Pollution as an Emerging Threat for the Conservation of the Galapagos Marine Reserve: Environmental Impacts and Management Perspectives. In: Denkinger J, Vinueza L, editors. The Galapagos Marine Reserve. Cham: Springer International Publishing; 2014. pp. 247-83. [DOI: 10.1007/978-3-319-02769-2_12]

Multiple anthropogenic stressors in the Galápagos Islands' complex social-ecological system: Interactions of marine pollution, fishing pressure, and climate change with management recommendations

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 2022;00:1-26. © 2022 SETAC.

Polluted paradise: Occurrence of pesticide residues within the urban coastal zones of Santa Cruz and Isabela (Galapagos, Ecuador)

Although pesticides are frequently used for agriculture in the Galapagos Islands (Ecuador), there are, to date, no investigations of pesticide occurrences in its coastal waters. We examined the presence of pesticide residues in the coastal waters of urban areas in two islands of the Galapagos archipelago using a repeated sampling design. Quantification was performed by solid-phase extraction, followed by chemical analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-electron capture detector (GC-ECD). The diversity and concentration of pesticide residues in Santa Cruz island were higher compared to Isabela island. In total, sixteen pesticides were detected, including three persistent organic pollutants. Carbendazim (23.93 μg·L^-1), cadusafos (4.74 μg·L^-1), DDT (2.99 μg·L^-1), diuron (1.61 μg·L^-1) and aldrin (1.55 μg·L^-1) were detected with the highest concentrations between samples. Repetitions in locations show that concentrations of pesticide residues varied considerably in space and time. Comparison with local products indicated agricultural activities on the islands as a possible source. Furthermore, evaluation through ecological risk quotients showed that the observed concentration levels of seven pesticides pose a relatively high risk for three biotic groups (i.e. algae, invertebrates and fishes). Taken together, this study provides insights into the need to regulate, monitor and assess the presence of pesticides in the islands. At a global scale, this study is moreover valuable for the many islands that are facing the same challenges.

The conservation status of the Galápagos marine iguanas, Amblyrhynchus cristatus: a molecular perspective

Traditionally, conservation management focuses efforts on taxonomic units. However, when the taxa used do not reflect biologically meaningful units, such methods should be reconsidered to avoid the loss of irreplaceable biodiversity. The Galápagos marine iguana (Amblyrhynchus cristatus) is listed as Vulnerable on the IUCN Red List of Threatened Species and is facing growing anthropogenic threats. Currently, management is based on a taxonomy which is questionable in the light of recent molecular data. As such, there is a danger that evolutionarily significant populations may be left vulnerable to extirpation. Herein, we apply molecular data to elucidate the population structure of this species across the Galápagos archipelago, and thus advise conservation management in the absence of a revised taxonomy. Applying a wealth of molecular data including 12 microsatellite loci and 1181 bp of the mitochondrial control region in over 1200 individuals, we delineate distinct populations and prioritize their management. Bayesian population structure analysis revealed 10 distinct population clusters, which we propose as management units (MUs). All MUs are significantly differentiated, with one unit on San Cristóbal Island being particularly distinct in terms of both microsatellite loci and mitochondrial data. Based on estimates of the genetic effective population size (Ne), we find the MUs comprised of populations occurring on Floreana, Española, Marchena, and San Cristóbal to be alarmingly small. In consideration of both Neand anthropogenic threats, we recommend that conservation practitioners focus efforts on Floreana and San Cristóbal islands, and argue that better census size estimates of populations are urgently needed.