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This article discusses the first recorded case of a stranded Southern Right Whale calf on Ecuador's north coast. The cause of the stranding is unknown, but it is speculated that the calf may have become separated from its mother. The text explores various factors that can contribute to whale strandings, including illness, predation, exposure to toxins, tidal changes, human activities, and climate change. Efforts are being made to rescue stranded whales and protect their populations through monitoring, regulations, and raising awareness. The document is a compilation of scientific articles and reports on southern right whales and other marine mammals, covering topics such as habitat suitability, migration patterns, genetic diversity, and anthropogenic threats. It provides valuable information for library patrons conducting research on southern right whales in the Eastern South Pacific. Additionally, a document published by the International Whaling Commission Scientific Committee provides an update on the movements and behavior of southern right whales in the southwest Atlantic, contributing to their understanding and conservation. [Extracted from the article]

Microplastic pollution threatens some of the world's most iconic locations for marine biodiversity, including the remote Galápagos Islands, Ecuador. Using the Galápagos penguin (Spheniscus mendiculus) as a sentinel species, the present study assessed microplastics and suspected anthropogenic cellulose concentrations in surface seawater and zooplankton near Santa Cruz and Galápagos penguin colonies (Floreana, Isabela, Santiago), as well as in penguin potential prey (anchovies, mullets, milkfish) and penguin scat. On average, 0.40 ± 0.32 microplastics L−1 were found in surface seawater (<10 μm; n = 63 L), while 0.003, 0.27, and 5.12 microplastics individual−1 were found in zooplankton (n = 3372), anchovies (n = 11), and mullets (n = 6), respectively. The highest concentration (27 microplastics individual−1) was observed in a single milkfish. Calculations based on microplastics per gram of prey, in a potential diet composition scenario, suggest that the Galápagos penguin may consume 2881 to 9602 microplastics daily from prey. Despite this, no microplastics or cellulose were identified in 3.40 g of guano collected from two penguins. Our study confirms microplastic exposure in the pelagic food web and endangered penguin species within the UNESCO World Heritage site Galápagos Islands, which can be used to inform regional and international policies to mitigate plastic pollution and conserve biodiversity in the global ocean. Environ Toxicol Chem 2024;43:1442–1457. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Bioaccumulation and biomagnification of anthropogenic particles are crucial factors in assessing microplastic impacts to marine ecosystems. Microplastic pollution poses a significant threat to iconic and often endangered species but examining their tissues and gut contents for contaminant analysis via lethal sampling is challenging due to ethical concerns and animal care restrictions. Incorporating empirical data from prey items and fecal matter into models can help trace microplastic movement through food webs. In this study, the Galápagos penguin food web served as an indicator species to assess microplastic bioaccumulation and biomagnification potential using trophodynamic Ecopath with Ecosim (EwE) modelling with Ecotracer. Empirical data collected from surface seawater near Galápagos penguin colonies, zooplankton, penguin prey, and penguin scat in October 2021 were used to inform the ecosystem model. Multiple scenarios, including a 99% elimination rate, were employed to assess model sensitivity. Model predictions revealed that microplastics can bioaccumulate in all predator-prey relationships, but biomagnification is highly dependent on the elimination rate. It establishes the need for more research into elimination rates of different plastics, which is a critical missing gap in current microplastic ecotoxicological and bioaccumulation science. Compared to empirical data, modelling efforts underpredicted microplastic concentrations in zooplankton and over-predicted concentrations in fish. Ultimately, the ecosystem modelling provides novel insights into potential microplastics' bioaccumulation and biomagnification risks. These findings can support regional marine plastic pollution management efforts to conserve native and endemic species of the Galápagos Islands and the Galápagos Marine Reserve. [ABSTRACT FROM AUTHOR]

Plastics, including microplastics, have generally been regarded as harmful to organisms because of their physical characteristics. There has recently been a call to understand and regard them as persistent, bioaccumulative, and toxic. This review elaborates on the reasons that microplastics in particular should be considered as "toxic pollutants". This view is supported by research demonstrating that they contain toxic chemicals within their structure and also adsorb additional chemicals, including polychlorinated biphenyls (PCBs), pesticides, metals, and polycyclic aromatic hydrocarbons (PAHs), from the environment. Furthermore, these chemicals can be released into tissues of animals that consume microplastics and can be responsible for the harmful effects observed on biological processes such as development, physiology, gene expression, and behavior. Leachates, weathering, and biofilm play important roles in the interactions between microplastics and biota. Global policy efforts by the United Nations Environmental Assembly via the international legally binding treaty to address global plastic pollution should consider the designation of harmful plastics (e.g., microplastics) with associated hazardous chemicals as toxic pollutants. [ABSTRACT FROM AUTHOR]

For decades, multiple anthropogenic stressors have threatened the Galápagos Islands. Widespread marine pollution such as oil spills, persistent organic pollutants, metals, and ocean plastic pollution has been linked to concerning changes in the ecophysiology and health of Galápagos species. Simultaneously, illegal, unreported, and unregulated fishing are reshaping the composition and structure of endemic and native Galápagos pelagic communities. In this novel review, we discuss the impact of anthropogenic pollutants and their associated ecotoxicological implications for Galápagos species in the face of climate change stressors. We emphasize the importance of considering fishing pressure and marine pollution, in combination with climate‐change impacts, when assessing the evolutionary fitness of species inhabiting the Galápagos. For example, the survival of endemic marine iguanas has been negatively affected by organic hydrocarbons introduced via oil spills, and endangered Galápagos sea lions exhibit detectable concentrations of DDT, triggering potential feminization effects and compromising the species' survival. During periods of ocean warming (El Niño events) when endemic species undergo nutritional stress, climate change may increase the vulnerability of these species to the impacts of pollutants, resulting in the species reaching its population tipping point. Marine plastics are emerging as a deleterious and widespread threat to endemic species. The Galápagos is treasured for its historical significance and its unparalleled living laboratory and display of evolutionary processes; however, this unique and iconic paradise will remain in jeopardy until multidisciplinary and comprehensive preventative management plans are put in place to mitigate and eliminate the effects of anthropogenic stressors facing the islands today. We present a critical analysis and synthesis of anthropogenic stressors with some progress from local and international institutional efforts and call to action more precautionary measures along with new management philosophies focused on understanding the processes of change through research to champion the conservation of the Galápagos. Integr Environ Assess Manag 2023;19:870–895. © 2022 SETAC Key Points: Ocean pollution, anthropogenic climate change, and fishing pressure (illegal, unregulated, and unreported fishing) are driving factors reshaping evolutionary processes and affecting marine biodiversity in the complex social–ecological systems of the UNESCO Global Heritage Site, Galápagos Islands.The combination of chemical pollution, marine debris, ocean plastics, climate change, and overfishing are conspiring to further contaminate marine life and food webs, which has obvious implications for ecosystems and the ocean, but also for the health of the islands' coastal communities.A proactive policy framework is essential to addressing and combating the multiple anthropogenic stressors, resulting from the intertwined nature of chemical pollution, climate change, and fishery pressure, across the biological and socioeconomic levels of organization in the Galápagos Islands.Although efforts for conservation and management are classic arenas to continue preserving the Galápagos Islands, an opportunity to frame solution‐oriented research to better understand the processes of change and conservation management remaking nature in the Anthropocene era is critical. [ABSTRACT FROM AUTHOR]

We examined how dietary factors recorded by C and N influence Hg uptake in 347 individuals of yellowfin tuna (Thunnus albacares), an important subsistence resource from the Galápagos Marine Reserve (Ecuador) and the Ecuadorian mainland coast in 2015–2016. We found no differences in total Hg (THg) measured in red muscle between the two regions and no seasonal differences, likely due to the age of the fish and slow elimination rates of Hg. Our THg concentrations are comparable to those of other studies in the Pacific (0.20‐9.60 mg/kg wet wt), but a subset of individuals exhibited the highest Hg concentrations yet reported in yellowfin tuna. Mercury isotope values differed between Δ199Hg and δ202Hg in both regions (Δ199Hg = 2.86 ± 0.04‰ vs. Δ199Hg = 2.33 ± 0.07‰), likely related to shifting food webs and differing photochemical processing of Hg prior to entry into the food web. There were significantly lower values of both δ15N and δ13C in tuna from Galápagos Marine Reserve (δ15N: 8.5–14.2‰, δ13C: −18.5 to −16.1‰) compared with those from the Ecuadorian mainland coast (δ15N: 8.3–14.4‰, δ13C: −19.4 to −11.9‰), of which δ13C values suggest spatially constrained movements of tuna. Results from the pooled analysis, without considering region, indicated that variations in δ13C and δ15N values tracked changes of Hg stable isotopes. Our data indicate that the individual tuna we used were resident fish of each region and were heavily influenced by upwellings related to the eastern Pacific oxygen minimum zone and the Humboldt Current System. The isotopes C, N, and Hg reflect foraging behavior mainly on epipelagic prey in shallow waters and that food web shifts drive Hg variations between these populations of tuna. Environ Toxicol Chem 2022;41:2732–2744. © 2022 SETAC [ABSTRACT FROM AUTHOR]

COVID-19, caused by SARS-CoV-2, was declared a global pandemic on 11 March 2020 by the World Health Organization. The pandemic has triggered an unprecedented increase in the production, consumption and disposal of multiple types of plastic-based personal protective equipment (PPE) as a measure to reduce the infection. Recent research shows that plastic surfaces can serve as a fomite for coronavirus transmission as it can remain stable and be viable on polypropylene for up to 72 h or on other plastic surfaces for up to 9 days. While it is unknown whether or to what extent macroplastic debris and ubiquitous microplastics emitted into the environment can serve as physical vectors or fomites of pathogenic viruses, recent studies have reported that both macroplastic and microplastics can serve as vectors for harmful pathogens and invasive species (biological pollution). Here, hypothetical scenarios based on the weight of evidence are proposed to plausibly state the role of plastic debris (e.g., single-use-plastics), discarded PPE supplies, including facemasks, sanitizer bottles, gloves, and plastic bags, as well as microplastics as potential physical vectors of SARS-CoV-2, serving as a route of exposure to humans and wildlife in the terrestrial, freshwater and marine ecosystems. [ABSTRACT FROM AUTHOR]

The article offers information on several aspects associated with the live-stranded killer whale (Orcinus orca) in Coastal Ecuador along with insights on an occurrence of Killer Whale in Ecuadorian Waters. The topics addressed include details on the documented observations and unpublished records of killer whales (Orcinus orca) in coastal waters of Ecuador from 1996 to June 2017.

Abstract Water and sediment quality, macrobenthos diversity and mercury levels were assessed in the Salado Estuary, Gulf of Guayaquil (Ecuador) during 2008, 2009 and 2014. Severe hypoxia, anoxia and large fluctuations of salinity occurred in an impacted sector within Guayaquil city relative to a mangrove area within the Salado Mangroves Faunal Production Reserve. Significant inter-site and temporal differences were observed for dissolved oxygen, salinity, total dissolved solids, percentage of silts and clays, and species diversity. Macrobenthos' species richness for both sectors was greater during 2008. Sediments revealed high concentrations of total mercury (THg) (1.20–2.76 mg kg−1 dw), exceeding Ecuador's SQG (0.1 mg kg−1 dw). Sediment THg were significantly lower in 2014 than 2008/09. Biota sediment sccumulation factor values for mussels (3.0 to 34), indicate high bioaccumulation potential from mercury-contaminated sediments. This work highlights the need to develop stronger environmental policies to protect the Salado Estuary from anthropogenic stressors. Highlights • The ecotoxicological and biological conditions of the Salado Estuary were assessed. • High mercury concentrations in sediments and mangrove mussels exceeded Ecuador's SQG. • Oligochaetes were the dominant macrobenthos and bioindicator of local contamination. • Mussels served as bioindicator to monitor mercury pollution in the Salado Estuary. • Anthropogenic pollution is linked to declining environmental quality in the estuary. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Chemistry is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate change is reshaping the way in which contaminants move through the global environment, in large part by changing the chemistry of the oceans and affecting the physiology, health, and feeding ecology of marine biota. Climate change-associated impacts on structure and function of marine food webs, with consequent changes in contaminant transport, fate, and effects, are likely to have significant repercussions to those human populations that rely on fisheries resources for food, recreation, or culture. Published studies on climate change-contaminant interactions with a focus on food web bioaccumulation were systematically reviewed to explore how climate change and ocean acidification may impact contaminant levels in marine food webs. We propose here a conceptual framework to illustrate the impacts of climate change on contaminant accumulation in marine food webs, as well as the downstream consequences for ecosystem goods and services. The potential impacts on social and economic security for coastal communities that depend on fisheries for food are discussed. Climate change-contaminant interactions may alter the bioaccumulation of two priority contaminant classes: the fat-soluble persistent organic pollutants ( POPs), such as polychlorinated biphenyls ( PCBs), as well as the protein-binding methylmercury (MeHg). These interactions include phenomena deemed to be either climate change dominant (i.e., climate change leads to an increase in contaminant exposure) or contaminant dominant (i.e., contamination leads to an increase in climate change susceptibility). We illustrate the pathways of climate change-contaminant interactions using case studies in the Northeastern Pacific Ocean. The important role of ecological and food web modeling to inform decision-making in managing ecological and human health risks of chemical pollutants contamination under climate change is also highlighted. Finally, we identify the need to develop integrated policies that manage the ecological and socioeconomic risk of greenhouse gases and marine pollutants. [ABSTRACT FROM AUTHOR]

To track the long term bioaccumulation of 137 Cs in marine organisms off the Pacific Northwest coast of Canada, we developed a time dependent bioaccumulation model for 137 Cs in a marine mammalian food web that included fish-eating resident killer whales. The model outcomes show that 137 Cs can be expected to gradually bioaccumulate in the food web over time as demonstrated by the increase of the apparent trophic magnification factor of 137 Cs, ranging from 0.76 after 1 month of exposure to 2.0 following 30 years of exposure. 137 Cs bioaccumulation is driven by relatively rapid dietary uptake rates, moderate depuration rates in lower trophic level organisms and slow elimination rates in high trophic level organisms. Model estimates of the 137 Cs activity in species of the food web, based on current measurements and forecasts of 137 Cs activities in oceanic waters and sediments off the Canadian Pacific Northwest, indicate that the long term 137 Cs activities in fish species including Pacific herring, wild Pacific salmon, sablefish and halibut will remain well below the current 137 Cs-Canada Action Level for consumption (1000 Bq/kg) following a nuclear emergency. Killer whales and Pacific salmon are expected to exhibit the largest long term 137 Cs activities and may be good sentinels for monitoring 137 Cs in the region. Assessment of the long term consequences of 137 Cs releases from the Fukushima aftermath should consider the extent of ecological magnification in addition to ocean dilution. [ABSTRACT FROM AUTHOR]

The fauna of the Galápagos Island chain is characterized by high biodiversity and endemism. Thus, the conservation of its terrestrial and marine wildlife, including the sustainable management of local fisheries, is of paramount importance., Although the commercial exploitation of fish in the Galápagos did not intensify until the mid-1900s, issues of overexploitation and mismanagement are already of serious concern. However, to date, research on Galápagos fisheries has been largely species or island specific, and no long-term cumulative catch statistics exist., In this study, total landings associated with the industrial and artisanal fisheries of the Galápagos Islands were compiled and analysed in an effort to assess accurately the amount of seafood that has been extracted from this region over the last six decades., The total catch for all sectors from 1950-2010 was 797 000 t, of which industrially caught tuna made up 80%., The results also show a high degree of fishing down within the in-shore ecosystem catch, whereby planktivorous mullets have replaced high trophic level groupers within the past three decades. This shift has coincided with the spatial expansion of the Galápagos fishing fleet to areas further off-shore, where predatory species are not yet depleted., In addition to legally caught and exported seafood, Galápagos waters are also prone to illegal fishing. Of primary concern are shark finning practices that have escalated in intensity since the 1980s. Despite attempts at mitigation, this ecologically destructive and wasteful practice continues to occur in the Galápagos Marine Reserve., Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2–7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula. [ABSTRACT FROM AUTHOR]

The article presents observations on attacks of killer whales Bryde's whales in Galápagos Islands in Ecuador. It states that eight photographs were analyzed, showing the predatory event that occurred in Bolívar Channel located between Isabela Islands and Fernandina. It mentions that Bryde's whales lacked resistance and did not have defensive mechanisms. It adds that killer whales showed effective predation and group coordination.

The development of an area-based polychlorinated biphenyl (PCB) food-web bioaccumulation model enabled a critical evaluation of the efficacy of sediment quality criteria and prey tissue residue guidelines in protecting fish-eating resident killer whales of British Columbia and adjacent waters. Model-predicted and observed PCB concentrations in resident killer whales and Chinook salmon were in good agreement, supporting the model's application for risk assessment and criteria development. Model application shows that PCB concentrations in the sediments from the resident killer whale's Critical Habitats and entire foraging range leads to PCB concentrations in most killer whales that exceed PCB toxicity threshold concentrations reported for marine mammals. Results further indicate that current PCB sediment quality and prey tissue residue criteria for fish-eating wildlife are not protective of killer whales and are not appropriate for assessing risks of PCB-contaminated sediments to high trophic level biota. We present a novel methodology for deriving sediment quality criteria and tissue residue guidelines that protect biota of high trophic levels under various PCB management scenarios. PCB concentrations in sediments and in prey that are deemed protective of resident killer whale health are much lower than current criteria values, underscoring the extreme vulnerability of high trophic level marine mammals to persistent and bioaccumulative contaminants. [ABSTRACT FROM AUTHOR]

Abstract: Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in blubber biopsy samples from 22 live-captured Steller sea lions (Eumetopias jubatus) that had just entered the Strait of Georgia, British Columbia, Canada, for their overwintering feeding season. ∑PBDE ranged from 50μgkg−1 (lipid weight) in adult females to 3780μgkg−1 in subadult individuals. ∑PCBs ranged from 272μgkg−1 in adult females to 14280μgkg−1 in subadult individuals. While most PBDE and PCB congeners were transferred through milk to pups, PCBs with log K OW >7.0 (PCBs 206, 207, 208 and 209) appeared constrained, resulting in a lighter mixture in pups compared to adult females. The ratio of individual PCB congeners by metabolic group (Groups I, II, III, IV and V) to PCB-153 regressed against length of males suggested poor biotransformation of these compounds (slopes did not differ from zero, p >0.05). PBDE congeners 49, 99, 153 and 183 appeared bioaccumulative (slopes of ratio BDE/PCB 153 versus length were higher than zero, p <0.05), but the dominance of the single congener, BDE-47 (64% of total PBDEs), likely due in part to debromination pathways, reduced our ability to explore congener-specific dynamics of PBDEs in these pinnipeds. With 80% of our Steller sea lions exceeding a recent toxicity reference value for PCBs, the fasting-associated mobilization of these contaminants raises concerns about a heightened vulnerability to adverse effects during annual migrations. [Copyright &y& Elsevier]

Persistent organic pollutants (POPs) are recognized manmade threats to sea turtle populations, but substantial uncertainty exists surrounding their exposure to contaminants and their sensitivity to toxic effects. This uncertainty creates difficulty for conservation managers to make informed decisions for the recovery of these threatened species. To provide baseline concentrations and spatial comparisons, we measured a large suite of POPs in loggerhead sea turtle ( Caretta caretta) egg yolk samples collected from 44 nests in three distinct U.S. locations: North Carolina (NC), eastern Florida (E FL), and western Florida (W FL). The POPs included polychlorinated biphenyls (PCBs), organochlorine pesticides such as dichlorodiphenyltrichloroethanes (DDTs), chlordanes, mirex, dieldin, hexachlorocyclohexanes (HCHs), hexachlorobenzene, and toxaphene congeners, as well as polybrominated diphenyl ether congeners (PBDEs). Persistent organic pollutant concentrations were lowest in W FL, intermediate in E FL, and highest in NC egg samples, with several statistically significant spatial differences. This increasing gradient along the southeast coast around the Florida peninsula to North Carolina was explained partly by the foraging site selection of the nesting females. Data from previous tracking studies show that NC nesting females feed primarily along the U.S. eastern coast, whereas W FL nesting females forage in the Gulf of Mexico and Caribbean Sea. The E FL nesting females forage in areas that overlap these two. The foraging site selection also results in exposure to different patterns of POPs. An unusual PBDE pattern was seen in the NC samples, with nearly equal contributions of PBDE congeners 47, 100, and 154. These findings are important to managers assessing threats among different stocks or subpopulations of this threatened species. Environ. Toxicol. Chem. 2011; 30:1677-1688. © 2011 SETAC [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents a study which is focused on the use of estimates of primary productivity, carbon flux and abundance of cetacean to infer tertiary production of cetaceans and their trophic role in marine ecosystems of the Galapagos Marine Reserve. To conduct the study, several bioecological parameters were associated and connected by theoretical calculations to deduct primary production, flux of carbon and cetacean production. The methods revealed data on chlorophyll a, cetacean density, energy consumption budgets by cetacean species, trophic position and trends on primary production versus tertiary production.

The article discusses a study on inshore feeding behavior of blue-footed boobies, or Sula nebouxii, in Ecuador during warming conditions in equatorial pacific ocean, citing that the boobies were feeding in a dense and coordinated group, and prey were highly local along the South American coast.

The article focuses on a study which examined carbon productivity and flux in the marine ecosystems of the Galapagos Marine Reserve according to cetacean abundances and trophic indices. The criteria for the selection of candidate species of cetaceans were outlined. Among the species considered were Bryde's and blue whales, sperm whales, bottlenose dolphins and killer whales. Considering primary and tertiary production, the abundance of marine mammals has been found to be higher at the west part of the reserve. Marine zones and upwelling located in the western side of islands were used to explain the transfer of energy within the marine system.

Abstract: Data are scarce describing the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides in sea turtle eggs. The purpose of this study was to establish appropriate sample collection methodology to monitor these contaminants in sea turtle eggs. Contaminant concentrations were measured in yolk samples from eggs that failed to hatch from three loggerhead sea turtle (Caretta caretta) nests collected in southern Florida to determine if concentrations change through embryonic development. One to three egg yolk samples per nest were analyzed from early, middle, and late developmental stages (n =22 eggs total). PCB and pesticide concentrations were determined by gas chromatography with electron capture detection (GC–ECD). Geometric mean concentrations of ∑PCBs (52 congeners), ∑DDTs, ∑chlordanes, and dieldrin in all eggs were 65.0 (range=7.11 to 3930 ng/g lipid), 67.1 (range=7.88 to 1340 ng/g lipid), 37.0 (range=4.04 to 685 ng/g lipid), and 11.1 ng/g lipid (range=1.69 to 44.0 ng/g lipid), respectively. Early and middle developmental stage samples had similar concentrations of PCBs and organochlorine pesticides on a wet-mass basis (ng/g tissue extracted), but the concentrations doubled by the late stage. This increase is most likely attributable to the 50% increase in lipid content observed in the late-stage yolk. These findings indicate that an early-stage sample cannot be directly compared to a late-stage sample, especially from different nests. These preliminary findings also allowed us to calculate the minimum number of eggs per nest required for analysis to obtain an acceptable mean concentration per nest. More research is required to investigate geographical trends of contaminant concentrations and potential health effects (i.e., abnormalities) caused by these contaminants on sea turtle development. [Copyright &y& Elsevier]

A comprehensive investigation of PAHs' occurrence and distribution in the water, sediment, and fish samples of Musa estuary was conducted. Concentrations of 16 PAHs in water, sediment and two commercial fish ranged from 0.14 to 0.66 ng/l, 67.21 to 82.92 ng/g dw, 50.25 to 99.39 ng/g fdw in J. belangerii , and 40.14 to 76.93 ng/g fdw in B. orentalis , respectively. High molecular weight PAHs (HMW-PAHs) were generally predominant compared to low molecular weight PAHs (LMW-PAHs). Additionally, the study of the PAHs fingerprints, using specific ratios, suggests the predominance of a pyrolytic origin for observed PAHs. 4-ring PAHs were observed more in the two species, whereas the PAHs in sediments were dominated by three and five ring compounds. The Incremental lifetime Cancer Risk (ILCR) for fish was ≤10 E 10−5, showed a minimal possible risk of cancer for children and adult. • Polycyclic Aromatic Hydrocarbons (PAHs) have been determined in tissues of fish, water, and sediments, from the Musa estuary and Persian Gulf. • The study of the PAHs fingerprints suggested that PAHs were primarily derived from different sources mainly petroleum and combustion sources. • Findings provide baseline data for further research on ecotoxicity of PAHs in biota and abiota. • The occurrence of PAHs in seafood for human consumption is cause for concern. [ABSTRACT FROM AUTHOR]

Abstract: The feeding behavior of marine predators varies with the level of competition to which they are exposed. Populations living in the same or overlapping geographic regions (sympatric) are generally subject to inter-specific competition, which can lead to the development of differing trophic strategies that maximize both nutritional and reproductive efficiency. The otariids of the islands in the western Galapagos Archipelago represent appropriate subjects for studying the response mechanisms of sympatric species exposed to strong competition, both trophic and spatial. The present study has focused on evaluating the possible differences in the trophic niches of the Galapagos sea lion (Zalophus wollebaeki) and the Galapagos fur seal (Arctocephalus galapagoensis) over time, based upon the analysis of stable isotope ratios of carbon and nitrogen (δ13C and δ15N), and observation of both species at sea. A comparative analysis of the isotopic signal of skin samples from pups of both species was performed for rookeries on Fernandina Island between 2003 and 2009. Analyses of the isotopic signal present in prey covering the entire trophic range of these predators were also performed, in order to relate this information to otariid sighting records collected during offshore cruises in 1993–1994 and 2000. The δ13C and δ15N values defined differences in the feeding zones and in the trophic level of each species; which were related with the interannual variability of the ecosystem, i.e. El Niño and La Niña events. Whereas Z. wollebaeki showed a coastal (inshore) foraging strategy, relying on the consumption of small epipelagic fishes, A. galapagoensis turned out to be a more oceanic (offshore) predator, with a preference for small squid. These results are in good agreement with the distribution of these animals at sea, as indicated by the sighting data. The findings of this study provide new insights to our understanding of how sympatric species exposed to strong inter-specific competition can develop foraging strategies leading to a decreasing level of food competition and facilitate their survival in a stochastic environment that is highly demanding in terms of the availability of resources. [Copyright &y& Elsevier]