Increasing human activities have caused the accumulation of dissolved organic nitrogen (DON) in the ocean, which can alter dominant coastal phytoplankton species. However, insights into DON's effects on marine phytoplankton growth are insufficient compared with those of dissolved inorganic nitrogen (DIN), especially regarding the role of specific DON components. Therefore, in this study, the effects of the hydrophilic (Hic) and low molecular weight (LMW) components of two anthropogenic DON sources on the growth and bioavailable nitrogen uptake of phytoplankton were studied using in situ cultural experiments conducted in Jiaozhou Bay, China. Animal-derived DON from domestic and livestock breeding showed a higher bioavailability compared with that of vegetal DON derived from agricultural sources, with bioavailable component proportions of 76% ± 4% and 66% ± 3%, respectively. Both forms of DON could be absorbed by Skeletonema costatum, stimulating it to become the dominant species in the mesocosm ecosystem; the hydrophilic components of DON contributed approximately 75% of the uptake of DON by S. costatum. The bioavailability of LMW DON was significantly (p < 0.05) lower than that of the Hic DON. The high bioavailability of the Hic DON was mainly associated with its protein-like T1 and T2 components, identified using parallel factor analysis on the excitation-emission-matrix spectra, while the low bioavailability of LMW DON was mainly associated with the humus-like A component. The protein-like T2 components may be directly absorbed by algae, while T1 may be transformed through mineralization and algal absorption. Understanding the impacts of anthropogenic DON and its components on phytoplankton will help improve coastal environmental management. More knowledge of the effect of anthropogenic DON on the phytoplankton community structure in coastal waters should be accumulated in the future.

Among the various pollutants released into the environment, there are persistent organic pollutants (POPs). Chelonia mydas are one of the species that can be exposed to these pollutants and it is classified in the IUCN Red List as “endangered”. The present study evaluated the occurrence of POPs in 49liver tissue samples of C. mydas juveniles collected on the southeastern Brazilian coast. Furthermore, the concentrations were correlated with carbon and nitrogen isotopic ratio, biometrics, and ecological factors. The main POPs found were ƴ-HCH and PCBs. Overall, the concentrations found were low and there were no significant correlations among POPs, isotopic ratios, size and weight, which may be related to the fact that the studied individuals are juveniles and occupy similar trophic positions despite the individual variations found. Despite the low concentrations, the presence of POPs, mainly PCBs, in the sea turtles' liver indicates their exposure to these compounds.

Natural coastlines are being replaced by artificial structures (pilings, pontoons, breakwaters), with negative environmental impacts, particularly in marinas. Ropes seeded with mussels (Mytilus galloprovincialis) were added to artificial structures in a marina, using aquaculture techniques, to reduce the colonisation of invasive taxa. After 6-months, droplines beneath pontoons had the highest seeded mussel survival and growth, richness of native and invasive taxa, and proportion of invasive to native taxa, compared with the other interventions. Mussel ropes on the intertidal structures (pilings and breakwaters) supported higher biomass of native taxa, whereas mussel ropes on subtidal structures (pontoons and breakwaters) had reduced biomass of invasive taxa, relative to the unseeded ropes. Droplines had the greater biomass of mussels, while mussel ropes placed under pontoons, and in subtidal gabion baskets limited the biomass but not the diversity of invasive species. Further study is required to determine whether these interventions can be upscaled to improve both the native biodiversity and functioning of marinas.

Recently, the quickly growing population living in urban location has caused numerous conflicts related to increase in water demand and water pollution. In urban areas, the surface water bodies allow runoffs and storms and in addition act as wastewater drainage pathways. Mostly, the imperfect separation of rainwater and clean wastewater has made large quantities of wastewater discharged into the surface water, resulting in serious pollution. There are many treatment methods for the polluted water bodies such as coagulation, filtration, and ecological floating bed which are related to nutrient removal. The above listed methods are usually capable in reducing pollution load. Wastewaters generated from two sources such as point source (domestic and industries) and non-point source (agricultural and storm water runoff). Finally it reaches nearby water bodies and the abovementioned methods are to be frequently employed in a wastewater treatment plant to remove nutrients. Most of the pollutants in the vastly polluted water are in dissolved forms; hence, an appropriate treatment method relevant to the design and development of the integrated multistage reactor with extended wastewater treatment is reviewed in this paper. Evaluating the accumulation, precipitation, retention, and removal of phosphorus, along with removal of nitrogen, is discussed in brief.

Angra dos Reis can receive up to 1.3 million tourists in the summer season. The lack of an adequate sanitary system makes sewage contamination a growing concern in Ribeira Bay, Angra dos Reis, Brazil. This study aims to investigate the seasonal variation of faecal indicator bacteria (FIB) and abiotic variables in Itanema cove situated within Ribeira Bay. Despite the seasonal population increase (>80 individuals) and the absence of an integrated sanitary system, our results indicate that Itanema is still a stable estuarine environment. From 2017 to 2019, the mean salinity was 27.91, pH was 7.82, and water temperature was 25.01 °C. However, the FIB number was 10⁵, suggesting the absence of sewage treatment in Itanema's outfall. Following current conservation status, baseline studies are mandatory for background references of endangered coastal areas such as Itanema cove. These studies are crucial for future governance decisions and sustainable tourism implementation in Angra dos Reis.

Marinas have ceased to be ports dedicated exclusively to recreational boating and nautical sports. Nowadays, marinas offer a variety of services that complement the tourist offering of its locality in addition to auxiliary activities that arise from its main activity. There are considerable economic and social resources generated by these types of facilities that benefit their localities, but they can also have negative effects such as compromising the sustainability of the environment.The objective of this article is to examine the terms related to changes in the ecosystem derived from marinas through the Keywords Plus and the Author Keywords extracted from the WoS database and obtain results that explain how several themes have evolved and how these concepts relate to each other and to other variables. In this way, it will be possible to critically examine the selection of terms that appear in scientific documents. The results show that pollution, antifouling paints, and invasive species are the terms of greatest concern and on which particular emphasis should be placed for future lines of research.

Nitrogen (N) from anthropogenic sources has been identified as a major pollutant of the Great Barrier Reef (GBR), Australia. We developed a conceptual framework to synthesise and visualise the fate and transport of N from the catchments to the sea from a literature review. The framework was created to fit managers and policymakers' requirements to reduce N in the GBR catchments. We used this framework to determine the N stocks and transformations (input, sources, and outputs) for ecosystems commonly found in the GBR: rainforests, palustrine wetlands, lakes, rivers (in-stream), mangroves and seagrasses. We included transformations of N such as nitrogen fixation, nitrification, denitrification, mineralisation, anammox, sedimentation, plant uptake, and food web transfers. This model can be applied to other ecosystems to understand the transport and fate of N within and between catchments. Importantly, this approach can guide management actions that attenuate N at different scales and locations within the GBR ecosystems. Finally, when combined with local hydrological modelling, this framework can be used to predict outcomes of management activities.

Progressive fragmentation of larger plastic debris due to the mechanical action of wind/waves, prolonged exposure to ultraviolet radiation, or biological degradation has led to the formation of microplastics or MPs (<5 mm). MPs are pervasive in nature and hence, ubiquitous in distribution across the global marine systems. The Arctic Ocean, despite its remoteness, has been reported to contain a high concentration of MPs. However, studies on the presence of MPs in the sediment compartments of the Arctic Ocean are relatively lesser than that of the water column, surface water and Arctic fauna. Similarly, MP pollution of the Arctic fjords remains understudied. Here, we present the occurrence of MPs in the sediments of Kongsfjorden, an Arctic fjord in the Svalbard archipelago. Sediment samples from eight locations in Kongsfjorden, when analyzed, reveal the presence of MPs in three sites, with values ranging from 4 to 24 MPs/kg (dry weight) sediment. The highest number of MPs was observed at site K5 (24 particles/kg). On an average, 2.87 MPs/kg were recorded and their size ranged from 55 μm to 381 μm. Stereomicroscopic observation of MPs indicated fragment and fibers as the morphotypes of MPs. Polymer profile analysis with micro-Raman spectroscope confirmed high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polyamide (PA) as the polymer components of the MPs found in the sediment samples. Of these, HDPE was the predominant polymer. Further detailed studies are needed to understand the source and the mechanisms involved in transporting MPs to the sediment and their impact on Arctic fjords.

Time-series datasets showing the gradual conformational change in the status and characteristics of microplastics (MP) in marine waters are needed to protect vulnerable marine ecosystems. In this study, the abundance, spatiotemporal distribution, polymer composition, size, and shapes of the MP in the seawater sampled from 0.5 (station-1), 2.5 (station-2), and 5 (station-3) miles off the coast of the southeastern Black Sea between 2009 and 2020 were investigated. The abundance of the MP ranged from 0.181 to 0.944 m⁻³. The amounts of MP in the stations, from the greatest to the smallest, were 0.65 MP m⁻³ (2), 0.45 MP m⁻³ (1), 0.29 MP m⁻³ (3). Thirteen types of polymers were detected by FTIR, the most abundant types of which were polyethylene (44.9%) and polyethylene terephthalate (25.3%). Sizes of MP ranged from 118 to 4998 μm, 50% being smaller than 2000 μm. The most dominant shape of the MPs was fragments (56.3%). Abundance did not show significant spatiotemporal changes. Periodical data presented herein may represent a remarkable projection and create a baseline for the ecosystem's future functioning and pollution research in the Black Sea.