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.

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.

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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.

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.

Climate change increases exposure and bioaccumulation of pollutants in marine organisms, posing substantial ecophysiological and ecotoxicological risks. Here, we applied a trophodynamic ecosystem model to examine the bioaccumulation of organic mercury (MeHg) and polychlorinated biphenyls (PCBs) in a Northeastern Pacific marine food web under climate change. We found largely heterogeneous sensitivity in climate-pollution impacts between chemicals and trophic groups. Concentration of MeHg and PCBs in top predators, including resident killer whales, is projected to be amplified by 8 and 3%, respectively, by 2100 under a high carbon emission scenario (Representative Concentration Pathway 8.5) relative to a no-climate change control scenario. However, the level of amplification increases with higher carbon emission scenario for MeHg, but decreases for PCBs. Such idiosyncratic responses are shaped by the differences in bioaccumulation pathways between MeHg and PCBs, and the modifications of food web dynamics between different levels of climate change. Climate-induced pollutant amplification in mid-trophic level predators (Chinook salmon) are projected to be higher (~10%) than killer whales. Overall, the predicted trophic magnification factor is ten-fold higher in MeHg than in PCBs under high CO2 emissions. This contribution highlights the importance of understanding the interactions with anthropogenic organic pollutants in assessing climate risks on marine ecosystems.

Three species of otariids are found in the coastal zone and marine area of Ecuador and the Galápagos Islands. Two species, Galápagos sea lion (Zalophus wollebaeki) and Galápagos fur seal (Arctocephalus galapagoensis), are endemic to the Galápagos. The South American sea lion (Otaria flavescens) has been recorded several times on the Ecuadorian coast, and even small semi-permanent or resident male groups (~10-30 animals) have frequently been observed in two southern locations (Santa Clara Island and Punta Brava-Salinas). The most recent estimates of Galápagos sea lion and fur seal populations, conducted in November 2001 by the Charles Darwin Foundation around the Galápagos Islands, were 14,000-16,000 and 6,000-8,000 animals, respectively. In the last two decades, anthropogenic impacts and natural phenomena have affected both Galápagos pinniped populations. Anthropogenic effects include oil spills (e.g., Jessica), fishery interactions, and illegal hunting (sea lions used for trade in reproductive organs). Natural events such as the 1982-1983 and 1997-1998 El Niños caused large reductions in populations, and diseases are being monitored to try to prevent negative impacts on the islands. Sightings of O. flavescens on the coast of Ecuador have been linked to El Niños since the displacement of this species from Peruvian colonies is Sea Lions of the World 495 Alaska Sea Grant College Program • AK-SG-06-01, 2006 caused by oceanographic changes (e.g., reduction of prey). Research and conservation of marine mammals, including rescue of sea lions, have been conducted by the Charles Darwin Foundation and the Ecuadorian Foundation for the Study of Marine Mammals in the last two decades.