Benthic octopuses have been widely documented in artificial shelters for decades, and this use is apparently increasing. Despite any possible positive effects, the use of litter as shelter could have negative implications. In this work, we aimed to elucidate the interactions of octopuses with marine litter, identifying types of interactions and affected species and regions. To achieve this, we obtained 261 underwater images from ‘citizen science’ records, and identified 8 genera and 24 species of benthic octopuses interacting with litter. Glass objects were present in 41.6% of interactions, and plastic in 24.7%. Asia presented the highest number of images, and most records were from 2018 to 2021. Citizen science provided important evidence on octopus/marine litter interactions, highlighting its value and the need for more investigations on the subject. This information is fundamental to help prevent and mitigate the impacts of litter on octopuses, and identify knowledge gaps that require attention.

The agrochemicals and nutrient losses from farming areas such as paddy farming significantly dictate quality and eutrophication of the freshwater resource. However, how farming and land use pattern affect water qualities and eutrophication remain poorly understood in most African agro-ecosystems. The present study characterized how paddy farming influences water qualities and eutrophication in 10 irrigation schemes in Usangu agro-ecosystem (UA). About 42 water samples were sampled from intakes, channels, paddy fields, and drainages and analyzed for EC, Cl, P, NH₄-N, NO₃-N, TN, Zn, Cu, Ca, and Mg. We observed water pH ranging from 4.89 to 6.76, which was generally below the acceptable range (6.5–8.4) for irrigation water. NH₄-N concentration was in a range of 10.6–70.0 mg/L, NO₃-N (8.4–33.9 mg/L), and TN (19.1–21,104 mg/L). NH₄-N increased along sampling transect (sampling points) from intakes (5.7–29.1 mg/L), channels (19–20 mg/L), fields (12.9–35.8 mg/L), and outflow (10.6–70.0 mg/L), the same trend were found for NO₃-N and TN. The TP determined in water samples were in the range of 0.01 to 1.65 mg/L; where some sites had P > 0.1 mg/L exceeding the allowable P concentration in freshwater resource, thus indicating P enrichment and eutrophication status. The P concentration was observed to increase from intake through paddy fields to drainages, where high P was determined in drainages (0.02–1.65 mg/L) and fields (0.0–0.54 mg/L) compared to channels (0.01–0.13 mg/L) and intakes (0.01–0.04 mg/L). Furthermore, we determined appreciable amount of potentially toxic elements (PTEs) such as Cu, Pb, Cd and Cr in studied water samples. The high N, P, and PTEs in drainages indicate enrichment from agricultural fields leading to water quality degradation and contaminations (eutrophication). The study demonstrates that water quality in UA is degrading potentially due to paddy rice farming and other associated activities in the landscape. Thus, the current study recommends starting initiatives to monitor irrigation water quality in UA for better crop productivity, and improved quality of drainage re-entering downstream through the introduction of mandatory riparian buffer, revising irrigation practices, to include good agronomic practices (GAP) to ensure water quality and sustainability.

Algal turfs form a critical interface on coral reefs that interacts with several key ecosystem processes. While we know these turfs have a remarkable propensity to accumulate sediments, which can have a range of ecosystem impacts, their role as sinks for heavy metals remains largely unexamined. Here we quantified the concentration of 15 metals in algal turf sediments from Lizard Island and Orpheus Island on the Great Barrier Reef, and specifically explored how the loads of arsenic, cobalt, iron and lead were related to turf length. Metal composition differed markedly between the two islands, with the composition at Orpheus Island suggesting closer links to terrestrial sediment sources. Furthermore, metal loads increased significantly with turf length, suggesting that longer turfs can accumulate these pollutants on reefs. Given that algal turfs are a crucial component of herbivorous/detritivorous trophic pathways, this could represent a key juncture at which these metals enter food chains.

We present an analysis of 2225 simulations of artificial oil well blowouts in nearshore and offshore waters of Newfoundland, Canada. In the simulations, we coupled the VDROP-J and TAMOC models to simulate the fate and transport of oil and gas from the release to the sea surface. Simulations were conducted with and without subsea dispersant injection. We analyzed the simulation database to quantify the mass fraction of oil and gas that surfaces, the mass fraction of released benzene that surfaces, and the horizontal offset to the surfacing zone. These data are also synthesized to yield empirical correlations to predict these output metrics from key input parameters. These correlations are summarized in an excel spreadsheet that allows rapid evaluation of spill dynamics with minimal initial knowledge of spill details. We call this tool an offshore response guidance table, which allows exploration of spill dynamics under diverse spill and response options.

The transporting of oil via the Arabian Gulf for centuries has resulted in the pollution of the coasts by heavy metals, and therefore, remediation actions are needed. In this review, we first evaluated heavy metal pollution on the coasts by assembling the research on published metal concentrations in sediments and water bodies surrounding the Arabian Peninsula. Research revealed uneven pollution of heavy metals, meaning that before remediation, the most polluted sites should be found. This could be done most conveniently using biomonitoring. The Arabian Peninsula is a unique ecoregion due to the extremely high temperature in summer, and therefore, it needs its specific standardization procedure for biomonitoring. To get an overview of the current information on biomonitoring, we gathered a dataset of 306 published macroalgal observations from the Arabian Gulf and the Gulf of Aden. The heavy metal concentration dataset of macroalgae was analyzed with a multivariate principal component analysis. As a result of the published works elsewhere and our data analysis, we recommend that green Ulva and brown Padina species are used in the biomonitoring of heavy metal pollution on the Arabian Peninsula's eastern and southern coasts. However, more species might be needed if these species do not occur at the site. The species incidence should first be monitored systematically in each area, and common species should be used. The species used should be chosen locally and sampled at the same depth at low tide in spring or early summer, from February to May, before the hottest season. The composite samples of different apical sections of the thallus should be collected. The standardization of the monitoring processes benefits future remediation actions.

Sea urchins are highly abundant in the marine ecosystem where they graze limiting algal biomass and also serving as food for other predators. In this work, the presence of microplastics in the digestive tracts and gonads of 33 Diadema africanum sea urchins collected at two sampling points in Tenerife (Canary Islands, Spain) was studied. After separation and digestion of the digestive tracts and the gonads, the visualization of the filtrates under the stereomicroscope revealed the presence of 320 items which were microfibers (97.5%), fragments (1.9%) and films (0.6%), mainly blue (43.3 and 47.0% in the two sampling points, Tajao and El Porís, respectively) and translucent white (32.5 and 39.5%, respectively). Statistical analysis revealed that there were no significative differences in the contents of gonads and digestive tracts between both sampling locations. Regarding microfibers lengths, significative differences were only observed between the two sampling points, not between tissues. μRaman analysis showed that they were mainly cellulosic (46.0%), polypropylene (24.3%) and polyethylene terephthalate (24.3%). This study confirms for the first time the presence of microplastics in sea urchins from the Macaronesian region and also from Spain.

The characterization of microplastics helps to improve sustainable management practices in aquatic ecosystems impacted by plastic litter. Plastic litter and microplastics from four ocean beaches in the Niterói municipality was evaluated in winter and summer. The collection and preparation of microplastic sample procedures followed on the protocol developed by the RLA7025 Project of the International Atomic Energy Agency. Marine debris followed to the United Nations Environment Program protocol. The polymer was characterized by ATR-FTIR technique.The Clean Coast Index was used to determine the degree of dirt on the beaches. Polyethylene (43%) and Polystyrene (52%) were the most abundant microplastics. The plastic is the most abundant category; representing 85% in winter and 73% in summer.The main sources are related to the consumption of drinks and food. These results emphasize the importance of reverse logistics and the value chain for packaging material and the need for effective actions managing solid waste.

Oil exploration and drilling activities are known to have catastrophic effects on marine environments and ecosystems, yet full understanding of these effects is hindered by sparse observations in many areas of the world. We present annual and bimonthly records of coral Ba/Ca from Weizhou Island in Beibu Gulf in the northern South China Sea (SCS) – the largest oilfield in the SCS. On interannual timescales, a significant increase in Ba/Ca ratios is associated with high barite consumption used for oil exploration and drilling activities. On seasonal timescales, a strong winter monsoon signal is seen in the skeletal Ba/Ca records. Our data provide a long-term and continuous on-site record for oil exploration and drilling activities that can be used for offshore oil management. Furthermore, our approach offers a means to study the influence of oil-related activities on the marine environment when no oil exploration and drilling records are available.

Molecular genetic studies of stools were performed to assess the spread of some clinically relevant antimicrobial resistance determinants (ARD) in a gentoo penguin (Pygoscelis papua) and an Antarctic fur seal (Arctocephalus gazella) on Livingston Island. Glycopeptide resistance genes (vanA/vanD and vanB) were detected in both fecal samples, while the penguin's one was also mecA-positive and blaNDM-positive. Because of the remoteness and the isolation of the sampling locations, the carriage of vancomycin-resistant Enterococcus spp., methicillin-resistant Staphylococcus aureus, and NDM-producing Enterobacterales or other gram-negative bacilli suggested an ocean pollution with antibiotic resistant bacteria (ARB). Additionally, due to the type of ARD we detected, our results are alarming, and they cannot be explained only with agricultural and/or aquacultural pollution. Even though the current study is a preliminary one, it also demonstrates the potential of the field genetics analyses carried out with minimal equipment as a reliable monitoring tool for pollution with ARB.

Most previous studies investigating the interplay of ocean acidification (OA) and heavy metal on marine phytoplankton were only conducted in short-term, which may provide conservative estimates of the adaptive capacity of them. Here, we examined the physiological responses of long-term (~900 generations) OA-adapted and non-adapted populations of the diatom Phaeodactylum tricornutum to different concentrations of the two heavy metals Cd and Cu. Our results showed that long-term OA selected populations exhibited significantly lower growth and reduced photosynthetic activity than ambient CO₂ selected populations at relatively high heavy metal levels. Those findings suggest that the adaptations to high CO₂ results in an increased sensitivity of the marine diatom to toxic metal exposure. This study provides evidence for the costs and the cascading consequences associated with the adaptation of phytoplankton to elevated CO₂ conditions, and improves our understanding of the complex interactions of future OA and heavy metal pollution in marine waters.