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• Eight nations have contributed 79% of all SARS-CoV-2 isolates that have been sequenced. • Two-thirds of SARS-CoV-2 variants that have been found were reported by five nations. • The number of detected variants increases at the square root of sequencing effort. • International cooperation for SARS-CoV-2 sequencing is urgently needed. • Effective monitoring and prevention require a global pathogen sequencing mechanism. To assess the efforts deployed by different nations and territories in sequencing SARS-CoV-2 isolates, thus enabling detection of variants, known and novel, of concern. The sources of over one million full genome sequences of SARS-CoV-2 virus available in the COVID-19 virus Mutation Tracker (CovMT) were analyzed to determine the number of variants in the RBD region of the genome determining infectivity detected in the various nations and territories. The number of detected variants increased as the square root of sequencing effort by nations. Eight nations have contributed 79% of all SARS-CoV-2 isolates that have been sequenced, with two-thirds of all unique variants, adding to 1118 RBD variants, reported by five nations. The median number of sequenced isolates required to detect, on average, one novel RBD variant is 24.05, which is a threshold achieved by 70 nations. Many developing nations have not contributed any sequences due to lack of capacity. This poses a risk of dangerous virus variants in these under-sampled regions spreading globally before being detected. A collaborative program to sequence SARS-CoV-2 isolates, and other pathogens of concern, is needed to monitor, track, and control the pandemic. [Display omitted] [ABSTRACT FROM AUTHOR]

Data gathered from diverse marine environments were analyzed to test the notion that the extent of phytoplankton heterogeneity is closely related to the extent of hydrographic variability. The results showed that the notion applies only to moderately complex systems, but not in hydrographically complex systems such as those found in estuaries. Mesoscale phytoplankton heterogeneity in moderately complex systems is controlled by growing conditions, whereas phytoplankton heterogeneity in hydrographically complex systems is determined mainly by physical factors.

Plastic debris accumulating on beaches pose a major threat to marine ecosystems. Unexpected events affecting human operations, such as the COVID-19 pandemic, which prompted governments to implement safety measures and restrictions, can serve as an unplanned investigation of anthropogenic pressure on the marine environment. This study aimed to explore deviations in macroplastic delivery rates to the central eastern Red Sea shoreline during three distinct population mobility periods: before, during, and after COVID-19 restrictions, spanning from January 2019 to June 2022. We observed a 50 % reduction in the estimated macroplastic delivery rates during the lockdown, followed by a 25 % increase after restrictions were eased. Seasonal variations in delivery rates were also observed, with higher values during the winter monsoon. Reduced shoreline litter delivery during the pandemic highlights human operations as a cause of macroplastic litter and suggests the potential of temporary measures to reduce plastic pollution in the coastal environment. • Estimated macroplastic delivery rate to the shore varied from 0 to 125 items km−1 d−1. • A 50 % decrease in delivery rate was noted when pandemic restrictions were enforced. • Post-pandemic lower rates may result from reduced litter stock available for exchange. • Macroplastic delivery rates varied seasonally, with higher values in winter monsoon. [ABSTRACT FROM AUTHOR]

This study assesses for the first time the ingestion of microplastics by giant clams and evaluates their importance as a sink for this pollutant. A total of 24 individuals of two size classes were collected from the Red Sea and then exposed for 12 days to 4 concentrations of polyethylene microbeads ranging from 53 to 500 μm. Experiments revealed that clams actively take up microplastic from the water column and the average of beads retained inside the animal was ∼7.55 ± 1.89 beads individual −1 day −1 (5.76 ± 1.16 MPs/g dw). However, the digestive tract itself cannot be considered the only sink of microbeads in Tridacnids. Indeed, shells play a key role as well. The abundance of microplastic adhering to the shells, which was estimated directly, was positively correlated to the concentration of beads found in the surrounding seawater. Therefore, clams' shells contribute to the removal of 66.03 ± 2.50% of the microplastic present in the water column. Furthermore, stress responses to the exposure to polyethylene were investigated. Gross Primary Production:Respiration (GPP:R) ratio decreased throughout of the experiment, but no significant difference was found between treatments and controls. Image 1 • Removal of plastic from the water by giant clams is assessed for the first time. • We identified two removal processes: active (ingestion) and passive (adhesion). • Passive removal is 35-fold higher that active removal. • Adhesion contributes to remove > 60% of plastic from the water column. • Removal rate depends on the concentration of plastic. Giant clams remove almost 70% of plastic from the water column mainly through a passive removal process of plastic adhesion to the shell. [ABSTRACT FROM AUTHOR]

It is hypothesized that pH fluctuations produced by seagrasses metabolism may confer marine calcifiers resistance to ocean acidification. Here, we tested this thesis by comparing the net population growth rate (NPGR) of a foraminifer species (Rosalina sp.) epiphytic of Mediterranean seagrass (Posidonia oceanica) to average current and projected pH scenarios under either stable conditions or diel fluctuations in pH of 0.3 units; variations similar to that experienced in their habitat. No significant differences were found in NPGRs between the fluctuating and stable pH treatments at current pH levels. NPGRs in treatments where pH fluctuated did not present significant differences to the treatment with high and stable pH conditions. In contrast, foraminifers exposed to stable low pH regimes experienced a steep decline in NPGR. These results suggest that diel pH fluctuations generated by P. oceanica photosynthetic activity could confer resistance to ocean acidification to Rosalina sp. • Forams epiphyte of Posidonia oceanica are resistant to ocean acidification scenarios. • Seagrasses may provide "refugia" from ocean acidification to associated biota. • There is an urgent need to incorporate pH fluctuations in the experimental designs. [ABSTRACT FROM AUTHOR]

Abstract To verify weather mangroves act as sinks for marine litter, we surveyed through visual census 20 forests along the Red Sea and the Arabian Gulf, both in inhabited and remote locations. Anthropogenic debris items were counted and classified along transects, and the influence of main drivers of distribution were considered (i.e. land-based and ocean-based sources, density of the forest and properties of the object). We confirmed that distance to major maritime traffic routes significantly affects the density of anthropogenic debris in Red Sea mangrove forests, while this was independent of land-based activities. This suggests ocean-based activities combined with surface currents as major drivers of litter in this basin. Additionally, litter was more abundant where the mangrove density was higher, and object distribution through the mangrove stand often depended on their shape and dimension. We particularly show that pneumatophores act as a sieve retaining large plastic objects, leading to higher plastic mass estimates in mangroves compared to those of beaches previously surveyed in the Red Sea. Graphical abstract Image 1 Highlights • Surveys aimed at quantifying anthropogenic debris in mangroves stands are scarce. • Mangroves are sinks for marine litter and traps for land originated litter. • Mangroves aerial roots act as a sieve that retains large objects. • Large plastic objects are more frequent in mangroves than on beaches. Mangrove forests, through pneumatophores, are filters that retain large floating plastic objects and therefore constitute a sink of marine plastic pollution. [ABSTRACT FROM AUTHOR]

Abstract Seagrass meadows provide multiple ecosystem services, yet they are among the most threatened ecosystems on earth. Because of their role as carbon sinks, protection and restoration of seagrass meadows contribute to climate change mitigation. Blue Carbon strategies aim to enhance CO 2 sequestration and avoid greenhouse gasses emissions through the management of coastal vegetated ecosystems, including seagrass meadows. The implementation of Blue Carbon strategies requires a good understanding of the habitat characteristics that influence C org sequestration. Here, we review the existing knowledge on Blue Carbon research in seagrass meadows to identify the key habitat characteristics that influence C org sequestration in seagrass meadows, those factors that threaten this function and those with unclear effects. We demonstrate that not all seagrass habitats have the same potential, identify research priorities and describe the implications of the results found for the implementation and development of efficient Blue Carbon strategies based on seagrass meadows. Highlights • We review the effects of habitat characteristics on seagrass C org sequestration. • Habitat characteristics that enhance or reduce C org sequestration are provided. • Habitat characteristics with unresolved effects are identified for future research. • Implications for the development of efficient Blue Carbon strategies are indicated. [ABSTRACT FROM AUTHOR]

This study assesses the presence of microplastic litter in the contents of the gastrointestinal tract of 26 commercial and non-commercial fish species from four difference habitats sampled along the Saudi Arabian coast of the Red Sea. A total of 178 individual were examined for microplastics. In total, 26 microplastic fragments were found. Of these, 16 being films (61.5%) and 10 being fishing thread (38.5%). FTIR analysis revealed that the most abundant polymers were polypropylene and polyethylene. The grouper ( Epinephelus spp.) sampled at Jazan registered the highest number of ingested microplastics. This fish species is benthic and feeds on benthic invertebrates. Although differences in the abundance of microplastic ingestion among species were not statistically significant, a significant change was observed when the level of ingestion of microplastics particles was compared among the habitats. The higher abundance of microplastics particles may be related to the habitats of fish and the presence of microplastics debris near the seabed. The results of this study represent a first evidence that microplastic pollution represents an emerging threat to Red Sea fishes, their food web and human consumers. [ABSTRACT FROM AUTHOR]

A global beach litter assessment is challenged by use of low-efficiency methodologies and incomparable protocols that impede data integration and acquisition at a national scale. The implementation of an objective, reproducible and efficient approach is therefore required. Here we show the application of a remote sensing based methodology using a test beach located on the Saudi Arabian Red Sea coastline. Litter was recorded via image acquisition from an Unmanned Aerial Vehicle, while an automatic processing of the high volume of imagery was developed through machine learning, employed for debris detection and classification in three categories. Application of the method resulted in an almost 40 times faster beach coverage when compared to a standard visual-census approach. While the machine learning tool faced some challenges in correctly detecting objects of interest, first classification results are promising and motivate efforts to further develop the technique and implement it at much larger scales. [ABSTRACT FROM AUTHOR]

Mobile phones and other geolocated devices have produced unprecedented volumes of data on human movement. Analysis of pooled individual human trajectories using big data approaches has revealed a wealth of emergent features that have ecological parallels in animals across a diverse array of phenomena including commuting, epidemics, the spread of innovations and culture, and collective behaviour. Movement ecology, which explores how animals cope with and optimize variability in resources, has the potential to provide a theoretical framework to aid an understanding of human mobility and its impacts on ecosystems. In turn, big data on human movement can be explored in the context of animal movement ecology to provide solutions for urgent conservation problems and management challenges. [ABSTRACT FROM AUTHOR]

Abstract: Seagrass meadows support high primary production rates and their canopies are efficient at filtering particles out of their water column as well as in preventing resuspension of the sediments. In addition, decomposition rates in seagrass sediments are slow, because of low nutrient concentration in seagrass detritus and low oxygen concentration in seagrass sediments. These characteristics result in high carbon burial rates in seagrass meadows, which have the capacity to accumulate large stores of carbon in their sediments, raising the seafloor. Carbon fingerprinting techniques allow to calculate both the age of these deposits and, therefore, the rate of carbon burial and identify the contribution of carbon produced by the seagrass. Yet, data on the regional cover and carbon stocks in seagrass meadows is sparse for some regions, particularly the Indo-Pacific, Africa and South America. In addition, our understanding of the factors regulating the variability in carbon sink capacity among seagrass meadows is limited. These gaps limit the capacity to formulate strategies to mitigate climate change based on the carbon sink capacity of seagrass meadows. A research strategy needs be formulated to address these gaps and provide the necessary protocols to ensure the accountability of mitigation actions involving the conservation and restoration of seagrass meadows. [Copyright &y& Elsevier]

Abstract: Shoot meristematic activity of Mediterranean seagrass Posidonia oceanica has been assessed in eleven different meadows located around Balearic Islands (Spanish Mediterranean). Moreover, in six of them, the meristematic activity has been determined hourly (or every 2 or 3h, depending on the meadow) for at least 24h, with the aim of detecting a possible circadian rhythm in the % of dividing nuclei. Meristematic activity was inferred by applying flow cytometry techniques combined with DNA labeling to determine the percentage of nuclei in each phase of the cell cycle (i.e. G0+G1, S, G2). The percentage of nuclei in G2 phase of the cell cycle reflects the percentage of nuclei that are dividing in a specific moment. In the meristems of vertical shoots of P. oceanica the percentage of nuclei in G2 phase was on average 7±0.11%, and it ranged from 2% to 12% across the meadows studied. The average percentage of nuclei in the G2 phase in P. oceanica meristems is lower than reported for other plants. No circadian rhythms were detected in meristems of P. oceanica. The variability observed for meristematic activity across meadows suggests that it could be used as indicator of seagrass stress and, thus, to assess impacts to meristems before population declines could be observed. [Copyright &y& Elsevier]

Abstract: Uncertainty analyses allow the identification and quantification of the factors that contribute to the potential misclassification of the ecological status of water bodies, helping to improve the sampling design used in monitoring. Here we used a Posidonia oceanica multivariate index (POMI) bio-monitoring dataset covering a total of 81 sites distributed throughout 28 water bodies from the coast of Catalonia, Balearic Islands and Croatia to determine the levels of uncertainty associated with each region and how they change according to the quality status of water bodies. Overall, variability among sites (meadows) within water bodies was the factor that generated the greatest risk of misclassification among the three regions, within which the Balearic Islands had the lowest uncertainty, followed by Croatia and Catalonia. When water bodies classified in good/high quality were separated from those in moderate/poor status classes, we found that the latter displayed higher levels of uncertainty than the former. [Copyright &y& Elsevier]

Abstract: Computational optimization strategies using algorithms (e.g., modified SIMPLEX method) present a fast, efficient alternative to univariant studies of chemical and physical experimental parameters of analytical flow systems. In this review, we give an overview of the applications of the SIMPLEX algorithm for optimizing analytical systems based on unsegmented flow techniques. We compare the different response functions used for evaluating the experimental data for optimization. We also discuss their advantages and shortcomings, and, with special focus on real-time applications, the problems involved in using SIMPLEX. We summarize in tabular form the analytical applications and the parameters optimized by the SIMPLEX method. [ABSTRACT FROM AUTHOR]

Abstract: A multi-residual method based on stir bar sorptive extraction coupled with thermal desorption-gas chromatography–mass spectrometry (SBSE-TD-GC–MS) has been developed to measure 49 organic pollutants (organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and nonylphenol) in seawater. Using 100ml of water, the method exhibited good linearity, with recoveries between 86% and 118% and relative standard deviation between 2% and 24% for almost all compounds. The method was applied to determine target contaminants in Catalonian seawater, including coastal areas, ports and desalination plant feed water. Overall individual compound levels oscillated between 0.16 and 597ngl−1; PAHs and nonylpenol were the compounds found at the highest concentrations. The method provided LODs between 0.011 and 2.5ngl−1, lower than the Environmental Quality Standards (EQS) fixed by Directive 2008/105/EC. In compliance with the directive, this method can be used as a tool to survey target compounds and is aimed at protecting coastal ecosystems from chemical pollution. [Copyright &y& Elsevier]

Abstract: The role of microorganisms in the transfer of carbon of marine systems is very important in open oligotrophic oceans. Here, we analyze the picoplankton structure, the heterotrophic bacterioplankton activity, and the predator–prey relationships between heterotrophic bacteria and nanoflagellates during two large scale cruises in the Central Atlantic Ocean (∼29°N to ∼40°S). Latitud cruises were performed in 1995 between March–April and October–November. During both cruises we crossed the regions of different trophic statuses; where we measured different biological variables both at the surface and at the deep chlorophyll maximum (DCM). The concentration of chlorophyll a varied between 0.1 and 0.8mgm−3, the abundance of heterotrophic bacteria varied between <1.0×105 and >1.0×106 cellsml−1, and that of heterotrophic nanoflagellates between <100 and >1.0×104 cellsml−1. The production of heterotrophic bacteria varied more than three orders of magnitude between <0.01 and 24μgCL−1 d−1; and the growth rates were in the range <0.01–2.1d−1. In the Latitud-II cruise, Prochlorococcus ranged between <103 and >3×105 cellsml−1, Synechococcus between <100 and >1.0×104 cellsml−1, and picoeukaryotes between <100 and >104 cellsml−1. Two empirical models were used to learn more about the relationship between heterotrophic bacteria and nanoflagellates. Most bacterial production was ingested when this production was low, the heterotrophic nanoflagellates could be controlled by preys during Latitud-I cruise at the DCM, and by predators in the surface and in the Latitud-II cruise. Our results were placed in context with others about the structure and function of auto- and heterotrophic picoplankton and heterotrophic nanoplankton in the Central Atlantic Ocean. [Copyright &y& Elsevier]

Abstract: How do inherent variations and uncertainties in empirical data constrain approaches to predictions and possibilities to identify critical thresholds and points of no return? This work addresses this question in discussing and reviewing key concepts and methods for coastal ecology and management. The main focus is not on the mechanisms regulating the concentration of a given variable but on patterns in variations in concentrations for many standard variables in entire lagoons, bays, estuaries or Fjords (i.e., on variations at the ecosystem scale). We address and review problems related to [(1)] The balance between the changes in predictive power and the accumulated uncertainty as models grow in size and include an increasing number of x-variables. [(2)] An approach to reduce uncertainties in empirical data. [(3)] Methods to maximize the predictive power of regression models by transformations of model variables and by creating time and area compatible model variables. [(4)] Patterns in variations within and among coastal systems of standard water variables. [(5)] Based on the results of the review, we also discuss the concept “Optimal Model Scale” (OMS) and an algorithm to calculate OMS, which accounts for key factors related to the predictive power at different time scales (daily to yearly prediction) and to uncertainties in predictions in relation to access to empirical data and the work (sampling effort) needed to achieve predictive power at different time scales. [Copyright &y& Elsevier]

This paper provides a synthesis of the EU project MedVeg addressing the fate of nutrients released from fish farming in the Mediterranean with particular focus on the endemic seagrass Posidonia oceanica habitat. The objectives were to identify the main drivers of seagrass decline linked to fish farming and to provide sensitive indicators of environmental change, which can be used for monitoring purposes. The sedimentation of waste particles in the farm vicinities emerges as the main driver of benthic deterioration, such as accumulation of organic matter, sediment anoxia as well as seagrass decline. The effects of fish farming on P. oceanica meadows are diverse and complex and detected through various metrics and indicators. A safety distance of 400 m is suggested for management of P. oceanica near fish farms followed by establishment of permanent seagrass plots revisited annually for monitoring the health of the meadows. [Copyright &y& Elsevier]

Abstract: Ecosystem transformation and depletion of natural resources by human activity with associated increase in species extinctions renders research to understand the consequences of these transformations and design strategies to conserve biological diversity a fundamental priority. Since the introduction of the term biodiversity, accumulated research in this field has expanded exponentially. An analysis of existing literature was conducted to examine patterns in the resulting research effort. The analysis, conducted using the Web of Science (WoS), identified 13336 published articles between 1987 and 2005 concerning biodiversity research. Research efforts are increasing, with 72% of the research effort addressing terrestrial ecosystems. Most of the research is experimental in nature, with few models developed, and focuses on species. Despite constant technical improvements, research on genetic diversity still represents a minor component. Research on different systems is disseminated through different publication outlets, fragmenting the community and derived knowledge. Reported results, here measured as strength of the correlation between biodiversity and ecosystem function, do not differ across ecosystems but are stronger when the study focused on functional groups instead of species level. Collaborative efforts remain limited, as the average number of authors per paper is not increasing with time, unlike patterns in other disciplines. The international distribution of research efforts is highly skewed, with the USA and the EU conducting nearly 90% of the research. [Copyright &y& Elsevier]

Sedimentation and sediment metabolism was measured at eight active milkfish fish pens and at one abandoned site in the Bolinao area, Philippines in order to examine the interactions between sediment and water in this shallow coastal zone. The rates of sedimentation were high in the area due to siltation, but the activities in the fish pens also contributed to enhanced sedimentation as indicated by the difference between the abandoned and active sites. The sediment metabolism appeared to decrease with increasing rates of sedimentation indicating that the microbial activity reached a saturation level in the fish pen sediments. Anaerobic processes dominated the organic matter decomposition, and sulfate reduction rates are among the highest measured in fish farm sediments. The rates decreased with increasing organic loading despite high concentrations of sulfate (>10 mM) at all sites. Presence of methane bubbles in the sediments suggests that sulfate reduction and methanogenesis were coexisting. The sediment metabolism was significantly reduced at the abandoned site indicating that the stimulation of microbial activities is due to active fish production. The anaerobic activity remained high at the abandoned site indicating that the sediment biogeochemical conditions remain affected long time after fish production has ceased. [Copyright &y& Elsevier]

Marine fish farming is increasing rapidly in the Mediterranean and in contrast to the Atlantic the coastal zone in the Mediterranean is characterized by clear waters with high transparency. This allows benthic primary producers such as the slow-growing seagrass Posidonia oceanica to grow at large depths at locations suitable for fish farming and generating a conflict between the conservation of these meadows and the growth of aquaculture operations in the Mediterranean. In this paper we review the current knowledge on environmental interactions between fish farming and benthic primary producers with particular focus on P. oceanica, as this seagrass is a key component along Mediterranean coasts. The recovery times of P. oceanica are very long, in the order of centuries, and losses of this species are thus considered to be irreversible at managerial time scales. [Copyright &y& Elsevier]

The scaling between shoot mass and spacer length was examined across 23 seagrass species by compiling field and literature data on architectural and stand features. The distance between shoots programmed in seagrass architecture was scaled at the 0.24 power of shoot mass. The predicted distance between neighboring shoots resulting from the scaling relationship investigated was compared with the spacing observed in 79 crowded natural seagrass stands. Seagrass architecture predicted 50% of the variability of the distance between neighbors observed in natural stands. Moreover, the growth programme of seagrass species predicted 29% of the variance of maximum aboveground biomass developed by seagrass meadows. The close agreement between the shoot density and biomass developed by closed natural stands and that predicted from seagrass architecture suggested that the upper limit to density and aboveground biomass, such as that defined by the self-thinning law, is already imprinted within the basic architecture of seagrasses (i.e. spacer length in between consecutive shoots). [Copyright &y& Elsevier]

Sediment oxygen consumption, TCO2 production and nutrient fluxes across the sediment–water interface were measured in sediments within and along a transect from four fish pens with production of milkfish (Chanos chanos) in the Bolinao area, The Philippines. The four fish pens were each representing a specific period in the production cycling. There was a positive linear relationship between the rates of sedimentation inside the fish pens and the sediment oxygen consumption indicating that the benthic processes were controlled by the input of organic matter from fish production. The nutrient fluxes were generally higher inside the fish pens, and nitrate was taken up (1.7–5.8 mmol m−2 d−1) whereas ammonium (1–22 mmol m−2 d−1) and phosphate (0.2–4.7 mmol m−2 d−1) were released from the sediments. The sediments were enriched in organic matter with up to a factor 4 compared to outside. A mass balance for one crop of milkfish was constructed based on production data and on measured fluxes of nutrients in the fish pens to assess the loss of carbon and nutrients to the environment. There was a loss to the surroundings of carbon and nitrogen of 51–68% of the total input, whereas phosphorus was buried in the sediments inside the fish pens which acted as net sinks of phosphorus. The results obtained suggest that fish pen culture as practiced in the Bolinao area, leads to even greater impacts on benthic carbon and nutrient cycling than those found in suspended cage cultures. [Copyright &y& Elsevier]

The biomass, shoot density, community production, and rhizome growth of Zostera marina stands were studied in the Hopavagen lagoon, Norway (63°35′65″N, 9°32′80″E), the northern-most location where seagrass growth and production has been studied. The nordic Z. marina patches were dense (>2700 shoot m−2), with relatively small shoots (33–54 mg DW), so that the aboveground biomass developed was relatively low (about 140 g DW m−2). The stands were moderately productive, at about 2 g O2 m−2 per day, similar to the average community respiration rate. The sequence of internodal lengths in the rhizome fragments harvested showed a clear annual cycle, indicating that the populations are perennial (rhizomes >2-year-old) producing about 25 leaves per shoot and 30 cm of rhizome annually. The leaf plastochrone interval, of about 15 days, was close to that reported for stands situated as much as 25°S. [Copyright &y& Elsevier]

Presents a study which examined the link between planktonic processes and biogeochemical fluxes in the eastern tropical North Atlantic Ocean. Coverage of the Latitude II cruise conducted between October 21 and November 16, 1995; Primary production and community respiration rates measured; Water mass distribution; Plankton community structure; Potential external sources of nitrogen in the area.

Ecosystem services provided by coral reefs may be susceptible to the combined effects of benthic species shifts and anthropogenic nutrient pollution, but related field studies are scarce. We thus investigated in situ how dissolved inorganic nutrient enrichment, maintained for two months, affected community-wide biogeochemical functions of intact coral- and degraded algae-dominated reef patches in the central Red Sea. Results from benthic chamber incubations revealed 87% increased gross productivity and a shift from net calcification to dissolution in algae-dominated communities after nutrient enrichment, but the same processes were unaffected by nutrients in neighboring coral communities. Both community types changed from net dissolved organic nitrogen sinks to sources, but the increase in net release was 56% higher in algae-dominated communities. Nutrient pollution may, thus, amplify the effects of community shifts on key ecosystem services of coral reefs, possibly leading to a loss of structurally complex habitats with carbonate dissolution and altered nutrient recycling. [Display omitted] • Nutrient enrichment affects coral- and algae-dominated reef communities differently. • Increased productivity in algae- but not in coral-dominated communities • Shift from net calcification to framework dissolution only in algal communities • Greater increase from sink to dissolved organic nitrogen source in algal communities • Nutrient pollution amplifies effects of community shifts on reef ecosystem services. [ABSTRACT FROM AUTHOR]

Beach litter assessments rely on time inefficient and high human cost protocols, mining the attainment of global beach litter estimates. Here we show the application of an emerging technique, the use of drones for acquisition of high-resolution beach images coupled with machine learning for their automatic processing, aimed at achieving the first national-scale beach litter survey completed by only one operator. The aerial survey had a time efficiency of 570 ± 40 m2 min−1 and the machine learning reached a mean (±SE) detection sensitivity of 59 ± 3% with high resolution images. The resulting mean (±SE) litter density on Saudi Arabian shores of the Red Sea is of 0.12 ± 0.02 litter items m−2, distributed independently of the population density in the area around the sampling station. Instead, accumulation of litter depended on the exposure of the beach to the prevailing wind and litter composition differed between islands and the main shore, where recreational activities are the major source of anthropogenic debris. [Display omitted] • We surveyed 26 ha of shore in just 8 h. • 60% of litter on high-resolution images was identified by deep learning. • It is the first time that litter objects are automatically classified in types. • We show that litter distribution is determined by exposure to the prevailing wind. • Recreational activities are the major contributors of beach litter on the mainland. A national-scale monitoring of beach litter along the Red Sea coast of Saudi Arabia, conducted by a single drone operator, shows that litter distributes according to wind exposure. [ABSTRACT FROM AUTHOR]

Marine/maritime spatial planning (MSP) is a process to optimise marine space allocation to various activities and the environment by avoiding negative interactions, improving synergies, thereby helping the advance towards a sustainable ocean economy. A bibliometric progress assessment of MSP was performed for the period 2003–2019 to analyse 1323 papers published in the ISI Web of Science and Scopus databases. The analysis revealed that MSP is a relatively new, however rapidly growing research field, as the number of MSP publications increased exponentially, at about 44% per year, between 2003 and 2019. The dominance of the journal "Marine Policy" on MSP publications and the presence of leading authors with government-related positions (i.e. 11%, n = 981) indicate the linkage of MSP to policy and governance. Almost 70% of the MSP publications are case-based indicating MSP's practical orientation. More than half of the authors leading MSP publications are affiliated in Europe, while the majority of reported MSP case studies are undertaken within the European Union. Most, 63%, of all MSP studies (n = 1323) approach the matter in a qualitative manner, whereas only 22% of the quantitative and/or modelling studies (n = 489) are describing MSP applications, suggesting that the development of MSP quantitative and/or modelling methodologies is still at its infancy. The dominance of ecologists among the leading authors of MSP publications outlines the ecosystem-based approach used to address MSP. This bibliometric study draws the landscape of the current state and trends of MSP, outlines gaps and indicates the roadmap for further developments to assist MSP processes. • Marine spatial planning (MSP) publications increased exponentially, at about 44% per year, between 2003 and 2019. • More than 50% of the studies used qualitative methods to conduct MSP. • European Union mandated MSP in 2014 and is currently the global leader in its applications. • Most MSP studies are led by ecologists, outlining their ecosystem-based nature. • MSP is applied in practice with almost 70% of the relevant studies being case-based. [ABSTRACT FROM AUTHOR]

Microfibers are reported as the most abundant microparticle type in the environment. Their small size and light weight allow easy and fast distribution, but also make it challenging to determine their chemical composition. Vibrational microspectroscopy methods as infrared and spontaneous Raman microscopy have been widely used for the identification of environmental microparticles. However, only few studies report on the identification of microfibers, mainly due to difficulties caused by their small diameter. Here we present the use of Stimulated Raman Scattering (SRS) microscopy for fast and reliable classification of microfibers from environmental samples. SRS microscopy features high sensitivity and has the potential to be faster than other vibrational microspectroscopy methods. As a proof of principle, we analyzed fibers extracted from the fish gastrointestinal (GIT) tract, deep-sea and coastal sediments, surface seawater and drinking water. Challenges were faced while measuring fibers from the fish GIT, due to the acidic degradation they undergo. However, the main vibrational peaks were still recognizable and sufficient to determine the natural or synthetic origin of the fibers. Notably, our results are in accordance to other recent studies showing that the majority of the analyzed environmental fibers has a natural origin. Our findings suggest that advanced spectroscopic methods must be used for estimation of the plastic fibers concentration in the environment. Image 1 • Ubiquitous environmental microfibers are challenging to classify due to their small size. • Stimulated Raman Scattering Microscopy reliably classifies environmental microfibers. • Spectroscopic methods are essential for classification of environmental microfibers. • Majority of the analyzed environmental microfibers are attributed to natural origin. Capsule: We present Stimulated Raman Microscopy as a new method to reliably classify environmental microfibers. The majority of analyzed microfibers were of natural origin. [ABSTRACT FROM AUTHOR]

A recent report by O’Connor et al. demonstrates that planktonic larval duration time declines with temperature, as predicted from metabolic theory. This observation enabled the authors to develop a unified model predicting the effects of temperature on planktonic larval duration and, therefore, dispersal potential in the marine environment. These results show metabolic theory to be a unifying ecological principle that bridges the marine and terrestrial divide, helping to address fundamental problems in marine biodiversity and conservation, as well as to understand the response of marine organisms to climate change. [Copyright &y& Elsevier]

Blue Carbon (BC) strategy refers to the approaches that mitigate and adapt to climate change through the conservation and restoration of seagrass, saltmarsh and mangrove ecosystems and, in some BC programs, also through the expansion of seaweed aquaculture. The major losses of coastal habitats in combination with the commitments of China under the Paris Agreement provide unique opportunity and necessity to develop a strong Chinese BC program. Here, we (1) characterize China's BC habitats, examine their changes since 1950 along with the drivers of changes; (2) consider the expansion of seaweed aquaculture and how this may be managed to become an emerging BC resource in China, along with the engineering solutions required to enhance its potential; and (3) provide the rationale and elements for BC program in China. We find China currently has 1326–2149 km2 wild and 2–15 km2 created mangrove, saltmarsh and seagrass habitats, while 9236–10059 km2 (77–87%) has been lost since 1950, mainly due to land reclamation. The current area of farmed seaweed habitat is 1252–1265 km2, which is close to the area of wild mangrove, saltmarsh and seagrass habitats. We conclude that BC strategies have potentials yet to be fully developed in China, particularly through climate change adaptation benefits such as coastal protection and eco-environmental co-benefits of seaweed farming such as habitat creation for fish and other biota, alleviation of eutrophication, hypoxia and acidification, and the generation of direct and value added products with lower environmental impact relative to land-based production. On this basis, we provide a roadmap for BC strategies adjusted to the unique characteristics and capacities of China. Blue Carbon (BC) plays important roles in climate change mitigation/adaptation. In this paper, we 1) characterize China's BC habitats and examine their changes since 1950 along with the drivers of changes; 2) consider the expansion of seaweed aquaculture and how this may be managed to become an emerging BC resource in China, along with the engineering solutions required to enhance its potential; 3) provide the rationale and elements for BC program in China; and 4) draw a roadmap for BC strategies adjusted to the unique characteristics and capacities of China.Porphyra farm in Dongtou, Wenzhou city, Zhejiang province, China. Image 1 • China's Blue Carbon (BC) habitats, changes and the drivers of changes since 1950. • Potential BC resources, seaweed aquaculture expansion with engineering solutions. • BC Benefits for climate adaptation and co-benefits for environment and economy. • Great potential of China's BC strategies through climate change adaptation benefits. • A roadmap for BC strategies adjusted to the China's characteristics and capacities. [ABSTRACT FROM AUTHOR]

Microplastic particles (MPs) in the gastrointestinal tracts of nine fish species of commercial importance from different habitats (coastal, pelagic, and reef-associated) in the Saudi EEZ of the Arabian Gulf were quantified and classified. A total of eight MPs were retrieved from a total of 140 individual fish examined, with an average of 0.057 ± 0.019 microplastic items per fish (excluding possible plastic fibers). On average, 5.71%, of the fish dissected contained MPs, ranging from 5 to 15% of individual fish examined containing MPs among species (Siganus canaliculatus and Rastrelliger kanagurta , respectively). Ingested plastic consisted primarily of fishing threads (1.04 ± 0.06 mm), followed by fragments (1.16 ± 0.11 mm). It is likely that the fibers, originated from the fisheries, recreational boating, laundry, domestic wastewater, and other human activities, which is also widespread and abundant (found in 58.58% of the fish studied). Polyethylene (PE) and polypropylene (PP) were identified as the most abundant polymers ingested by the fishes. There was no significant difference (p < 0.05) between the presence of microplastic in fish depending on their habitat. The prevalence of MPs is relatively low compared to those in other regions, despite the massive industrialization of the Saudi Arabian Gulf. Unlabelled Image • This study assessed the presence of microplastics in nine Arabian Gulf commercial species from 3 different habitat types. • Microplastics were found in 5.75% of the individuals across the nine fish species assessed. • Fishing threads and fragments were identified as polyethylene and Polypropylene by FTIR analysis. • The prevalence of MPs in the Arabian Gulf species is below levels reported elsewhere but remains a cause of concern. [ABSTRACT FROM AUTHOR]

Only 1% of plastic entering the ocean is found floating on its surface, with high loads in ocean accumulation zones and semi-enclosed seas, except for the Red Sea, which supports one of the lowest floating plastic loads worldwide. Given the extension of reefs in the Red Sea, we hypothesize a major role of scleractinian corals as sinks, through suspension-feeding, and assessed microplastic removal rates by three Red Sea coral species. Experimental evidence showed removal rates ranging from 0.25 × 10−3 to 14.8 × 10−3 microplastic particles polyp−1 hour−1, among species. However, this was only 2.2 ± 0.6% of the total removal rate, with passive removal through adhesion to the coral surface being 40 times higher than active removal through suspension-feeding. These results point at adhesion of plastic to coral reef structures as a major sink for microplastics suspended in the water column after sinking, helping explain low concentrations in Red Sea surface waters. Image 1 • We exposed 3 species of corals to microplastics with and without natural prey. • We assessed active (ingestion) and passive (surface adhesion) removal of plastic. • Adhesion is 40 times more efficient than ingestion as removal process. • Mucus production is a defense mechanism that inhibits plastic adhesion. • Natural feeding is not impaired by microplastic exposure. Corals remove microplastics from the water mainly through a passive mechanism of surface adhesion, which is a removal process 40 times more efficient than retention after ingestion. [ABSTRACT FROM AUTHOR]