The heavy metals (Cu, Cr, Zn, Cd, Pb) were analysed for 217 surface sediment samples collected across 14 typical intertidal zone areas in China. The data reveals the heavy metals spatial distribution patterns and correlations among their concentrations. Cu, Zn, Cd and Cr showed similar trends of spatial variation and the correlations between the concentrations of every two heavy metals were significantly positive except for the correlation between Pb and Cr concentrations. By using Nemerow index method, Enrichment factor and Sediment Quality Guidelines, it is found that Hangzhou Bay and Jiulong River Estuary were polluted, Yingluo Bay and Dongzhaigang Bay were Cd-rich areas. Except Beidaihe shoal, Sishili Bay and Yingluo Bay that were not exposed to any ecological risk of heavy metals and had no adverse biotoxic effects, the other 11 typical intertidal zone areas were exposed to moderate ecological risk of heavy metals in the sediment with potential adverse biotoxic effects.

Sediment samples were collected from Caofeidian Long Island, China to investigate the contamination level and distribution pattern of 16 polycyclic aromatic hydrocarbons (PAHs). Source identification and risk assessment were also performed on these PAHs. The distribution patterns and source identification results indicated that the PAHs in the survey area originated from coal, biomass, and petroleum combustion as well as the combination of these three processes. Although the concentration of fluorene in the sediment exceeded the ERL level in some sampling sites, the effect range low–effect range median ratio implied a relatively low level of toxicity in these sediments. Meanwhile, the mean effects range–median quotient indicated that the 16 PAHs in sediments from Caofeidian Long Island pose a low ecological risk.

The strandline is one of the first deposition habitats of microplastics before they are integrated to the beach as a standing stock or finally removed. Beaches, entirely or partially protected by beachrocks, have different sediment dynamics and therefore may present variation in microplastic deposition. The aim of this work was to test if protected and unprotected (i.e., exposed to waves) areas of a sandy beach present different microplastic accumulation on the strandline – a habitat greatly influenced by both water and sediment dynamics. Microplastic (MP) amounts were significantly higher at the protected area (Mprotected = 642.6 ± 514.8 MP m−2, Mexposed = 130.6 ± 126.8 MP m−2, Mann-Whitney U test, U = 14.5, p = 0.0009), showing that beachrocks influence microplastic accumulation on the beach face. Therefore, hard structures parallel to the beach may also affect microplastics deposition on beach sediments, being important to consider these structures on microplastic surveys.

Shipping is understood to be a major vector for the introduction and spread of marine non-indigenous species (NIS). However, recreational boating is still unregulated and its influence as vector has not yet been assessed for the Mediterranean Sea, which is the second most popular recreational boating destination worldwide. This is the first large-scale study to examine this by a combined biological (analyzing hull and marina fouling) and social approach (boaters surveys on maintenance habits, travel patterns and awareness), focused on peracarid crustaceans. A surprisingly high number of NIS were found on vessels cruising Mediterranean waters, and species compositions suggest an exchange between marina and vessel assemblages. This means recreational boating presents a risk for NIS spread which should warrant regulation. Results also implied that regionally coordinated management should be supported by effective local-scale-based management in the Mediterranean, which could improve upon with targeted environmental education to solve lack of awareness.

Toxicity of weathered oil was investigated using Atlantic cod (Gadus morhua) larvae. A novel exposure system was applied to differentiate effects associated with dissolved and droplet oil with and without dispersant. After a 4-day exposure and subsequent 4-day recovery period, survival and growth were determined. Analytical data characterizing test oil composition included polyaromatic hydrocarbons (PAH) based on GC/MS and unresolved hydrocarbon classes obtained by two-dimensional chromatography coupled with flame ionization detection was used as input to an oil solubility model to calculate toxic units (TUs) of dissolved PAHs and whole oil, respectively. Critical target lipid body burdens derived from modeling characterizing the sensitivity of effect endpoints investigated were consistent across treatments and within the range previously reported for pelagic species. Individually measured PAHs captured only 3–11% of the TUs associated with the whole oil highlighting the limitations of traditional total PAH exposure metrics for expressing oil toxicity data.

The Eastern Arabian Sea (EAS) is affected by oil pollution, as often evidenced by the presence of tarballs along the West Coast of India (WCI). Tarball samples collected during May 2017 along the Goa coast were subject to biomarker fingerprints, and the results matched with Bombay High (BH) oil fingerprints. The present study primarily aims at identifying the potential minor spill areas using Sentinel-imagery. Interestingly, repeated occurrence of oil spills detected at two locations, perfectly matched with BH platforms. The simulated Lagrangian trajectories also depict that tarball particles have originated from those detected locations. In 2017 alone, the quantity of spilled oil was estimated to be 129,392 l. However, spills detected offshore regions of Kachchh and Mangalore were found to be caused by ships. This is the first comprehensive study, tracking the oil pollution sources in the EAS through multi-technique approach - chemical, remote sensing and numerical modeling.

The present study describes the novel use of fatty acids (FAs) and element profiles of Octopus vulgaris inhabiting three coastal areas in the W-Mediterranean Sea. These populations are exposed to different anthropogenic activities, and were compared at different geographical scales. The FA composition in the mantle of O. vulgaris exhibited significant differences in 22:6 n−3 (DHA) and 22:5 n−3 (EPA) among the sampled populations. The essential microelements Fe, Cu, Zn and Ni, and the non-essential microelements As, Sr, Al and Cd were the main contributors of variability among sampled octopus populations, with some notable differences among tissues. The variations in the FAs and elemental composition in octopus tissues were detected with other populations throughout the species distribution range, which might reflect differences in natural habitats and foraging strategies. Therefore, these may be considered biomarkers as a proxy to distinguish the origin of octopus specimens at different scales.

Understanding the fate of spilled oil in cold environments is essential for oil spill response in Arctic areas. The potential for oils to adhere to sea ice and mechanical skimmers can significantly impact the success of oil spill response and influence the fate of oil in the marine environment. Therefore, the affinity of oil to sea ice and skimmer material was quantified experimentally for three different types of oils at various degrees of weathering. Contact angle measurements of crude oil droplets were performed on the top of and under sea ice and polyethylene-based skimmer material, being submerged in seawater (−2 °C). In addition, “dip- and refloat” tests were performed to quantify the adhesion and study the re-floating process of oil from sea ice at −2 °C (moist ice) and −20 °C (cold dry ice), and from a skimmer material prior to and subsequently to its submersion in seawater (−2 °C). The results indicated limited interaction of oils with sea ice submerged in seawater, but a strong affinity of oils towards polyethylene-based skimmer material.

Marine litter is a global concern. Since most of the litter sinks, understanding the composition of benthic marine litter is crucial for addressing this concern. However, high costs of seafloor monitoring inhibit such understanding. Consequently, benthic marine litter in the Baltic Sea has not been comprehensively addressed yet. Here we present data from 2377 hauls, which collected 6828 litter items and 2412 kg on the Baltic seafloor during six years of the Baltic International Trawl Survey (BITS) by seven nations. Our results show lower percentages of plastic (35%) than the widely cited world average (70%) and less fishery-originated litter (2.2–5.6%) than was previously reported for the Baltic Sea (4–24%). Natural products, mostly residuals of burnt coal, were identified as the most common litter category (42–57%) and were largely ignored in the past. Our results highlight the importance of using several evaluation metrics, particularly number of items, weight and encounter probability.

Ocean acidification (OA) has potential to affect marine phytoplankton in ways that are partly understood, but there is less knowledge about how it may alter the coupling to secondary producers. We investigated the effects of OA on phytoplankton primary production, and its trophic transfer to zooplankton in a subtropical eutrophic water (Wuyuan Bay, China) under present day (400 μatm) and projected end-of-century (1000 μatm) pCO2 levels. Net primary production was unaffected, although OA did lead to small decreases in growth rates. OA had no measurable effect on micro-/mesozooplankton grazing rates. Elevated pCO2 had no effect on phytoplankton fatty acid (FA) concentrations during exponential phase, but saturated FAs increased relative to the control during declining phase. FA profiles of mesozooplankton were unaffected. Our findings show that short-term exposure of plankton communities in eutrophic subtropical waters to projected end-of-century OA conditions has little effect on primary productivity and trophic linkage to mesozooplankton.