Pile driving occurs during construction of marine platforms, including offshore windfarms, producing intense sounds that can adversely affect marine animals. We quantified how a commercially and economically important squid (Doryteuthis pealeii: Lesueur 1821) responded to pile driving sounds recorded from a windfarm installation within this species' habitat. Fifteen-minute portions of these sounds were played to 16 individual squid. A subset of animals (n = 11) received a second exposure after a 24-h rest period. Body pattern changes, inking, jetting, and startle responses were observed and nearly all squid exhibited at least one response. These responses occurred primarily during the first 8 impulses and diminished quickly, indicating potential rapid, short-term habituation. Similar response rates were seen 24-h later, suggesting squid re-sensitized to the noise. Increased tolerance of anti-predatory alarm responses may alter squids' ability to deter and evade predators. Noise exposure may also disrupt normal intraspecific communication and ecologically relevant responses to sound.

Underwater survey was conducted to assess the accumulation and impact of marine debris in the reef areas of Gulf of Mannar in southeast India. A combination of roving diver technique and belt transect method was applied for the assessment, which was conducted during the period between February 2018 and March 2019. An estimated total reef area of 1152 m² has been affected by marine debris. Abandoned fishing nets were found to constitute the major portion of 43.17 ± 5.48% of the marine debris. Live corals were found to be dominant substrates for marine debris with 39.11%. The average prevalence of coral colonies in contact with marine debris was 3.28 ± 0.27%. Prevalence of corals in contact with debris was very high in genus Acropora with 8.23 ± 1.29% followed by Montipora with 4.63 ± 1.29% due to their complex growth form. Of the corals in contact with debris, 47.56% were fragmented and 34% were found with tissue loss.

Three species of mangroves and six species of salt marshes were collected from various locations along the Tuticorin coast for the estimation of metals like Cu, Cd, Pb, and Zn. The bioaccumulation of metals in mangroves is in the order of Cu > Pb > Zn > Cd, and the season-wise accumulation was higher in monsoon followed by summer, post-monsoon, and pre-monsoon seasons. The accumulation of metals in mangroves showed higher in Rhizophoraapiculata followed by Avicenniamarina, and Rhizophoramucronata. The concentration of metals in salt marshes is in the order of Pb > Zn > Cu > Cd, and the species-wise accumulation showed in the order of Suaeda maritime > Ipomoea sp. > Suaeda sp. > Spinifix littoreous > Sesuvium portacastrum > Ipomoea pes-capras. BAF in salt marhes and mangroves is as Cd < Pb < Cu < Zn and Cd < Cu < Pb < Zn, respectively.

The distribution characteristics, correlation, and bioavailability of 14 trace elements in different fishes and corals collected from the coral-reef systems of the Xisha Islands, China were systematic studied for the first time. All detected elements were measured using inductively coupled plasma mass spectrometry after pretreatment by microwave digestion. The fishes had slight differences in element enrichment selectivity and bioavailability with average levels as follows: V, 0.100 mg·kg⁻¹; Cr, 0.683 mg·kg⁻¹; Mn, 1.178 mg·kg⁻¹; Fe, 51.806 mg·kg⁻¹; Co, 0.072 mg·kg⁻¹; Ni, 1.286 mg·kg⁻¹; Cu, 1.428 mg·kg⁻¹; Zn, 10.384 mg·kg⁻¹; As, 6.437 mg·kg⁻¹; Se, 0.830 mg·kg⁻¹; Mo, 0.101 mg·kg⁻¹; Cd, 0.051 mg·kg⁻¹; Pb, 0.308 mg·kg⁻¹; and U, 0.008 mg·kg⁻¹. Trace element contents in corals were higher than those in fishes. The distribution characteristics of trace elements in fishes and corals presented a significant correlation in North Reef and Yongle Atoll, thereby indicating an evident effect on living areas compared with trace elements in fishes from the Spratly Islands. Cluster analysis of fishes and corals based on trace elements showed that they had different selectivities and bioavailabilities to trace elements. The EDI and THQ ratios of Cu, As, Cd, Cr, and Pb demonstrated that fishes were unlikely to experience serious adverse effects, except for As in Chaetodon auriga, Myripristis kuntee, Gnathodentex aureolineatus, and Hemigymnus melapterus in Xisha Islands.

The aim of the present study was to risk screen 45 jellyfish species (30 hydromedusae, 14 scyphomedusae, one cubomedusa) for their potential invasiveness in the Mediterranean Sea to aid managers in making informed decisions on targeting appropriate species for management. Using the Aquatic Species Invasiveness Screening Kit (AS-ISK), calibrated basic and climate-change threshold assessment scores of 6.5 and 12.5, respectively, were identified for distinguishing reliably between species that pose ‘low-to-medium’ and ‘high’ risk of becoming invasive in the risk assessment area. Using these thresholds, 16 species were classified as high risk, 23 as medium risk and six as low risk under current climate conditions. Whereas, under future climate conditions, 13, 30 and two species, respectively, were classified as high, medium and low risk, respectively. Upside-down jellyfish Cassiopea andromeda, Australian spotted jellyfish Phyllorhiza punctata, sea nettle Chrysaora quinquecirrha and Rhopilema nomadica were the highest-scoring species, with the maximum increase in risk score under predicted climate change conditions being achieved by C. andromeda.

Microplastic pollution is a problem of global scale, posing a threat to marine biota. To determine the current state of microplastic pollution on four popular sandy beaches of the coast of Lima, Peru, a sampling campaign was carried out in both intertidal and supralittoral zones. Microplastic abundance, type, size, color and distribution were recorded. The overall microplastic abundance was of the same order of magnitude as previous data obtained in Peru. Foams were the most abundant (78.3%) microplastic type. Statistical analyses revealed significant differences between sites and zones. High variability of microplastic abundance was found among adjacent beaches and zones. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that all foams were identified as polystyrene. The present results revealed an alarming level of microplastics present on Peruvian sandy beaches, but information about the sources, local dynamics and impacts of microplastics in this region are scarce, and thus further research is needed.

The application of chemical dispersants is one option of oil spill response (OSR). Here, Northern shrimp (Pandalus borealis) larvae were experimentally exposed for short periods (6 h and 1 h) to a realistic concentration of chemically dispersed oil (CDO) (~10 mg L⁻¹ THC), mechanically dispersed oil (MDO) (~7 mg L⁻¹ THC), and dispersant only (D). A control (C) with seawater served as reference. Short-term effects on survival and feeding were examined right after exposure and longer-term consequences on survival, feeding, growth and development following 30 days of recovery. Both exposure durations provoked long lasting effects on larval fitness, with 1 h exposure leading to minor effects on most of the selected endpoints. The 6 h exposure affected all endpoints with more adverse impacts after exposure to CDO. This study provides important data for assessing the best OSR option relevant to NEBA (Net Environmental Benefit Analysis).

This work provides the first spatial distribution report of micropollutants (MPs) in the entire Portuguese coast, comprising the ocean shore (sea water, SW) and whenever possible the nearest river discharging on it (estuarine water, EW). This surface water monitoring programme aimed to assess the spatial distribution of 37 MPs with a wide chemical nature, including some substances prioritized by the European Union Directive 39/2013/EU and contaminants of emerging concern targeted in the Watch List of Decisions 495/2015/EU and 840/2018/EU. The risk quotients were estimated in each sampling point for the detected MPs. High concentrations of diclofenac, tramadol and carbamazepine were determined, the latter with medium to high risk for algae. Some pharmaceuticals and perfluorooctanesulfonic acid (PFOS) were broadly distributed, maybe due to the direct discharge into the sea. Atrazine and alachlor were found in the majority of the samples, with alachlor levels often considered as medium to high risk.

Hypoxia (O₂ ≤ 2 mg L⁻¹) can severely threaten the survival of marine life and alter the biogeochemical cycles of coastal ecosystems. Its impacts are dependent on its duration. In the present study, hypoxia was observed in autumn at the end of October 2011. It may be one of the latest recorded annual hypoxic events in the East China Sea (ECS). In the hypoxic regions, a large amount of nutrients and dissolved inorganic carbon were observed to regenerate. Also, acidification (low pH) was observed. On the other hand, hypoxic dissipation may be due to the destratification caused by the upwelling of the hypoxic regions in the ECS. These results suggest that hypoxia may occur for longer periods of time than expected and, accordingly, the effects of hypoxia on the ECS ecosystems should be reconsidered and further evaluated.

Oil weathering is often described subjectively after a spill. Adjectives like “moderate” and “severe” help define the extent of oil loss but fail to communicate quantitatively and reproducibly the degree of weathering. The use of subjective weathering terms often leads to misperceptions about persistence and toxicity of oil residues in the environment. The weathering of MC252 oil from the Deepwater Horizon spill started immediately after release during the 1500-m ascent to the sea surface and continued as it was transported on the surface and reached the shoreline. Weathering processes included evaporation, dissolution, photo-degradation, and biodegradation, among others. With extensive sample collection and detailed chemistry and source fingerprinting analyses, the Deepwater Horizon data provide a unique opportunity to evaluate weathering processes semi-quantitatively. An objective method of defining the degree of oil weathering is developed based on the detailed chemical results for over 700 MC252 oil samples from the environment.