Effect of temperature and sunlight on the leachability potential of BPA and phthalates from plastic litter under marine conditions.

This study investigates the leaching potential of several additives embedded in six different plastic types when exposed to extreme simulated marine conditions for 140 days. The findings achieved herein contribute to a better understanding of the impact of macro- and microplastics leaching harmful compounds (bisphenol A (BPA) and phthalates) in the marine environment when exposed to harsh climatic conditions. Leachability experiments showed that bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and BPA were detected in seawater (SW) samples. Furthermore, while analysing 100 mL of SW per each sample, the total leachate concentrations of the identified compounds ranged from 5 µg/L to 123 µg/L, after 140 days of exposing a total of 120 plastic samples (96 samples micro- and 24 macro-plastics) to SW conditions It was observed that the leaching of DEHP was promoted by wave abrasion, high temperature and sunlight, while the leaching of DBP was favoured by wave abrasion. Findings showed that polypropylene (PP) was the most attributable plastic type in the leaching of DBP with an average concentration of 5.3 µg/L, whereas high-density polyethylene (HDPE) was the most responsible plastic-type for the leaching of DEHP, with an average concentration of 123 µg/L. Our results suggest that most of the phthalates and BPA will, ultimately, leach out to the SW environment after a longer period.

Contamination of planktonic food webs in the Mediterranean Sea: Setting the frame for the MERITE-HIPPOCAMPE oceanographic cruise (spring 2019).

This paper looks at experiential feedback and the technical and scientific challenges tied to the MERITE-HIPPOCAMPE cruise that took place in the Mediterranean Sea in spring 2019. This cruise proposes an innovative approach to investigate the accumulation and transfer of inorganic and organic contaminants within the planktonic food webs. We present detailed information on how the cruise worked, including 1) the cruise track and sampling stations, 2) the overall strategy, based mainly on the collection of plankton, suspended particles and water at the deep chlorophyll maximum, and the separation of these particles and planktonic organisms into various size fractions, as well as the collection of atmospheric deposition, 3) the operations performed and material used at each station, and 4) the sequence of operations and main parameters analysed. The paper also provides the main environmental conditions that were prevailing during the campaign. Lastly, we present the types of articles produced based on work completed by the cruise that are part of this special issue.

Acute and chronic toxicity assessments of 17ß-estradiol (E2) and 17α-ethinylestradiol (EE2) on the calanoid copepod Acartia clausi: Effects on survival, development, sex-ratio and reproduction.

Estrogens, such as the 17ß-estradiol (E2) and the 17α-ethinylestradiol (EE2), have been regarded as a global threat to aquatic ecosystems due to their pseudo-persistence, their high estrogenic activity and their toxicity towards non-target species. Data regarding their ecotoxicological effects on marine calanoid copepods are very scarce. In this study, the calanoid copepod Acartia clausi was used as a model organism for estrogens exposure in marine pelagic ecosystems. Lethal effects of estrogens on A. clausi life-stages (Embryos, one day old nauplii: N1, three day old nauplii: N3, copepodites: C1-C3 and adults: C6) were investigated using 48 h acute tests. Copepods showed stage-specific responses against E2 and EE2 acute exposure. The most resistant life stage was N1 with LC50 values > 1500 µg L-1 and >5000 µg L-1, respectively for E2 and EE2. For N3, C1-C3, and C6, sensitivity to estrogens decreased with age and survival was affected at concentrations above those detected in the environment reflecting low estrogens acute toxicity for these life stages. In contrast, embryonic stage revealed high vulnerability to E2 and EE2 acute effects. Embryos showed non-monotonic dose-response and hatching success was significantly reduced at low realistic concentrations of E2 (0.005, 0.5, and 5 µg L-1) and EE2 (0.05 and 5 µg L-1). Survival, development and sex ratio of A. clausi to EE2 exposure at 1 and 100 µg L-1 were also determined during a life cycle experiment. Fitness of the females of the generation F0 was evaluated by measuring lifespan, prosome length and egg production. The main observed effects were the decrease of females' prosome length, the feminization of the population and the reduction of the egg production for the generation F0 at 100 µg L-1 of EE2. This concentration is above those reported in the environment indicating the tolerance of A. clausi to EE2 at environmentally relevant concentrations.

Effects of nickel oxide nanoparticles on survival, reproduction, and oxidative stress biomarkers in the marine calanoid copepod Centropages ponticus under short-term exposure.

Excessive use of nickel oxide nanoparticles (NiO NPs) in various industrial and commercial products can lead to various negative effects in human and environmental health due to their possible discharge into the environment. Nerveless, information about their ecotoxicological effects on marine organisms are lacking. Copepods are good ecotoxicological models because of their high sensitivity to environmental stress and their key role in the marine food webs. In this study, 48 h acute tests were conducted on the marine planktonic copepod Centropages ponticus to assess lethal and sublethal toxicities of NiO NPs. The results revealed LC50 (48 h) of 4 mg/L for adult females. Aggregation and settling of NiO NPs were observed at concentrations ≥ 2 mg/L. Exposure to sublethal concentrations (≥ 0.02 mg/L for 48 h) had significant negative effects on reproductive success in C. ponticus. Egg production after 24 h and 48 h decreased by 32% and 46%, respectively at 0.02 mg/L and 70% and 82%, respectively, at 2 mg/L. Hatching success was reduced by 70% and 79% at 2 mg/L for eggs produced after 24 h and 48 h respectively. Antioxidant enzymatic activity increased significantly with NiO NP concentration and time, indicating that NiO NPs can cause oxidative stress in C. ponticus even under short-term exposure, while significant inhibition of acetylcholinesterase activity at 2 mg/L after 48 h suggests neurotoxic effects of NiO NPs.