Seagrass meadows are recognized as critical and among the most vulnerable habitats on the planet. As a worldwide concern, there is an urgent need to develop techniques to restore and preserve these vital coastal ecosystems due to their alarming decline rate. To effectively preserve and restore seagrasses, more research is required on the germination ecology of seeds. The seagrass Zostera japonica Asch. & Graebn is an endangered species in its native range, the Northwestern Pacific Coast. The present study investigated the germination and seedling establishment in Z. japonica seeds (collected from northern China) under different temperature and salinity conditions to explore suitable seed germination and establishment conditions, as well as the seedling formation process. Results showed that salinity had a more significant influence on seed germination rate. Germination rate decreased with an increase in salinity, and seeds did not germinate when salinity was higher than 40 psu. Temperature was more likely to influence germination speed, which increased with an increase in temperature, with high germination rates and the most rapid germination speed observed at 30 °C. Therefore, the optimal culture conditions were 10 psu salinity at 30 °C for germination and 10–20 psu salinity at 20 °C for seedling establishment, with a seed germination rate of 45.6% after 6 days of germination culture and a seedling establishment rate of 14.3% after 6 days of seedling culture, respectively. A new seedling raising method with low salinity (5 psu) germination and high salinity (20 psu) seedling establishment was proposed and a flow chart of seedling formation of Z. japonica was created. The results provide insight into the seed germination and seedling establishment in Z. japonica, and will facilitate future large-scale seedling culture and field restoration activities for this seagrass species.

Oceanographic processes are examined and used to assess their effect on the movement and dilution of wastewater discharged from Sydney's three deepwater ocean outfalls. Such processes link wastewater discharges with observed changes in biological communities and the accumulation of contaminants in the sediments. The East Australian Current, coastal trapped waves and local winds contribute 40%, 20% and 10% respectively to the total spectral energy in the along-shore currents off Sydney. Median dilutions at the edge of the initial dilution zone range between 185:1 and 347:1. Plumes remain submerged 95% of the time, surfacing only in the middle of winter and during large storms. Negatively buoyant particles sink from the plumes and first reach the ocean floor within 10 km of the discharge location. Resuspension of the sediments due to currents occurs 2.5% of the time and due to waves 1%–4% of the time.

Zooplankton were studied in the largest scale investigation in the South Yellow Sea in spring 2007 by using large plankton net when the green tide hasn't yet occurred. Ninety-six zooplankton species were identified. Copepods, pelagic larvae and hydromedusae were comprised of the largest number of species; Calanus sinicus, Paracalanus parvus, Aidanosagitta crassa, Euphausiidae larvae, Oithona plumifera and Corycaeus affinis were dominant species and their abundance comprised 81.65% of total abundance. Three high abundance areas contained with an average of 224.31 ± 247.93 individual/m³, with an average total biomass of 674.33 ± 1696.92 mg/m³; The average of Shannon-Wiener diversity, Pielou evenness and Margalef richness was 1.96 ± 0.61, 0.50 ± 0.14 and 2.31 ± 0.95, respectively. The Shannon-Wiener diversity and Pielou evenness showed positive correlation with bottom temperature, while Shannon-Wiener diversity and Margalef richness were positively correlated with bottom salinity. Additionally, Pielou evenness and Margalef richness showed negative correlation with total abundance which indicated that sampling efforts might affect the findings.

Seabed debris is much less investigated in respect to the sea surface and shores due to sampling difficulties and costs. However, detecting marine benthic litter is fundamental for developing policies aimed at achieving the Good Environmental Status in European Seas by 2020, as requested by the Marine Strategy Framework Directive.This study estimates seafloor litter abundance, composition, spatial distribution and main sources in the North-Central Adriatic Sea (FAO GSA 17) over a six-year period (2011–2016) with 67 stations sampled per year, representing the longest data set for the basin. Litter items collected using a “rapido” trawl were classified in six major categories.The average density of the litter collected over six years was 102.66 ± 41.91 kg/km2. The highest concentration of litter was found in stations close to the coast within 30 m depth with a mean weight of 142.90 ± 27.20 kg/km2, while the lowest value was recorded between 30 and 50 m of depth (41.12 ± 9.62 kg/km2). Plastic was dominant followed by metal and other litter materials. Lost fishing nets and mussel culture debris accounted for 50% of the overall plastic litter collected. These data and the systematic monitoring of marine litter provide useful information to implement necessary measures to manage marine litter and minimize this type of anthropogenic pollution in the Adriatic region.

The impact of ghost fishing in large coastal ecosystems has generated considerable interest. In smaller, understudied systems with fewer stakeholders, derelict fishing gear (DFGs) may have impacts similar to these larger systems at the same relative scale. Four years of side scan sonar surveys in the Mullica River-Great Bay Estuary (New Jersey, USA) supported the recovery of 1776 DFGs off-season by commercial partners. Locations with high densities of recovered DFGs (>200 DFGs/km²) occupied intersections of recreational vessel traffic and commercial crabbing activity. Condition and depth-in-sediment of recovered DFGs was used to evaluate true bycatch (terrapins, whelks, blue crabs) versus species utilizing degraded gear as habitat (juvenile tautog, oyster toadfish). Critically, gear recovered in-season with low cost sonars (an additional 225 DFGs) prevented the accumulation of new DFGs which likely generate the highest percentages of bycatch. Removal of DFGs in this system led to significant ecological (reduced bycatch), economic (>$61,000 in direct pay, reused gear), and anticipated future benefits (increased harvest).

The hypothesis that carnivorous consumers associated with the seabed are more likely to ingest marine debris was tested based on stomach content analysis of fish (Trichiurus lepturus and species of Ariidae) and cetaceans (Sotalia guianensis and Pontoporia blainvillei). Among 596 stomach contents, only 22 (3.7%) contained debris. The debris was flexible plastic, nylon yard, paper, latex, styrofoam and cigarette filter. The proportion of stomach contents with debris varied among species: P. blainvillei (pelagic demersal consumer) presented the highest frequency of ingestion (15.7%), while T. lepturus (pelagic consumer), S. guianensis (pelagic consumer) and Ariidae (demersal consumer) presented similar frequencies (1.3–1.8%). Therefore, a feeding site in the water column does not predict the probability of debris ingestion. Concerning these species, this probability seems to be more associated with prey-capture strategies (or feeding behavior), regardless of debris availability in the environment.

As microplastic pollution evolved to a well-established research field, microplastic scientists started to explore new avenues in the field. Yet, while a multitude of different types of microplastics (microbeads, fibres, fragments) have been well-documented in microplastic literature, our analysis of this literature shows that glitter particles have been overlooked by the field. However, due to the presence of glitter-based research in forensic science, we explore the idea that glitter may have the potential to act as “flag items” - or markers – of a likely source, due to the often complex and individual composition of glitter particles compared to traditional microplastics, such as microbeads. As such, this article demonstrates glitter has insofar been overlooked as a microplastic particle, and demonstrates that glitter may have an important role in explaining microplastic pollution dynamics from source to sink.

Particle flux material collected in 2000 m depth in the Northeast Atlantic at 33°N and 22°W was analyzed for trace metals and persistent organic pollutants. Element enrichment factors relative to lithogenic Al were elevated indicating possible anthropogenic contributions for all trace metals except V. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls and the pesticide DDT exhibited median fluxes of 10.40 μg m⁻²d⁻¹,0.29 μg m⁻² d⁻¹, and 0.90 μg m⁻² d⁻¹, respectively. Flux composition reflected long range transport, with low molecular weight and low-chlorinated compounds dominating ∑₁₅PAH and ∑₂₃PCB. PAH isomer ratios identified fossil fuel combustion as the main ∑₁₅PAH source. The composition of ∑₄DDT suggested inputs of the fresh technical pesticide during high dust intensity periods. Pollutant fluxes showed seasonality linked to export production in the region, as well as a dependence on annual and sub-annual dust input events.

Despite the increasing interest in microplastic (MP) research, the accurate prevalence, distribution and fate of these materials in the environment is yet poorly known and, consequently, a focus of debate. Hence, to better ascertain the presence of microplastics in specific environments, samples from 35 random sites distributed across a 4200-meter long section from the area of Sidi Mansour, Sfax-Tunisia, were collected and analyzed. MPs were extracted, digested with potassium hydroxide and dyed with Eosin B, for visual microscopy counting and sorting. Polymer composition and surface morphology were identified by FTIR-ATR spectroscopy and SEM microscopy. Total abundances ranged from 252 to-5332 particles per m² where fragments and granules were the most frequent types of microplastics. These findings highlight the considerable presence of these materials in the studied harbor region and underscore the density dependence on the distribution and occurrence of MPs and how these tend to accumulate in the sandy sediments.

The Sergipe River estuary has been subjected to a range of anthropogenic activities including food, plastic, textile, ceramic and metallurgical production plants along with domestic sewage inputs, all of which are of environmental concern. In this study, the levels of fecal coliforms (FC) in surface water samples and sterols in superficial sediment samples collected from the Sergipe River estuary were determined. Based on the FC concentrations, 58% of the water samples were considered Water Potentially Unusable (WPU) according to the United States Environmental Protection Agency (USEPA). Concentrations of coprostanol ranged from 13 to 1072 ng g−1, indicating a significant input of sewage at some points in the estuary. Principal Component Analysis (PCA) showed that there is no clear correlation between the coprostanol and coliform data, which may be due to the high resistance to degradation of coprostanol in sediments and to recent inputs of sewage at the water sample collection points.