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From January to December 2022, a study on biofouling was conducted in the southeast wharf of Leizhou Bay. Over a year, a total of 44 species were recorded, belonging to 10 phyla. The dominant species in the community were coastal warm-water organisms typical of subtropical inner bay environments. The peak settlement period occurred between April and September, with the highest adhesion strength observed in summer. Among the dominant and representative species, Perna viridis stood out, followed by Podocerus brasiliensis, Crassostrea ariakensis, Musculus senhousei, Dreissena polymorphia, Caprella equilibra, Gammaropsis digitata, Stenothoe gallensis, Parhyale hawaiensis, Amphibalanus reticulatus, EnteromorpHa prolifera, Gracilaria bailinae, and Pennaria disticha. Due to competition for settlement space and food, individuals in the biofouling community exhibited mutual dependence or restraint and displayed a specific spatiotemporal distribution pattern adapted to environmental factors. Temperature was the most crucial environmental factor determining the geographic distribution of biofouling species, reflecting the differences in community composition across various climate zones. The number of species, settlement stage, and settlement rate of biofouling organisms were closely tied to water temperature. Additionally, local natural conditions such as salinity, dissolved oxygen, and light, as well as human activities such as aquaculture production, played significant roles in the settlement of biofouling organisms. [ABSTRACT FROM AUTHOR]

Benthic macro- and micro-biota often play significant roles in controlling the biogeochemical dynamics in sediments. Their activity can be influenced by oxygen availability and impacted by the rise in global hypoxia in coastal regions over the last decades. To understand how these organisms interact with coastal hypoxia and influence sediment biogeochemistry, we undertook a study of early diagenesis in Bedford Basin, a seasonally hypoxic fjord on the West Atlantic coast in Nova Scotia, Canada, using a combination of observations and reaction-transport modeling. We observed that the seafloor was a source of ammonium and sink of nitrate with average fluxes of 2.2 ± 1.8 and −0.9 ± 0.7 mmol m−2 d−1 respectively. The diffusive oxygen uptake was 14 ± 4.6 mmol m−2 d−1 and the total organic carbon content in collected sediment cores was 5–7 % with a C/N ratio of ∼10. The pyrite content increased steadily from 0.5 wt% Fe at surface to ∼2 wt% Fe at 20 cm depth. Hydrogen sulfide was negligible down to 25 cm depth most of the time. The sediment was inhabited by tube-forming polychaete Spiochaetopterus sp. that formed tubes up to ∼30 cm in length. The living foraminiferal assemblage in the top 5 cm sediment was found to be dominated (>85 %) by nitrate-storing and denitrifying benthic foraminifera Stainforthia fusiformis. These observations were used to develop and constrain a biogeochemical reaction-transport model. The model results suggest that the observed decrease in porewater concentrations of ammonium and dissolved inorganic carbon below 5 cm depth, was due to deep bioirrigation by tubeworms, accounting for almost 50 % of the benthic efflux. The model further revealed that the deep bioirrigation along with bioturbation and iron cycling prevented accumulation of free sulfide in the top 25 cm sediment despite oxygen penetration depths of ∼1 mm. Modelled organic carbon and nitrogen deposition was 25.2 and 2.9 mmol m−2 d−1 with burial efficiencies of 23 % and 17 %, respectively. The model indicated a total denitrification rate of 1.3 mmol N m−2 d−1 that was largely (∼70 %) driven by benthic foraminifera. This study reports the first evidence of foraminiferal denitrification in western Atlantic coastal sediments, and suggests that eukaryote mediated denitrification is an important driver of sediment N-loss in seasonally hypoxic environments, a process that has been traditionally assumed to be carried out by prokaryotic microbes. [ABSTRACT FROM AUTHOR]

The global demand for coastal urbanization is rising with the increasing population. Alas, living close to the ocean threatens human endeavors with high currents, waves, and increasing storm frequency. Accordingly, the need for more coastal defense structures (CDSs) rises. Structures built from complex units meant to prevent and/or mitigate coastal erosion and floods, additionally providing wave protection or wave attenuation, are constructed on and near natural habitats where they alter local ecosystems. Traditional CDSs mostly fail to harbor diverse and abundant communities. However, this can be changed by eco-friendly methodologies and designs that are being tested and implemented to improve CDSs' ecological value. Some of these can be implemented during the construction period, while others can fit on existing structures, such as wave breakers and seawalls. Effective methods include augmenting surface rugosity through strategic perforations, integrating artificial panels for increased complexity, implementing soft (naturally based) engineering solutions such as geotextiles, replacing industrial concrete mixtures for CDS construction with "green concrete" and ecologically friendly mixtures, and using alternative, eco-friendly units in CDS erections. In this mini review, we suggest that by integrating sustainable practices into coastal development, we can significantly mitigate the ecological damage caused by traditional CDSs and promote more harmonious relationships between human construction and the marine environment. This shift towards environmentally conscious coastal defenses is essential and a responsibility for ensuring the long-term sustainability of our coastal communities and the health of our oceans. We present current methodologies used on breakwaters worldwide. [ABSTRACT FROM AUTHOR]

Organisms in coastal brackish ecosystems face not only highly variable environmental conditions, but the intensity and stochasticity of these environmental conditions are anticipated to increase due to climate change. While environmental changes are often presented unilaterally as stressors, there are some anthropogenic environmental transformations, such as the introduction of habitat forming plant species, that may mitigate physiological stress imposed by warming. In Suisun Marsh in the California Delta, native plant canopies allow light and heat to penetrate to the understory yet the canopies of the introduced Phragmites australis reed block out sunlight and heat for organisms living below. We set out to understand the physiological performance of mud‐dwelling invertebrates in this context: can invasion stress mitigate climate stress? We raised field collected Gammarus amphipods in the laboratory under simulated ‘native canopy’ and ‘Phragmites canopy’ temperature/light conditions based on data from our field environmental loggers. We assessed survival, body mass, fecundity, glycogen and protein content every 2 weeks from our lab population of amphipods. We found that amphipods raised under the Phragmites conditions had better survival, greater stores of protein, and similar body mass and stores of glycogen, which could positively impact available food resource quality for juvenile fishes. We support this with field data showing higher use of Phragmites canopies by amphipods, especially in the water column, across the year of sampling. Synthesis and applications: Understanding the potential benefits of Phragmites as climate stress refugia can inform management decisions around its mitigation in future restoration. [ABSTRACT FROM AUTHOR]

The burgeoning industrialization and urbanization along the Indian coastline have led to an increased prevalence of port infrastructure and effluent discharge, raising concerns about their potential impact on the delicate macrobenthic communities in coastal ecosystems. This comprehensive review aims to evaluate and synthesize existing literature on the ecological repercussions of port activities and effluent discharge on macrobenthic organisms in Indian coastal regions. The study encompasses a thorough analysis of relevant research articles, government reports, and scientific databases, focusing on diverse ecosystems such as estuaries, mangroves, and open coastlines. The review discusses the various stressors associated with port operations, including dredging, habitat alteration, and chemical contamination from effluent discharge. Furthermore, it explores the response mechanisms of macrobenthic communities, encompassing changes in species composition, abundance, and diversity. Special attention is given to the potential long‐term impacts on ecosystem functioning and services. The synthesis of available data enables the identification of knowledge gaps and the formulation of recommendations for future research and management strategies. Understanding the cumulative effects of port activities on macrobenthic communities is crucial for developing sustainable practices and policies to mitigate adverse impacts while fostering the resilience of coastal ecosystems in the face of anthropogenic pressures. This review contributes to the growing body of knowledge on the ecological consequences of human activities in Indian coastal areas, providing valuable insights for researchers, policymakers, and environmental managers alike. [ABSTRACT FROM AUTHOR]

An extensive study on 210Po was conducted at Castillos Lagoon, a shallow brackish lagoon on the east coast of Uruguay, aiming to determine the activity concentrations of 210Po in various compartments and to derive the activity fluxes among them. The activity concentration of 210Po was determined in water, sediments, six different species of fishes, crabs, shrimps, phytoplankton, and zooplankton. 210Po was determined using alpha spectrometry, performing radiochemical separation and self-deposition on silver disc. The activity concentrations of 210Po obtained in the water samples ranged from 0.5 ± 0.1 to 30.5 ± 0.7 mBq/L, while in the sediment samples varied between 24 ± 1 and 129 ± 5 Bq/kg. In the case of biota, the ranges obtained were 15 ± 1 to 33 ± 2 Bq/kg in phytoplankton, 33 ± 2 to 200 ± 6 Bq/kg in mixed zooplankton, 125 ± 4 to 183 ± 6 Bq/kg in the soft tissue of razor clam (Tagelus aff. plebeius), 94 ± 2 Bq/kg in the soft tissue of blue crab (Callinectes sapidus), 10 ± 1 to 28 ± 2 Bq/kg in shrimp muscle, and 232 ± 6 to 422 ± 10 Bq/kg in shrimp hepatopancreas (Penaeus paulensis). In the case of fish, the ranges were 1.8 ± 0.2 to 497 ± 10 Bq/kg in muscle tissue and 47 ± 2 to 1750 ± 32 Bq/kg in stomach and intestine tissue. The transfer coefficient (CR) values vary between 101 and 105 depending on the aquatic organism and the tissue considered. The results obtained in this work are consistent with the theory that 210Po is primarily absorbed from water and concentrated by phytoplankton and zooplankton, then transferred to the next trophic levels along food chains. This theory has also been observed by F.P. Carvalho (2018a) and IAEA (2017). These data contribute to increase the limited CR 210Po datasets in fresh and brackish waters and in the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

Oceans are repositories of radionuclides. Radionuclides are transferred through the food chain and cause ionizing radiation hazards for marine organisms. In this study, the transfer characteristics of 226Ra, 40K, 14C, 3H, 137Cs and 90Sr in organisms at different trophic levels in the eastern coast of Yantai city were investigated. The risk of ionizing radiation to organisms was assessed using the ERICA Tool 2.0. The results show no significant changes in the concentration of any of the nuclides in the coastal area compared to the preoperation period of the nuclear power plant. The transfer factor of 137Cs, 40K, 226Ra, 14C, 90Sr and 3H at the different trophic levels of marine organisms were 2.09, 1.29, 1.17, 1.15, 1.06 and 0.74, respectively. The dose rates of ionizing radiation to organisms from six radionuclides ranged from 32.02 nGy·h-1 to 195.49 nGy·h-1 and had a mean value of 102.86 ± 57.30 nGy·h-1. The main artificial radionuclides (14C, 3H, 90Sr, 137Cs) released by nuclear power plants in the study area produced negligible radiation doses to marine organisms. However, other artificial radionuclides present in the effluents of nuclear power plants (99Tc, 110mAg and 131I) as well as other natural radionuclides (includes 210Po, 210Pb, etc) were not included, and further evaluation of these is recommended. [ABSTRACT FROM AUTHOR]

Recent rapid changes in climate and environmental conditions have significantly impacted coastal ecosystem functioning. However, the complex interplay between global and local effects makes it challenging to pinpoint the primary drivers. In a multi‐ecosystem study, we analyzed pluri‐decadal trends of bivalve‐δ13C as recorder of global environmental changes. These trends were correlated with large‐scale natural and anthropogenic climate proxies to identify whether coastal biota responded to global effects. Our findings revealed decreasing bivalve‐δ13C trends in all sea regions, mainly linked with increased temperature and atmospheric‐CO2 concentrations, the later generating a decrease in atmospheric‐CO2 δ13C values (Suess effect) because of fossil‐fuel burning. After removing the Suess effect from bivalve‐δ13C trends, ongoing global climate variability continues to affect most ecosystems, possibly intensified by combined, interacting regional or local effects. These results highlight the need to consider large‐scale effects to fully understand ecosystem and food web responses to the multiple effects of global change. [ABSTRACT FROM AUTHOR]

Seagrass provides habitat and resources for various organisms in coastal areas. However, the productivity of a seagrass meadow might vary by its size, which can influence the contribution of primary sources to fauna and the food web structure. This study uses stable isotopes to investigate the contribution of sources to faunas and the associated food web structure in two tropical seagrass meadows. The carbon (δ13C) and nitrogen (δ15N) stable isotopes of primary sources such as mangrove leaf, coastal and riverine particulate organic matter, seagrass material and associated fauna (fish, bivalves, gastropods, crab, shrimp) were investigated from samples collected seagrass meadows of different sizes, at Libong Island and Tharai Island in Thailand. The contribution of the primary sources to the fauna diet showed that seagrass material was the main food source for fauna in both sites. Moreover, the trophic niche did not overlap among the groups of each fauna guild, reflecting the support seagrass provides to resident fauna. The study emphasizes the important role of seagrass as a habitat and feeding ground in tropical coastal ecosystems. [ABSTRACT FROM AUTHOR]

Seabirds are important vectors for nutrient transfer across ecosystem boundaries. In this seasonal study, we evaluate the impact of an Arctic colony (Alkhornet, Svalbard) of Black-legged Kittiwakes (Rissa tridactyla) and Brünnich's Guillemots (Uria lomvia) on stream nutrient concentrations and fluxes, as well as utilization by coastal biota. Water samples from seabird-impacted and control streams were collected regularly throughout the melt season (June–September) for nutrient and organic carbon analysis. Stable carbon and nitrogen isotope analysis (δ13C and δ15N) was used to assess whether seabird-derived nitrogen (N) could be traced into filamentous stream algae and marine algae as well as consumers (amphipods). Concentrations of nitrate (NO3−) and nitrite (NO2−) peaked in July at 9200 µg N L−1 in seabird-impacted streams, 70 times higher than for control streams. Mean concentrations of phosphate (PO43−) in seabird-impacted streams were 21.9 µg P L−1, tenfold higher than in controls. Areal fluxes from seabird-impacted study catchments of NO3− + NO2− and PO43− had estimated ranges of 400–2100 kg N km−2 and 15–70 kg P km−2, respectively. Higher δ15N was found in all biota collected from seabird-impacted sites, indicating utilization of seabird-derived nitrogen. Acrosiphonia sp. from seabird-impacted sites had higher δ15N values (20–23‰ vs. 3–6‰) and lower C:N ratios (10.9 vs. 14.3) than specimens collected from control sites, indicating reliance on seabird-derived nitrogen sources and potentially higher N-availability at seabird-impacted nearshore sites. Our study demonstrates how marine nutrients brought onshore by seabirds also can return to the ocean and be utilized by nearshore primary producers and consumers. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles (TiO2 NPs) are among the most universally engineered nanomaterials and widely used nanomaterials in the world. In order to predict the environmental impact and interaction between these NPs and coastal organisms, the amphipod Talitrus saltator was exposed to TiO2 NPs C1 = 151.5 µg.L−1 and TiO2 NPs C2 = 303 µg.L−1. Catalase activity increased significantly and reaches a maximum of about 0.8 ± 0.02 µMol/min/mg proteins after exposure to TiO2 NPs C2 showing possible oxidative mechanisms. In addition, acetylcholinesterase activity reduced significantly (p < 0.05) after exposure to the highest TiO2 NPs concentration, indicating neurotransmission disturbance treated with 303 µg.L−1 of TiO2 NPs. Locomotor behaviour for untreated and treated specimens with TiO2 NPs was studied under constant darkness (DD). Results revealed the existence of ultradian and circadian components. In addition, locomotor activity patterns were generally bimodal for untreated specimens and became multimodal for treated ones. We noted also a slippage of the activity peak from the middle of the subjective night for the control until the subjective day after TiO2 NPs exposure. Furthermore, the most important stability was observed for control individuals who were more active than treated ones. Overall, this laboratory study provides preliminary toxicity data for Talitrus saltator exposed to TiO2 NPs. [ABSTRACT FROM AUTHOR]

Biological data collection often overlooks short-term environmental variations, potentially leading to under- or over-estimation of species abundance and ineffective conservation actions. This study investigated the complex relationship between oceanic and meteorological processes and the short-term abundance patterns of two economically important fish species in Bahía Santa Elena, a tropical bay on the north Pacific coast of Costa Rica. Using two months of continuous acoustic telemetry data from 14 Colorado (Lutjanus colorado) and 16 Pacific dog (Lutjanus novemfasciatus) snappers, we investigated temporal and spatial changes in their relative abundance patterns. A wavelet analysis revealed dominant diurnal and semidiurnal frequencies in both species. The observed semi-diurnal and diurnal periodicity in fish abundance was correlated with water level and sunlight, particularly near the mangrove in the inner bay, suggesting that both species may be using these habitats for food and shelter during periods of high tide and at night. Understanding how oceanic and meteorological conditions influence the dynamics of marine organisms in coastal environments, particularly those that are often exploited by fisheries is crucial for developing effective management and conservation approaches. [ABSTRACT FROM AUTHOR]

Recent scientific investigations have highlighted concerning levels of microplastic contamination in marine ecosystems, posing significant risks to marine organisms and human populations. This study aimed to assess the prevalence of microplastics in water, sediment, and tissues of commercially important fish species along the Malabar coast in Northwest Kerala, India. Using Fourier transform infrared spectroscopy (FTIR), six predominant polymer types were identified, including HDPE, PET, and nylon. The investigation revealed notable abundances of transparent microplastic particles, measuring <1 mm in diameter, particularly in gastrointestinal and gill tissues, with gastrointestinal tissues exhibiting the highest concentration of microplastics. A diverse array of morphotypes, including fragments (48.08%), fibers (28.84%), filaments (19.23%), and granules (3.85%), were observed within the coastal zone. The study implicates various sources of contamination, such as direct discharges, runoff, and inadequate wastewater management practices, contributing to the substantial presence of microplastics in coastal environments. In light of these findings, the study emphasizes the urgent need for the implementation of effective regulatory measures to mitigate plastic pollution in marine ecosystems. These results underscore the critical importance of proactive intervention to safeguard the health of marine ecosystems and human populations in coastal regions. [ABSTRACT FROM AUTHOR]

The dinoflagellate Karenia selliformis forms red tides in coastal waters and damages fishery industries in some countries, although its toxicity remains understudied. In recent years, blooms of K. selliformis have killed a vast amount of marine organisms on the Pacific coast of Hokkaido, Japan, representing the first reports of fishery damage by K. selliformis in this country. It is necessary to understand the lethal density of K. selliformis to marine organisms and environmental conditions that increase its toxicity to establish an alert level for K. selliformis red tides. In the present study, we aimed to identify the level of toxicity to fish of K. selliformis and its environmental modulators by conducting a toxicity assay with medaka fish (Oryzias latipes). First, medaka was exposed to the culture strain of K. selliformis isolated from coastal waters in Hokkaido and a culture strain of a noxious red-tide dinoflagellate Karenia mikimotoi. As a result, the toxicity of K. selliformis was extremely high compared to that of K. mikimotoi. Next, we examined growth and toxicity to O. latipes of K. selliformis cultured under several light intensities. The K. selliformis culture strain could grow at more than 20 µmol photons m-2 s-1, and its maximum growth rate reached 0.54 day-1 at 400 µmol photons m-2 s-1. The toxicities of K. selliformis grown under different light intensities positively correlated with its growth rates. Our results revealed that K. selliformis exerts strong toxicity under moderate light intensity, suggesting that its high toxicity to fish requires its active growth. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of malachite green on the post-exposure filtration rate of Blood Clam, Barbatia virescens. Blood Clams were collected from the rocky coast and acclimated to laboratory conditions for 18 days. Bioassays were conducted wherein Blood Clams were exposed for 24 h to a clean medium (no malachite green), 0.06 mg l-1 malachite green, 0.32 mg l-1 malachite green, 5.06 mg l-1 malachite green, and then to the same concentrations for 48 h. Filtration rate in all concentrations and malachite green-exposure durations were determined at 0.5, 1, 2, 3, 4, and 6 h. Blood Clams exposed for 24 h and 48 h to 0.32 and 5.06 mg l-1 had significantly lower filtration rates than the control (p<0.05). Similarly, those exposed to 0.06 mg l-1 for 48 h showed significant reduction in their filtration rates. The lower rate was associated with longer exposure to malachite green. In addition, Blood Clams exposed for 48 h were not able to improve their filtration rate, although they were transferred to a clean medium for 6 h. The green colouration on Blood Clams' muscles was also not eliminated. These findings suggest the ecological risk of malachite green to bivalves and its implications to the health of sessile coastal organisms. [ABSTRACT FROM AUTHOR]

The collection of photos during the systematic monitoring activities is useful to witness the ecological role of marine phanerogams as hosts for a rich variety of organisms in coastal and transitional waters. Cymodocea nodosa is present in the Taranto seas. In Mar Piccolo, it reached high coverage in a short amount of time, up to 100%, due to the improvement in environmental conditions. The most recent observations showed that it offers a welcoming habitat for several vertebrates and invertebrates, native and non-indigenous, as well as to micro- and macroalgae. The NPPR-funded activities will make these observations more robust and structural. [ABSTRACT FROM AUTHOR]

The Mangrove ecosystem is an ecosystem that is around the edge of the coast and many organisms live in this ecosystem, one of them is crabs. The crabs that are often found are deposit crabs from the Ocypodidae and Sesarmidae families that act as balancers in the mangrove ecosystem. This study aimed to analyze species, diversity, evenness, and dominance in the mangrove vegetation area of Koto XI Tarusan District, West Sumatera, Indonesia. The method used is the descriptive method. The biodiversity of brachyuran crabs' families, Ocypodidae and Sesarmidae, was analyzed with the Shannon-Wiener index (H'). Four indices were calculated for crabs Ocypodidae and Sesarmidae: species identification, Shannon-wiener (H') diversity, evenness, and dominance indices. The results showed that there were six species of deposited crabs from the Ocypodidae and Sesarmidae families, namely Uca bellator, U. rosea, Perisesarma eumolpe, P. plicatum, Sarmatium germaimi, and Sesarma curoense. The most abundant species (Di) came from the family Sesarmidae. However, for all stations, diversity (H') has a value that is in the medium category, and evenness (E) is in the high category at each station. The dominance (D) obtained a value categorized as low at each observation station. The condition of environmental parameters in the mangrove vegetation area is included in the category of a good environment. It is still within normal limits for the crabs of the Ocypodidae and Sesarmidae families to live. Two substrate types are found in each observation path: muddy and sandy mud. [ABSTRACT FROM AUTHOR]

Seagrasses, rooted aquatic plants growing completely underwater, are extremely important for the coastal ecosystem. They are an important component of the total carbon burial in the ocean, they provide food, shelter, and nursery to many aquatic organisms in coastal ecosystems, and they improve water quality. Due to human activity, seagrass coverage has been rapidly declining, and there is an urgent need to monitor seagrasses consistently. Seagrass coverage has been closely monitored in the Chesapeake Bay since 1970 using air photos and ground samples. These efforts are costly and time-consuming. Many studies have used remote sensing data to identify seagrass bed outlines, but few have mapped seagrass bed density. This study used Sentinel-2 satellite data and machine learning in Google Earth Engine and the Chesapeake Bay Program field data to map seagrass density. We used seagrass density data from the Chincoteague and Sinepuxent Bay to train machine learning algorithms and evaluate their accuracies. Out of the four machine learning models tested (Naive Bayes (NB), Classification and Regression Trees (CART), Support Vector Machine (SVM), and Random Forest (RF)), the RF model outperformed the other three models with overall accuracies of 0.874 and Kappa coefficients of 0.777. The SVM and CART models performed similarly and NB performed the poorest. We tested two different approaches to assess the models' accuracy. When we used all the available ground samples to train the models, whereby our analysis showed that model performance was associated with seagrass density class, and that higher seagrass density classes had better consumer accuracy, producer accuracy, and F1 scores. However, the association of model performance with seagrass density class disappeared when using the same training data size for each class. Very sparse and dense seagrass classes had replacedhigherbetter accuracies than the sparse and moderate seagrass density classes. This finding suggests that training data impacts machine learning model performance. The uneven training data size for different classes can result in biased assessment results. Selecting proper training data and machine learning models are equally important when using machine learning and remote sensing data to map seagrass density. In summary, this study demonstrates the potential to map seagrass density using satellite data. [ABSTRACT FROM AUTHOR]

Increasing habitat modification and species loss demand consistent efforts to describe and understand biodiversity patterns. The BIOTA/FAPESP Program was created in this context and it has been a successful initiative to promote studies on biodiversity and conservation in Brazil. The BIOTA/Araçá is an interdisciplinary project that provided a detailed evaluation of the biodiversity of Araçá Bay, a coastal seascape located on the North coast of the state of São Paulo, Southeast Brazil. The bay encompasses multiple habitats, such as beaches, mangroves, rocky shores, and a tidal flat, and provides important ecosystem services. Unfortunately, the bay is the subject of complex social-environmental conflicts that oppose economic, social, and environmental demands (i.e., the expansion of neighboring harbor activities vs. small-scale artisanal fisheries and protection of biodiversity). The present study presents a survey of the benthic species occurring in the different habitats of Araçá Bay, including data obtained during the BIOTA/Araçá project and previous assessments of the area. The benthic species play an important role in marine environments and studying the diversity of these organisms that live associated with the bottom is indispensable for comprehending the environment's functioning. The macrofauna, meiofauna, and microorganisms associated with soft and hard bottom were listed, and additional information, such as the habitat and geographical distribution, were provided for each species. The checklist includes 826 species, almost 70% recorded during the BIOTA/Araçá project. The most speciose taxa were the annelids (225 spp.), mollusks (194 spp.), and crustaceans (177 spp.). Seven benthic species are endemic to Araçá Bay, 14 are considered threatened, and seven are economically exploited. Furthermore, the bay is the type locality of many taxa, and 11 new benthic species were described based on specimens sampled during the project. This project shows the importance of Araçá Bay as a unique biologically rich environment and highlights the need for conservation efforts in light of the current threats. [ABSTRACT FROM AUTHOR]

Kelp species function as foundation organisms in coastal marine ecosystems, where they alter environmental conditions and promote local biodiversity by providing complex biogenic habitat for an array of associated organisms. The structure and functioning of kelp forest ecosystems in some regions, such as along the Peruvian coastline, remain critically understudied. We quantified the structure and diversity of faunal assemblages within both holdfast and understory reef habitats within Eisenia cokeri forests. We sampled both habitat types within four subtidal kelp forests on multiple occasions between 2016 and 2020, and quantified fauna at a fine taxonomic level (mostly species). We recorded a total of ~ 55,000 individuals representing 183 taxa across the study, with holdfast assemblages typically exhibiting higher richness, abundance and biomass values compared with understory reef-associated assemblages. Holdfast assemblages were structurally and functionally dissimilar to those on reef surfaces and were less variable and consistent across sites and sampling events. Even so, assemblages associated with both habitat types varied significantly between sites and sampling events, with variation in upwelling strength, ocean currents, and grazing pressure among potential drivers of this ecological variability. Overall, E. cokeri supports diverse and abundant holdfast assemblages and functions as a foundation organism in Peru. Given that no other habitat-forming kelp species persist at the low latitudes of E. cokeri in mid-to-north Peru, the lack of functional redundancy suggests that effective management and conservation of this species is vital for wider ecosystem processes and biodiversity maintenance. [ABSTRACT FROM AUTHOR]

Pelagic organisms inhabiting coastal upwelling regions face a high risk of advection away from the nearshore productive habitat, potentially leading to mortality. We explored how animals remain in a productive yet highly advective environment in the Northern California Current System using the cabled observatory system located off the Oregon coast. Acoustic scatterers consistent with swimbladder‐bearing fish were only present during the downwelling season as these animals avoided the cold waters associated with strong upwelling conditions in summer and fall. Fish responded to short‐term upwelling events by increasing the frequency of diel vertical migration. Throughout the study, their vertical positions corresponded to the depth of minimum cross‐shelf transport, providing a mechanism for retention. The observed behavioral response highlights the importance of studying ecological processes at short timescales and the abilities of pelagic organisms to control their horizontal distributions through fine‐tuned diel vertical migration in response to upwelling. Plain Language Summary: Coastal upwelling regions are characterized by high nearshore productivity supported by wind‐driven nutrient supply. This high productivity cascades through the food web supporting high abundance of fish and providing feeding habitat for seabirds and marine mammals. Organisms living in the upwelling ecosystems constantly face challenges of being swept offshore into habitat with fewer food resources due to strong offshore‐moving currents near the surface. Studying how pelagic organisms remain in these nearshore productive waters despite the highly advective physical processes has been difficult. We used simultaneous observations of biological and physical properties to quantify how upwelling variability affects fish behavior and distributions in the Northern California Current System on the Oregon shelf throughout the year. Fish appeared at the nearshore study site during the downwelling season (fall—spring), avoiding cold waters associated with the summer upwelling season. Within the downwelling season, fish responded to short‐term upwelling events by conducting diel vertical migration more frequently during upwelling than downwelling conditions. Regardless of the upwelling strength, fish positioned themselves at the depth of minimum advection risk which aids in retention at the nearshore habitat. These observations highlight the survival strategies of animals in the environment where physical forcing exceeds their swimming capabilities. Key Points: Acoustic scatterers responded to short‐term upwelling events outside of the summer upwelling season on the Oregon shelfDiel vertical migration occurred more frequently during upwelling than downwellingAcoustic scatterers positioned themselves at the depth of minimum cross‐shelf transport during both upwelling and downwelling [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) constitutes a growing threat to coastal ecosystems by altering natural light cycles, which could impair organisms' biological rhythms, with resulting physiological and ecological consequences. Coastal ecosystems are strongly exposed to ALAN, but its effects on coastal organisms are poorly studied. Besides ALAN's intensity, ALAN's quality exposure may change the impacts on organisms. This study aims to characterize the effects of different ALAN's spectral compositions (monochromatic wavelength lights in red (peak at 626 nm), green (peak at 515 nm), blue (peak at 467 nm), and white (410–680 nm) light) at low and realistic intensity (1 lx) on the oyster Crassostrea gigas daily rhythm. Results reveal that all ALAN's treatments affect the oysters' daily valve activity rhythm in different manners and the overall expression of the 13 studied genes. Eight of these genes are involved in the oyster's circadian clock, 2 are clock-associated genes, and 3 are light perception genes. The blue light has the most important effects on oysters' valve behavior and clock and clock-associated gene expression. Interestingly, red and green lights also show significant impacts on the daily rhythm, while the lowest impacts are shown with the green light. Finally, ALAN white light shows the same impact as the blue one in terms of loss of rhythmic oysters' percentage, but the chronobiological parameters of the remaining rhythmic oysters are less disrupted than when exposed to each of the monochromatic light's treatments alone. We conclude that ALAN's spectral composition does influence its effect on oysters' daily rhythm, which could give clues to limit physiological and ecological impacts on coastal environments. [ABSTRACT FROM AUTHOR]

Simple Summary: Geloina erosa, an important animal in mangrove ecosystems, possesses both economic and environmental value. However, to date, there has been no research conducted on its miRNA. This study utilized high-throughput sequencing to identify 1412 miRNAs in three tissues: the gills, hepatopancreas, and muscles. Among these, 1047 miRNAs were identified as known conserved sequences. In conjunction with mRNA research, it was observed that approximately 33% of the transcripts were predicted to be predicted targets for miRNAs. Building upon our team's previous research on mRNA, it is worth noting that the majority of genes suppressed by miRNAs in different tissues align with their respective organ functions. Specifically, in gills, miRNAs predominantly regulated immune-related genes, substance transport, and cytoskeletal organization. In the hepatopancreas, miRNAs suppress genes involved in shell formation while also influencing cellular motor activity and metabolism. In muscle tissue, miRNAs were found to participate in metabolism, photoreceptive processes, and immune regulation. These findings suggest that miRNA regulation is finely tuned to swiftly respond to environmental changes. Overall, these discoveries provide significant insights into the molecular mechanisms and biological processes of miRNA within G. erosa. They serve as a foundation for further validation and elucidation of these regulatory relationships. Geloina erosa is an important benthic animal in the mangrove, serving as an indicator organism for coastal environmental pollution. This study aimed to investigate the tissue-specific expression of miRNAs and their regulatory roles in predicted targets in G. erosa. Through miRNA sequencing and co-expression network analysis, we extensively studied the miRNA expression in three tissues: gills, hepatopancreas, and muscle. The results revealed a total of 1412 miRNAs, comprising 1047 known miRNAs, and 365 newly predicted miRNAs. These miRNAs exhibited distinct tissue-specific expression patterns. In the miRNA target gene prediction, a total of 7404 potential predicted targets were identified, representing approximately 33% of all unique transcripts associated with miRNAs. Further co-expression network analysis revealed nine modules, each showing a positive correlation with specific tissues (gills, hepatopancreas, or muscle). The blue module showed a significant correlation with gills (r = 0.83, p-value = 0.006), the black module was significantly related to the hepatopancreas (r = 0.78, p-value = 0.01), and the purple module was significantly correlated with muscle (r = 0.83, p-value = 0.006). Within these modules, related miRNAs tended to cluster together, while their correlations with other modules were relatively weak. Functional enrichment analysis was performed on miRNAs and their predicted targets in each tissue. In the gills, miRNAs primarily regulate immune-related genes, substance transport, and cytoskeletal organization. In the hepatopancreas, miRNAs suppressed genes involved in shell formation and played a role in cellular motor activity and metabolism. In muscle, miRNAs participate in metabolism and photoreceptive processes, as well as immune regulation. In summary, this study provides valuable insights into the tissue-specific regulation of miRNAs in G. erosa, highlighting their potential roles in immune response, metabolism, and environmental adaptation. These findings offer important clues for understanding the molecular mechanisms and biological processes in G. erosa, laying the foundation for further validation and elucidation of these regulatory relationships. [ABSTRACT FROM AUTHOR]

We investigated the dynamics of tritium (3H) from 2003 to 2012 in the marine environment off Aomori and Iwate prefectures. To better understand this radionuclide's behavior, we compared 3H and 137Cs in collected samples. In the comparison, for the activity concentrations of 3H, these data excluded the period from 2006 to 2008 during intermittent test operation of the Rokkasho Nuclear Fuel Reprocessing Plant; for the activity concentrations of 137Cs, the data excluded the period from 2011 to 2012 after the Fukushima Daiichi Nuclear Power Station accident. The mean concentration ratio (CR) of tissue-free water tritium (TFWT) was close to 1.0, indicating that the concentration of this nuclide in marine biota was almost equal to that in seawater, and it therefore was not accumulated to high levels in marine biota. The lowest CR of 137Cs was higher than 30, suggesting that this nuclide was accumulated to relatively high levels in marine biota. Furthermore, the lack of correlations by Spearman's test (R < 0.4, P > 0.05) between the CR of TFWT and that of 137Cs for three different species (Gadus macrocephalus, Lophius litulon, and Oncorhynchus keta) provides convincing evidence that the dynamics of TFWT and 137Cs in marine ecology are decoupled. [ABSTRACT FROM AUTHOR]

Ocean pollution poses a significant issue in the marine ecosystem. Coastal areas are particularly impacted by this pollution, and consequently, organisms associated with these coasts bear the brunt of its effects. Therefore, the presence of robust bioindicators, such as the shrimp species Palaemon elegans, is critically important. In this study, 20 P. elegans specimens were examined in each of the five areas on Gran Canaria Island. Water samples were collected to assess the potential existence of elevated concentrations. Significant discrepancies were observed in the levels of Al and Li across all zones, except those previously mentioned. The highest concentrations were recorded in Arguineguín (Southern sector), reaching 49.14 ± 4.51 mg/kg (Al) and 47.64 ± 2.86 mg/kg (Li). The authors contend that P. elegans proves to be a reliable bioindicator for tourist and port-related pollution, specifically for the metals Al, Zn, Cd, Pb, Ni, Fe, B, and Li analyzed in this research. [ABSTRACT FROM AUTHOR]

Circadian clocks in terrestrial animals are encoded by molecular feedback loops involving the negative regulators PERIOD, TIMELESS or CRYPTOCHROME2 and positive transcription factors CLOCK and BMAL1/CYCLE. The molecular basis of circatidal (~12.4 hour) or other lunar-mediated cycles (~15 day, ~29 day), widely expressed in coastal organisms, is unknown. Disrupting circadian clockworks does not appear to affect lunar-based rhythms in several organisms that inhabit the shoreline suggesting a molecular independence of the two cycles. Nevertheless, pharmacological inhibition of casein kinase 1 (CK1) that targets PERIOD stability in mammals and flies, affects both circadian and circatidal phenotypes in Eurydice pulchra (Ep), the speckled sea-louse. Here we show that these drug inhibitors of CK1 also affect the phosphorylation of EpCLK and EpBMAL1 and disrupt EpCLK-BMAL1-mediated transcription in Drosophila S2 cells, revealing a potential link between these two positive circadian regulators and circatidal behaviour. We therefore performed dsRNAi knockdown of Epbmal1 as well as the major negative regulator in Eurydice, Epcry2 in animals taken from the wild. Epcry2 and Epbmal1 knockdown disrupted Eurydice's circadian phenotypes of chromatophore dispersion, tim mRNA cycling and the circadian modulation of circatidal swimming, as expected. However, circatidal behaviour was particularly sensitive to Epbmal1 knockdown with consistent effects on the power, amplitude and rhythmicity of the circatidal swimming cycle. Thus, three Eurydice negative circadian regulators, EpCRY2, in addition to EpPER and EpTIM (from a previous study), do not appear to be required for the expression of robust circatidal behaviour, in contrast to the positive regulator EpBMAL1. We suggest a neurogenetic model whereby the positive circadian regulators EpBMAL1-CLK are shared between circadian and circatidal mechanisms in Eurydice but circatidal rhythms require a novel, as yet unknown negative regulator. Author summary: Molecular feedback loops underlie expression of circadian ~24-hour behavioural and physiological rhythms in terrestrial animals, with PERIOD, TIMELESS and CRYPTOCHROME2 representing the negative, and CLOCK and BMAL1/CYC the positive regulators, with casein kinase 1 (CK1) acting as a modulator. In coastal marine animals, the lunar-mediated ~12.4 hour circatidal rhythm represents the dominant biological cycle but its molecular basis is unknown. The available evidence indicates that circadian and circatidal mechanisms are molecularly independent yet in the speckled-sea louse, Eurydice pulchra (Ep), pharmacological manipulation of CK1 generates correlated changes in both types of cycles, suggesting a shared component. Here, using a Drosophila cell system, we show that CK1 inhibitors alter post-translational modifications of EpCLOCK-BMAL1 leading to a reduction in their transcriptional ability and suggesting that these functional changes in EpCLOCK-BMAL1 may have produced the CK1 inhibitor-mediated circatidal phenotypes. To test this directly we used dsRNAi to knockdown the expression of EpBMAL1 in adult Eurydice captured from the wild. We also downregulated the main negative regulator EpCRY2. We observe consistent disruptions to circatidal rhythms in EpBMAl1 but not EpCRY2 knockdowns suggesting that the positive circadian regulator is involved in both circadian and lunar-mediated behaviour. [ABSTRACT FROM AUTHOR]

The Mediterranean Sea is recognized as a marine biodiversity hotspot. This enclosed basin is facing several anthropogenic-driven threats, such as seawater warming, pollution, overfishing, bycatch, intense maritime transport and invasion by alien species. The present review focuses on the diversity and ecology of specific marine trophically transmitted helminth endoparasites (TTHs) of the Mediterranean ecosystems, aiming to elucidate their potential effectiveness as 'sentinels' of anthropogenic disturbances in the marine environment. The chosen TTHs comprise cestodes and nematodes sharing complex life cycles, involving organisms from coastal and marine mid/upper-trophic levels as definitive hosts. Anthropogenic disturbances directly impacting the free-living stages of the parasites and their host population demographies can significantly alter the distribution, infection levels and intraspecific genetic variability of these TTHs. Estimating these parameters in TTHs can provide valuable information to assess the stability of marine trophic food webs. Changes in the distribution of particular TTHs species can also serve as indicators of sea temperature variations in the Mediterranean Sea, as well as the bioaccumulation of pollutants. The contribution of the chosen TTHs to monitor anthropogenic-driven changes in the Mediterranean Sea, using their measurable attributes at both spatial and temporal scales, is proposed. [ABSTRACT FROM AUTHOR]

Until the 1960s, Lake Maruit was one of Egypt's most productive coastal brackish lakes. Continuous polluted discharge from Alexandria city resulted in long-term deterioration. The Egyptian government started a lake restoration program in 2010. Biological linkages between pelagic and benthic communities were assessed in November 2012 using parasitism and predation. This study examined ectoparasites infesting tilapia fish from 300 samples. The platyhelminth ectoparasite, Monogenea, and parasitic-copepod Ergasilus lizae were detected. Platyhelminthes parasitized Oreochromis niloticus and Oreochromis aureus, whereas the crustacean parasitized Coptodon zillii. The parasitic prevalence was low for Cichlidogyrus sp. and Ergasilus lizae. Benthic biotas were similar across basins. Fish abundance does not respond directly to benthic biotic components. Phytoplankton and benthic microalgae were not the main fish diet. Data on Halacaridae and fish clustered, indicating that either Halacaridae responds to their environment like fish or fish prey upon them because of their size. Linear correlations between pelagic, benthic biota, and parasite-infected fish indicate parasites may control their hosts. Some bioindicators indicate that stressed ecosystems differ from unstressed ecosystems. Fish species and biota abundances were low. Inconsistency in the food web and an absence of direct interactions between prey and predators are bioindicators of disturbed ecosystems. The low prevalence of ectoparasites and lack of heterogenous distribution of the various examined biota are bioindicators of habitat rehabilitation. Ongoing biomonitoring to better understand habitat rehabilitation is suggested. [ABSTRACT FROM AUTHOR]

Supralittoral zones of 13 sandy beaches of remote Rutland Island were divided into three zones to identify the litter contamination, its source, pathway of plastic transport to determine the level of macro-litter contamination, and its impact on coastal biota. Owing to the floral and faunal diversity, apart of the study area is protected under Mahatma Gandhi Marine National Park (MGMNP). The supralittoral zones of each sandy beach (between low-tide and high-tide line) were individually calculated from 2021 Landsat-8 satellite imagery before conducting the field survey. The total area of the surveyed beaches was 0.52 km2 (5,20,020.79 m2), and 317,565 litters representing 27 distinct litter types were enumerated. Two beaches in Zone-II and six in Zone-III were clean; however, all five in Zone-I were very dirty. The highest litter density (1.03 items/m2) was observed in Photo Nallah 1 and Photo Nallah 2, whereas the lowest (0.09 items/m2) was observed in Jahaji Beach. According to the Clean Coast Index (CCI), Jahaji Beach (Zone-III) is the very cleanest beach (1.74) while other beaches of Zone-II and Zone-III are clean. The findings of the Plastic Abundance Index (PAI) indicate that Zone-II and Zone-III beaches have a low abundance of plastics (< 1), while two beaches of Zone-I, viz., Katla Dera and Dhani Nallah, exhibited a moderate abundance of plastics (< 4) while a high abundance of plastics (< 8) was observed in the rest of three beaches of the same zone. The primary contributor of litter on Rutland's beaches was plastic polymers (60–99%), which were presumed to originate from the Indian Ocean Rim Countries (IORC). A collective litter management initiative by the IORC is essential in preventing littering on remote islands. [ABSTRACT FROM AUTHOR]

A total of 413 diatom taxa were known for aquatic habitats of the Lena Delta Nature Reserve. We identified 385 taxa in 14 small tundra lakes near the reserve that significantly enriched the diatom diversity of the region (666 taxa including definitions to the genus level). Thus, the species composition of diatoms in the reserve and adjacent territories was increased by 278 species. We showed that the species of the genera Pinnularia (57) and Eunotia (51) have predominance at the family and generic levels. The index of intraspecific variability Ssp./Sp. for the lakes of the reserve was 1.11, and that for the lakes of the Tiksi region 1.14, which is typical for high-latitude and high-mountain communities. The number of rare or endangered species varied in different lakes from 1 to 10, totaling 42 species for the entire study area. Bioindication has shown that potentially threatened species prefer moderate temperatures, and slightly acidic or neutral environments free from organic pollution. A comparative analysis of the species composition of diatoms in the vicinity of the Lena Delta and other northern water bodies of Yakutia and the Arctic Islands showed that the species composition of each lake in the Arctic has a discernably different species distribution. The indicator characteristics show a certain response of the species composition of diatoms to changes in salinity, pH, and organic pollution. Regularities in the spatial distribution of diatoms in the study area were revealed in connection with the environmental variables of their habitat. Statistical mapping of diatom diversity data and bioindicators revealed a pronounced response to point pollution, and also let us assume the influence of summer northeast winds on species composition of the studied lake communities. We suggest that the high diversity inherent in the diatom lakes of the Tiksi coastal zone, which can even be updated in further studies, can be considered as a property of coastal biota inherent in ecotones. Since it is in the coastal Tiksi region that a surge in the number of species is observed, this region can be considered not only an ecotone, but also a hotspot of diatom diversity. The results of the study are important for developing the basis for monitoring biodiversity under the conditions of anthropogenic and climatic changes in the Arctic. [ABSTRACT FROM AUTHOR]

The widespread use of triclosan as an antimicrobial agent has led to its presence in the aquatic environment and potential effects on aquatic organisms. In this study, we used reversed-phase high-performance chromatography to quantify triclosan in marine snail (Conus hyaena) and algal biofilm from the Versova Creek in India. Triclosan was found in the range of 1.97-11.8 ng/g wet weight in marine snails and 1.7-7.2 ng/g wet weight in algal biofilm. The mean bioaccumulation factor based on water (BAFw 6.51) and sediment (BAFs 3.15) for Conus sp. and water (BAFw 4.61) and sediment (BAFs 2.2) for algal biofilm in the Versova Creek showed that triclosan is accumulative in both the organisms and reflects its trophic transport. Bioaccumulation of TCS is majorly from water than the sediment matrices. A comparison of accumulation potential between carnivores and primary producers revealed, higher accumulation in euryphagic carnivores. This is the first report of triclosan bioaccumulation in coastal organisms (marine snail and algal biofilm) from India. Our findings suggest that marine snail and algal biofilm can serve as a biomarker for triclosan exposure and can be used for future monitoring of triclosan pollution in the environment. [ABSTRACT FROM AUTHOR]

Background: Long-distance rafting on anthropogenic marine debris (AMD) is thought to have a significant impact on global marine biogeography and the dispersal of non-indigenous species. Therefore, early identification of arrival sites of AMD and its epibionts is crucial for the prioritization of preventive measures. As accumulation patterns along global coastlines are largely unstudied, we tested if existing oceanographic models and knowledge about upstream sources of litter and epibionts can be used as a simple and cost-efficient approach for predicting probable arrival sites of AMD-rafting biota in coastal zones. Methods: Using the Southeast Pacific as a model system, we studied daily accumulation rates, composition, and minimum floating times of AMD with and without epibionts on seven sandy beaches, covering the oceanic environment (Rapa Nui/Easter Island) and three regions (south, centre, north) along the Chilean continental coast, over a minimum of 10 consecutive days, and we contrast our results with predictions from published models. Results: Total AMD accumulation rates varied from 56 ± 36 (mean ± standard deviation) to 388 ± 433 items km-1 d-1 and differed strongly between regions, in accordance with local geomorphology and socioeconomic conditions (presence of larger cities and rivers upstream, main economic activities, etc.). Daily accumulation of items with pelagic epibionts (indicators of a pelagic trajectory) ranged from 46 ± 29 (Rapa Nui) to 0.0 items km-1 d-1 (northern continental region). Minimum floating times of rafts, as estimated from the size of pelagic epibionts, were longest in the South Pacific Subtropical Gyre's (SPSG) centre region, followed by the high-latitude continental region under the influence of the onshore West Wind Drift, and decreased along the continental alongshore upwelling current, towards lower latitudes. Apart from pelagic rafters, a wide range of benthic epibionts, including invasive and cryptogenic species, was found on rafts at the continental beaches. Similarly, we present another record of local benthic corals Pocillopora sp., on Rapa Nui rafts. Discussion: Our results agree with the predictions made by recent models based on the prevailing wind and surface current regimes, with high frequencies of long-distance rafting in the oceanic SPSG centre and very low frequencies along the continental coast. These findings confirm the suitability of such models in predicting arrival hotspots of AMD and rafting species. Moreover, storm surges as well as site-related factors seem to influence AMD arrival patterns along the Chilean continental coast and might cause the observed high variability between sampling sites and days. Our results highlight the possible importance of rafting as a vector of along-shore dispersal and range expansions along the SE Pacific continental coast and add to the discussion about its role in benthic species dispersal between South Pacific oceanic islands. [ABSTRACT FROM AUTHOR]

In order to preliminarily explore the distribution of antibiotic pollution in the coastal waters of eastern China, the concentrations of 13 antibiotics in 5 representative coastal rivers in Jiangsu and 21 sampling sites in the coastal waters of Jiangsu were analyzed. The total antibiotic concentrations in the 5 rivers ranged from 33.14 to 417.78 ng L−1, and the total antibiotic concentrations in the 21 sampling sites ranged from 0.90 to 86.33 ng L−1. Macrolides exhibited the highest total concentration and the maximum detection frequency in both coastal rivers and the coastal waters. The concentrations of antibiotics in a sampling site decreased as the distance of the sampling site from the coastline increased, indicating that river inputs are important sources of antibiotic pollution in the coastal waters of Jiangsu. The detection frequencies of roxithromycin, lincomycin, azithromycin, and sulfamethoxazole in the rivers and sampling sites were above 70%. Correlation analysis showed that the concentrations of antibiotics were positively correlated with the levels of chemical oxygen demand, total phosphorus, and total nitrogen. Risk assessments revealed that roxithromycin and ofloxacin posed medium ecological and resistance risks, respectively, to the most sensitive aquatic organisms in the coastal waters of Jiangsu. The results of this study highlight the significance of monitoring and controlling the concentrations of antibiotic contaminants in the coastal waters of Jiangsu. [ABSTRACT FROM AUTHOR]

One of the primary ways in which climate change will impact coastal freshwater wetlands is through changes in the frequency, intensity, timing and distribution of extreme weather events. Disentangling the direct and indirect mechanisms of population‐ and community‐level responses to extreme events is vital to predicting how species composition of coastal wetlands will change under future conditions.We extended static structural equation modelling approaches to incorporate system dynamics in a multi‐year multispecies occupancy model to quantify the effects of extreme weather events on a coastal freshwater wetland system.We used data from an 8‐year study (2009–2016) on St. Marks National Wildlife Refuge in Florida, USA, to quantify species‐specific and community‐level changes in amphibian and fish occupancy associated with two flooding events in 2012 and 2013. We examine how physical changes to the landscape, including potential changes in salinity and increased wetland connectivity, may have contributed to or exacerbated the effects of these extreme weather events on the biota of isolated coastal wetlands.We provide evidence that the primary effects of flooding on the amphibian community were through indirect mechanisms via changes in the composition of the sympatric fish community that may have had lethal (i.e. through direct predation) or non‐lethal (i.e. through direct or indirect competitive interactions) effects. In addition, we have shown that amphibian species differed in their sensitivity to direct flooding effects and indirect changes in the fish community and wetland‐specific conductance, which led to variable responses across the community. These effects led to the overall decline in amphibian species richness from 2009 to 2016, suggesting that wetland‐breeding amphibian communities on St. Marks National Wildlife Refuge may not be resilient to predicted changes in coastal disturbance regimes because of climate change.Understanding both direct and indirect effects, as well as species interactions, is important for predicting the effects of a changing climate on individual species, communities and ecosystems. [ABSTRACT FROM AUTHOR]

Limited information exists on mercury concentrations and environmental drivers of mercury bioaccumulation in high latitude terrestrial carnivores. Spatial patterns of mercury concentrations in wolverine (Gulo gulo, n = 419) were assessed across a 1,600,000 km2 study area in relation to landscape, climate, diet and biological factors in Arctic and boreal biomes of western Canada. Hydrogen stable isotope ratios were measured in wolverine hair from a subset of 80 animals to assess the spatial scale for characterizing environmental conditions of their habitat. Habitat characteristics were determined using GIS methods and raster datasets at two scales, the collection location point and a 150 km radius buffer, which was selected based on results of a correlation analysis between hydrogen stable isotopes in precipitation and wolverine hair. Total mercury concentrations in wolverine muscle ranged >2 orders of magnitude from 0.01 to 5.72 μg/g dry weight and varied geographically, with the highest concentrations in the Northwest Territories followed by Nunavut and Yukon. Regression models at both spatial scales indicated diet (based on nitrogen stable isotope ratios) was the strongest explanatory variable of mercury concentrations in wolverine, with smaller though statistically significant contributions from landscape variables (soil organic carbon, percent cover of wet area, percent cover of perennial snow-ice) and distance to the Arctic Ocean coast. The carbon and nitrogen stable isotope ratios of wolverine muscle suggested greater mercury bioaccumulation could be associated with feeding on marine biota in coastal habitats. Landscape variables identified in the modelling may reflect habitat conditions which support enhanced methylmercury transfer to terrestrial biota. Spatially-explicit estimates of wet atmospheric deposition were positively correlated with wolverine mercury concentrations but this variable was not selected in the final regression models. These landscape patterns provide a basis for further research on underlying processes enhancing methylmercury uptake in high latitude terrestrial food webs. [ABSTRACT FROM AUTHOR]

Due to its high concentration and persistence, microplastic (MP) pollution is a major threat to marine environments. Expanded polystyrene (EPS) particles are the most abundant MP type in Asian regions, including the Korean coastal region. Although many previous studies have reported the toxicity of MPs to marine biota, the toxicity of environmentally relevant MPs to coastal organisms is not well understood. Thus, we investigated the toxicity of EPS on the growth and energy metabolism of the juvenile marine isopods, Ligia cinerascens , obtained from a population that has been exposed to EPS through multiple generations. After 14 and 21 days of dietary EPS exposure, body weight and molting of L. cinerascens were unaffected. However, the energy reserves (carbohydrates, proteins, and lipids) were significantly reduced, resulting in a decrease in the total energy budget (E a) by dietary EPS exposure. The transcriptional modulation patterns of genes related to energy metabolism suggested that dietary EPS exposure may increase the digestion of non-carbohydrate sources, such as proteins and lipids, to compensate for increased energy expenditure. Our findings suggest that dietary EPS exposure, although no toxic at the individual level, can reduce the energy status of juvenile marine isopods, which provides useful information on the toxic effects of environmentally relevant MPs to coastal ecosystem. [Display omitted] • Expanded polystyrene (EPS) toxicity on marine isopod energy metabolism was investigated. • Dietary EPS showed no toxic effects on growth and molting in the isopod Ligia cinerascens over 21 days. • Energy reserves and total energy budget were significantly reduced after exposure to dietary EPS. • Transcriptional modulation patterns imply that metabolic disorder was induced by dietary EPS exposure. • Dietary EPS exposure has potential toxicity on energy metabolism of coastal organisms. [ABSTRACT FROM AUTHOR]

Discarded cigarette butts (CBs) are a significant source of environmental pollution. In areas with large amounts of cigarette waste, environmental hazards may arise due to the leaching of chemicals from filters and smoked tobacco. Accurately estimating the number of CBs on beaches requires a standardized method. Additionally, estimating the release of metals from these pollutants can provide important insights into beach pollution. This study compares two sampling methods to estimate CB waste on recreational beaches and evaluate the potential release of metals. In this combined experimental and meta-analysis study, circular methods with diameters of 5, 10, and 15 m were compared to a Flood Accumulation Zone (FAZ) method (1 m by 10 m, parallel to the waterline). Systematic study methods and meta-analysis were applied to estimate the release of metals along the Caspian Sea beaches. The Kruskal-Wallis test revealed significant differences in the averages of at least one sampling method (P < 0.006). Follow-up Mann-Whitney U tests showed no significant differences among the circular methods, but all circular methods significantly differed from the FAZ method (P < 0.05). The difference between the circular methods was smaller than the difference with the FAZ method. The minimum and maximum metal concentrations, in micrograms per square meter of Caspian Sea beaches, were associated with mercury and manganese. Circular methods with different diameters did not significantly differ and are effective in reducing CB accumulation due to coastal waves and wind. These methods can be considered standard for estimating CBs on beaches. Cigarette waste acts as a point source of metal pollution, with rapid leaching of metals increasing the risk of acute harm to coastal and marine organisms. • We comprise two sampling methods to estimate amount of cigarette butts trash on the recreational beaches. • We estimate the number of metals that can be released in these environmental pollutants. • We evaluate cigarette butt's pollution and metals pollution in Caspian Sea beaches. [ABSTRACT FROM AUTHOR]

Marine and coastal environments are constantly subjected to increasing pressures associated with population growth, industrialization development, pollution and higher demand feeding society's consumerism. Among these pressures, there has been an increasing concern towards UV filters occurrence in aquatic ecosystems due to a greater use of personal care products (PCPs). 2-ethylhexyl-4-methoxycinnamate (EHMC) is one of the most used UV filters in sunscreen formulations, yet few reports address its effects in biota. This literature review intends to collect the available information concerning the environmental presence of EHMC in marine and coastal ecosystems and their effects in biota. The EHMC effects have been reported for the taxonomic groups: Actinomycetes, Alphaproteobacteria, Bacilli, Cytophagia, Flavobacteriia, Gammaproteobacteria, Actinopterygii, Anthozoa, Bacillariophyceae, Bivalvia, Branchiopoda, Coccolithophyceae, Echinoidea, Gastropoda, Malacostraca, Annelida and Thecostraca. The reported literature evaluated endpoints mainly related to development, viability, mortality, estrogenicity, gene transcription disruptions, biochemical alterations and morphophysiological changes. Based on the available information, there is still a clear need for further investigations related to EHMC and its toxicological effects on marine and coastal organisms. [Display omitted] • Up to 1520 ng L−1 and 930 ng g−1 of EHMC in water and sediment samples • Greece and China presented higher levels of EHMC in sediment samples. • Most lab exposures ranged between 100,000 and 4,000,000 ng L−1 of EHMC. • Growth inhibition, mortality and bleaching are the most assessed parameters. • Higher sensitivity of Anthozoa, Bivalvia and Annelida to lower levels of EHMC [ABSTRACT FROM AUTHOR]

Following the Hebei Spirit oil spill (HSOS) in December 2007, benthic organisms of the Taean coast on the west coast of Korea were heavily affected. A month after HSOS, the alkyl PAHs in the oyster body elevated to 13,500 ng/g dry wt, although it dropped to 5335 ng/g dry wt in December 2008, and returned to the levels before the accident (547–858 ng/g dry wt) by 2010. In 2008 spring, the damaged oysters exhibited deteriorated growth and reproduction, exhibiting signs of physiological stress. However, a year after the accident, oysters exhibited signs of recovery from the stresses. Gonad maturation, reproductive effort, and carbohydrate content recorded in 2010 were comparable to the levels in 2009 and the levels in undamaged oysters. Our study suggested that the Pacific oysters recovered from the HSOS stresses within a year, although long-term monitoring of oyster health must be carried out to ascertain the recovery. • This study assesses the sublethal impacts of the Hebei Spirit oil spill on the Pacific oyster (Crassostrea gigas) at Taean, Korea. • Post-spill analyses revealed elevated polycyclic aromatic hydrocarbons (PAHs) in oyster tissues, which gradually decreased to baseline within a year. • Initial physiological assessments in 2008 showed reduced growth, reproductive effort, and body condition due to PAH exposure. • Recovery of the affected oysters was observed within two years, with growth and reproductive parameters reaching near baseline by 2010. [ABSTRACT FROM AUTHOR]

Petroleum industry in the southern Gulf of Mexico possesses relevant importance for the Mexican economy but it has also impacted the marine and coastal environments of this region. The objective of the current review is to provide a substantial panorama of the polycyclic aromatic hydrocarbons (PAHs) during the XXI century. The highest PAHs concentration in water was found in the Dos Bocas Maritime Terminal and the Mecoacán Lagoon; sediments and cores were found in Sontecomapan, Mandinga, and La Mancha Lagoons; maximum PAHs levels in biota were found in fish in Términos Lagoon. PAHs in water and oysters were comparable to others around the world; sediments concentrations were higher than in other regions. Mecoacán Lagoon, coastal shelf Tamaulipas, and Cayo Arcas Reef Complex showed a higher risk estimation based on sediment concentrations. It is necessary to establish monitoring programs in the study region due to the trends found in PAHs. [Display omitted] • The major petroleum industry in Mexico is located in the southern Gulf of Mexico. • PAHs impacted marine environments and coastal lagoons from the southern Gulf of Mexico. • High PAHs levels were found in produced waters and sediments from coastal lagoons. • For biota, comparable PAHs levels to other regions in the world have been found. • Regional Environmental Risk is urgent due to historical petroleum exploitation. [ABSTRACT FROM AUTHOR]

Microplastic pollution on bathing beaches threatens the health of human beings and coastal organisms. There is a lack of assessment on the level of microplastic pollution and the health risk associated with plastics. As one of the earliest open bathing beaches in China, Liandao is well known as the two high-quality beaches. However, little is known about the extent of microplastic pollution on these bathing beaches. Based on the analysis of microplastic pollution abundance, distribution, shape, size, color, and composition at the Liandao bathing beaches, this study puts forward a novel approach to comprehensively evaluate the microplastic pollution level and risk level by using the Nemerow pollution index (NPI) and polymer hazard index (PHI). The results show that the average abundance of microplastics on the Liandao bathing beaches is 135.42 ± 49.58 items/kg; the main shapes are fibers, fragments, and granules. Most of the microplastics are transparent, brown, and black, accounting for 71.54%, and they have an average particle size of 0.63 ± 0.43 mm. The main components are PE, PP, PS, PET, and nylon, of which nylon appears in the highest proportion (54.77%). The microplastic NPI and PHI values are 0.38 and 74.81, respectively, indicating that the pollution level and health risk index of microplastics on the Liandao bathing beaches are both low. With the increase in population and per capita consumption, plastic waste generated on land will continue to increase. Finally, this study puts forward some suggestions regarding microplastic monitoring, plastic waste management, and environmental attitudes and behavior. [ABSTRACT FROM AUTHOR]

Increasing human-induced climate issues, such as water pollution, have triggered rapid physiochemical changes, especially in coastal regions. These changes have directly impacted aquatic animals that live near coastal areas, such as bivalves and crustaceans (e.g., clams, crabs), as well as those that live in the lower areas of the habitat (i.e., sediment). Heavy metal pollution (e.g., mercury) is one of the most concerning physiochemical changes in these areas. The effects of heavy metals on coastal environments and organisms can be substantial, in spite of restoration efforts. Thus, more studies are needed to analyze the current situation of the impacts of climate-change-related issues on heavy metal concentrations in coastal areas. In this paper, we provide a scientometrics analysis of the interactions between climate change and heavy metal concentrations in coastal regions around the world. Scientometrics is the quantitative analysis of the available literature, with a focus on research patterns, using continuous and systematic methods. Our results showed that there was a total of 7922 related studies from 1979 to 2021. Heavy metal contamination, ecological quality status and ocean acidification are among the most influential keywords in this field. We concluded that among climate change issues, heavy metals are becoming a popular topic within research associated with climate change. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a global pollutant capable of bioaccumulates/biomagnifies along the trophic chain and posing concerns for organisms and humans. The historical mining in Idrija (NW Slovenia) and the more recent activity of a chlor-alkali plant (CAP) sited in Torviscosa (NE Italy) causes diffuse Hg contamination in the Marano and Grado Lagoon (MGL, northern Adriatic Sea, Italy). Despite the importance of fishing and aquaculture for local inhabitants, knowledge of the Hg content of MGL fish is still scarce and fragmentary. This paper reports the results obtained from the collection of sediments, water, and biota during the implementation of the WFD/2000/60/CE. The solid phase is characterised by high Hg concentrations (up to 7.4 mg kg−1) with a net positive gradient moving eastward, but chemical speciation suggests the prevalence of cinnabar (not mobile) species. The scarce mobility of Hg is attested to by the low concentrations found in surface waters. Hg in fish often exceeds the limit set for commercialization (0.5 mg kg−1 ww), especially in the Grado basin, but its content is variable depending on the size and habits of species. Although there was a significant linear relationship between THg content in sediment and tissues of Chelon auratus, the values of the biota sediment accumulation factor (BSAF), which were always less than one, suggest that the Hg bioavailable for transfer from sediment to biota is low. Additionally, the Target Hazard Quotient (THQ) calculated on C. auratus's daily consumption showed that adverse effects on human health are out of the question at least for the Marano basin. [ABSTRACT FROM AUTHOR]

High levels of fecal-indicator organisms (FIOs) at bathing water sites can cause disease and impose threats to public health. There is a need for predicting FIO levels to inform the public and reduce exposure. Data-driven models are one of the main tools being considered as predictive models. However, identifying the main inputs of the data-driven models is a major challenge in developing FIO predictor models. This paper develops a data-driven model for FIO concentration prediction based on a limited number of critical input variables. Essential variables were identified with be a combination of the gamma test and Genetic Algorithm (Gamma-GA test). Artificial neural networks (ANNs) and linear regression models were developed using these two variable identification approaches for comparison. The models were applied to a case study, and it was found that the model using the Gamma-GA test has a high potential to predict FIO levels more accurately, although this requires further investigation with different case studies. A correlation analysis was required prior to the variable identification approaches in this study. The need of this analysis highlights the significance of understanding the waterbody and the data set in the development and application of data-driven models. Models using a Gamma-GA test were more capable of predicting extreme (high) FIO concentrations, making a Gamma-GA test more suitable for a bathing water quality early warning system. The importance of nonlinearity in such predictive models was also demonstrated by the better performance of nonlinear ANN models compared with linear regression models regardless of the variable identification approaches used. This paper highlights the importance of nonlinearity in bathing water quality prediction and encourages further utilization of nonlinear models for this application. [ABSTRACT FROM AUTHOR]

During the Spanish colonial era, ships frequently transported mercury across the Atlantic to the New World to be used in gold mining. As many of those eventually sank, shipwrecks may represent a local source of mercury contamination in the marine environment. In this context, evaluating mercury contamination in coastal sediments and mercury magnification in marine food webs is crucial for understanding mercury dynamics and estimating exposure to marine life in locations where shipwrecks occurred. This study investigated mercury concentration present in coastal sediments and biota from three distinct groups: macroalgae (Asparagopsis armata and Ulva lactuca), gastropods (Littorina striata and Patella candei gomesii) and crustaceans (Palaemon elegans and Pachygrapsus marmoratus) collected in the Azores Archipelago, Portugal (one site near a 16th-century shipwreck and others in locations further away). Mercury analyses indicated that the sediments and species from the shipwreck area had significantly higher mercury levels than the other areas. Fine sediments showed values above those established in sediment quality guidelines; however, considering the mercury concentration of the total sediment fraction, adverse biological effects are not expected to occur. Moreover, increased mercury concentration from primary producers to consumers reinforced the biomagnification potential of this metal. [ABSTRACT FROM AUTHOR]

Twelve-hour (12 h) ultradian rhythms are a well-known phenomenon in coastal marine organisms. While 12 h cycles are observed in human behavior and physiology, no study has measured 12 h rhythms in the human brain. Here, we identify 12 h rhythms in transcripts that either peak at sleep/wake transitions (approximately 9 AM/PM) or static times (approximately 3 PM/AM) in the dorsolateral prefrontal cortex, a region involved in cognition. Subjects with schizophrenia (SZ) lose 12 h rhythms in genes associated with the unfolded protein response and neuronal structural maintenance. Moreover, genes involved in mitochondrial function and protein translation, which normally peak at sleep/wake transitions, peak instead at static times in SZ, suggesting suboptimal timing of these essential processes. [ABSTRACT FROM AUTHOR]

We provide the first inventory of terrestrial arthropods from La Chimba National Reserve (Antofagasta Region, Chile), a protected area whose purpose is to preserve the biota of the Coastal desert of Tocopilla embedded in the larger transitional coastal desert. The study was conducted during spring of 2019. A total of 2,852 specimens were recorded, distributed across 188 species. Among the collected specimens, 5 new species were identified: two species of scorpions, Brachistosternus chimba Ojanguren-Affilastro, Alfaro & Pizarro-Araya, 2021 and Rumikiru sp. nov. (Scorpiones: Bothriuridae); a solpugid (Solifugae: Ammotrechidae); a spider (Araneae: Filistatidae), and a centipede (Scutigeromorpha: Scutigeridae). The richness estimations showed large values for most arthropod groups, which is evidence of an incomplete inventory of species richness. The article also discusses the current threats faced by these communities of endemic arthropods and suggests immediate actions to preserve these groups in extremely fragile semiarid ecosystems. [ABSTRACT FROM AUTHOR]

Coastal marine environments are subject to a variety of anthropogenic pressures that can negatively impact habitats and the biodiversity they harbor. Conservation actions such as marine protected areas, marine reserves, and other effective area-based conservation measures, are pivotal tools for protecting coastal biodiversity. However, to be effective, conservation area networks must be planned through a systematic conservation planning (SCP) approach. Recently, such approaches have begun to orient their goals toward the conservation of different biodiversity facets and to integrate different types of data. In this review, we illustrate how genetic data and molecular techniques can bring useful knowledge for SCP approaches that are both more comprehensive (sampling the full range of biodiversity) and more adequate (ensuring the long-term persistence of biodiversity). With an emphasis on coastal organisms and habitats, we focus on phylogenetic analysis, the estimation of neutral and adaptive intraspecific genetic diversity at different spatial levels (alpha, beta, and gamma), the study of connectivity and dispersal, and the information obtainable from environmental DNA techniques. For each of these applications, we discuss the benefits of its integration into SCP for coastal systems, its strengths and weaknesses, and the aspects yet to be developed. [ABSTRACT FROM AUTHOR]

Compared with the open ocean, knowledge of pH variability in coastal waters is rudimentary, especially in Africa. This is concerning as quantifying local pH conditions is critical when assessing the response of coastal species to future ocean acidification scenarios. The objective of this study was to capture some of the variability in pH at scales and sites relevant to coastal marine organisms in a South African temperate embayment (Algoa Bay, Indian Ocean). We used a sampling approach that captured spatial (at a resolution of ∼10 km), monthly and diel (24-hour) variability in pH and associated physical and biological parameters at offshore and shallow inshore sites in Algoa Bay. We found that pH and associated parameters (temperature, calculated pCO2, chlorophyll a) varied over space and time in Algoa Bay. The range in pH was 0.30 units at offshore sites and 0.46 at inshore sites, and the average pH was 8.10 (SD 0.06) and 8.10 (SD 0.13) at these sites, respectively, which is typical for coastal environments. Our results showed that both biological factors (at the offshore sites) and salinity (at the inshore sites) may influence temporal and spatial variability in pH. We also identified a shallow inshore site with high levels of macroalgal growth that had consistently higher average daytime pH levels (8.33 [SD 0.07]), which may serve as an ocean acidification refuge for coastal marine species. This is the first comprehensive pH-monitoring study to be implemented in a nearshore coastal area in Africa and provides recommendations for monitoring in other understudied regions. [ABSTRACT FROM AUTHOR]

Marine organisms inhabiting coastal waters are known to be driven by periodic cycles such as diel, tidal, and seasonal changes. Humpback whales (Megaptera novaeangliae) breed in shallow and warm coastal waters, with males singing complex songs during the breeding season. To investigate periodic variations in humpback whale singing activities, we conducted fixed passive acoustic monitoring in the Ogasawara (Bonin) Islands, Japan, from winter to spring during 2016–2018. The singing activity and individual number of singers were observed throughout the day and night using a very long baseline passive acoustic array. The occurrence of singers peaked before sunrise and in the evening and was reduced during the daytime. The frequency of song reception depended on the tidal phase. A generalised additive model demonstrated that the occurrence of singers increased during the flood tide and decreased during the ebb tide in the waters west of Chichijima Island. These results suggest that the singing behaviour of humpback whales in breeding areas is affected by the diel and tidal cycles. Male humpback whales may change their behaviour or singing location depending on the strength and direction of the tidal current, considering that the selection of a stable location is beneficial for singing whales. [ABSTRACT FROM AUTHOR]