chemical pollution is particularly tackled here with focus on legacy pollutants and newly emerging man-made compounds (xenobiotics) or anthropogenic forcing in the increase of natural chemical substances. It has been estimated that more than 100,000 chemicals are currently on the market [ECHA (European Chemicals Agency), 2017], and thousands of new substances are being introduced every year due to industrialization, intensive agriculture, and urban development. This has led to a continuous flow of chemical products to the oceans that have the potential to alter the structure of ecosystems by causing changes in the biotic communities that constitute them.

Rapid Assessment of Floating Macroplastic Transport in the Rhine

Vriend P, van Calcar C, Kooi M, Landman H, Pikaar R, van Emmerik T. Rapid Assessment of Floating Macroplastic Transport in the Rhine. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/article/10.3389/fmars.2020.00010/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Most marine litter pollution is assumed to originate from land-based sources, entering the marine environment through rivers. To better understand and quantify the risk that plastic pollution poses on aquatic ecosystems, and to develop effective prevention and mitigation methods, a better understanding of riverine plastic transport is needed. To achieve this, quantification of riverine plastic transport is crucial. Here, we demonstrate how established methods can be combined to provide a rapid and cost-effective characterization and quantification of floating macroplastic transport in the River Rhine. We combine visual observations with passive sampling to arrive at a first-order estimate of macroplastic transport, both in number (10–75 items per hour) and mass per unit of time (1.3–9.7 kg per day). Additionally, our assessment gives insight in the most abundant macroplastic polymer types the downstream reach of the River Rhine. Furthermore, we explore the spatial and temporal variation of plastic transport within the river, and discuss the benefits and drawbacks of current sampling methods. Finally, we present an outlook for future monitoring of major rivers, including several suggestions on how to expand the rapid assessment presented in this paper.

Knowledge gaps and management recommendations for future paths of sustainable seaweed farming in the Western Indian Ocean

Eggertsen M, Halling C. Knowledge gaps and management recommendations for future paths of sustainable seaweed farming in the Western Indian Ocean. Ambio [Internet]. 2020 . Available from: https://link.springer.com/article/10.1007%2Fs13280-020-01319-7
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Farming of eucheumatoid seaweeds is a widespread, promising activity and an important livelihood option in many tropical coastal areas as for example in East Africa, Western Indian Ocean (WIO). Compared to other types of aquaculture, seaweed farming has generally low impact on the environment. Nonetheless, there are potential direct or indirect negative effects of seaweed farming, such as introduction of alien species and changes in local environmental conditions. Although farming has been practiced in this region during several decades, the knowledge concerning the actual environmental impacts from faming non-native eucheumatoid haplotypes and consequently how to manage farming activities to mitigate those is highly limited. In this review, we provide a summary of the current scientific knowledge of potential direct and indirect negative environmental effects linked to eucheumatoid seaweed farming such as alterations of benthic macrophyte habitats and loss of native biodiversity. Furthermore, we highlight knowledge gaps that are of importance to address in the near future, e.g., large-scale ecosystem effects and farms as potential vectors of pathogens. We also provide a number of feasible management recommendations to be implemented for a continued development of environmentally sustainable seaweed farming practices in the WIO region, which includes spatial planning of farms to avoid sensitive areas and farming of native haplotypes of eucheumatoids instead of introduced specimens.

Seasonal effect on the spatial distribution of macro debris in Tunda Island, Banten

Maharani A, Yuliadi LPS, Syamsuddin ML, Ismail MR. Seasonal effect on the spatial distribution of macro debris in Tunda Island, Banten. IOP Conference Series: Earth and Environmental Science [Internet]. 2020 ;429:012006. Available from: https://iopscience.iop.org/article/10.1088/1755-1315/429/1/012006
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The small island coast is an area that is vulnerable to environmental problems. Debris problems occur in some areas of Tunda Island with low human activity, due to current and wind factors that can distribute the debris. The speed and direction of wind and currents in Indonesia are influenced by the seasons, so the seasons have an influence on the accumulation of debris in a place. This study aims to determine the effect of the season on the distribution of debris and potential sources that influence the presence of debris on the coast of Tunda Island, Banten. This study uses MIKE 21 software to determine current and wind patterns and movement of macro debris particles. Based on season research, it influences the pattern of macro debris distribution in this area. In the east season, the increase in the litter is 9 kg from the weight of the debris in the west season. Also, there is an increase in debris in several categories including the most likely to find items, fishing gear, packaging material, small pieces trash, and base wood materials. The potential source that affects the presence of debris on the coast of Tunda Island, Banten is Muara Ciujung.

The Blue Economy and the United Nations’ sustainable development goals: Challenges and opportunities

Lee K-H, Noh J, Khim JSeong. The Blue Economy and the United Nations’ sustainable development goals: Challenges and opportunities. Environment International [Internet]. 2020 ;137:105528. Available from: https://www.sciencedirect.com/science/article/pii/S0160412019338255
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The “Blue Economy (BE)” is an increasingly popular concept as a strategy for safeguarding the world’s oceans and water resources. It may emerge when economic activity is in balance with the long term capacity of ocean ecosystems to support the activity in a sustainable manner. Importantly, the concept of BE posits the inherent conflicts between two discourses—growth and development, and protection of ocean resources. The inherent conflicts require solutions to embrace the opportunities associated with the ocean economy while recognizing and addressing its threats. The potential solutions on a global scale are advocated by the United Nations in their Sustainable Development Goals (SDGs). However, we notice that the identification of the scope and boundaries of the BE in line with the UN’s SDGs is vague even challenging, and the key stakeholders and their interests and roles in the BE are also vague. This review examines the scientific evidence of the association between the BE and the UN’s SDGs, and relevance and alignment of stakeholders on the link between the BE and SDGs. Based on a literature survey between 1998 and 2018, we find that BE is highly associated with SDGs 14–17. Notably, we find that stakeholders prefer SDG 3 Good Health & Well-Being and SDG 8 Decent Work & Economic Growth in the BE context. As stakeholder involvement shows some differences and variations in the relationship between the BE and SDGs, we consider that stakeholders can play some roles directly or indirectly in the BE-SDGs context. In order to set achievable goals and targets in BE-SDGs, we support that key stakeholders should be identified to play several important roles in prosperous economic, societal development and setting tolerable ranges for the ocean biosphere.

Ecological status of target fishes inside and outside marine conservation area of Batbitim, Misool, Raja Ampat

Sala R, Marsaoly D, Dasmasela HY, Parenden D, Orisu D, Tarigan RB. Ecological status of target fishes inside and outside marine conservation area of Batbitim, Misool, Raja Ampat. IOP Conference Series: Earth and Environmental Science [Internet]. 2020 ;429:012054. Available from: https://iopscience.iop.org/article/10.1088/1755-1315/429/1/012054
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Batbitim marine conservation area (MCA) of Misool, Raja Ampat has been set as an area that is prohibited for fishing activities since 2005. The only activities allowed in that area are tourism and research activities. The difference in the management status between area inside the Batbitim MCA and outside the MCA might affect ecosystem components such as fish and coral reef in the respective area. The present study aims to investigate the ecological status of target fishes in the two areas. Data were collected by using an underwater visual census at 5 sites, in which at each site 3 transects were placed. Collected data are then used to assess ecological indices for the target fishes. It is found that there were 38 species of target fish belonging to 13 families. The diversity index of Shannon was found to be in the range between 0.99 (inside MCA) to 1.67 (outside MCA) and dominance index ranged between 0.26 (outside MCA) and 0.61(inside MCA). The abundance of individual target fish in each location varies between 960 ind ha−1 (outside MCA) and 9413 ind.ha−1 (inside MCA). Those results indicate that there is a discrepancy between the ecological status of the target fish at locations inside and outside the MCA.

Adapting Coastal Collection Methods for River Assessment to Increase Data on Global Plastic Pollution: Examples From India and Indonesia

Owens KA, Kamil PI. Adapting Coastal Collection Methods for River Assessment to Increase Data on Global Plastic Pollution: Examples From India and Indonesia. Frontiers in Environmental Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fenvs.2019.00208/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Marine debris often begins as litter or waste on land. Rivers play an important role in transporting this debris from communities to ocean systems, and yet we lack data on debris in freshwater systems. This work promotes eliminating the gap in knowledge between debris in marine and freshwater systems through use of a consistent, replicable methodology that can be used to improve data on freshwater shoreline debris. Expansion in the application of this method globally can allow researchers to ground-truth estimates of the debris entering the world's oceans via rivers. Widespread use of this method would provide data on the litter degrading in the world's riverine systems, an important ecological problem in its own right often sidelined in work on marine debris. Improved ground-truthing will also shed light on the missing plastics question: the disparity between input estimates and measurement of plastic waste in the world's oceans. Cataloging the way debris moves through, and remains a part of, freshwater systems is imperative to addressing the global plastic waste problem. Here we share examples of how the method has been applied in the Tukad Badung river in Indonesia and the Karamana river in India.

Recovery of critically endangered Nassau grouper (Epinephelus striatus) in the Cayman Islands following targeted conservation actions

Waterhouse L, Heppell SA, Pattengill-Semmens CV, McCoy C, Bush P, Johnson BC, Semmens BX. Recovery of critically endangered Nassau grouper (Epinephelus striatus) in the Cayman Islands following targeted conservation actions. Proceedings of the National Academy of Sciences [Internet]. 2020 ;117(3):1587 - 1595. Available from: https://www.pnas.org/content/117/3/1587
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Many large-bodied marine fishes that form spawning aggregations, such as the Nassau grouper (Epinephelus striatus), have suffered regional overfishing due to exploitation during spawning. In response, marine resource managers in many locations have established marine protected areas or seasonal closures to recover these overfished stocks. The challenge in assessing management effectiveness lies largely in the development of accurate estimates to track stock size through time. For the past 15 y, the Cayman Islands government has taken a series of management actions aimed at recovering collapsed stocks of Nassau grouper. Importantly, the government also partnered with academic and nonprofit organizations to establish a research and monitoring program (Grouper Moon) aimed at documenting the impacts of conservation action. Here, we develop an integrated population model of 2 Cayman Nassau grouper stocks based on both diver-collected mark–resight observations and video censuses. Using both data types across multiple years, we fit parameters for a state–space model for population growth. We show that over the last 15 y the Nassau grouper population on Little Cayman has more than tripled in response to conservation efforts. Census data from Cayman Brac, while more sparse, show a similar pattern. These findings demonstrate that spatial and seasonal closures aimed at rebuilding aggregation-based fisheries can foster conservation success.

Pages