Literature Library

Currently indexing 8100 titles

Micro- and Nanoplastic Exposure Effects in Microalgae: A Meta-Analysis of Standard Growth Inhibition Tests

Reichelt S, Gorokhova E. Micro- and Nanoplastic Exposure Effects in Microalgae: A Meta-Analysis of Standard Growth Inhibition Tests. Frontiers in Environmental Science [Internet]. 2020 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fenvs.2020.00131/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1411754_25_Enviro_20200825_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Background: Ecological impacts of micro- and nanoplastics particles (MNP) are among the most discussed environmental concerns. In algae, MNP are commonly hypothesized to reduce growth, which is a standard ecotoxicological endpoint. However, the reported test outcomes vary, with both growth inhibition and stimulation being observed. Due to this conflict of information, a data synthesis for MNP potential to cause growth inhibition in toxicity testing is needed.

Methods: We performed a meta-analysis study to assess the effect of MNP exposure on algal growth. Twenty studies published between 2010 and 2020 and representing 16 algal species and five polymer materials administered as particles in size range 0.04–3,000 μm were included in this meta-analysis. A random-effect model was used to estimate the effect size in three datasets: (1) Low concentration range (<100 mg/L), (2) High concentration range (≥100 mg/L), and (3) Full range model (0.004–1,100 mg/L), which encompassed all studies using the combination of experimental settings (test species, MNP concentration, polymer material, and particle size) yielding the highest effect size within a study.

Results: The exposure to MNP was not significantly associated with growth inhibition in any of the models tested. However, a high heterogeneity between the studies was found in all three models. Neither MNP concentration nor polymer material contributed significantly to the heterogeneity, whereas polymer density had a significant moderating effect, with a higher risk of growth inhibition at lower densities. We also identified a publication bias, with small studies that reported significant inhibition being overrepresented in our dataset.

Conclusions: The meta-analysis found limited evidence for MNP effect on microalgal growth in the standard algal growth inhibition test. The heterogeneity and varying methodological quality of studies limited the interpretation and the confidence in the findings. For hazard assessment, standardization and controlled exposure are needed as well as more sensitive endpoints that can inform us about the effect mechanisms. Finally, using particle-free controls in such tests cannot account for the presence of inert particulates in the test system, and, hence, does not allow to attribute observed effects to the test polymers.

Using GIS and stakeholder involvement to innovate marine mammal bycatch risk assessment in data-limited fisheries

Verutes GM, Johnson AF, Caillat M, Ponnampalam LS, Peter C, Vu L, Junchompoo C, Lewison RL, Hines EM. Using GIS and stakeholder involvement to innovate marine mammal bycatch risk assessment in data-limited fisheries Duplisea DE. PLOS ONE [Internet]. 2020 ;15(8):e0237835. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237835
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Fisheries bycatch has been identified as the greatest threat to marine mammals worldwide. Characterizing the impacts of bycatch on marine mammals is challenging because it is difficult to both observe and quantify, particularly in small-scale fisheries where data on fishing effort and marine mammal abundance and distribution are often limited. The lack of risk frameworks that can integrate and visualize existing data have hindered the ability to describe and quantify bycatch risk. Here, we describe the design of a new geographic information systems tool built specifically for the analysis of bycatch in small-scale fisheries, called Bycatch Risk Assessment (ByRA). Using marine mammals in Malaysia and Vietnam as a test case, we applied ByRA to assess the risks posed to Irrawaddy dolphins (Orcaella brevirostris) and dugongs (Dugong dugon) by five small-scale fishing gear types (hook and line, nets, longlines, pots and traps, and trawls). ByRA leverages existing data on animal distributions, fisheries effort, and estimates of interaction rates by combining expert knowledge and spatial analyses of existing data to visualize and characterize bycatch risk. By identifying areas of bycatch concern while accounting for uncertainty using graphics, maps and summary tables, we demonstrate the importance of integrating available geospatial data in an accessible format that taps into local knowledge and can be corroborated by and communicated to stakeholders of data-limited fisheries. Our methodological approach aims to meet a critical need of fisheries managers: to identify emergent interaction patterns between fishing gears and marine mammals and support the development of management actions that can lead to sustainable fisheries and mitigate bycatch risk for species of conservation concern.

Using graph theory and social media data to assess cultural ecosystem services in coastal areas: Method development and application

Ruiz-Frau A, Ospina-Alvarez A, Villasante S, Pita P, Maya-Jariego I, de Juan S. Using graph theory and social media data to assess cultural ecosystem services in coastal areas: Method development and application. Ecosystem Services [Internet]. 2020 ;45:101176. Available from: https://www.sciencedirect.com/science/article/pii/S2212041620301182?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The use of social media (SM) data has emerged as a promising tool for the assessment of cultural ecosystem services (CES). Most studies have focused on the use of single SM platforms and on the analysis of photo content to assess the demand for CES. Here, we introduce a novel methodology for the assessment of CES using SM data through the application of graph theory network analyses (GTNA) on hashtags associated to SM posts and compare it to photo content analysis. We applied the proposed methodology on two SM platforms, Instagram and Twitter, on three worldwide known case study areas, namely Great Barrier Reef, Galapagos Islands and Easter Island. Our results indicate that the analysis of hashtags through graph theory offers similar capabilities to photo content analysis in the assessment of CES provision and the identification of CES providers. More importantly, GTNA provides greater capabilities at identifying relational values and eudaimonic aspects associated to nature, elusive aspects for photo content analysis. In addition, GTNA contributes to the reduction of the interpreter’s bias associated to photo content analyses, since GTNA is based on the tags provided by the users themselves. The study also highlights the importance of considering data from different SM platforms, as the type of users and the information offered by these platforms can show different CES attributes. The ease of application and relative short computing processing times involved in the application of GTNA makes it a cost-effective method with the potential of being applied to large geographical scales.

The low impact of fish traps on the seabed makes it an eco-friendly fishing technique

Kopp D, Coupeau Y, Vincent B, Morandeau F, Méhault S, Simon J. The low impact of fish traps on the seabed makes it an eco-friendly fishing technique Coelho R. PLOS ONE [Internet]. 2020 ;15(8):e0237819. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237819
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Besides understanding the effects of fishing on harvested fish stocks, effects on non-target species, habitats and seafloor integrity also need to be considered. Static fishing gears have often been mentioned as a lower impact fishing alternative to towed gears, although studies examining their actual impact on the seafloor are scarce. In this study, we aimed to describe fish trap movements on the seafloor related to soaking time and trap retrieval. Impacts on the seafloor of lightweight rectangular traps and heavier circular traps were compared. We used 3D video cameras to estimate sweeping motion on the seabed and penetration into the sediment during soaking time. The area and distance swept by each type of trap during retrieval was determined by a camera set up facing the sea bottom. The potential rotation of the traps around the mainline was assessed using an Acoustic Doppler Current Profiler. Results showed that no penetration and almost no movements could be detected during soaking time for either lightweight or heavy commercial traps, even for high tidal coefficient (maximum 6 cm). No rotation could be observed when the tide turned. The swept area covered by a trap during retrieval was low (maximum 2.04 m2) compared to towed fishing gear and other static gear.

Comparing feedback and spatial approaches to advance ecosystem-based fisheries management in a changing Antarctic

Klein ES, Watters GM. Comparing feedback and spatial approaches to advance ecosystem-based fisheries management in a changing Antarctic Ropert-Coudert Y. PLOS ONE [Internet]. 2020 ;15(9):e0231954. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0231954
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

To implement ecosystem-based approaches to fisheries management, decision makers need insight on the potential costs and benefits of the policy options available to them. In the Southern Ocean, two such options for addressing trade-offs between krill-dependent predators and the krill fishery include “feedback management” (FBM) strategies and marine protected areas (MPAs); in theory, the first adjusts to change, while the latter is robust to change. We compared two possible FBM options to a proposed MPA in the Antarctic Peninsula and Scotia Sea given a changing climate. One of our feedback options, based on the density of Antarctic krill (Euphasia superba), projected modest increases in the abundances of some populations of krill predators, whereas outcomes from our second FBM option, based on changes in the abundances of penguins, were more mixed, with some areas projecting predator population declines. The MPA resulted in greater increases in some, but not all, predator populations than either feedback strategy. We conclude that these differing outcomes relate to the ways the options separate fishing and predator foraging, either by continually shifting the spatial distribution of fishing away from potentially vulnerable populations (FBM) or by permanently closing areas to fishing (the MPA). For the krill fishery, we show that total catches could be maintained using an FBM approach or slightly increased with the MPA, but the fishery would be forced to adjust fishing locations and sometimes fish in areas of relatively low krill density–both potentially significant costs. Our work demonstrates the potential to shift, rather than avoid, ecological risks and the likely costs of fishing, indicating trade-offs for decision makers to consider.

Interventions to help coral reefs under global change—A complex decision challenge

Anthony KRN, Helmstedt KJ, Bay LK, Fidelman P, Hussey KE, Lundgren P, Mead D, McLeod IM, Mumby PJ, Newlands M, et al. Interventions to help coral reefs under global change—A complex decision challenge Chen CAllen. PLOS ONE [Internet]. 2020 ;15(8):e0236399. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236399
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Climate change is impacting coral reefs now. Recent pan-tropical bleaching events driven by unprecedented global heat waves have shifted the playing field for coral reef management and policy. While best-practice conventional management remains essential, it may no longer be enough to sustain coral reefs under continued climate change. Nor will climate change mitigation be sufficient on its own. Committed warming and projected reef decline means solutions must involve a portfolio of mitigation, best-practice conventional management and coordinated restoration and adaptation measures involving new and perhaps radical interventions, including local and regional cooling and shading, assisted coral evolution, assisted gene flow, and measures to support and enhance coral recruitment. We propose that proactive research and development to expand the reef management toolbox fast but safely, combined with expedient trialling of promising interventions is now urgently needed, whatever emissions trajectory the world follows. We discuss the challenges and opportunities of embracing new interventions in a race against time, including their risks and uncertainties. Ultimately, solutions to the climate challenge for coral reefs will require consideration of what society wants, what can be achieved technically and economically, and what opportunities we have for action in a rapidly closing window. Finding solutions that work for coral reefs and people will require exceptional levels of coordination of science, management and policy, and open engagement with society. It will also require compromise, because reefs will change under climate change despite our best interventions. We argue that being clear about society’s priorities, and understanding both the opportunities and risks that come with an expanded toolset, can help us make the most of a challenging situation. We offer a conceptual model to help reef managers frame decision problems and objectives, and to guide effective strategy choices in the face of complexity and uncertainty.

Assessing the environmental status of selected North Atlantic deep-sea ecosystems

Kazanidis G, Orejas C, Borja A, Kenchington E, Henry L-A, Callery O, Carreiro-Silva M, Egilsdottir H, Giacomello E, Grehan A, et al. Assessing the environmental status of selected North Atlantic deep-sea ecosystems. Ecological Indicators [Internet]. 2020 ;119:106624. Available from: https://www.sciencedirect.com/science/article/pii/S1470160X20305616?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The deep sea is the largest biome on Earth but the least explored. Our knowledge of it comes from scattered sources spanning different spatial and temporal scales. Implementation of marine policies like the European Union’s Marine Strategy Framework Directive (MSFD) and support for Blue Growth in the deep sea are therefore hindered by lack of data. Integrated assessments of environmental status require tools to work with different and disaggregated datasets (e.g. density of deep-sea habitat-forming species, body-size distribution of commercial fishes, intensity of bottom trawling) across spatial and temporal scales. A feasibility study was conducted as part of the four-year ATLAS project to assess the effectiveness of the open-access Nested Environmental status Assessment Tool (NEAT) to assess deep-sea environmental status. We worked at nine selected study areas in the North Atlantic focusing on five MSFD descriptors (D1-Biodiversity, D3-Commercial fish and shellfish, D4-Food webs, D6-Seafloor integrity, D10-Marine litter). The objectives of the present study were to i) explore and propose indicators that could be used in the assessment of deep-sea environmental status, ii) evaluate the performance of NEAT in the deep sea, and iii) identify challenges and opportunities for the assessment of deep-sea status. Based on data availability, data quality and expert judgement, in total 24 indicators (one for D1, one for D3, seven for D4, 13 for D6, two for D10) were used in the assessment of the nine study areas, their habitats and ecosystem components. NEAT analyses revealed differences among the study areas for their environmental status ranging from “poor” to “high”. Overall, the NEAT results were in moderate to complete agreement with expert judgement, previous assessments, scientific literature on human-pressure gradients and expected management outcomes. We suggest that the assessment of deep-sea environmental status should take place at habitat and ecosystem level (rather than at species level) and at relatively large spatial scales, in comparison to shallow-water areas. Limited knowledge across space (e.g. distribution of habitat-forming species) and the scarcity of long-term data sets limit our knowledge about natural variability and human impacts in the deep sea preventing a more systematic assessment of habitat and ecosystem components in the deep sea. However, stronger cross-sectoral collaborations, the use of novel technologies and open data-sharing platforms will be critical for establishing environmental baseline indicator values in the deep sea that will contribute to the science base supporting the implementation of marine policies and stimulating Blue Growth.

Gaps in current Baltic Sea environmental monitoring – Science versus management perspectives

Kahlert M, Eilola K, Mack L, Meissner K, Sandin L, Strömberg H, Uusitalo L, Viktorsson L, Liess A. Gaps in current Baltic Sea environmental monitoring – Science versus management perspectives. Marine Pollution Bulletin [Internet]. 2020 ;160:111669. Available from: https://www.sciencedirect.com/science/article/pii/S0025326X20307876?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Legislations and commitments regulate Baltic Sea status assessments and monitoring. These assessments suffer from monitoring gaps that need prioritization. We used three sources of information; scientific articles, project reports and a stakeholder survey to identify gaps in relation to requirements set by the HELCOM's Baltic Sea Action Plan, the Marine Strategy Framework Directive and the Water Framework Directive. The most frequently mentioned gap was that key requirements are not sufficiently monitored in space and time. Biodiversity monitoring was the category containing most gaps. However, whereas more than half of the gaps in reports related to biodiversity, scientific articles pointed out many gaps in the monitoring of pollution and water quality. An important finding was that the three sources differed notably with respect to which gaps were mentioned most often. Thus, conclusions about gap prioritization for management should be drawn after carefully considering the different viewpoints of scientists and stakeholders.

Struggling over shellfish: How diverging perceptions of marine nature distort deliberative governance

de Koning S, Steins NA, Toonen HM. Struggling over shellfish: How diverging perceptions of marine nature distort deliberative governance. Ocean & Coastal Management [Internet]. 2020 ;198:105384. Available from: https://www.sciencedirect.com/science/article/pii/S0964569120302921?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Deliberative governance is gaining increasing attention in the management of natural resources with conflicting stakes. Although disputed knowledge is known to affect deliberation, the role of perceptions is understudied. Based on a case study in the Dutch Wadden Sea, a marine protected area, we examine the social representations of shellfish fisheries and marine nature of stakeholders within one deliberative governance arrangement, the Mussel Covenant. Our results show that within this covenant there are two opposing social representations of marine nature which both are not in line with the agreed objectives. Instead, governmental policies still form the guidelines to covenant decisions. We conclude that diverging representations and state-influence decrease deliberation. Therefore, we argue that deliberative governance is not possible without explicitly considering the different cognitive, normative and expressive meanings attached to the marine area or issue at stake. To achieve deliberation, values of stakeholders should explicitly be acknowledged and discussed, and state-influence should be kept to a minimum.

Assessing the environmental status of selected North Atlantic deep-sea ecosystems

Kazanidis G, Orejas C, Borja A, Kenchington E, Henry L-A, Callery O, Carreiro-Silva M, Egilsdottir H, Giacomello E, Grehan A, et al. Assessing the environmental status of selected North Atlantic deep-sea ecosystems. Ecological Indicators [Internet]. 2020 ;119:106624. Available from: https://www.sciencedirect.com/science/article/pii/S1470160X20305616?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The deep sea is the largest biome on Earth but the least explored. Our knowledge of it comes from scattered sources spanning different spatial and temporal scales. Implementation of marine policies like the European Union’s Marine Strategy Framework Directive (MSFD) and support for Blue Growth in the deep sea are therefore hindered by lack of data. Integrated assessments of environmental status require tools to work with different and disaggregated datasets (e.g. density of deep-sea habitat-forming species, body-size distribution of commercial fishes, intensity of bottom trawling) across spatial and temporal scales. A feasibility study was conducted as part of the four-year ATLAS project to assess the effectiveness of the open-access Nested Environmental status Assessment Tool (NEAT) to assess deep-sea environmental status. We worked at nine selected study areas in the North Atlantic focusing on five MSFD descriptors (D1-Biodiversity, D3-Commercial fish and shellfish, D4-Food webs, D6-Seafloor integrity, D10-Marine litter). The objectives of the present study were to i) explore and propose indicators that could be used in the assessment of deep-sea environmental status, ii) evaluate the performance of NEAT in the deep sea, and iii) identify challenges and opportunities for the assessment of deep-sea status. Based on data availability, data quality and expert judgement, in total 24 indicators (one for D1, one for D3, seven for D4, 13 for D6, two for D10) were used in the assessment of the nine study areas, their habitats and ecosystem components. NEAT analyses revealed differences among the study areas for their environmental status ranging from “poor” to “high”. Overall, the NEAT results were in moderate to complete agreement with expert judgement, previous assessments, scientific literature on human-pressure gradients and expected management outcomes. We suggest that the assessment of deep-sea environmental status should take place at habitat and ecosystem level (rather than at species level) and at relatively large spatial scales, in comparison to shallow-water areas. Limited knowledge across space (e.g. distribution of habitat-forming species) and the scarcity of long-term data sets limit our knowledge about natural variability and human impacts in the deep sea preventing a more systematic assessment of habitat and ecosystem components in the deep sea. However, stronger cross-sectoral collaborations, the use of novel technologies and open data-sharing platforms will be critical for establishing environmental baseline indicator values in the deep sea that will contribute to the science base supporting the implementation of marine policies and stimulating Blue Growth.

An Interdisciplinary Approach for Valuing Changes After Ecological Restoration in Marine Cultural Ecosystem Services

Pouso S, Borja A, Uyarra MC. An Interdisciplinary Approach for Valuing Changes After Ecological Restoration in Marine Cultural Ecosystem Services. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00715/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Ecological restoration in marine ecosystems is considered strategic to recover environmental conditions and ecosystem services. However, the traditional single-discipline perspectives followed for analyzing the results of both restoration projects (focused in the analysis of biophysical changes) and valuation of ecosystem services (focused in economic valuation), do not provide useful theoretical frameworks when working with cultural ecosystem services, where socio-economic and environmental components are complexly interrelated. We propose an interdisciplinary approach for analyzing changes in cultural ecosystem services in restored marine ecosystems, based on the DAPSI(W)R(M) framework and following a social-ecological system approach. Our methodology considers environmental, social and economic elements that may be contributing to changes in the provision and demand for cultural ecosystem services in restored ecosystems. Our approach was tested in the Nerbioi estuary, a system that, after the implementation of a wastewater treatment plant at the end of the 20th Century, changed from being one of the most polluted estuaries in Europe to a nearly recovered system. Based on previous studies that have analyzed partial components of the restoration process and of the recreational ecosystem services, here we provide an interdisciplinary picture of the changes occurred in the last 25 years, directly linking the management measures adopted to an increase in human well-being. In the applied methodology, the three discipline domains (social, economic, and environmental) transcend each other to provide a new holistic view, completely different from what one would expect from the addition of the parts. In conclusion, this interdisciplinary approach provides a systematic framework for studying changes in cultural ecosystem services in restored systems, with a practical application for valuing human benefits as outcomes of marine restoration projects.

Overcoming the Obstacles Faced by Early Career Researchers in Marine Science: Lessons From the Marine Ecosystem Assessment for the Southern Ocean

Brasier MJ, McCormack S, Bax N, Caccavo JA, Cavan E, Ericson JA, Figuerola B, Hancock A, Halfter S, Hellessey N, et al. Overcoming the Obstacles Faced by Early Career Researchers in Marine Science: Lessons From the Marine Ecosystem Assessment for the Southern Ocean. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00692/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Pressure in academia and science is rapidly increasing and early career researchers (ECRs) have a lot to gain from being involved in research initiatives such as large international projects. But just how inclusive are they? Here we discuss experiences of ECRs directly involved in the Marine Ecosystem Assessment for the Southern Ocean (MEASO), an Australian led international research project to assess the status and trends of Southern Ocean ecosystems. We review the benefits of ECR involvement in large-scale initiatives to the project deliverables, the leadership team and ECRs themselves. Using insights from MEASO, we outline the obstacles that may become barriers to ECRs in scientific research in general but with a focus on large-scale research projects and suggest potential actions to overcome these at the individual, institutional and scientific community level. We consider the potential for ECRs to lead future Antarctic science programmes with a focus on science communication and applied research for policy makers within a global setting.

Discrete Pulses of Cooler Deep Water Can Decelerate Coral Bleaching During Thermal Stress: Implications for Artificial Upwelling During Heat Stress Events

Sawall Y, Harris M, Lebrato M, Wall M, Feng EYuming. Discrete Pulses of Cooler Deep Water Can Decelerate Coral Bleaching During Thermal Stress: Implications for Artificial Upwelling During Heat Stress Events. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00720/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Global warming is considered to be the most severe threat to coral reefs globally, which makes it important for scientists to develop novel strategies that mitigate the impact of warming on corals and associated habitats. Artificial upwelling of cooler deep water to the surface layer may be a possible mitigation/management tool. In this study, we investigated the effect of simulated artificial upwelling with deep water off Bermuda collected at 50 m (24°C) and 100 m (20°C) on coral symbiont biology of 3 coral species (Montastrea cavernosaPorites astreoides, and Pseudodiploria strigosa) in a temperature stress experiment. The following treatments were applied over a period of 3 weeks: (i) control at 28°C (ii) heat at 31°C, (iii) heat at 31°C+ deep water from 50 m depth, and (iv) heat at 31°C+ deep water from 100 m depth. Artificial upwelling was simulated over a period of 25 min on a daily basis resulting in a reduction of temperature for 2 h per day and the following degree-heating-weeks: 5.7°C-weeks for ii, 4.6°C-weeks for iii and 4.2°C-weeks for iv. Comparative analysis of photosynthetic rate, chlorophyll-a concentration and zooxanthellae density revealed a reduction of heat stress responses in artificial upwelling treatments in 2 of the 3 investigated species, and a stronger positive effect of 100-m water than 50-m water. These results indicate that artificial upwelling could be an effective strategy to mitigate coral bleaching during heat stress events allowing corals to adjust to increasing temperatures more gradually. It will still be necessary to further explore the ecological benefits as well as potential ecosystem impacts associated with different artificial upwelling scenarios to carefully implement an effective in situ artificial upwelling strategy in coral reefs.

Will COVID-19 Containment and Treatment Measures Drive Shifts in Marine Litter Pollution?

Canning-Clode J, Sepúlveda P, Almeida S, Monteiro J. Will COVID-19 Containment and Treatment Measures Drive Shifts in Marine Litter Pollution?. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00691/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The persistence and global presence of plastic materials in both aquatic (Andrady, 2011Akindele et al., 2019) and terrestrial ecosystems (Al-Jaibachi et al., 2018) has resulted in the conception of a new era—“The Plasticene” (Reed, 2015). The idea of a “Plasticene” era has been receiving growing support in recent years as research confirms the long-term persistence of plastic pollution and contaminants in the marine environment and suggests that discarded plastics can be traceable through future fossil records (Corcoran et al., 2014). Researchers are still finding new forms of plastic pollution and contamination worldwide (Gestoso et al., 2019Haram et al., 2020), but one thing is clear: tackling plastic pollution in the marine environment requires concerted strategies and strong actions from policy makers and stakeholders on a global scale. Indeed, several efforts are already in place at the international, regional, and national levels, with several instruments [e.g., United Nations Convention on the Law of the Sea (UNCLOS), United Nations Environment Programme (UNEP), Regional Sea Programme, and the European Union Marine Strategy Framework Directive (MSFD)] being developed in recent decades to reduce and manage marine litter (Chen, 2015).

The incessant and growing delivery of plastic trash and debris to our oceans is recognized now as one of the most relevant pollution problems across the planet, impacting marine life through its ingestion, entanglement, or suffocation (Kühn et al., 2015Rochman et al., 2016Villarrubia-Gómez et al., 2018). In addition, marine litter is now considered a growing vector for the introduction of non-indigenous species with transoceanic rafting, potentially amplifying species invasions at a global scale (Carlton et al., 2017) and can promote microbial colonization by pathogens implicated in outbreaks of coral disease (Lamb et al., 2018).

In recent years, discussions and debates regarding marine litter have intensified around the globe. Governments, industries, scientists, and the public are increasingly seeking strategies and policies to respond to marine plastic pollution by reducing or banning single-use plastic (SUP) (Chen, 2015Newman et al., 2015European Commission, 2018Tiller et al., 2019UNEP–United Nations Environment Programme, 2019). In 2018 alone, environmental actions have reached hundreds of millions of people, with countries and several companies making commitments to ban SUP, which estimates suggest will represent 80% of all marine litter, by 2025 (UNEP–United Nations Environment Programme, 2019).

Variation in Seagrass Carbon Stocks Between Tropical Estuarine and Marine Mangrove-Fringed Creeks

Juma GA, Magana AM, Michael GN, Kairo JG. Variation in Seagrass Carbon Stocks Between Tropical Estuarine and Marine Mangrove-Fringed Creeks. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00696/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Seagrass and associated blue carbon ecosystems are important carbon sinks, and hence understanding their spatial and temporal variability is vital in appreciating their potential roles in climate change mitigation and adaptation. The Indo-Pacific region has the highest seagrass biodiversity, yet little focus has been made to compare seagrass habitat extent and carbon dynamics with their temperate counterparts. The present study assessed habitat characteristics and seagrass species distribution, diversity, and carbon storage in Eastern (marine) and Western (estuarine) mangrove-fringed creeks of Gazi Bay, Kenya. Data on species composition, canopy cover, biomass, and sediment organic carbon were collected in 80 plots of 0.25 × 0.25 m laid along transects established perpendicular to the waterline. Five species formation, viz., Thalassia hemprichiiCymodocea rotundataCymodocea serrulataEnhalus acoroides, and Thalassidendron ciliatum, were encountered as either single or mixed stands. There was a significant difference in total seagrass biomass between creeks (p < 0.01), with the Eastern creek recording a mean of 10.2 ± 0.6 Mg C ha–1 while the Western creek recording 4.3 ± 0.3 Mg C ha–1. In addition, sediment carbon to 1-m depth varied significantly (p < 0.01) between species in the two creeks and ranged from 98 to 302 Mg C ha–1, with the Eastern and Western creeks recording means of 258 ± 90 and 107 ± 21 Mg C ha–1, respectively. The total carbon stock from 50 ha of seagrasses in the Eastern creek was 13,420 Mg C, whereas in the 70 ha of the Western creek it was 7,769 Mg C. The study shows that seagrass community attributes such as species composition and productivity can vary dramatically over a small spatial extent due to differences in biophysical conditions and caution estimations of site-specific carbon stocks using generalized global values.

Marine Heatwave Stress Test of Ecosystem-Based Fisheries Management in the Gulf of Alaska Pacific Cod Fishery

Barbeaux SJ, Holsman K, Zador S. Marine Heatwave Stress Test of Ecosystem-Based Fisheries Management in the Gulf of Alaska Pacific Cod Fishery. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00703/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

In 2014–2016 an unprecedented warming event in the North Pacific Ocean triggered changes in ecosystem of the Gulf of Alaska (GOA) impacting fisheries management. The marine heatwave was noteworthy in its geographical extent, depth range, and persistence, with evidence of shifts in species distribution and reduced productivity. In 2017 a groundfish survey indicated that GOA Pacific cod (Gadus macrocephalus) had experienced a 71% decline in abundance from the previous 2015 survey. The GOA Pacific cod fishery supports a $103 million fishery which is 29% of the groundfish harvest value in the GOA. In this paper, we demonstrate that an increase in metabolic demand during this extended marine heatwave as well as a reduced prey supply can explain the decline in GOA Pacific cod biomass. Although increased mortality likely led to the decline in the Pacific cod population, historically low recruitment concurrent with the heatwave portends a slow recovery for the stock and gives a preview of impacts facing this region due to climate change. We evaluate the intersection of climate change with ecosystem-based fisheries management in the context of GOA Pacific cod with a description of the sensitivities of the ecosystem, how the changes in the ecosystem affected the Pacific cod stock, and a description of how the management system in the North Pacific handled this shock. We also provide suggestions on how fisheries management systems could be improved to better contend with the impacts of climate change such as the effects of heatwaves like that experienced in 2014–2016.

 

Stakeholder perspectives on large-scale marine protected areas

Artis E, Gray NJ, Campbell LM, Gruby RL, Acton L, Zigler SBess, Mitchell L. Stakeholder perspectives on large-scale marine protected areas Hewitt J. PLOS ONE [Internet]. 2020 ;15(9):e0238574. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0238574
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Large-scale marine protected areas (LSMPAs), MPAs greater than 100,000km2, have proliferated in the past decade. However, the value of LSMPAs as conservation tools is debated, in both global scientific and policy venues as well as in particular sites. To add nuance and more diverse voices to this debate, this research examines the perspectives of stakeholders directly engaged with LSMPAs. We conducted a Q Method study with forty LSMPA stakeholders at five sites, including three established LSMPAs (the Marianas Trench Marine National Monument, United States; the Phoenix Islands Protected Area, Kiribati; the National Marine Sanctuary, Palau) and two sites where LSMPAs had been proposed at the time of research (Bermuda and Rapa Nui (Easter Island), Chile). The analysis reveals five distinct viewpoints of LSMPAs. These include three more optimistic views of LSMPAs we have named EnthusiastPurist, and Relativist. It also depicts two more cautious views of LSMPAs, which we have named Critic and Skeptic. The findings demonstrate the multi-dimensionality of stakeholder viewpoints on LSMPAs. These shared viewpoints have implications for the global LSMPA debate and LSMPA decision-makers, including highlighting the need to focus on LSMPA consultation processes. Better understanding of these viewpoints, including stakeholder beliefs, perspectives, values and concerns, may help to facilitate more nuanced dialogue amongst LSMPA stakeholders and, in turn, promote better governance of LSMPAs.

Artificial habitats host elevated densities of large reef-associated predators

Paxton AB, Newton EA, Adler AM, Van Hoeck RV, Iversen ES, J. Taylor C, Peterson CH, Silliman BR. Artificial habitats host elevated densities of large reef-associated predators Chapman MGeraldine. PLOS ONE [Internet]. 2020 ;15(9):e0237374. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237374
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Large predators play important ecological roles, yet many are disproportionately imperiled. In marine systems, artificial reefs are often deployed to restore degraded reefs or supplement existing reefs, but it remains unknown whether these interventions benefit large predators. Comparative field surveys of thirty artificial and natural reefs across ~200 km of the North Carolina, USA coast revealed large reef-associated predators were more dense on artificial than natural reefs. This pattern was associated with higher densities of transient predators (e.g. jacks, mackerel, barracuda, sharks) on artificial reefs, but not of resident predators (e.g., grouper, snapper). Further analyses revealed that this pattern of higher transient predator densities on artificial reefs related to reef morphology, as artificial reefs composed of ships hosted higher transient predator densities than concrete reefs. The strength of the positive association between artificial reefs and transient predators increased with a fundamental habitat trait–vertical extent. Taller artificial reefs had higher densities of transient predators, even when accounting for habitat area. A global literature review of high trophic level fishes on artificial and natural habitats suggests that the overall pattern of more predators on artificial habitats is generalizable. Together, these findings provide evidence that artificial habitats, especially those like sunken ships that provide high vertical structure, may support large predators.

Shorebirds Affect Ecosystem Functioning on an Intertidal Mudflat

Booty JM, Underwood GJC, Parris A, Davies RG, Tolhurst TJ. Shorebirds Affect Ecosystem Functioning on an Intertidal Mudflat. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00685/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Ecosystem functioning and services have provided a rationale for conservation over the past decades. Intertidal muddy sediments, and the microphytobenthic biofilms that inhabit them, perform crucial ecosystem functions including erosion protection, nutrient cycling and carbon sequestration. It has been suggested that predation on sediment macrofauna by shorebirds may impact biofilms, and shorebirds are known to consume biofilm, potentially causing significant top-down effects on mudflat ecosystem functioning. We carried out an exclusion experiment on the Colne Estuary, Essex, to examine whether shorebird presence significantly affects sediment erodibility measured with a Cohesive Strength Meter (CSM) and microphytobenthos biomass measured using PAM fluorescence (Fo) and chlorophyll a content. We also tested for treatment effects on sediment-water nutrient fluxes [nitrate, nitrite, ammonia, phosphate and dissolved organic carbon (DOC)] during periods of both dark and light incubation. Excluding shorebirds caused statistically significant changes in regulating and provisioning ecosystem functions, including mudflat erodibility and nutrient fluxes. The presence of shorebirds lowered the sediment critical erosion threshold τcr, reduced nitrate fluxes into the sediment under illumination, lowered nitrate efflux, and reduced phosphate uptake, compared to sediments where birds were excluded. There were no significant differences in macrofauna community composition within the sediment between treatments after 45 days of bird exclusion, suggesting a direct link between shorebird presence or absence and the significant differences in biofilm-related variables. This study introduces previously unknown effects of shorebird presence on ecosystem functions within this system and highlights an area of shorebird science that could aid joint conservation and human provisioning action.

Perceptions of Marine Environmental Issues by Saudi Citizens

Almahasheer H, Duarte CM. Perceptions of Marine Environmental Issues by Saudi Citizens. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00600/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1418755_45_Marine_20200903_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

We depend on the sea, economically, social well-being, and for the quality of our lives, yet direct and indirect human activities have affected the marine environment, causing many problems such as overfishing and pollution at the local scale and ocean warming and acidification at the global one. Hence, addressing the cumulative effects of these activities is required to conserve the marine environment for our current and future generations. Social commitment and support for these actions depend, however, on awareness and requires, therefore, an understanding of citizens’ awareness and perceptions on these issues. We assessed the awareness and the perceptions of Saudi citizens on ocean issues through an online questionnaire about environmental issues globally and in the country. The survey was completed by 1,524 Saudi citizens 18 years old and above, with different geographic distributions, gender, and educational status. The participants identified climate change within the top three global problems, with variable level of information and trust on different sources of environmental information. Littering, sewage pollution, and chemical pollution were identified as the top three major marine issues in Saudi Arabia, with the respondents demanding an immediate action through imposing fines to polluters and more regulatory constraints to activities that act as sources of pollution as well as supporting research in science and technologies to address these environmental issues.

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