Literature Library

Currently indexing 8182 titles

Biophysical and anthropogenic influences on the status of Tonga’s coral reefs and reef fish fishery

Smallhorn-West P, Gordon S, Stone K, Ceccarelli D, Malimali S’a, Halafihi T’ikolongahau, Wyatt M, Bridge T, Pressey R, Jones G. Biophysical and anthropogenic influences on the status of Tonga’s coral reefs and reef fish fishery Ferse SCA. PLOS ONE [Internet]. 2020 ;15(11):e0241146. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241146
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Despite increasing threats to Tonga’s coral reefs from stressors that are both local (e.g. overfishing and pollution) and global (e.g. climate change), there is yet to be a systematic assessment of the status of the country’s coral reef ecosystem and reef fish fishery stocks. Here, we provide a national ecological assessment of Tonga’s coral reefs and reef fish fishery using ecological survey data from 375 sites throughout Tonga’s three main island groups (Ha’apai, Tongatapu and Vava’u), represented by seven key metrics of reef health and fish resource status. Boosted regression tree analysis was used to assess and describe the relative importance of 11 socio-environmental variables associated with these key metrics of reef condition. Mean live coral cover across Tonga was 18%, and showed a strong increase from north to south correlated with declining sea surface temperature, as well as with increasing distance from each provincial capital. Tongatapu, the southernmost island group, had 2.5 times greater coral cover than the northernmost group, Vava’u (24.9% and 10.4% respectively). Reef fish species richness and density were comparable throughout Tongatapu and the middle island group, Ha’apai (~35 species/transect and ~2500 fish/km2), but were significantly lower in Vava’u (~24 species/transect and ~1700 fish/km2). Spatial patterns in the reef fish assemblage were primarily influenced by habitat-associated variables (slope, structural complexity, and hard coral cover). The biomass of target reef fish was greatest in Ha’apai (~820 kg/ha) and lowest in Vava’u (~340 kg/ha), and was negatively associated with higher human influence and fishing activity. Overall mean reef fish biomass values suggest that Tonga’s reef fish fishery can be classified as moderately to heavily exploited, with 64% of sites having less than 500 kg/ha. This study provides critical baseline ecological information for Tonga’s coral reefs that will: (1) facilitate ongoing management and research; and (2) enable accurate reporting on conservation targets locally and internationally.

Enhancing coral recruitment through assisted mass settlement of cultured coral larvae

Cruz DW dela, Harrison PL. Enhancing coral recruitment through assisted mass settlement of cultured coral larvae Chen CAllen. PLOS ONE [Internet]. 2020 ;15(11):e0242847. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0242847
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The escalating rate at which coral communities are declining globally requires urgent intervention and new approaches to reef management to reduce and halt further coral loss. For reef systems with limited natural larval supply, the introduction of large numbers of competent coral larvae directly to natural reef substrata provides a potentially useful approach to replenish adult coral populations. While few experiments have tested this approach, only one experiment has demonstrated its long-term success to date. Given the differences in life-history traits among corals, and different sensitivities of larvae to abiotic and biotic factors, coupled with the dynamic nature of post-settlement survivorship and recruitment processes, trials of the larval enhancement technique with larvae of different coral species are needed to test the broader applicability and viability of this approach. Accordingly, in this paper we examine the applicability of the larval enhancement technique to restore a population of Acropora loripes in the Bolinao-Anda Reef Complex, Pangasinan, northwestern Philippines. Larvae were cultured ex situ following spawning of collected Aloripes colonies in June 2014. Competent larvae were transported to degraded reef areas and approximately 300,000 larvae were introduced in each of three 6 × 4 m plots directly on the reef. Fine mesh enclosures retained the larvae inside each treatment plot for five days. Three adjacent 6 × 4 m plots that served as controls were also covered with mesh enclosures, but no larvae were introduced. Each plot contained ten 10 × 10 cm conditioned settlement tiles cut from dead tabulate Acropora that were used to quantify initial larval settlement. After allowing larval settlement for five days, mean settlement on tiles from the larval enhancement plots that were monitored under stereomicroscopes was significantly higher (27.8 ± 6.7 spat per tile) than in control plots, in which not a single recruit was recorded. Post-settlement survivorship and growth of spat and coral recruits on tiles and reef substrata inside the experimental plots were monitored periodically for 35 months. After 35 months, the mean size of each of the remaining 47 Aloripes coral colonies surviving on the reef substrata was 438.1 ± 5.4 cm3, with a mean diameter of 7.9 ± 0.6 cm. The average production cost for each of the surviving Aloripes colonies at 35 months was USD 35.20. These colonies are expected to spawn and contribute to the natural larval pool when they become reproductively mature, thereby enhancing natural coral recovery in the area. This study demonstrates that mass coral larval enhancement can be successfully used for restoring populations of coral species with different life-history traits, and the techniques can rapidly increase larval recruitment rates on degraded reef areas, hence catalysing the regeneration of declining coral populations.

Prescribing sea water quality criteria for arsenic, cadmium and lead through species sensitivity distribution

Karthikeyan P, Marigoudar SR, Mohan D, Sharma KVenkataram, Murthy MVRamana. Prescribing sea water quality criteria for arsenic, cadmium and lead through species sensitivity distribution. Ecotoxicology and Environmental Safety [Internet]. 2021 ;208:111612. Available from: https://www.sciencedirect.com/science/article/pii/S0147651320314494?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Water quality standards are essential for regulation of contaminants in marine environment. Seawater quality criteria (SWQC) for arsenic (As), cadmium (Cd) and lead (Pb) have not been developed for India. The aim of this study is to derive the SWQC for the metals based on Species Sensitivity Distribution (SSD). Eight species of sensitive marine organisms belonging to five phyla were assessed for their sensitivity to toxicity of As, Cd and Pb. Median effective concentrations (EC50) and Median Lethal Concentrations (LC50) were derived from the acute toxicity bio-assays. No Observed Effect Concentrations (NOEC), Lowest Observed Effect Concentrations (LOEC) and chronic values were derived from chronic toxicity bio-assays. Diatoms were more sensitive to As with 96 h EC50 of 0.1 mg/l and copepods were more sensitive to Cd and Pb with 96 h EC50 of 0.019 mg/l and 0.05 mg/l respectively. Estimated NOECs ranged from 4.87 to 21.55 µg/l of As, 1.0 to 120 µg/l of Cd and 5.67 to 91.67 µg/l of Pb. Similarly, chronic values (µg/l) were in the range of 6.71–26.1, 1.38–170, and 7.67–91.67 of As, Cd and Pb respectively. The Criterion Maximum Concentration (CMC), Criterion Continuous Concentration (CCC) and Predicted No Effect Concentration (PNEC) values were prescribed as SWQC. The CMC (µg/l) of 19, 1.7 and 17 for As, Cd, and Pb were derived respectively for acute exposure during accidental marine outfalls. The CCC (µg/l) for As was 4.6, 1.1 for Cd and 5.9 for Pb are recommended as SWQC for protection of 95% of marine organisms. PNEC (µg/l) of 3.8 for As, 0.92 for Cd and 4.3 for Pb are suggested for highly disturbed ecosystems, shell fishing and mariculture uses of water bodies. These values are recommended as a baseline for site specific water quality criteria for the coastal waters of the country.

Microplastics contamination along the coastal waters of NW Portugal

Rodrigues SM, C. Almeida MR, Ramos S. Microplastics contamination along the coastal waters of NW Portugal. Case Studies in Chemical and Environmental Engineering [Internet]. 2020 ;2:100056. Available from: https://reader.elsevier.com/reader/sd/pii/S2666016420300542?token=B2E3FE1BB307A15E0529CED61D8D448567B42D20A3FCC3931BA8C2184D5645115EBF6E2B1C5AC348BCBF1F24D4DAB9AE
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

To evaluate the current microplastics (MPs) contamination on the NW coast of Portugal, opportunistic samples from coastal areas with different levels of anthropogenic impacts were analyzed. Water samples were collected from a coastal marine protected area, an urban estuary, a submarine wreck, and a recreational marina. An optimized protocol for the quantification of MPs, followed by visual identification and FTIR spectroscopy analysis was used to characterize MPs (polymer, type, size, color). MPs were found in all the case studies. A total of 2456 ​MPs particles were identified and classified as fibers (39%), film (39%), and fragments (22%). Up to 54% of MPs had a size range between 1 and 3 ​mm. Transparent was the dominant color (56%), followed by white (19%). Polyethylene and polypropylene were the main MPs polymers detected. Higher MPs concentration were found in areas associated with high intense fishing and shipping activities. This study showed that different types of MPs were present in all the aquatic environments surveyed, mainly in areas with more anthropogenic activities, emphasizing the need for measures to properly manage plastic litter and mitigate marine plastic pollution.

Five Organizational Features That Enable Successful Interdisciplinary Marine Research

Blythe J, Cvitanovic C. Five Organizational Features That Enable Successful Interdisciplinary Marine Research. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.539111/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

To generate innovative solutions for marine sustainability challenges, scientists, policymakers, and funders are increasingly calling for interdisciplinary research that transcends disciplinary boundaries. However, challenges associated with doing interdisciplinary research persist and undermine progress toward tackling the complex challenges faced by marine social-ecological systems. One barrier for engaging in effective interdisciplinary research is a lack of understanding about the institutional capacities that support interdisciplinary knowledge production. Based on in-depth qualitative interviews with members of the Centre for Marine Socioecology in Australia, we identify five principles that underpin effective interdisciplinary research organizations. The principles are: (1) support female leadership; (2) forge partnerships outside of academia; (3) develop impact-based performance metrics; (4) focus on long-term funding; and (5) cultivate a visible brand. Going forward, these principles could be used to inform organizational design that transforms institutional barriers into enablers of innovative interdisciplinary research for more sustainable, desirable, and equitable futures.

3D printing as an enabling technology to implement maritime plastic Circular Economy

Garrido J, Sáez J, Armesto JI, Espada AM, Silva D, Goikoetxea J, Arrillaga A, Lekube B. 3D printing as an enabling technology to implement maritime plastic Circular Economy. Procedia Manufacturing [Internet]. 2020 ;51:635 - 641. Available from: https://www.sciencedirect.com/science/article/pii/S2351978920319466?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

CircularSeas European Project, as part of the European Union Circular Economy [1], aims at promoting the Green Economy by encouraging the development of green products, parts and components by Maritime Industries. The strategy is a combination of Circular Economy principles, with the use of ocean plastic waste for developing new greener materials, and the uptake of advanced manufacturing technology, 3D printing, flexible enough to adapt to the manufacturing conditions for new eco-innovative small and medium parts and components. The paper presents the ongoing research in the project about strategies to introduce Circular Economy in the maritime sector from plastic wastes. This first prospective phase is focused on a series of interviews with each node stakeholders. The paper presents the survey results, together with the challenges to be faced for the implementation of Circular Economy in that specific scenario, despite the -apriori- short term low-profit disadvantages.

Using interpersonal communication strategies to encourage science conversations on social media

Martin C, MacDonald BH. Using interpersonal communication strategies to encourage science conversations on social media. PLOS ONE [Internet]. 2020 ;15(11):e0241972. Available from: https://doi.org/10.1371/journal.pone.0241972
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Today, many science communicators are using social media to share scientific information with citizens, but, as research has shown, fostering conversational exchanges remains a challenge. This largely qualitative study investigated the communication strategies applied by individual scientists and environmental non-governmental organizations on Twitter and Instagram to determine whether particular social media practices encourage two-way conversations between science communicators and citizens. Data from Twitter and Instagram posts, interviews with the communicators, and a survey of audience members were triangulated to identify emergent communication strategies and the resulting engagement; provide insight into why particular practices are employed by communicators; and explain why audiences choose to participate in social media conversations with communicators. The results demonstrate that the application of interpersonal communication strategies encourage conversational engagement, in terms of the number of comments and unique individuals involved in conversations. In particular, using selfies (images and videos), non-scientific content, first person pronoun-rich captions, and responding to comments result in the formation of communicator-audience relationships, encouraging two-way conversations on social media. Furthermore, the results indicate that Instagram more readily supports the implementation of interpersonal communication strategies than Twitter, making Instagram the preferred platform for promoting conversational exchanges. These findings can be applicable to diverse communicators, subjects, audiences, and environments (online and offline) in initiatives to promote awareness and understanding of science.

Shifting seas, shifting boundaries: Dynamic marine protected area designs for a changing climate

Cashion T, Nguyen T, Brink Tten, Mook A, Palacios-Abrantes J, Roberts SM. Shifting seas, shifting boundaries: Dynamic marine protected area designs for a changing climate Belgrano A. PLOS ONE [Internet]. 2020 ;15(11):e0241771. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241771
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Marine protected areas (MPAs) are valuable tools for marine conservation that aim to limit human impacts on marine systems and protect valuable species or habitats. However, as species distributions shift due to ocean warming, acidification, and oxygen depletion from climate change, the areas originally designated under MPAs may bear little resemblance to their past state. Different approaches have been suggested for coping with species on the move in conservation. Here, we test the effectiveness of different MPA designs, including dynamic, network, and different directional orientations on protecting shifting species under climate change through ecosystem modeling in a theoretical ecosystem. Our findings suggest that dynamic MPAs may benefit some species (e.g., whiting and anchovy) and fishing fleets, and these benefits can inform the design or adaptation of MPAs worldwide. In addition, we find that it is important to design MPAs with specific goals and to account for the effects of released fishing pressure and species interactions in MPA design.

That’s All I Know: Inferring the Status of Extremely Data-Limited Stocks

Pantazi V, Mannini A, Vasilakopoulos P, Kapiris K, Megalofonou P, Kalogirou S. That’s All I Know: Inferring the Status of Extremely Data-Limited Stocks. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.583148/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

There is a growing number of methods to assess data-limited stocks. However, most of these methods require at least some basic data, such as commercial catches and life history information. Meanwhile, there are many commercial stocks with an even higher level of data limitation, for which the inference of stock status and the formulation of advice remain challenging. Here, we present a stepwise approach to achieve the best possible understanding of extremely data-limited stocks and facilitate their management. As a case study we use a stock of the shrimp Plesionika edwardsii (Decapoda, Pandalidae) from the eastern Mediterranean Sea, where the only available data was a sub-optimal sample of length frequencies coming from a small-scale trap fishery. We use a suite of different methods to explore and process the data, estimate the growth parameters, estimate the natural and fishing mortalities, and approximate the reference points, in order to provide a preliminary evaluation of stock status. We implement multiple methods for each step of this process, highlighting the strong and weak points of each one of them. Our approach illustrates the better insights that can be gained by applying ensembles of models, rather than a single ‘best’ model when working with limited data of poor quality. The stepwise approach we propose here is transferable to other extremely data-limited stocks to elucidate their status and inform their management.

Fin Whale Song Patterns Shift Over Time in the Central North Pacific

Helble TA, Guazzo RA, Alongi GC, Martin CR, Martin SW, E. Henderson E. Fin Whale Song Patterns Shift Over Time in the Central North Pacific. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.587110/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Male fin whales sing by producing 20 Hz pulses in regular patterns of inter-note intervals. While singing, fin whales may also alternate the frequency ranges of their notes. Different song patterns have been observed in different regions of the world's oceans. New song patterns suddenly emerging in an area have been hypothesized to either be indicators of new groups of whales in the area or signs of cultural transmission between groups. Since the status of fin whales around Hawaii is unknown and visual surveys are expensive and difficult to conduct in offshore areas, passive acoustic monitoring has been proposed as a way to monitor these whales. We used passive acoustic recordings from an array of 14 hydrophones to analyze the song patterns of 115 fin whale encounters made up of 50,034 unique notes off Kauai, Hawaii from 2011 to 2017. Fin whale singing patterns were more complicated than previously described. Fin whales off Hawaii sang in five different patterns made of two 20 Hz note types and both singlet and doublet inter-note interval patterns. The inter-note intervals present in their songs were 28/33 s for the lower frequency doublet, 30 s for the lower frequency singlet, 17/24 s for the higher frequency doublet, 17 s for the higher frequency singlet, and 12/20 s for the doublet that alternated between both note types. Some of these song patterns were unique to these fin whales in Hawaiian waters, while others were similar to song patterns recorded from fin whales off the U.S. west coast. Individual fin whales often utilized several different song patterns which suggests that multiple song patterns are not necessarily indicators of different individuals or groups. The dominant song pattern also changed over these years. Cultural transmission may have occurred between fin whales in Hawaiian waters and off the U.S. west coast, which has resulted in similar songs being present at both locations but on lagged timescales. Alternatively, groups occupying the Hawaiian waters could shift over time resulting in different song patterns becoming dominant. This work has implications for the population structure and behavior of Hawaii fin whales.

Coral calcification responses to the North Atlantic Oscillation and coral bleaching in Bermuda

Courtney TA, Kindeberg T, Andersson AJ. Coral calcification responses to the North Atlantic Oscillation and coral bleaching in Bermuda Caroselli E. PLOS ONE [Internet]. 2020 ;15(11):e0241854. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241854
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The North Atlantic Oscillation (NAO) has been hypothesized to drive interannual variability in Bermudan coral extension rates and reef-scale calcification through the provisioning of nutritional pulses associated with negative NAO winters. However, the direct influence of the NAO on Bermudan coral calcification rates remains to be determined and may vary between species and reef sites owing to implicit differences in coral life history strategies and environmental gradients across the Bermuda reef platform. In this study, we investigated the connection between negative NAO winters and Bermudan Diploria labyrinthiformisPseudodiploria strigosa, and Orbicella franksi coral calcification rates across rim reef, lagoon, and nearshore reef sites. Linear mixed effects modeling detected an inverse correlation between Dlabyrinthiformis calcification rates and the winter NAO index, with higher rates associated with increasingly negative NAO winters. Conversely, there were no detectable correlations between Pstrigosa or Ofranksi calcification rates and the winter NAO index suggesting that coral calcification responses associated with negative NAO winters could be species-specific. The correlation between coral calcification rates and winter NAO index was significantly more negative at the outer rim of the reef (Hog Reef) compared to a nearshore reef site (Whalebone Bay), possibly indicating differential influence of the NAO as a function of the distance from the reef edge. Furthermore, a negative calcification anomaly was observed in 100% of Dlabyrinthiformis cores in association with the 1988 coral bleaching event with a subsequent positive calcification anomaly in 1989 indicating a post-bleaching recovery in calcification rates. These results highlight the importance of assessing variable interannual coral calcification responses between species and across inshore-offshore gradients to interannual atmospheric modes such as the NAO, thermal stress events, and potential interactions between ocean warming and availability of coral nutrition to improve projections for future coral calcification rates under climate change.

Subregional variation in cover and diversity of hard coral (Scleractinia) in the Western Province, Solomon Islands following an unprecedented global bleaching event

Denley D, Metaxas A, Scheibling R. Subregional variation in cover and diversity of hard coral (Scleractinia) in the Western Province, Solomon Islands following an unprecedented global bleaching event Pinheiro HTercio. PLOS ONE [Internet]. 2020 ;15(11):e0242153. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0242153
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Coral reefs are critically important marine ecosystems that are threatened worldwide by cumulative impacts of global climate change and local stressors. The Solomon Islands comprise the southwestern boundary of the Coral Triangle, the global center of coral diversity located in the Indo-Pacific, and represent a bright spot of comparatively healthy coral reef ecosystems. However, reports on the status of coral reefs in the Solomon Islands are based on monitoring conducted at 5 stations in 2003–2004 and 2006–2007, with no information on how corals in this region have responded to more recent global bleaching events and other local stressors. In this study, we compare reef condition (substrate composition) and function (taxonomic and morphological diversity of hard corals) among 15 reefs surveyed in the Western Province, Solomon Islands that span a range of local disturbance and conservation histories. Overall, we found high cover of live hard coral (15–64%) and diverse coral assemblages despite an unprecedented 36-month global bleaching event in the three years leading up to our surveys in 2018. However, there was significant variation in coral cover and diversity across the 15 reefs surveyed, suggesting that impacts of global disturbance events are moderated at smaller scales by local anthropogenic factors (fisheries extraction, land-use impacts, marine management) and environmental (hydrodynamics) conditions. Our study provides evidence that relatively healthy reefs persist at some locations in the Solomon Islands and that local stewardship practices have the potential to impact reef condition at subregional scales. As coral reef conservation becomes increasingly urgent in the face of escalating cumulative threats, prioritising sites for management efforts is critical. Based on our findings and the high dependency of Solomon Islanders on coral reef ecosystem services, we advocate that the Western Province, Solomon Islands be considered of high conservation priority.

Evaluating the small-scale epidemiology of the stony-coral -tissue-loss-disease in the middle Florida Keys

Sharp WC, Shea CP, Maxwell KE, Muller EM, Hunt JH. Evaluating the small-scale epidemiology of the stony-coral -tissue-loss-disease in the middle Florida Keys Keshavmurthy S. PLOS ONE [Internet]. 2020 ;15(11):e0241871. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241871
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Along the Florida reef tract, stony-coral-tissue-loss disease (SCTLD) has caused extensive mortality of more than 20 scleractinian coral species. The pathogen is unknown, but its epizoology indicates that the disease, facilitated by water currents, has progressed linearly along the tract, affecting reefs at the scale of hundreds of kilometers. To inform ongoing disease mitigation efforts, we examined the small-scale spatial and temporal epidemiology of SCTLD. We established a series of sites in the middle Florida Keys at offshore and inshore locations that had not yet shown signs of SCTLD. We then conducted high-frequency monitoring from February 2018 through September 2019 and documented the onset of SCTLD and its progression through the sites. SCTLD was first observed at one site during early February 2018 and by early March 2018 all sites showed signs of the disease. A dynamic multistate model suggested that disease transmission was independent of coral density and found little evidence of a positive association between a colony showing signs of SCTLD and the condition or distance to its neighboring colonies. The model did, however, indicate that the probability of a colony showing signs of SCTLD increased with increasing colony surface area. These results are consistent with the water-borne transmission of a pathogen that progressed rapidly through the survey area. However, by the end of our survey the progression of SCTLD had slowed, particularly at inshore sites. Many affected colonies no longer exhibited progressive tissue mortality typical of the disease, suggesting the existence of differentially resilient colonies or coral communities, meriting their use for future coral rescue and propagation and disease research. These results are useful for refining ongoing SCTLD mitigation strategies, particularly by determining when disease rates are sufficiently low for direct intervention efforts designed to arrest disease progression on individual coral colonies will be most effective.

Environmental and Biological Factors Influencing Dispersal of Neonate Leatherback Turtles (Dermochelys coriacea) From an Endangered Costa Rican Nesting Population

Barbour N, Shillinger GL, Hoover AL, Williamson SA, Coles VJ, Liang D, Fagan WF, Bailey H. Environmental and Biological Factors Influencing Dispersal of Neonate Leatherback Turtles (Dermochelys coriacea) From an Endangered Costa Rican Nesting Population. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.582933/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Quantifying early life movements is essential to understanding migratory pathways and habitat use that can impact individuals’ success later in life. To gauge how neonatal movements set the stage for later habitat use, we tracked neonate leatherback turtles (n = 94) with acoustic tags from Pacuare, Costa Rica, in 2016 and 2018. We analyzed movements using a first passage time analysis and random walk models, the results of which indicated neonates followed a fixed compass direction as they traveled away from shore and that strong currents in these areas resulted in advection. We combined the tracking data with concurrent environmental variables in a generalized additive mixed model framework. Our results showed the south-east current flow in this area has spatial and temporal structure consistent with large-scale geostrophic currents and not tidal current or local wind speed influences. After accounting for advection by currents, true neonate swimming speed was significantly related to current speed, first passage time, and the year. Neonates had three main response strategies to currents above 0.5 m s–1, with most increasing their swimming speed and the rest maintaining either a constant or decreased swimming speed. Neonates were significantly larger in 2018 than in 2016 but their average swimming speed was not significantly related to body size, indicating that environmental factors were more important contributors to their dispersal. We conclude that abiotic factors, including the strength and direction of the currents, significantly affect the swimming and dispersal strategy of neonate leatherback turtles and these results can help to inform strategies for releases of neonate turtles from hatcheries, future tracking studies, and conservation efforts.

Challenges for Restoration of Coastal Marine Ecosystems in the Anthropocene

Abelson A, Reed DC, Edgar GJ, Smith CS, Kendrick GA, Orth RJ, Airoldi L, Silliman B, Beck MW, Krause G, et al. Challenges for Restoration of Coastal Marine Ecosystems in the Anthropocene. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.544105/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Coastal marine ecosystems provide critical goods and services to humanity but many are experiencing rapid degradation. The need for effective restoration tools capable of promoting large-scale recovery of coastal ecosystems in the face of intensifying climatic stress has never been greater. We identify four major challenges for more effective implementation of coastal marine ecosystem restoration (MER): (1) development of effective, scalable restoration methods, (2) incorporation of innovative tools that promote climate adaptation, (3) integration of social and ecological restoration priorities, and (4) promotion of the perception and use of coastal MER as a scientifically credible management approach. Tackling these challenges should improve restoration success rates, heighten their recognition, and accelerate investment in and promotion of coastal MER. To reverse the accelerating decline of marine ecosystems, we discuss potential directions for meeting these challenges by applying coastal MER tools that are science-based and actionable. For coastal restoration to have a global impact, it must incorporate social science, technological and conceptual advances, and plan for future climate scenarios.

Consistency and Challenges in the Ocean Carbon Sink Estimate for the Global Carbon Budget

Hauck J, Zeising M, Le Quéré C, Gruber N, Bakker DCE, Bopp L, Chau TTuyet Tran, Gürses Ö, Ilyina T, Landschützer P, et al. Consistency and Challenges in the Ocean Carbon Sink Estimate for the Global Carbon Budget. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.571720/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Based on the 2019 assessment of the Global Carbon Project, the ocean took up on average, 2.5 ± 0.6 PgC yr−1 or 23 ± 5% of the total anthropogenic CO2 emissions over the decade 2009–2018. This sink estimate is based on simulation results from global ocean biogeochemical models (GOBMs) and is compared to data-products based on observations of surface ocean pCO2 (partial pressure of CO2) accounting for the outgassing of river-derived CO2. Here we evaluate the GOBM simulations by comparing the simulated surface ocean pCO2 to observations. Based on this comparison, the simulations are well-suited for quantifying the global ocean carbon sink on the time-scale of the annual mean and its multi-decadal trend (RMSE <20 μatm), as well as on the time-scale of multi-year variability (RMSE <10 μatm), despite the large model-data mismatch on the seasonal time-scale (RMSE of 20–80 μatm). Biases in GOBMs have a small effect on the global mean ocean sink (0.05 PgC yr−1), but need to be addressed to improve the regional budgets and model-data comparison. Accounting for non-mapped areas in the data-products reduces their spread as measured by the standard deviation by a third. There is growing evidence and consistency among methods with regard to the patterns of the multi-year variability of the ocean carbon sink, with a global stagnation in the 1990s and an extra-tropical strengthening in the 2000s. GOBMs and data-products point consistently to a shift from a tropical CO2 source to a CO2 sink in recent years. On average, the GOBMs reveal less variations in the sink than the data-based products. Despite the reasonable simulation of surface ocean pCO2 by the GOBMs, there are discrepancies between the resulting sink estimate from GOBMs and data-products. These discrepancies are within the uncertainty of the river flux adjustment, increase over time, and largely stem from the Southern Ocean. Progress in our understanding of the global ocean carbon sink necessitates significant advancement in modeling and observing the Southern Ocean carbon sink including (i) a game-changing increase in high-quality pCO2 observations, and (ii) a critical re-evaluation of the regional river flux adjustment.

Toward Balancing the Budget: Surface Macro-Plastics Dominate the Mass of Particulate Pollution Stranded on Beaches

Ryan PG, Weideman EA, Perold V, Moloney CL. Toward Balancing the Budget: Surface Macro-Plastics Dominate the Mass of Particulate Pollution Stranded on Beaches. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.575395/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Most studies report the abundance of plastic items in the environment, but mass is an equally important currency for monitoring plastic pollution, particularly given attempts to balance the global plastic budget. We determined the size/mass composition of litter stranded on a remote, infrequently-cleaned sandy beach on the west coast of South Africa. Traditional surveys of superficial macro-litter were augmented by sieved transects for buried macro-litter (8-mm mesh), meso-litter (2-mm mesh) and sediment cores for micro-litter. Aggregating the data across all sampling scales, the total density was ∼1.9 × 105 anthropogenic particulate pollutants per linear meter of beach, 99.7% of which were microfibers (most of which are likely not ‘plastic’). Plastics comprised 99.6% of beach macro- and meso-litter by number and 89% by mass. Small items dominated samples numerically, but were trivial relative to larger items in terms of their mass. Buried litter accounted for 86% of macro-plastic items, but only 5% of the mass of macro-plastics, because smaller items are buried more easily than large items. The total density of plastic (∼1.2 kg⋅m–1), at least half of which was from fisheries and shipping, is much lower than predicted by global models of plastic leakage from land-based sources. Ongoing degradation of plastic items already in the environment, particularly on beaches, is likely to result in a marked increase in plastic fragments, even if we stop leaking additional plastic. The collection of large items from beaches is a useful stop-gap measure to limit the formation of micro-plastics while we formulate effective steps to prevent plastic leakage into the environment.

Fishing Gear as a Data Collection Platform: Opportunities to Fill Spatial and Temporal Gaps in Operational Sub-Surface Observation Networks

Van Vranken C, Vastenhoud BMJ, Manning JP, Plet-Hansen KS, Jakoboski J, Gorringe P, Martinelli M. Fishing Gear as a Data Collection Platform: Opportunities to Fill Spatial and Temporal Gaps in Operational Sub-Surface Observation Networks. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.577098/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

While the observation of the open ocean is well achieved by automated ocean measurement instruments, coastal and shelf seas suffer the lack of sub-surface collection platforms. Commercial fishing gear such as bottom trawls, pots, traps and long lines can act as platforms for sensors, which collect physical oceanographic data concurrently with normal fishing operations. The lack of observed in situ ocean data in coastal and shelf seas limits operational oceanography, weather forecasting, maritime industries, and climate change monitoring. In addition, using fishing gear as an ocean observation platform has auxiliary benefits for fisheries management including stakeholder involvement. This study quantifies and compares the existing sub-surface in situ data coverage with the spatial distribution of fishing activities. The results show that integration with fishing could contribute to filling some of the most pressing gaps in existing ocean observation systems in coastal and shelf seas. There are limitations related to opportunistic data collection, mainly related to spatial and temporal heterogeneity of fishing activities. However, we make the case that fishery-based observations have the potential to complement existing ocean observing systems in areas where oceanographic data are lacking and needed most in order to ensure long term sustainability of ocean monitoring.

Virtopsy as a Revolutionary Tool for Cetacean Stranding Programs: Implementation and Management

Tsui HCL, Kot BCW, Chung TYT, Chan DKP. Virtopsy as a Revolutionary Tool for Cetacean Stranding Programs: Implementation and Management. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.542015/fullhttps://www.frontiersin.org/articles/10.3389/fmars.2020.542015/full
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

On top of conventional necropsy, virtopsy (postmortem computed tomography and postmortem magnetic resonance imaging) has been integrated into the Cetacean Stranding Response Programme in Hong Kong since March 2014. To date, 177 out of 240 local stranded cetaceans have been examined by virtopsy. This integration has modernised the characterisation and documentation of cetacean biological health and profiles, and causes of death. During this 6-year period, critical pitfalls regarding logistics, carcass recovery, handling, and preservation have been identified. A strategic management scheme is crucial for the successful incorporation of virtopsy into this pioneer programme. This study explains the workflow of the Cetacean Virtopsy Stranding Response Programme in Hong Kong waters. Difficulties encountered are highlighted and practical solutions to address management issues are proposed to consolidate the stranding response network.

Changes in Phytoplankton Communities Along the Northern Antarctic Peninsula: Causes, Impacts and Research Priorities

Ferreira A, Costa RR, Dotto TS, Kerr R, Tavano VM, Brito AC, Brotas V, Secchi ER, Mendes CRB. Changes in Phytoplankton Communities Along the Northern Antarctic Peninsula: Causes, Impacts and Research Priorities. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.576254/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1481182_45_Marine_20201112_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The Northern Antarctic Peninsula (NAP), located in West Antarctica, is amongst the most impacted regions by recent warming events. Its vulnerability to climate change has already led to an accumulation of severe changes along its ecosystems. This work reviews the current findings on impacts observed in phytoplankton communities occurring in the NAP, with a focus on its causes, consequences, and the potential research priorities toward an integrated comprehension of the physical–biological coupling and climate perspective. Evident changes in phytoplankton biomass, community composition and size structure, as well as potential bottom-up impacts to the ecosystem are discussed. Surface wind, sea ice and meltwater dynamics, as key drivers of the upper layer structure, are identified as the leading factors shaping phytoplankton. Short- and long-term scenarios are suggested for phytoplankton communities in the NAP, both indicating a future increase of the importance of small flagellates at the expense of diatoms, with potential devastating impacts for the ecosystem. Five main research gaps in the current understanding of the phytoplankton response to climate change in the region are identified: (i) anthropogenic signal has yet to be disentangled from natural climate variability; (ii) the influence of small-scale ocean circulation processes on phytoplankton is poorly understood; (iii) the potential consequences to regional food webs must be clarified; (iv) the magnitude and risk of potential changes in phytoplankton composition is relatively unknown; and (v) a better understanding of phytoplankton physiological responses to changes in the environmental conditions is required. Future research directions, along with specific suggestions on how to follow them, are equally suggested. Overall, while the current knowledge has shed light on the response of phytoplankton to climate change, in order to truly comprehend and predict changes in phytoplankton communities, there must be a robust collaboration effort integrating both Antarctic research programs and the whole scientific community under a common research framework.

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