Recent Publications
Authors shown in bold are UNC- and/or Galapagos Science Center-affiliated scientists, students, or staff.
Muñoz-Pérez JP, Lewbart G, Alarcón-Ruales D, Skehel A, Cobos E, Rivera R, Jaramillo A, Vivanco H, Zurita-Arthos L, Wallace B, Valle CA, Townsend KA, (2023). Galápagos and the plastic problem. Frontiers in Sustainability.
Rhea S, Camacho BE, Amoriello CW, Correa M, Lewbart GA, Cruz M, Vélez A, Castillo P, Pairis-Garcia M, (2023). Assessing Livestock Production Practices on Small-Scale Multi-Species Farms Located on Floreana Island, Galápagos Islands. MDPI.
Christman JE, Lohmann KJ, Hirschfeld M, Muñoz-Pérez, Garcia J, Hernandez JA, Westermeyer H, Lewbart GA, (2023). Intraocular pressure using rebound tonometry in the Galápagos marine iguana (Amblyrhynchus cristatus). International Journal of Veterinary Research.
Masterson CA, Locklear TR, Páez-Rosas D, Muñoz-Pérez JP, Ortega C, Lewbart GA, Vaden SL (2022). Intraocular pressure using rebound tonometry in the San Cristobal Galapagos tortoise (Chelonoidis chathamensis). International Journal of Veterinary Research.
Jahnke JR, Thompson AL, Archer NT, Bentley ME, Houck KM, Fuentes MF, Ochoa J, (2022). Health Across the First 1000 Days in the Galápagos Islands. Water, Food and Human Health in the Galapagos, Ecuador. Social and Ecological Interactions in the Galapagos Islands. Springer, Cham.
Thompson AL, Teran E, Bentley ME, (2022). Syndemic Water and Food Insecurity: Impacts on the Dual Burden of Disease in Galapagos. Water, Food and Human Health in the Galapagos, Ecuador. Social and Ecological Interactions in the Galapagos Islands. Springer, Cham.
Nicholas K, Bentley M, Terán E, Thompson A, (2022). Navigating Globalized Food Environments: Market Access, Consumer Behavior, and Dietary Diversity in the Galapagos Islands of Ecuador. Current Developments in Nutrition 6 (Supplement_1).
Jahnke JR, Archer NT, Thompson AL, Ocampo J, Bentley ME, (2022). Health-Seeking Behavior and Perceptions of Care: A Qualitative Study Investigating the Underutilization of Public Health Care on the Galápagos Islands. Water, Food and Human Health in the Galapagos, Ecuador. Social and Ecological Interactions in the Galapagos Islands. Springer, Cham.
Miller J, Adair L, Stewart J, Terán E, Bentley M, Thompson A, (2022). Water Insecurity Is Differentially Associated With Food Insecurity Across Seasons: Evidence From the Galápagos. Current Developments in Nutrition 6 (Supplement_1).
Hyeon Jang S, Lim P, Torano O, Neave EF, Seim H, Marchetti A, (2022). Protistan Communities Within the Galápagos Archipelago With an Emphasis on Micrograzers. Frontiers in Marine Science, Volume 9.
Souza AR, Huffman AM, Muñoz-Pérez JP, Vaden S, Diaz R, Vasquez G, Donnelly KA, Páez-Rosas D, Lewbart GA, (2021). Cross-Matching the San Cristóbal Galápagos Tortoise (Chelonoidis chathamensis). Journal of Herpetological Medicine and Surgery 31 (4).
Neave EF, Seim H, Gifford SM, Torano O, Johnson ZI, Páez-Rosas D, Marchetti A, (2022). Protistan plankton communities in the Galápagos Archipelago respond to changes in deep water masses resulting from the 2015/16 El Niño. Environ Microbiol.
Cambra M, Lara-Lizardi F, Peñaherrera-Palma C, Hearn A, Ketchum JT, et al. (2021). A first assessment of the distribution and abundance of large pelagic species at Cocos Ridge seamounts (Eastern Tropical Pacific) using drifting pelagic baited remote cameras. PLOS ONE 16(11).
Larsen W, Liu X, Riveros-Iregui D, (2021). Rare earth element behavior in springs and streams on a basaltic island: San Cristóbal, Galápagos, Applied Geochemistry, Volume 131.
Chiriboga-Paredes Y, Palomino Á, Goodman L et al. (2022). Discovery of a putative scalloped hammerhead shark Sphyrna lewini (Carcharhiniformes: Sphyrnidae) nursery site at the Galapagos Islands, Eastern Tropical Pacific. Environ Biol Fish.
John Schofield, Jerry Aylmer, Andy Donnelly, Jen Jones, Juan Pablo Muñoz-Pérez, Elena Perez, Callum Scott, Kathy A. Townsend. (2021). Contemporary Archaeology as a Framework for Investigating the Impact of Disposable Plastic Bags on Environmental Pollution in Galápagos. Journal of Contemporary Archaeology. 7.
Jen S. Jones, Adam Porter, Juan Pablo Muñoz-Pérez, Daniela Alarcón-Ruales, Tamara S. Galloway, Brendan J. Godley, David Santillo, Jessica Vagg, Ceri Lewis, (2021). Plastic contamination of a Galapagos Island (Ecuador) and the relative risks to native marine species. Science of The Total Environment, Volume 789, 147704.
María Sarzosa, Pádraig Duignan, Eugene DeRango, Cara Field, Carlos Ríos, Susan Sanchez, Eduardo Espinoza, Andrea Loyola, Danny Rueda, Diego Páez-Rosas. (2021). Occurrence of Mycoplasmas in Galapagos Sea Lions (Zalophus wollebaeki) and their Association with Other Respiratory Pathogens. J Wildl Dis 1, 57 (3): 623–627.
Bonaccorso E., Ordóñez-Garza N., Pazmiño D.A. et al. (2021). International fisheries threaten globally endangered sharks in the Eastern Tropical Pacific Ocean: the case of the Fu Yuan Yu Leng 999 reefer vessel seized within the Galápagos Marine Reserve. Sci Rep 11, 14959.
Emily Tucker-Retter, Zoë Velsey-Gross, Diane Deresienski, Catalina Ulloa, Juan-Pablo Muñoz-Pérez, et. al, (2021). Health Status of Nazca Boobies (Sula granti) on Daphne Major island in the Galapagos determined by hematology, biochemistry, and physical examination. Journal of Zoo and Wildlife Medicine 52(2), 671-679.
Álvarez-Varas Rocío, Rojas-Hernández Noemi, Heidemeyer Maike, Riginos Cynthia et. al. (2021). Green, yellow or black? Genetic differentiation and adaptation signatures in a highly migratory marine turtle. Proc. R. Soc. B.2882021075420210754.
Neave E, Seim H, Gifford S, Torano O, Johnson Z, Páez-Rosas D, Marchetti A. (in review). Protistan plankton communities in the Galapagos Archipelago respond to changes in deep water masses resulting from the 2015/16 El Niño. Environmental Microbiology.
(2021). Whole blood fatty acid concentrations in the San Cristóbal Galápagos tortoise (Chelonoidis chathamensis) PeerJ 9:e11582.
Kate A Berry, Juan Pablo Muñoz-Pérez, Cristina P Vintimilla-Palacios, Christofer J Clemente, ( 2021). Morphological and performance modifications in the world’s only marine lizard, the Galápagos marine iguana, Amblyrhynchus cristatus, Biological Journal of the Linnean Society, Volume 133, Issue 1, 68-80,
Diego Páez-Rosas, Jorge Torres, Eduardo Espinoza, Adrian Marchetti, Harvey Seim, Marjorie Riofrío. (2021). Declines and Recovery in endangered Galapagos pinnipeds during the El Niño event. Scientific Reports 11, 8785.
William F. Vásquez, Nejem Raheem, Diego Quiroga, Valeria Ochoa-Herrera. (2021). Household preferences for improved water services in Galapagos Islands. Water Resources and Economics 34.
Bonaccorso E, Ordóñez-Garza N, Pazmiño D, Hearn A, Páez-Rosas D, Cruz S, Muñoz-Pérez J, Espinoza J, Suárez J, Muñoz-Rosado K, Vizuete A, Chaves J, Torres M, Bustos W, Rueda D, Hirschfeld M, Guayasamin J. 2021. International fisheries threaten globally endangered sharks in the Eastern Tropical Pacific Ocean. Scientific Reports.
Dass K, Lewbart G, Muñoz-Pérez J, Yépez M, Loyola A, Chen E, Páez-Rosas D. 2021. Evaluation of Fatty Acid Whole Blood Concentrations in the San Cristóbal Galápagos Tortoise (Chelonoidis chathamensis). PeerJ.
Yang Shao, Austin J. Cooner, Stephen J. Walsh. (2021). Assessing Deep Convolutional Neural Networks and Assisted Machine Perception for Urban Mapping. Remote Sens 168, 13: 100180.
Isabel Silva Romero, John F. Bruno, Nyssa. J. Silbiger, Margarita Brandt. (2021). Local conditions influence thermal sensitivity of pencil urchin populations (Eucidaris galapagensis) in the Galápagos Archipelago. Mar Biol 168, 34.
Izurieta-Benítez S, Urquía DO, Torres J, Riofrío-Lazo M, Páez-Rosas D. (2021). Age prediction model for adult male Galapagos sea lions based on skull measures. Mamm Res 66, 201–210.
Páez-Rosas D, Torres J, Espinoza E, Marchetti A, Seim H, Riofrío-Lazo M. 2021. Declines and recovery in endangered Galapagos pinnipeds during the El Niño event. Scientific Reports.
Lorenzo-Carballa M, Garrison R, Encalada A, Cordero-Rivera A. (2020). Darwin Returns to the Galapagos: Genetic and Morphological Analyses Confirm the Presence of Tramea darwini at the Archipelago (Odonata, Libellulidae). Insects. 12(1), 21.
Jahnke JR, Terán E, Murgueitio F, Cabrera H, Thompson AL. (2020) Maternal stress, placental 11β-hydroxysteroid dehydrogenase type 2, and infant HPA axis development in humans: Psychosocial and physiological pathways. Placenta. 104: 179-187
Gifford SM, Zhao L, Stemple B, et al. (2020) Microbial Niche Diversification in the Galápagos Archipelago and Its Response to El Niño. Front Microbiol. 11:575194.
Walsh, Stephen J., Riveros-Iregui, Diego, Arce-Nazario, Javier, Page, Philip H. Guest Editors (2020). Land Cover and Land Use Change on Islands: Social & Ecological Threats to Sustainability, Springer Nature. In: Galapagos Book Series, “Social and Ecological Interactions in the Galapagos Islands,” Stephen J. Walsh & Carlos F. Mena, Series Editors.
Included Chapters:
- Godfrey Baldacchino, “Prologue – Geographies of Hope and Despair: Land Cover and Land Use on Islands,” pp. 1-10.
- Richard E. Bilsborrow, “Economic and Related Aspects of Land Use on Islands: A Meta-Analysis,” pp. 11-62.
- Stephen J. Walsh, Laura Brewington, Francisco Laso, Yang Shao, Richard E. Bilsborrow, Javier Arce-Nazario, Hernando Mattei, Philip H. Page, Brian G. Frizzelle, Francesco Pizzitutti, “Social-Ecological Drivers of Land Cover/Land Use Change on Islands: A Synthesis of the Patterns and Processes of Change,” pp. 63-88.
- Laura Brewington, “Transitions and Drivers of Land Use/Land Cover Change in Hawai’i: A Case Study of Maui,” pp. 89-118.
- Carlos F. Mena, Homero A. Paltan, Fatima L. Benitez, Carolina Sampedro, Marilu Valverde, “Threats of Climate Change in Small Oceanic Islands: The Case of Climate and Agriculture in the Galapagos Islands, Ecuador,” pp. 119-136.
- Francisco Laso, “Galapagos is a Garden,” pp. 137-166.
- Yang Shao, Heng Wan, Alexander Rosenman, Francisco J. Laso, Lisa M. Kennedy, “Evaluating Land Cover on the Island of Santa Cruz, Galapagos Archipelago of Ecuador through Cloud-Gap Filling and Multi-Sensor Analysis, pp. 167-182.
- Francesco Pizzitutti, Laura Brewington, Stephen J. Walsh, “Human and Natural Environments, Island of Santa Cruz, Galapagos: A Model-Based Approach to Link Land Cover/Land Use Changes to Direct and Indirect Socio-Economic Drivers of Change,” pp. 183-204.
- Jia Hu, Claire Qubain, Diego Riveros-Iregui, “How Do Non-Native Plants Influence Soil Nutrients along a Hydroclimate Gradient on San Cristobal Islands? “ pp. 205-220.
- Lisa C. Kelley, “A Critical Physical Geography of Landscape Changes in Southeast Sulawesi, Indonesia, 1950s – 2005,” pp. 221-240.
- Chong Seok Choi, Iskandar Z. Siregar, Sujith Ravi, “Reframing the Competition for Land Between Food and Energy Production in Indonesia, “ pp. 241-260.
- Sarah G. McQueen, Diego A. Riveros-Iregui, Jia Hu, “The Carbon Balance of Tropical Islands: Lessons from Soil Respiration,” pp. 261-276.
- Nicola Weber and Sam Weber, “Impacts and Management of Invasive Species in the UK Overseas Territories, “ pp. 277-298.
Fernández-Mazuecos M, Vargas P, McCauley R, Chaves JA, Guevara Andino J, Rivas-Torres G et al (2020) The Radiation of Darwin’s Giant Daisies in the Galapagos Islands, Current Biology 30, 1–10.
Valle CA, Ulloa C, Regalado C, Muñoz-Pérez JP, Garcia J, Hardesty BD, Skehel A, Deresienski D, Passingham RK, Lewbart GA (2020) Baseline haematology, biochemistry, blood gas values and health status of the Galapagos swallow-tailed gull (Creagrus furcatus). Conserv Physiol 8(1): coaa064.
Laso FJ, Benítez FL, Rivas-Torres G, Sampedro C, & Arce-Nazario J (2020). Land Cover Classification of Complex Agroecosystems in the Non-Protected Highlands of the Galapagos Islands. Remote Sensing, 12(65), 1–39.
Colloredo-Mansfeld M, Laso FJ, & Arce-Nazario J (2020). Drone-based participatory mapping: examining local agricultural knowledge in the Galapagos. Drones, 4(62), 1–19.
Grube AM, Stewart JR, Ochoa-Herrera V (2020). The challenge of achieving safely managed drinking water supply on San Cristobal island, Galápagos. International Journal of Hygiene and Environmental Health 228:113547.
Valle CA, Ulloa C, Deresienski D, Regalado C, Muñoz-Pérez JP, Garcia J, Hardesty BD, Skehel A, Lewbart GA. (2020). Health status and baseline hematology, biochemistry and blood gas values of Galapagos shearwaters (Puffinus subalaris). J Zoo Wild Med 50(4):1026-1030.
Lewbart GA, Grijalva CJ, Calle PP, Muñoz-Pérez JP, Quezada G, Vera CA, Gentile G, Valle C (2019). Health assessment of Conolophus subcristatus, Conolophus pallidus, and C. subcristatus X Amblyrhynchus cristatus hybrid (Galápagos land iguanas). PLoS ONE 14(10):e0222884.
Cerreta A, Vaden SL, Lewbart GA, Muñoz-Pérez JP, Páez-Rosas D (2019). Increased BUN and glucose in a group of San Cristóbal Galapagos tortoises (Chelonoidis chathamensis). Vet Rec Case Report, 7:3000699.
Nicholas KM, Bentley ME, Terán E, Thompson AL. (2019). Water security in the Galápagos: Socioecological determinants and health implications. EcoHealth.
Thompson AL, Nicholas KM, Watson E, Terán E, Bentley, ME. (2019). Water, food, and the dual burden of disease in Galápagos, Ecuador. American Journal of Human Biology.
Valle CA, Grijalva CJ, Calle PP, Muñoz-Pérez JP, Quezada G, Vera CA, Lewbart GA (2019). Methods of body temperature assessment in Conolophus subcristatus, Conolophus pallidus (Galápagos land iguanas), and Amblyrhynchus cristatus X C. subcristatus hybrid. PeerJ 7:e6291.
Houck KM, Terán E, Ochoa J, Zapata GN, Gomez AM, Parra R, Dvorquez D, Stewart JR, Bentley ME, Thompson, AL. (2019). Drinking water improvements and rates of urinary and gastrointestinal infections in Galápagos, Ecuador: Assessing household and community factors. American Journal of Human Biology, e23358.
Arteaga A, Bustamante L, Vieira J, Tapia W, Guayasamin JM. 2019. Reptiles of the Galápagos: Life on the Enchanted Islands. Tropical Herping, 208.
Páez-Rosas D, Vaca L, Pepolas R, Wollocombe R, Rivas-Torres G. 2019. Hunting and social foraging behavior of Galapagos sea lion: a corporate attack on large pelagics. Marine Mammals Science.
Carreta A, Vaden S, Lewbarth G, Muñoz-Perez J, Páez-Rosas D. 2019. Increased BUN and glucosa in a group of San Cristobal Galapagos tortoises (Chelonoidis chathamensis). Veterinarian Record Case Reports.
Blaney L, Waldrop J, Ortiz A, Gregory L, Rosado-Cordova M, Sherwood, G. (2019). Partnering for continuing professional development in the Galapagos. Journal of Continuing Education in Nursing; 50(9):417-422.
Thompson AL, Houck KM, & Jahnke JR (2019). Pathways linking caesarean delivery to early health in a dual burden context: Immune development and the gut microbiome in infants and children from Galápagos, Ecuador. American Journal of Human Biology, 31, e23219.
Pera MF, Katz BNH, & Bentley ME (2019). Dietary diversity, food security, and body image among women and children on San Cristobal Island, Galapagos. Maternal and Child Health Journal, 23(6), 830–838.
Sampedro C, Pizzitutti F, Quiroga D, Walsh SJ, Mena CF (2018). Food supply system dynamics in the Galapagos Islands: Agriculture, livestock, and imports. Renewable Agriculture and Food Systems, 33(1):1-5.
Arguedas-Porras R, Lewbart GA, Deresienski D, Lohmann K, Steinberg D, Muñoz-Pérez JP, Valle CA. (2018). Haematology and biochemistry of the San Cristobal Lava Lizard (Microlophus bivittatus). Conservation Physiology, 6(1):coy046.
Carr LA, Gittman RK, Bruno JF. (2018). Temperature influences herbivory and algal biomass in the Galápagos Islands. Frontiers in Marine Science 5:279.
Carreta A, Lewbarth G, Diaz R, Vasquez G, Muñoz-Perez J, Páez-Rosas D. 2018. Methods of body temperature assessment in (Chelonoidis chathamensis). Herpetological Review.
Phillips BE, Páez-Rosas D, Flowers JR, Cullen JM, Law JM, Colitz C, Deresienski D, Lohmann KJ, Lewbart GA (2018). Evaluation of the ophthalmic disease and histopathologic effects due to the ocular trematode Philophthalmus zalophi on juvenile Galápagos sea lions (Zalophus wollebaeki). J Zoo Wild Med 49(3):581-590 .
Valle CA, Ulloa C, Deresienski D, Regalado C, Muñoz-Pérez JP, Garcia J, Hardesty BD, Skehel A, Lewbart GA (2018). Health status of great frigatebirds (Fregata minor) determined by hematology, biochemistry, blood gases, and physical examination. Conservation Physiology, 6(1), coy034.
Lewbart GA, Cohen E, Hirschfeld M, Muñoz-Pérez JP, García J, Fu A, Chen EP, Lohmann KJ (2018). Field-based radiographic imaging of marine megafauna: Marine iguanas (Amblyrhynchus cristatus) as a case study. Frontiers In Marine Science.
Páez-Rosas D, Hirschfeld M, Deresienski D, Lewbart G. 2016. Health Status of Galapagos Sea Lions (Zalophus wollebaeki) on San Cristóbal Island Rookeries Determined by Hematology, Biochemistry, Blood Gases, and Physical Examination. Journal of Wildlife Diseases.
Gerhard WA, Choi WS, Houck KM, Stewart JR. (2017). Water quality at points-of-use in the Galapagos Islands. International Journal of Hygiene and Environmental Health. 220(2, Pt B): 485- 493.
Lewbart GA, Griffioen J, Savo A, Muñoz-Pérez JP, Ortega C, Loyola A, Roberts S, Schaaf G, Steinberg D, Osequeda SB, Levy MG, Páez-Rosas D (2018). Biochemistry and hematology parameters of the San Cristóbal Galápagos tortoise. Conservation Physiology.
Lewbart GA, Cohen E, Hirschfeld M, Muñoz-Pérez JP, García J, Fu A, Chen EP, Lohmann K. (2018). Field-based radiographic imaging of marine megafauna: Marine iguanas (Amblyrhynchus cristatus) as a case study. Frontiers In Marine Science.
Cerreta AJ, Lewbart GA, Diaz R, Vasquez G, Muñoz-Pérez JP, Paéz-Rosas, . (2018). Chelonoidis chathamensis. Methods of body temperature assessment. Herp Review 49(4):696-697.
Phillips BE, Páez-Rosas D, Flowers JR, Cullen JM, Law JM, Colitz C, Deresienski D, Lohmann KJ, Lewbart GA (2018). Evaluation of the ophthalmic disease and histopathologic effects due to the ocular trematode Philophthalmus zalophi on juvenile Galápagos sea lions (Zalophus wollebaeki). J Zoo Wild Med 49(3):581-590.
Lewbart GA, Ulloa C, Deresienski D, Regalado C, Muñoz-Pérez, JP Garcia J, Hardesty BD, Valle CA (2017). Health status of red-footed boobies (Sula sula) determined by hematology, biochemistry, blood gases, and physical examination. J Zoo Wild Med 48(4):1230-1233.
Muñoz-Pérez JP, Lewbart GA, Hirschfeld M, Denkinger J, Castañeda JG, García J, Lohmann KJ (2017). Blood gases, biochemistry, and haematology of Galápagos hawksbill turtles (Eretmochelys imbricata). Conservation Physiology 5(1):cox028.
Lewbart GA, Valle C, Muñoz-Perez JP (2017). Microlophus indefatigabilis diet. Herp Review 48(4):851-852.
Lewbart GA, Hirschfeld M, Ricuarte O, Lohmann KJ (2017). Amblyrhynchus cristatus diet. Herp Review 48(2):439.
Pizzitutti F, Walsh SJ, Rindfuss RR, Reck G, Quiroga D, Tippett R, Mena CF (2017). Scenario planning for tourism management: A participatory and system dynamics model applied to the Galapagos Islands of Ecuador. Journal of Sustainable Tourism, 25(8): 1117-1137.
Walsh SJ, and Mena CF (2016). Interactions of social, terrestrial, and marine sub-systems in the Galapagos Islands, Ecuador. Sackler Colloquium on Coupled Human and Environmental Systems (Social Sciences, Environmental Sciences, Sustainability Science), Proceedings of the National Academy of Sciences 113(51): 14536-14543.
Waldrop J, Page R, & Bentley M. (2016). Perceptions of body size in mothers and their young children in the Galapagos Islands . Maternal and Child Health Journal, 20, 2012-2018.
Paéz-Rosas D, Hirschfeld M, Deresienski D, Lewbart GA. (2016). Health status of Galápagos sea lions (Zalophus wollebaeki) on San Cristobal Island rookeries determined by hematology, biochemistry, blood gases, and physical examination. Journal of Wildlife Diseases 52(1):100-105.
Lewbart GA, Hirschfeld M, Muñoz-Perez JP, Denkinger J, Vinueza L, Brothers JR, García J, Lohmann KJ (2015). Blood gases, biochemistry, and hematology of marine iguanas (Amblyrhynchus cristatus). Conservation Physiology 3(1):cov034.
Overbey KN, Hatcher SM, Stewart JR. (2015). Water quality and antibiotic resistance at beaches of the Galápagos Islands. Frontiers in Public Health. 3(64).
Bruno, JF, Carr LA, O’Connor MI. (2015). Marine Metabolic Ecology: Exploring the role of temperature in the ocean through metabolic scaling. Ecology 96:3126-3140.
Lewbart GA, Hirschfeld M, Denkinger J, Vasco K, Guevara N, García J, Muñoz-Perez JP, Lohmann, KJ (2014). Blood gases, biochemistry, and hematology of Galápagos green turtles (Chelonia mydas). PLoS ONE. 9(5): e96487.
Page R, Bentley ME, Waldrop, J (2013). People Live Here: Maternal and Child Health on Isla Isabela, Galapagos. In SJ Walsh & CF Mena (Eds.), Science and Conservation in the Galapagos Islands: Frameworks & Perspectives (pp. 141–153). New York: Springer.
Carr LA and Bruno JF (2013). Warming increases the top-down effects and metabolism of a subtidal herbivore. PeerJ 1:e109.
Carr LA, Stier AC, Fietz K, Montero I, Gallagher AJ, Bruno JF (2013). Illegal shark fishing in the Galapagos marine reserve. Marine Policy 39: 317-321.