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Although Antarctica is the most isolated continent on Earth, its remote location does not protect it from the impacts of human activities. Antarctic metazoans such as filter-feeding invertebrates are a crucial component of the Antarctic benthos. They play a key role in the benthic-pelagic carbon flux in coastal areas by filtering particles and planktonic organisms from the sediment-water interface. Due to their peculiar ecological niche, these organisms can be considered a wasp-waist in the ecosystem, making them highly sensitive to marine pollution. Recently, anthropogenic particles such as micro-nanoplastics and manufactured nanoparticles (MNP) have been classified as contaminants of emerging concern (CEC) due to their small size range, which also overlaps with the preferred particle size ingested by aquatic metazoans. Indeed, it has been demonstrated that some species such as Antarctic krill can ingest, transform, and release MNPs, making them newly bioavailable for other Antarctic filter-feeding organisms. Similarly, the production and use of anthropogenic MNP are rapidly increasing, leading to a growing presence of materials, such as nano-sized metal-oxides, in the environment. For these reasons, it is important to provide evidence of the adverse effects of such emerging contaminants at sub-lethal concentrations in environmental risk assessments. These contaminants may cause cascade effects with consequences not only on individuals but also at the community and ecosystem levels. In this review, we discuss the state-of-the-art knowledge on the physiological and molecular effects of anthropogenic MNP in Antarctic aquatic metazoans. We further highlight the importance of identifying early biomarkers using sessile metazoans as sentinels of environmental health.

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In recent years micro- and nanoplastics and metal-oxide nanomaterials have been found in several environmental compartments. The Antarctic soft clam Laternula elliptica is an endemic Antarctic species having a wide distribution in the Southern Ocean. Being a filter-feeder, it could act as suitable bioindicator of pollution from nanoparticles also considering its sensitivity to various sources of stress. The present study aims to assess the impact of polystyrene nanoparticles (PS-NP) and the nanometal titanium-dioxide (n-TiO2) on genome-wide transcript expression of L. elliptica either alone and in combination and at two toxicological relevant concentrations (5 and 50 µg/L) during 96 h exposure. Transcript-target qRT-PCR was performed with the aim to identify suitable biomarkers of exposure and effects. As expected, at the highest concentration tested, the clustering was clearer between control and exposed clams. A total of 221 genes resulted differentially expressed in exposed clams and control ones, and 21 of them had functional annotation such as ribosomal proteins, antioxidant, ion transport (osmoregulation), acid-base balance, immunity, lipid metabolism, cell adhesion, cytoskeleton, apoptosis, chromatin condensation and cell signaling. At functional level, relevant transcripts were shared among some treatments and could be considered as general stress due to nanoparticle exposure. After applying transcript-target approach duplicating the number of clam samples, four ecologically relevant transcripts were revealed as biomarkers for PS-NP, n-TiO2 and their combination at 50 µg/L, that could be used for monitoring clams' health status in different Antarctic localities.

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Decreasing ocean surface pH, called ocean acidification (OA), is among the major risks for marine ecosystems due to human-driven atmospheric pCO2 increase. Understanding the molecular mechanisms of adaptation enabling marine species to tolerate a lowered seawater pH could support predictions of consequences of future OA scenarios for marine life. This study examined whether the ATP-binding cassette (ABC)-like gene slr2019 confers tolerance to the marine cyanobacterium Halomicronema metazoicum to low seawater pH conditions (7.7, 7.2, 6.5) in short- and long-term exposures (7 and 30 d). Photosynthetic pigment content indicated that the species can tolerate all three lowered-pH conditions. At day 7, slr2019 was up-regulated at pH 7.7 while no changes were observed at lower pH. After 30-d exposure, a significant decrease in slr2019 transcript levels was observed in all low-pH treatments. These first results indicate an effect of low pH on the examined transporter expression in H. metazoicum.

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Nanoplastics and engineering nanomaterials (ENMs) are contaminants of emerging concern (CECs), increasingly being detected in the marine environment and recognized as a potential threat for marine biota at the global level including in polar areas. Few studies have assessed the impact of these anthropogenic nanoparticles in the microbiome of marine invertebrates, however combined exposure resembling natural scenarios has been overlooked. The present study aimed to evaluate the single and combined effects of polystyrene nanoparticles (PS NP) as proxy for nanoplastics and nanoscale titanium dioxide (nano-TiO2) on the prokaryotic communities associated with the gill tissue of the Antarctic soft-shell clam Laternula elliptica, a keystone species of marine benthos Wild-caught specimens were exposed to two environmentally relevant concentrations of carboxylated PS NP (PS-COOH NP, ∼62 nm size) and nano-TiO2 (Aeroxide P25, ∼25 nm) as 5 and 50 µg/L either single and combined for 96h in a semi-static condition.Our findings show a shift in microbiome composition in gills of soft-shell clams exposed to PS NP and nano-TiO2 either alone and in combination with a decrease in the relative abundance of OTU1 (Spirochaetaceae). In addition, an increase of gammaproteobacterial OTUs affiliated to MBAE14 and Methylophagaceae (involved in ammonia denitrification and associated with low-quality water), and the OTU Colwellia rossensis (previously recorded in polluted waters) was observed. Our results suggest that nanoplastics and nano-TiO2 alone and in combination induce alterations in microbiome composition by promoting the increase of negative taxa over beneficial ones in the gills of the Antarctic soft-shell clam. An increase of two low abundance OTUs in PS-COOH NPs exposed clams was also observed. A predicted gene function analysis revealed that sugar, lipid, protein and DNA metabolism were the main functions affected by either PS-COOH NP and nano-TiO2 exposure. The molecular functions involved in the altered affiliated OTUs are novel for nano-CEC exposures.

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In the framework of a safe-by-design approach, we previously assessed the eco-safety of nanostructured cellulose sponge (CNS) leachate on sea urchin reproduction. It impaired gamete quality, gamete fertilization competence, and embryo development possibly due to the leaching of chemical additives used during the CNS synthesis process. To extend this observation and identify the component(s) that contribute to CNS ecotoxicity, in the present study, we individually screened the cytotoxic effects on sea urchin Arbacia lixula and Paracentrotus lividus gametes and embryos of the three main constituents of CNS, namely cellulose nanofibers, citric acid, and branched polyethylenimine. The study aimed to minimize any potential safety risk of these components and to obtain an eco-safe CNS. Among the three CNS constituents, branched polyethylenimine resulted in the most toxic agent. Indeed, it affected the physiology and fertilization competence of male and female gametes as well as embryo development in both sea urchin species. These results are consistent with those previously reported for CNS leachate. Moreover, the characterisation of CNS leachate confirmed the presence of detectable branched polyethylenimine in the conditioned seawater even though in a very limited amount. Altogether, these data indicate that the presence of branched polyethylenimine is a cause-effect associated with a significant risk in CNS formulations due to its leaching upon contact with seawater. Nevertheless, the suggested safety protocol consisting of consecutive leaching treatments and conditioning of CNS in seawater can successfully ameliorate the CNS ecotoxicity while maintaining the efficacy of its sorbent properties supporting potential environmental applications.

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How Antarctic species are facing historical and new stressors remains under-surveyed and risks to wildlife are still largely unknown. Adélie penguins Pygoscelis adeliae are well-known bioindicators and sentinels of Antarctic ecosystem changes, a true canary in the coal mine. Immuno-haematological parameters have been proved to detect stress in wild animals, given their rapid physiological response that allows them tracking environmental changes and thus inferring habitat quality. Here, we investigated variation in Erythrocyte Nuclear Abnormalities (ENAs) and White Blood Cells (WBCs) in penguins from three clustered colonies in the Ross Sea, evaluating immuno-haematological parameters according to geography, breeding stage, and individual penguin characteristics such as sex, body condition and nest quality. Concentrations of mercury (Hg) and stable isotopes of carbon and nitrogen (as proxies of the penguin's trophic ecology) were analysed in feathers to investigate the association between stress biomarkers and Hg contamination in Adélie penguins. Colony and breeding stage were not supported as predictors of immuno-haematological parameters. ENAs and WBCs were respectively ∼30 % and ∼20 % higher in male than in female penguins. Body condition influenced WBCs, with penguins in the best condition having a ∼22 % higher level of WBCs than those in the worst condition. Nest position affected the proportion of micronuclei (MNs), with inner-nesting penguins having more than three times the proportion of MNs than penguins nesting in peripheral positions. Heterophils:Lymphocytes (H:L) ratio was not affected by any of the above predictors. Multiple factors acting as stressors are expected to increase prominently in Antarctic wildlife in the near future, therefore extensive monitoring aimed to assess the health status of penguin populations is mandatory.

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The ability to employ waste products, such as vegetable scraps, as raw materials for the synthesis of new promising adsorbing materials is at the base of the circular economy and end of waste concepts. Dextrin-based nanosponges (D_NS), both cyclodextrin (CD) and maltodextrin (MD), have shown remarkable adsorption abilities in the removal of toxic compounds from water and wastewater, thus representing a bio-based low-cost solution which is establishing itself in the market. Nevertheless, their environmental safety for either aquatic or terrestrial organisms has been overlooked, raising concern in terms of potential hazards to natural ecosystems. Here, the environmental safety (ecosafety) of six newly synthesized batches of D_NS was determined along with their full characterization by means of dynamic light scattering (DLS), thermogravimetric analysis (TGA), Fourier transformed infrared spectroscopy with attenuated total reflection (FTIR-ATR) and transmission electron microscopy (SEM). Ecotoxicity evaluation was performed using a battery of model organisms and ecotoxicity assays, such as the microalgae growth inhibition test using the freshwater Raphidocelis subcapitata and the marine diatom Dunaliella tertiolecta, regeneration assay using the freshwater cnidarian Hydra vulgaris and immobilization assay with the marine brine shrimp Artemia franciscana. Impact on seedling germination of a terrestrial plant of commercial interest, Cucurbita pepo was also investigated. Ecotoxicity data showed mild to low toxicity of the six batches, up to 1 mg/mL, in the following order: R. subcapitata > H. vulgaris > D. tertiolecta > A. franciscana > C. pepo. The only exception was represented by one batch (NS-Q+_BDE_(GLU2) which resulted highly toxic for both freshwater species, R. subcapitata and H. vulgaris. Those criticalities were solved with the synthesis of a fresh new batch and were hence attributed to the single synthesis and not to the specific D_NS formulation. No effect on germination of pumpkin but rather more a stimulative effect was observed. To our knowledge this is the first evaluation of the environmental safety of D_ NS. As such we emphasize that current formulations and exposure levels in the range of mg/mL do not harm aquatic and terrestrial species thus representing an ecosafe solution also for environmental applications.

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Nanocellulose constitutes a sustainable and biobased solution both as an efficient sorbent material for water treatment and as support for other inorganic nanomaterials with sorbent properties. Herein, we report the synthesis of a nanocomposite by deposition of in situ-generated silver nanoparticles (AgNPs) onto TEMPO-oxidized cellulose nanofibers (TOCNFs). Following an in-depth analytical investigation, we unveil for the first time the key role of AgNPs in enhancing the adsorption efficiency of TOCNF toward Cd2+ ions, chosen as model heavy metal contaminants. The obtained nanocomposite shows a value of Cd2+ sorption capacity at equilibrium from 150 mg L-1 ion aqueous solutions of ∼116 mg g-1 against the value of 78 mg g-1 measured for TOCNF alone. A combination of field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) analyses suggests that Cd2+ ions are mainly adsorbed in the neighborhood of AgNPs. However, XPS characterization allows us to conclude that the role of AgNPs relies on increasing the exposure of carboxylic groups with respect to the original TOCNF, suggesting that these groups are still responsible for absorption. In fact, X-ray absorption spectroscopy (XAS) analysis of the Cd-K edge excludes a direct interaction between Ag0 and Cd2+, supporting the XPS results and confirming the coordination of the latter with carboxyl groups.

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Due to its persistence and potential ecological and health impacts, mercury (Hg) is a global pollutant of major concern that may reach high concentrations even in remote polar oceans. In contrast to the Arctic Ocean, studies documenting Hg contamination in the Southern Ocean are spatially restricted and large-scale monitoring is needed. Here, we present the first circumpolar assessment of Hg contamination in Antarctic marine ecosystems. Specifically, the Adélie penguin (Pygoscelis adeliae) was used as a bioindicator species, to examine regional variation across 24 colonies distributed across the entire Antarctic continent. Mercury was measured on body feathers collected from both adults (n = 485) and chicks (n = 48) between 2005 and 2021. Because penguins' diet represents the dominant source of Hg, feather δ13C and δ15N values were measured as proxies of feeding habitat and trophic position. As expected, chicks had lower Hg concentrations (mean ± SD: 0.22 ± 0.08 µg·g‒1) than adults (0.49 ± 0.23 µg·g‒1), likely because of their shorter bioaccumulation period. In adults, spatial variation in feather Hg concentrations was driven by both trophic ecology and colony location. The highest Hg concentrations were observed in the Ross Sea, possibly because of a higher consumption of fish in the diet compared to other sites (krill-dominated diet). Such large-scale assessments are critical to assess the effectiveness of the Minamata Convention on Mercury. Owing to their circumpolar distribution and their ecological role in Antarctic marine ecosystems, Adélie penguins could be valuable bioindicators for tracking spatial and temporal trends of Hg across Antarctic waters in the future.

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Ultraviolet filters (UVFs) added to sunscreens (SS) are emerging contaminants in marine environments due to their adverse effects on organisms and ecosystems. UVFs have also been detected in beach-dune systems, but their influence on resident organisms has not been explored yet. Native plants are fundamental components of coastal dunes, and these ecologically/economically important systems are currently among the most threatened globally. Thus, understanding whether UVFs may act as threats to dune plants is crucial. This field study evaluated and compared the effects of titanium dioxide nanoparticles (nTiO2), one of the inorganic UVFs most commonly added to sunscreens, and those of a commercial sunscreen product containing it (SS-nTiO2) on the performance of adult dune plants of a native (Thinopyrum junceum) and a non-native invasive species (Carpobrotus sp. pl.) and their competitive interactions at environmentally realistic concentrations. The effects of nTiO2, SS-nTiO2 and of a sunscreen product containing just organic UVFs (SS-OF) on early life stages of T. junceum were also examined. Ti bulk content in sand and plants at the study site ranged from 970 to 1069 mg kg-1 and from 2 to 7.9 mg kg-1, respectively. Thinopyrum junceum adult plants periodically exposed during the summer season to seawater contaminated by SS-nTiO2 produced less biomass than un-exposed plants and nTiO2 exposed plants. nTiO2 and SS-nTiO2 reduced the capacity of T. junceum to control the spread of Carpobrotus. Both SS-nTiO2 and SS-OF reduced seedling emergence in T. junceum whereas nTiO2 did not. These results demonstrated that the periodical exposures of native dune plants to sunscreens could reduce their establishment success and growth and favor invasive plant spread potentially resulting in community structure changes. They also emphasize the need to assess the phytotoxicity not only of single UVFs but especially that of complete sunscreen products to design more eco-friendly formulations in the future.

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Nanostructured cellulose sponges (CNS) have been developed as eco-friendly and sustainable engineered materials for marine environmental remediation. Despite their functionality, sensitivity, efficiency and specificity have been proved, CNS application is still limited since their environmental safety (eco-safety) has not been completely assessed. In this study, CNS were allowed to leach in natural seawater simulating the remediation process condition and the eco-safety of CNS leachate on sea urchin reproduction has been assessed by carrying out a multi-response integrated approach, combining standardized ecotoxicity tests, innovative bioassays and gamete quality assessment. Overall, the ecotoxicity data indicate that CNS leachate affects gamete quality, gamete fertilisation competence, and embryo development probably associated with the release of chemical additives used during the synthesis process. However, in the framework of the eco-design approach, consecutive leaching treatments and conditioning of CNS in seawater open the route for a new safety protocol successfully solving the ecotoxicity while maintaining CNS sorbent properties. A safe environmental application of the resulting conditioned CNS for seawater pollution remediation is envisaged.

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Today application of sewage sludge (SL) and hydrochar (HC) in agriculture is a common practice for soil conditioning and crop fertilization, however safety concerns for human and environmental health due to the presence of toxic compounds have recently been expressed. Our aim was to test the suitability of proteomics coupled with bioanalytical tools for unravelling mixture effects of these applications in human and environmental safety assessment. We conducted proteomic and bioinformatic analysis of cell cultures used in the DR-CALUX® bioassay to identify proteins differentially abundant after exposure to SL and the corresponding HC, rather than only using the Bioanalytical Toxicity Equivalents (BEQs) obtained by DR-CALUX®. DR-CALUX® cells exposed to SL or HC showed a differential pattern of protein abundance depending on the type of SL and HC extract. The modified proteins are involved in antioxidant pathways, unfolded protein response and DNA damage that have close correlations with the effects of dioxin on biological systems and with onset of cancer and neurological disorders. Other cell response evidence suggested enrichment of heavy metals in the extracts. The present combined approach represents an advance in the application of bioanalytical tools for safety assessment of complex mixtures such as SL and HC. It proved successful in screening proteins, the abundance of which is determined by SL and HC and by the biological activity of legacy toxic compounds, including organohalogens.

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The use of eco-friendly engineered nanomaterials represents a recent solution for an effective and safe treatment of contaminated dredging sludge. In this study, an eco-designed engineered material based on cross-linked nanocellulose (CNS) was applied for the first time to decontaminate a real matrix from heavy metals (namely Zn, Ni, Cu, and Fe) and other undesired elements (mainly Ba and As) in a lab-scale study, with the aim to design a safe solution for the remediation of contaminated matrices. Contaminated freshwater sludge was treated with CNS coupled with a filtering fine-mesh net, and the obtained waters were tested for acute and sublethal toxicity. In order to check the safety of the proposed treatment system, toxicity tests were conducted by exposing the bacterium Aliivibrio fischeri and the crustacean Heterocypris incongruens, while subtoxicity biomarkers such as lysosomal membrane stability, genetic, and chromosomal damage assessment were performed on the freshwater bivalve Dreissena polymorpha. Dredging sludge was found to be genotoxic, and such genotoxicity was mitigated by the combined use of CNS and a filtering fine-mesh net. Chemical analyses confirmed the results by highlighting the abetment of target contaminants, indicating the present model as a promising tool in freshwater sludge nanoremediation.

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It is now known that the Mediterranean Sea currently is one of the major hotspot for microplastics (MPs; < 5 mm) pollution and that the risks will be even more pronounced in the coming years. Thus, the in-depth study of the mechanisms underlying the MPs toxicity in key Mediterranean organisms, subjected to high anthropic pressures, has become a categorical imperative to pursue. Here, we explore for the first time the sea urchins immune cells profile combined to their proteome upon in vivo exposure (72 h) to different concentrations of polystyrene-microbeads (micro-PS) starting from relevant environmental concentrations (10, 50, 103, 104 MP/L). Every 24 h, immunological parameters were monitored. After 72 h, the abundance of MPs was examined in various organs and coelomocytes were collected for proteomic analysis based on a shotgun label free proteomic approach. While sea urchins treated with the lowest concentration tested (10 and 50 micro-PS/L) did not show the presence of micro-PS in any tissue, in the specimens exposed to the highest concentration (103 and 104 micro-PS) there was an internalisation of 9.75 ± 2.75 and 113.75 ± 34.5 MP/g, respectively. Proteomic analyses revealed that MPs exposure altered coelomocytes protein profile not only compared to the control group but also among the different micro-PS concentrations and these variations are micro-PS concentration dependent. The proteins exclusively expressed in the coelomocytes of specimens exposed to MPs are mainly metabolite interconversion enzymes, involved in cellular processes, indicating a severe alteration of the cellular metabolic pathways. Overall, these findings provide new insights on the mode of action of MPs in the sea urchin immune cells both at the molecular and cellular level.

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Since the first explorers reached Antarctica, their activities have quickly impacted both land and sea and thus, together with the long-range transport, hazardous chemicals began to accumulate. It is commonly recognized that anthropogenic pollution in Antarctica can originate from either global or local sources. Heavy metals, organohalogenated compounds, hydrocarbons, and (more recently) plastic, have been found in Antarctic biota, soil sediments, seawater, air, snow and sea-ice. Studies in such remote areas are challenging and expensive, and the complexity of potential interactions occurring in such extreme climate conditions (i.e., low temperature) makes any accurate prediction on potential impacts difficult. The present review aims to summarize the current state of knowledge on occurrence and distribution of legacy and emerging pollutants in Antarctica, such as plastic, from either global or local sources. Future actions to monitor and mitigate any potential impact on Antarctic biodiversity are discussed.

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The growing concern on nanoplastics (<1 µm) impact on marine life has stimulated a significant amount of studies aiming to address ecotoxicity and disclose their mechanisms of action. Here, we applied an integrative approach to develop an Adverse Outcome Pathway (AOP) upon acute exposure to amino-modified polystyrene nanoparticles (PS-NH2 NPs, 50 nm), as proxy for nanoplastics, during the embryogenesis of the chordate Ciona robusta. Genes related to glutathione metabolism, immune defense, nervous system, transport by aquaporins and energy metabolism were affected by either concentration tested of 10 or 15 µg mL-1 of PS-NH2. Transcriptomic data and in vivo experiments were assembled into two putative AOPs, identifying as key events the adhesion of PS-NH2 as (molecular) initiating event, followed by oxidative stress, changes in transcription of specific genes, morphological defects, increase in reactive oxygen species level, impaired swimming behavior. As final adverse outcomes, altered larval development, reduced metamorphosis and inhibition of hatching were identified. Our study attempts to define AOPs for PS-NH2 without excluding that chemicals leaching from them might also have a potential role in the observed outcome. Overall data provide new insights into the mechanism of action of PS-NH2 NPs during chordate embryogenesis and offer further keys for a better knowledge of nanoplastics impact on early stages of marine life.

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Nanosafety is paramount considering the risks associated with manufactured nanomaterials (MNMs) whose implications could outweigh their advantages for environmental applications. Although nanotechnology-based solutions to implement pollution control, remediation and prevention are incremental with clear benefits for public health and Earth' natural ecosystems, nanoremediation is having a setback due to the risks associated with the safety of MNMs for humans and the environment. MNMs are diverse, work differently and bionano-interactions occurring upon environmental exposure will guide their fate and hazardous outcomes. Here we propose a new ecologically-based design strategy (eco-design) having its roots in green nanoscience and LCA that will ground on an Ecological Risk Assessment approach, which introduces the evaluation of MNMs' ecotoxicity along with their performances and efficacies at the design stage. As such, the proposed eco-design strategy will allow recognition and design-out since the very beginning of material synthesis, those hazardous peculiar features that can be hazardous to living beings and the natural environment. A more ecologically sound eco-design strategy in which nanosafety is conceptually included in MNMs design will sustain safer nanotechnologies including those for the environment as remediation by leveraging any risks for humans and natural ecosystems.

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Nanosilver applications, including sensing and water treatment, have significantly increased in recent years, although safety for humans and the environment is still under debate. Here, we tested the environmental safety of a novel formulation of silver nanoparticles functionalized with citrate and L-cysteine (AgNPcitLcys) on freshwater cnidarian Hydra vulgaris as an emerging ecotoxicological model for the safety of engineered nanomaterials. AgNPcitLcys behavior was characterized by dynamic light scattering (DLS), while Ag release was measured by inductively coupled plasma mass spectrometry (ICP-MS). H. vulgaris (n = 12) subjects were evaluated for morphological aberration after 96 h of exposure and regeneration ability after 96 h and 7 days of exposure, after which the predatory ability was also assessed. The results show a low dissolution of AgNPcitLcys in Hydra medium (max 0.146% of nominal AgNPcitLcys concentration) and highlight a lack of ecotoxicological effects, both on morphology and regeneration, confirming the protective role of the double coating against AgNP biological effects. Predatory ability evaluation suggests a mild impairment of the entangling capacity or of the functionality of the tentacles, as the number of preys killed but not ingested was higher than the controls in all exposed animals. While their long-term sub-lethal effects still need to be further evaluated on H. vulgaris, AgNPcitLcys appears to be a promising tool for environmental applications, for instance, for water treatment and sensing.

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Since the industrial revolution, fossil fuel combustion has led to a 30 %-increase of the atmospheric CO2 concentration, also increasing the ocean partial CO2 pressure. The consequent lowered surface seawater pH is termed ocean acidification (OA) and severely affects marine life on a global scale. Cellular and molecular responses of marine species to lowered seawater pH have been studied but information on the mechanisms driving the tolerance of adapted species to comparatively low seawater pH is limited. Such information may be obtained from species inhabiting sites with naturally low water pH that have evolved remarkable abilities to tolerate such conditions. This review gathers information on current knowledge about species naturally facing low water pH conditions and on cellular and molecular adaptive mechanisms enabling the species to survive under, and even benefit from, adverse pH conditions. Evidences derived from case studies on naturally acidified systems and on resistance mechanisms will guide predictions on the consequences of future adverse OA scenarios for marine biodiversity.

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