Case report of plastic nurdles pollution in Galicia (NW Atlantic) following the Toconao's spill in December 2023: The VIEIRA Collaborative.

Plastic nurdles pose a significant environmental threat due to recurrent accidental spills into marine ecosystems. This report examines the nurdle pollution over the 1498 km of the Galician coastline (Spain) following the spill of 25 t of nurdles into the Northwest Atlantic after the loss of six containers from the Toconao vessel in December 2023. This accident highlights the urgent need for proactive, effective measures in maritime transport to prevent and mitigate such environmental catastrophes. The complexity of nurdle dispersion challenges the evaluation of their fate at sea, and the potential long-term consequences on the marine ecosystem and food web remain uncertain and yet to be investigated. This report also presents the VIEIRA collaborative and underscores the critical role of citizen-led initiatives in responding to such environmental disasters, and advocates for efficient policy reforms, involving cross-border collaboration. Furthermore, we call for greater international cooperation to underpin effective regulatory frameworks to address the growing hazard of plastic nurdle pollution worldwide.

Detection of SARS-CoV-2 in Wastewater Associated with Scientific Stations in Antarctica and Possible Risk for Wildlife.

Before December 2020, Antarctica had remained free of COVID-19 cases. The main concern during the pandemic was the limited health facilities available at Antarctic stations to deal with the disease as well as the potential impact of SARS-CoV-2 on Antarctic wildlife through reverse zoonosis. In December 2020, 60 cases emerged in Chilean Antarctic stations, disrupting the summer campaign with ongoing isolation needs. The SARS-CoV-2 RNA was detected in the wastewater of several scientific stations. In Antarctica, treated wastewater is discharged directly into the seawater. No studies currently address the recovery of infectious virus particles from treated wastewater, but their presence raises the risk of infecting wildlife and initiating new replication cycles. This study highlights the initial virus detection in wastewater from Antarctic stations, identifying viral RNA via RT-qPCR targeting various genomic regions. The virus's RNA was found in effluent from two wastewater plants at Maxwell Bay and O'Higgins Station on King George Island and the Antarctic Peninsula, respectively. This study explores the potential for the reverse zoonotic transmission of SARS-CoV-2 from humans to Antarctic wildlife due to the direct release of viral particles into seawater. The implications of such transmission underscore the need for continued vigilance and research.

Dichlorodiphenyltrichloroethane (DDT) and Dichlorodiphenyldichloroethylene (DDE) levels in air and surface sea waters along the Antarctic Peninsula.

Persistent organic pollutants (POPs) are widespread worldwide, even reaching polar regions. Among POPs, dichlorodiphenyltrichloroethane (DDT) and their metabolites have been reported scarcely in the Antarctic environment. Here we report the levels of p,p'-DDT, o,p'-DDT, p,p'-DDE, and o,p'-DDE in air and water samples collected during austral summer 2009. The levels found ranged from 0.25 to 4.26 pg m-3 in the atmospheric samples while in the water samples ranged from 0.07 to 0.25 pg L-1. These concentrations were within the range of the reported concentrations in the last 20 years in Antarctica. However, the source ratio showed that most of p,p'-DDT comes from fresh applications and Dicofol formulations. The back-trajectories estimated for the air masses revealed that most of the p,p'-DDT came from the continental Antarctic peninsula and surrounding waters. The diffusive exchange direction showed that Antarctic surface waters are the final sink of the studied compounds during the survey period.

Monitoring persistent organic chemicals in Antarctica in support of global chemical policy: a horizon scan of priority actions and challenges.

Global production and emission of chemicals exceeds societal capacities for assessment and monitoring. This situation calls for improved chemical regulatory policy frameworks and increased support for expedited decision making within existing frameworks. The polar regions of the Earth represent unique sentinel areas for the study of global chemical behaviour, and data arising from these areas can strengthen existing policy frameworks. However, chemical pollution research and monitoring in the Antarctic is underdeveloped, with geopolitical complexities and the absence of legal recognition of international chemical policy serving to neutralise progress made in other global regions. This Personal View represents a horizon scan by the action group Input Pathways of Persistent Organic Pollutants to Antarctica, of the Scientific Committee for Antarctic Research. Four priority research and research facilitation gaps are outlined, with recommendations for Antarctica Treaty parties for strategic action against these priorities.

Environmental signature and health risk assessment of polybrominated diphenyl ethers (PBDEs) emitted from a landfill fire in Santiago de Chile.

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in building materials, electronics, furnishings, vehicles, airplanes, plastics, polyurethane foams, and textiles for many years. Currently, the primary commercial mixtures, penta-, octa-, and deca-BDE, are globally restricted. Still, products containing PBDEs are expected to impact waste management and the environment for many years. In January 2016, an open fire in the Santa Marta landfill close to Santiago de Chile affected the city and surroundings. The fire caused several acute health effects and an increase in emergency hospitalizations. We measured PBDE levels in the areas affected by the fire in the air (gaseous and particulate) and soil, and PBDE emissions were estimated using a dispersion model. The results showed an increase in PBDE concentrations by a factor of 2-4 one day after the start of the fire. However, PBDE concentrations measured after the fire in PM10 and the gas phase were considered low compared to other regions. Interestingly, PBDEs' patterns differed across the sites; however, BDE209 was the dominant congener for all environmental matrices. A preliminary risk assessment was conducted using the daily exposure dose (DED) by air inhalation estimation. The results showed low DED values for adults and children and suggested no direct health risk due to PBDE exposure. This study brings new data useful for future solid waste management initiatives in the country.

Role of Microbes in the degradation of organic semivolatile compounds in polar ecosystems: A review.

The Arctic and the Antarctic Continent correspond to two eco-regions with extreme climatic conditions. These regions are exposed to the presence of contaminants resulting from human activity (local and global), which, in turn, represent a challenge for life forms in these environments. Anthropogenic pollution by semi-volatile organic compounds (SVOCs) in polar ecosystems has been documented since the 1960s. Currently, various studies have shown the presence of SVOCs and their bioaccumulation and biomagnification in the polar regions with negative effects on biodiversity and the ecosystem. Although the production and use of these compounds has been regulated, their persistence continues to threaten biodiversity and the ecosystem. Here, we summarize the current literature regarding microbes and SVOCs in polar regions and pose that bioremediation by native microorganisms is a feasible strategy to mitigate the presence of SVOCs. Our systematic review revealed that microbial communities in polar environments represent a wide reservoir of biodiversity adapted to extreme conditions, found both in terrestrial and aquatic environments, freely or in association with vegetation. Microorganisms adapted to these environments have the potential for biodegradation of SVOCs through a variety of genes encoding enzymes with the capacity to metabolize SVOCs. We suggest that a comprehensive approach at the molecular and ecological level is required to mitigate SVOCs presence in these regions. This is especially patent when considering that SVOCs degrade at slow rates and possess the ability to accumulate in polar ecosystems. The implications of SVOC degradation are relevant for the preservation of polar ecosystems with consequences at a global level.

Continuous bioreactors enable high-level bioremediation of diesel-contaminated seawater at low and mesophilic temperatures using Antarctic bacterial consortia: Pollutant analysis and microbial community composition.

In 2020, more than 21,000 tons of diesel oil were released accidently into the environment with most of it contaminating water bodies. There is an urgent need for sustainable technologies to clean up rivers and oceans to protect wildlife and human health. One solution is harnessing the power of bacterial consortia; however isolated microbes from different environments have shown low diesel bioremediation rates in seawater thus far. An outstanding question is whether Antarctic microorganisms that thrive in environments polluted with hydrocarbons exhibit better diesel degrading activities when propagated at higher temperatures than those encountered in their natural ecosystems. Here, we isolated bacterial consortia, LR-30 (30 °C) and LR-10 (10 °C), from the Antarctic rhizosphere soil of Deschampsia antarctica (Livingston Island), that used diesel oil as the only carbon substrate. We found that LR-30 and LR-10 batch bioreactors metabolized nearly the entire diesel content when the initial concentration was 10 (g/L) in seawater. Increasing the initial diesel concentration to 50 gDiesel/L, LR-30 and LR-10 bioconverted 33.4 and 31.2 gDiesel/L in 7 days, respectively. The 16S rRNA gene sequencing profiles revealed that the dominant bacterial genera of the inoculated LR-30 community were Achromobacter (50.6%), Pseudomonas (25%) and Rhodanobacter (14.9%), whereas for LR-10 were Pseudomonas (58%), Candidimonas (10.3%) and Renibacterium (7.8%). We also established continuous bioreactors for diesel biodegradation where LR-30 bioremediated diesel at an unprecedent rate of (34.4 g/L per day), while LR-10 achieved (24.5 g/L per day) at 10 °C for one month. The abundance of each bacterial genera present significantly fluctuated at some point during the diesel bioremediation process, yet Achromobacter and Pseudomonas were the most abundant member at the end of the batch and continuous bioreactors for LR-30 and LR-10, respectively.

South American National Contributions to Knowledge of the Effects of Endocrine Disrupting Chemicals in Wild Animals: Current and Future Directions.

Human pressure due to industrial and agricultural development has resulted in a biodiversity crisis. Environmental pollution is one of its drivers, including contamination of wildlife by chemicals emitted into the air, soil, and water. Chemicals released into the environment, even at low concentrations, may pose a negative effect on organisms. These chemicals might modify the synthesis, metabolism, and mode of action of hormones. This can lead to failures in reproduction, growth, and development of organisms potentially impacting their fitness. In this review, we focused on assessing the current knowledge on concentrations and possible effects of endocrine disruptor chemicals (metals, persistent organic pollutants, and others) in studies performed in South America, with findings at reproductive and thyroid levels. Our literature search revealed that most studies have focused on measuring the concentrations of compounds that act as endocrine disruptors in animals at the systemic level. However, few studies have evaluated the effects at a reproductive level, while information at thyroid disorders is scarce. Most studies have been conducted in fish by researchers from Brazil, Argentina, Chile, and Colombia. Comparison of results across studies is difficult due to the lack of standardization of units in the reported data. Future studies should prioritize research on emergent contaminants, evaluate effects on native species and the use of current available methods such as the OMICs. Additionally, there is a primary focus on organisms related to aquatic environments, and those inhabiting terrestrial environments are scarce or nonexistent. Finally, we highlight a lack of funding at a national level in the reviewed topic that may influence the observed low scientific productivity in several countries, which is often negatively associated with their percentage of protected areas.

Multicompartmental analysis of POPs and PAHs in Concepciόn Bay, central Chile: Part II - Air-sea exchange during Austral summer.

Air-sea exchange of POPs and PAHs was assessed in Concepción Bay during January, summer 2015. Results showed low levels, in air and water, for POPs (1-20 pg m-3, and 6-50 pg L-1, respectively) and for ΣPAHs (1-2 ng m-3 and 1-2 ng L-1, respectively). The highest levels were found for PBDEs (200-20,000 pg L-1) in the water samples (3-fold times higher than PCBs and OCP) and PBDE209 accounted for 90% of total ΣPBDEs. Air-sea exchange fluxes (ng m-2 d-1) were low in general, with exception of PBDEs showing values up to 40,000 ng m-2 d-1. Net deposition was found for PAHs, HCB and some PBDEs; while, BDE99, and BDE100 showed net volatilization. These findings contribute with new data of diffusive air-sea exchange on the southern hemisphere Pacific coast.

Pharmaceutical pollution of the world's rivers.

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Occurrence and air-water diffusive exchange legacy persistent organic pollutants in an oligotrophic north Patagonian lake.

In this study, the occurrence and diffusive air-water exchange of POPs in Panguipulli Lake (39°42'S-72°13'W), an oligotrophic lake located in northern Patagonia (Chile), were determined. Air and water samples were collected between March and August 2017 (autumn-winter) and analyzed for concentrations of OCPs (α-HCH, ß-HCH, γ-HCH and HCB) and PCBs (PCB-28,-52,-101,-118,-153,-158,-180) using gas chromatography coupled with an electron capture detector. The direction of air-water exchange direction was evaluated using a fugacity approach (ƒw ƒa-1), and net diffusive exchange fluxes (FAW, ng m-2 d-1) were also estimated. Total ∑4OCP levels in air ranged from 0.31 to 37 pg m-3, with a maximum for ß-HCH, while Σ7PCB levels ranged from 3.05 to 43 pg m-3. The most abundant congener was PCB-153, accounting for 60% of the total PCBs in air. Surface water ∑4OCPs measured in this study ranged from 1.01 to 3.9 pg L-1, with γ-HCH predominating, while surface water Σ7PCB levels ranged from 0.32 to 24 pg L-1, with PCB-101, PCB-118, and PCB-153 presenting the highest levels. Diffusive air-water exchanges of HCB, α-HCH, γ-HCH and PCBs in the form of volatilization from the lake to air predominated; in contrast, for ß-HCH net deposition dominated during the sampling period. Estimates suggested faster microbial degradation in the dissolved phase compared to atmospheric degradation for all analyzed POPs. Overall, these results could indicate that the oligotrophic lakes of northern Patagonia act as a secondary source of atmospheric POPs, mainly PCBs and some OCPs. This study is a first attempt to understand the occurrence of POPs in air and water, as well as their dynamics in oligotrophic lakes in the southern hemisphere.

Towards understanding the effects of oceanic plastic pollution on population growth for a South American fur seal (Arctocephalus australis australis) colony in Chile.

Entanglement of pinnipeds with plastic debris is an emerging conservation and animal welfare issue worldwide. However, the origins and long-term population level consequences of these entanglements are usually unknown. Plastic entanglement could produce a combination of wounds, asphyxiation, or inability to feed that results in the death of a certain percentage of individuals from the total population. In this research, we report on the consequent effect of plastic entanglement on population growth demographics in a South American fur seal (Arctocephalus australis australis) colony on Guafo Island, southern Chile. Using a stochastic matrix population model structured according to age and sex, and assuming an otherwise stable population, we explored population growth rates under five scenarios with differing rates of entanglement: A) a zero rate of plastic entanglement, B) entanglement rates (number of entangled individuals as a proportion of the total number of individuals) as observed in our study population (overall entanglement ratio of 1.2 × 10-3); and for the other scenarios, entanglement ratios as reported in the literature for other pinniped colonies around the world: C) 3.04 × 10-3, D) 4.42 × 10-2, and E) 8.39 × 10-2. Over the 30 years forecasting period and starting with a population size of ∼2950 individuals, the population growth rate was lower under all scenarios with rates of entanglement greater than zero (scenarios B-E). In comparison with scenario A, at the end of the 30-year period forecasted, we calculated a projected decrease in population size of between 20.34% (scenario B) and 91.38% (scenario E). These results suggest that even the lowest levels of entanglement in pinnipeds as reported in the literature might have significant effects over time on population-level dynamics. Our research offers potential insight when devising policy for the management and limitation of plastic pollution in the oceans, and indeed for the conservation and management policy of affected marine species. Furthermore, whilst there are some limitations to our methodology, it offers a straightforward and potentially useful approach for the standardized prediction of impacts at a population level of different rates of plastic pollution and entanglement and could be applied in distinct populations of the same species around the world.

Legacy and novel flame retardants from indoor dust in Antarctica: Sources and human exposure.

The air humidity in Antarctica is very low and this peculiar weather parameter make the use of flame retardants in research facilities highly needed for safety reasons, as fires are a major risk. Legacy and novel flame retardants (nFRs) including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), Dechlorane Plus (DP), and other nFRs were measured in indoor dust samples collected at research Stations in Antarctica: Gabriel de Castilla, Spain (GCS), Julio Escudero, Chile (JES), and onboard the RRS James Clark Ross, United Kingdom (RRS JCR). The GC-HRMS and LC-MS-MS analyses of dust samples revealed ∑7PBDEs of 41.5 ± 43.8 ng/g in rooms at GCS, 18.7 ± 11.6 ng/g at JES, and 27.2 ± 37.9 ng/g onboard the RRS JCR. PBDE pattern was different between the sites and most abundant congeners were BDE-183 (40%) at GCS, BDE-99 (50%) at JES, and BDE-153 (37%) onboard the RRS JCR. The ∑(4)HBCDs were 257 ± 407 ng/g, 14.9 ± 14.5 ng/g, and 761 ± 1043 ng/g in indoor dust collected in rooms at GCS, JES, and RRS JCR, respectively. The ∑9nFRs were 224 ± 178 ng/g at GCS, 14.1 ± 13.8 ng/g at JES, and 194 ± 392 ng/g on the RRS JCR. Syn- and anti-DP were detected in most of the samples and both isomers showed the highest concentrations at GCS: 163 ± 93.6 and 48.5 ± 61.1 ng/g, respectively. The laboratory and living room showed the highest concentration of HBCDs, DPs, BTBPE. The wide variations in FR levels in dust from the three research facilities and between differently used rooms reflect the different origin of furnishing, building materials and equipment. The potential health risk associated to a daily exposure via dust ingestion was assessed for selected FRs: BDEs 47, 99, and 153, α-, ß-, and γ-HBCD, BTBPE, syn- and anti-DP. Although the estimated exposures are below the available reference doses, caution is needed given the expected increasing use of novel chemicals without a comprehensive toxicological profile.

Latitudinal patterns in the diet of Andean condor (Vultur gryphus) in Chile: Contrasting environments influencing feeding behavior.

Human-dominated environments alter the availability and quality of resources for many species, especially for scavengers that have large home ranges and plastic foraging behaviors that enable them to exploit novel resources. Along the western slope of the Andes, the modification of natural landscapes have resulted in significant declines in native prey, the introduction of non-native species, and an increase in the availability of anthropogenic resources. These factors have likely influenced the resources available to Andean condors (Vultur gryphus), however, data are lacking as to how condor's diet vary along their large latitudinal range. We evaluated differences in Andean condor diet along a ~2500 km latitudinal gradient in Chile from the heavily modified Central zone (32-34°S) to the more pristine Austral zone (44-56°S). We assessed diet composition through the identification of prey remains in condor pellets, and carbon and nitrogen isotope analysis of condor feathers and their primary prey identified from pellet analysis. Our results identified medium- and large-bodied domesticated mammals (ungulates) and introduced exotic species (lagomorphs) as common prey across the study area. Condors from the Central zone had the largest isotopic niche width, probably related to consumption of anthropogenic resources with distinctly high carbon isotope values indicative of C4-based foods likely acquired from landfills or corn-fed livestock. Isotopic niches for condors from the Southern and Austral zones almost completely overlapped. Andean condor diet is strongly influenced by local conditions determining differential access to prey sources. The high dependence of Andean condors on livestock across a large geographical area, and landfills in more (sub)urban areas, may help stabilize their populations via anthropogenic resources subsidies. Long-term dependence on such resources, however, may have health costs including contaminant exposure and greater mortality risk. These data will help identify potential threats related to resource availability and use, and better inform management and conservation decisions.

Sources and diffusive air-water exchange of polycyclic aromatic hydrocarbons in an oligotrophic North-Patagonian lake.

Polycyclic aromatic hydrocarbons (PAHs) are semivolatile organic compounds of environmental concern. This study aims to investigate the influence of local sources of anthropogenic PAHs and their air-water exchange fluxes in an oligotrophic North-Patagonian lake in Chile. The monitoring was carried out in Panguipulli Lake during a six-month period during the autumn and winter seasons (March to August 2017) using a high-volume air sampler and a pump system for water samples. We detected and quantified fifteen PAHs in the gas phase (mean ∑15PAHs = 11.6 ng m-3) and dissolved water phase (mean ∑15PAHs = 961.8 pg L-1). Methylphenanthrenes and pyrene dominated the concentrations of PAHs in the studied phases. To determine sources of PAHs we used the PAH ratios of Light Molecular Weight/Heavy Molecular Weight (∑LMW/∑HMW) and Phenanthrene/Anthracene (Phe/Ant). The PAH ratio results revealed a pyrogenic source. We estimated the air-water diffusive exchange fluxes and fugacity ratios for the studied compounds. In general, air-water diffusive exchanges of PAHs showed a net volatilization for the less hydrophobic (log KOW < 4) and lighter PAHs (MW ≤ 170 g mol-1), and a net deposition trend for the more hydrophobic (log KOW 4-7) and higher molecular weight PAHs (MW ≥ 178 g mol-1). We found a significant correlation between log water/air fugacity ratios and log KOW of PAHs. Therefore, it is suggested that this oligotrophic lake acts as a sink by accumulating hydrophobic and mid-high molecular weight PAHs derived mainly from pyrogenic sources. This study is the first attempt to understand the sources and behavior of PAHs in oligotrophic lakes in the Southern Chile where information is scarce regarding the occurrence of PAHs.

Monitoring the occurrence of microplastic ingestion in Otariids along the Peruvian and Chilean coasts.

Repeated reports of microplastic pollution in the marine pinniped diet have emerged in the last years. However, only few studies address the drivers of microplastics presence and the potential implications for monitoring microplastic pollution in the ocean. This study monitored their in the scats (N = 205) of four pinniped species/subspecies at five different locations in the southern Pacific Ocean (Peru and Chile). Samples from all rookeries contained microplastics, and overall, 68% of the examined scats contained fragments/fibers, mostly blue colored. We confirmed that 81.5% of the fragments/fibers were anthropogenic in origin , but only 30% were polymers. Scats from Juan Fernández Archipelago presented higher microplastic concentrations than continental rookeries. Also, the common diet in each location may influence the levels found in the samples. This study presents a useful non-invasive technique to track plastic pollution in top predator diets as bioindicators for future surveillance/management plans applied to different location.

Refuge quality to cope with UV radiation affects energy allocation in an intertidal fish.

Ultraviolet (UV) radiation is a primary environmental stressor for marine species inhabiting intertidal pools. Thus, the use of microhabitats as refuges is key to protect organisms against this stressor. In this study, we compared the quality of rocky and algae as refuges for the intertidal fish Girella laevifrons exposed to UV radiation. Refuge quality was studied by evaluating oxygen consumption and weight gain in control and UV-exposed fish. Rocky-refuge fish consumed less oxygen and gained significantly more weight than algal-refuge fish. The obtained results support the importance of refuge quality on energetic balance of intertidal organisms, where energy can be differentially allocated towards key life processes such as protection/repair or growth. Energy trade-offs need to be considered in research concerning animals inhabiting stressful habitats.

Persistent organic pollutants in krill from the Bellingshausen, South Scotia, and Weddell Seas.

Persistent organic pollutants (POPs) reach Antarctica through atmospheric transport, oceanic currents, and to minor extent, by migratory animals. The Southern Ocean is a net sink for many POPs, with a key contribution of the settling fluxes of POPs bound to organic matter (biological pump). However, little is known about POP transfer through the food web in the Southern Ocean and Antarctic waters, where krill is an important ecological node. In this study, we assessed the occurrence of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in Antarctic krill (Euphausia superba) from the Bellingshausen, South Scotia and Weddell Seas around the Antarctic Peninsula. The concentrations of PCDD/Fs, PBDEs and PCBs in krill showed a large variability and the average were higher (generally within a factor 3) than those previously reported for eastern Antarctica. This result highlights regional differences related to atmospheric transport and deposition, and also probable regional sources due to human activities. Bioaccumulation and biomagnification factors for PCBs in krill were estimated using previously reported phytoplankton and seawater concentrations for this region. These suggested a near water-krill equilibrium for PCBs, which was not observed for water-phytoplankton partitioning. The estimated removal settling fluxes of PCBs due to the biological pump were several orders of magnitude higher than the estimated fluxes of PCBs transferred from phytoplankton to krill.

Seawater-temperature and UV-radiation interaction modifies oxygen consumption, digestive process and growth of an intertidal fish.

UV-radiation (UVR) and temperatures have increased substantially over recent decades in many regions of the world. Both stressors independently have shown to affect the metabolism and growth in fish. However, because increase of both stressors are occurring concomitantly, to better understand their influences on marine species, their combined effects were evaluated. We test the hypothesis that UVR and temperature act synergistically affecting the metabolism, digestive process and growth of an intertidal fish. Two UVR conditions (with and without UVR) and two temperature levels (20° C and 25° C) were used. UVR increase the oxygen consumption and this was associated to opaque feces production. The absorption efficiency was higher without UVR at high temperatures (25 °C) and with UVR at low temperatures (20 °C). Finally, independent of UVR treatment, fish subjected to low temperature have higher biomass than those of high temperature. The interaction between UVR and temperature may influence on the physiology and growth of animals that inhabit in extreme habitats as upper intertidal, it could pose significant functional for aquatic animal survivorship.