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Urquía DO, Anslan S, Asadobay P, Moreira‐Mendieta A, Vences M, Chaves JA, Páez‐Rosas D. DNA-metabarcoding supports trophic flexibility and reveals new prey species for the Galapagos sea lion. Ecol Evol 2024; 14:e10921. [PMID: 38435015 PMCID: PMC10905234 DOI: 10.1002/ece3.10921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 12/02/2023] [Accepted: 12/22/2023] [Indexed: 03/05/2024] Open
Abstract
Tropical ecosystems are challenging for pinnipeds due to fluctuating food availability. According to previous research, the Galapagos sea lion (GSL, Zalophus wollebaeki) adopts trophic flexibility to face such conditions. However, this hypothesis comes from studies using traditional methods (hard-parts analysis of scat and isotopic analysis from tissue). We studied the diet of five rookeries in the southeastern Galapagos bioregion (which harbors the highest GSL density), via DNA-metabarcoding of scat samples. The DNA-metabarcoding approach may identify consumed prey with a higher taxonomic resolution than isotopic analysis, while not depending on hard-parts remaining through digestion. Our study included five different rookeries to look for evidence of trophic flexibility at the bioregional level. We detected 98 prey OTUs (124 scats), mostly assigned to bony-fish taxa; we identified novel prey items, including a shark, rays, and several deep-sea fish. Our data supported the trophic flexibility of GSL throughout the studied bioregion since different individuals from the same rookery consumed prey coming from different habitats and trophic levels. Significant diet differentiations were found among rookeries, particularly between Punta Pitt and Santa Fe. Punta Pitt rookery, with a more pronounced bathymetry and lower productivity, was distinguished by a high trophic level and consumption of a high proportion of deep-sea prey; meanwhile, Santa Fe, located in more productive, shallow waters over the shelf, consumed a high proportion of epipelagic planktivorous fish. Geographic location and heterogeneous bathymetry of El Malecon, Española, and Floreana rookeries would allow the animals therein to access both, epipelagic prey over the shelf, and deep-sea prey out of the shelf; this would lead to a higher prey richness and diet variability there. These findings provide evidence of GSL adopting a trophic flexibility to tune their diets to different ecological contexts. This strategy would be crucial for this endangered species to overcome the challenges faced in a habitat with fluctuating foraging conditions.
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Affiliation(s)
- Diego O. Urquía
- Maestría en Ecología Tropical y Conservación, Universidad San Francisco de Quito USFQQuitoEcuador
- Galapagos Science Center, Universidad San Francisco de Quito USFQIslas GalápagosEcuador
| | - Sten Anslan
- Institute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
- Deptartment of Biological and Environmental ScienceUniversity of JyväskyläJyväskyläFinland
| | - Pacarina Asadobay
- Galapagos Science Center, Universidad San Francisco de Quito USFQIslas GalápagosEcuador
| | - Andrés Moreira‐Mendieta
- Maestría en Ecología Tropical y Conservación, Universidad San Francisco de Quito USFQQuitoEcuador
- Galapagos Science Center, Universidad San Francisco de Quito USFQIslas GalápagosEcuador
| | - Miguel Vences
- Zoological Institute, Technische Universität BraunschweigBraunschweigGermany
| | - Jaime A. Chaves
- Galapagos Science Center, Universidad San Francisco de Quito USFQIslas GalápagosEcuador
- Department of BiologySan Francisco State UniversitySan FranciscoCaliforniaUSA
- Colegio de Ciencias Biológicas y AmbientalesUniversidad San Francisco de QuitoQuitoEcuador
| | - Diego Páez‐Rosas
- Galapagos Science Center, Universidad San Francisco de Quito USFQIslas GalápagosEcuador
- Colegio de Ciencias Biológicas y AmbientalesUniversidad San Francisco de QuitoQuitoEcuador
- Dirección Parque Nacional Galápagos, Unidad Técnica Operativa San CristóbalIslas GalápagosEcuador
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Moreira-Mendieta A, Garcia-Garin O, Muñoz-Pérez JP, Urquía DO, Drago M, Borrell A, Páez-Rosas D. Detection and quantification of microplastic pollution in the endangered Galapagos sea lion. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:166223. [PMID: 37586531 DOI: 10.1016/j.scitotenv.2023.166223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/18/2023]
Abstract
Marine debris pollution poses a significant global threat to biodiversity, with plastics being the primary debris type found in oceans due to their low-cost production and high demand worldwide. Microplastics (MPs, <5 mm in size) are highly bioavailable to a wide range of marine taxa, including marine mammals, through direct and indirect ingestion routes (i.e., trophic transfer). Recently, MP pollution has been detected on the Galapagos Marine Reserve, so in this study we developed a baseline framework for MP pollution in the Galapagos sea lion (GSL, Zalophus wollebaeki) through scat-based analysis. We collected 180 GSL scat samples from the southeast region following strict quality assurance/quality control protocols to detect, quantify and characterize physical-chemical properties of MPs through visual observations and μFT-IR spectroscopy. We recovered 81 MPs of varying sizes and colors in 37 % of samples (n = 66/180), consisting mostly of fibers (69 %, x¯ = 0.31 ± 0.57 particles scat-1). The number of particles per gram of sample wet weight ranged from 0.02 to 0.22 (x¯ = 0.04 ± 0.05 particles scat wet g-1). El Malecón and Punta Pitt rookeries at San Cristobal Island had the highest number of MPs (x¯ = 0.67 ± 0.51 and 0.43 ± 0.41 particles scat-1, respectively), and blue-colored particles were the most common in all samples. We identified eleven polymers in 46 particles, consisting mostly of polypropylene-polyethylene copolymer, polypropylene, cellulose, polyethylene, and polyvinyl chloride. The textile, fishing, and packaging industries are likely significant sources of microfibers into this insular ecosystem. Our results suggest that the GSL is exposed to MPs due to anthropogenic contamination that is subsequently transferred through trophic processes. These findings provide an important baseline framework and insights for future research on MP pollution in the region, as well as for management actions that will contribute to the long-term conservation of the GSL.
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Affiliation(s)
- Andrés Moreira-Mendieta
- Universidad San Francisco de Quito USFQ, Maestría en Ecología Tropical y Conservación, Diego de Robles s/n y Pampite, Quito, Ecuador; Universidad San Francisco de Quito USFQ, Galapagos Science Center, Av. Alsacio Northia s/n, Isla San Cristóbal, Galápagos, Ecuador.
| | - Odei Garcia-Garin
- Universitat de Barcelona, Department of Evolutionary Biology, Ecology and Environmental Sciences, Barcelona 08028, Spain; Universitat de Barcelona, Institute of Biodiversity Research (IRBio), Barcelona 08028, Spain
| | - Juan Pablo Muñoz-Pérez
- Universidad San Francisco de Quito USFQ, Galapagos Science Center, Av. Alsacio Northia s/n, Isla San Cristóbal, Galápagos, Ecuador; University of the Sunshine Coast UniSC, School of Science, Technology and Engineering, Hervey Bay, Queensland, Australia
| | - Diego O Urquía
- Universidad San Francisco de Quito USFQ, Maestría en Ecología Tropical y Conservación, Diego de Robles s/n y Pampite, Quito, Ecuador; Universidad San Francisco de Quito USFQ, Galapagos Science Center, Av. Alsacio Northia s/n, Isla San Cristóbal, Galápagos, Ecuador
| | - Massimiliano Drago
- Universitat de Barcelona, Department of Evolutionary Biology, Ecology and Environmental Sciences, Barcelona 08028, Spain; Universitat de Barcelona, Institute of Biodiversity Research (IRBio), Barcelona 08028, Spain
| | - Asunción Borrell
- Universitat de Barcelona, Department of Evolutionary Biology, Ecology and Environmental Sciences, Barcelona 08028, Spain; Universitat de Barcelona, Institute of Biodiversity Research (IRBio), Barcelona 08028, Spain
| | - Diego Páez-Rosas
- Universidad San Francisco de Quito USFQ, Galapagos Science Center, Av. Alsacio Northia s/n, Isla San Cristóbal, Galápagos, Ecuador; Dirección del Parque Nacional Galápagos, Unidad Técnica Operativa San Cristóbal, Isla San Cristóbal, Galápagos, Ecuador
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Asadobay P, Urquía DO, Künzel S, Espinoza-Ulloa SA, Vences M, Páez-Rosas D. Time-calibrated phylogeny and full mitogenome sequence of the Galapagos sea lion ( Zalophus wollebaeki) from scat DNA. PeerJ 2023; 11:e16047. [PMID: 37790631 PMCID: PMC10542389 DOI: 10.7717/peerj.16047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 08/16/2023] [Indexed: 10/05/2023] Open
Abstract
Background The Galapagos sea lion, Zalophus wollebaeki, is an endemic and endangered otariid, which is considered as a sentinel species of ecosystem dynamics in the Galapagos archipelago. Mitochondrial DNA is an important tool in phylogenetic and population genetic inference. In this work we use Illumina sequencing to complement the mitogenomic resources for Zalophus genus-the other two species employed Sanger sequencing-by a complete mitochondrial genome and a molecular clock of this species, which is not present in any case. Materials and Methods We used DNA obtained from a fresh scat sample of a Galapagos sea lion and shotgun-sequenced it on the Illumina NextSeq platform. The obtained raw reads were processed using the GetOrganelle software to filter the mitochondrial Zalophus DNA reads (∼16% survive the filtration), assemble them, and set up a molecular clock. Results From the obtained 3,511,116 raw reads, we were able to assemble a full mitogenome of a length of 16,676 bp, consisting of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNA), and two ribosomal RNAs (rRNA). A time-calibrated phylogeny confirmed the phylogenetic position of Z. wollebaeki in a clade with Z. californianus, and Z. japonicus, and sister to Z. californianus; as well as establishing the divergence time for Z. wollebaeki 0.65 million years ago. Our study illustrates the possibility of seamlessly sequencing full mitochondrial genomes from fresh scat samples of marine mammals.
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Affiliation(s)
- Pacarina Asadobay
- Galapagos Science Center, Universidad San Francisco de Quito, Isla San Cristóbal, Islas Galápagos, Ecuador
| | - Diego O. Urquía
- Galapagos Science Center, Universidad San Francisco de Quito, Isla San Cristóbal, Islas Galápagos, Ecuador
| | - Sven Künzel
- Department of Evolutionary Genetics, Max Planck Institute, Plön, Germany
| | - Sebastian A. Espinoza-Ulloa
- Facultad de Medicina, Pontificia Universidad Católica del Ecuador, Quito, Pichincha, Ecuador
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Diego Páez-Rosas
- Galapagos Science Center, Universidad San Francisco de Quito, Isla San Cristóbal, Islas Galápagos, Ecuador
- Oficina Técnica San Cristóbal, Dirección Parque Nacional Galápagos, Isla San Cristóbal, Islas Galápagos, Ecuador
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Culda CA, Dionnet R, Barbu AC, Cârstolovean AS, Dan T, Grijalva J, Espin P, Vinueza RL, Cruz M, Páez-Rosas D, Renato L, Mihalca AD. The Presence of Dirofilaria immitis in Domestic Dogs on San Cristobal Island, Galapagos. Pathogens 2022; 11:1287. [PMID: 36365038 PMCID: PMC9696258 DOI: 10.3390/pathogens11111287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 07/30/2023] Open
Abstract
This study's concept was outlined around the principle of conservation medicine in a biodiversity hotspot from the Neotropical realm: the Galapagos Islands. The wildlife balance has been modified by multi-host parasites introduced with some domestic animals (dogs and cats). The endemic and endangered species, the Galapagos sea lion (GSL, Zalophus wollebaeki), has been exposed to pathogens of canine and feline origin that could become a significant conservation problem for this species. One of these potential cases is the filarial heartworm infection, Dirofilaria immitis, which has been reported on other pinnipeds, with fatalities and clinical symptoms. Therefore, this study evaluated the presence of the microfilaria of D. immitis in dogs from Puerto Baquerizo Moreno, San Cristobal Island, where the largest rookery of GSLs lives and where the proximity to domestic dogs is the most intimate compared to other rookeries of the archipelago. Between July and September 2021, 587 blood samples were collected from owned dogs of Puerto Baquerizo Moreno. Overall, 10 dogs (1.7%) were positive for the presence of the microfilaria of D. immitis with a confidence interval of 0.7%-2.8%. No other filarial species were identified. Significant differences in prevalence between different dog categories were observed only for the age (p = 0.001). This study represents the first report of D. immitis, the agent of canine heartworm disease, in dogs from San Cristobal Island. Hence, the presence of the microfilaria of D. immitis in the blood of dogs could increase the risk of infection to which the GSL is exposed in the region.
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Affiliation(s)
- Carla Andreea Culda
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372 Cluj-Napoca, Romania
| | - Romane Dionnet
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372 Cluj-Napoca, Romania
| | - Andra Celia Barbu
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372 Cluj-Napoca, Romania
| | - Andrada Silvia Cârstolovean
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372 Cluj-Napoca, Romania
| | - Teodora Dan
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372 Cluj-Napoca, Romania
| | - Jaime Grijalva
- Escuela de Medicina Veterinaria, Universidad San Francisco de Quito, Cumbayá, Quito 150157, Ecuador
| | - Priscilla Espin
- Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos, Isla San Cristóbal 200152, Galápagos, Ecuador
| | - Rommel Lenin Vinueza
- Escuela de Medicina Veterinaria, Universidad San Francisco de Quito, Cumbayá, Quito 150157, Ecuador
- Laboratorio de Entomología Médica & Medicina Tropical LEMMT, Universidad San Francisco de Quito, Cumbayá, Quito 150157, Ecuador
| | - Marylin Cruz
- Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos, Isla San Cristóbal 200152, Galápagos, Ecuador
| | - Diego Páez-Rosas
- Galapagos Science Center, Universidad San Francisco de Quito, Isla San Cristóbal 200150, Islas Galápagos, Ecuador
- Dirección del Parque Nacional Galápagos, Unidad Técnica Operativa San Cristóbal, Isla San Cristóbal 200150, Islas Galápagos, Ecuador
| | - Leon Renato
- Laboratorio de Entomología Médica & Medicina Tropical LEMMT, Universidad San Francisco de Quito, Cumbayá, Quito 150157, Ecuador
| | - Andrei Daniel Mihalca
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 400372 Cluj-Napoca, Romania
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Gregory TM, Parker M, Deresienski D, Alarcón-Ruales D, Muñoz-Pérez JP, Torres J, Gavilanes GI, Lewbart GA, Páez-Rosas D. Evaluating the Possibility of Transfusion Medicine, Through Crossmatching in Juvenile Galapagos Sea Lions ( Zalophus wollebaeki). Front Vet Sci 2022; 9:830272. [PMID: 35529842 PMCID: PMC9070388 DOI: 10.3389/fvets.2022.830272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/14/2022] [Indexed: 11/25/2022] Open
Abstract
The Galapagos sea lion (Zalophus wollebaeki) is an endemic pinniped to the Galapagos archipelago, and like most wild mammals, is at risk for anemia due to trauma, infectious disease, and poor nutrition. This study evaluated the health status of 26 juvenile Galapagos sea lions on the island of San Cristobal prior to evaluating 100 crossmatch combinations. On evaluation, all but one sea lion had no major systemic abnormalities. Of the 100 crossmatches performed, 23% had minor reactions. The most significant reaction was weak macroscopic agglutination found in 4% of samples. The small percentage of agglutination reactions suggests a small proportion of naturally occurring alloantibodies in this species and may be consistent with a low risk of acute immune-mediated hemolytic transfusion reaction.
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Affiliation(s)
- Taylor M Gregory
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, United States
| | - Maryanna Parker
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, United States
| | - Diane Deresienski
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, United States.,USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
| | - Daniela Alarcón-Ruales
- USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador.,Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Galápagos, Ecuador.,USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Galápagos, Ecuador
| | - Juan Pablo Muñoz-Pérez
- USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador.,Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Galápagos, Ecuador.,USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Galápagos, Ecuador
| | - Jorge Torres
- Dirección Parque Nacional Galápagos, Oficina Técnica San Cristobal, Galápagos, Ecuador
| | - Gabriela I Gavilanes
- USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador.,Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Galápagos, Ecuador
| | - Gregory A Lewbart
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC, United States.,USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
| | - Diego Páez-Rosas
- USFQ & UNC-Chapel Hill Galápagos Science Center (GSC), Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador.,Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Galápagos, Ecuador.,Dirección Parque Nacional Galápagos, Oficina Técnica San Cristobal, Galápagos, Ecuador
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OUP accepted manuscript. J Mammal 2022. [DOI: 10.1093/jmammal/gyac023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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7
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Zenth F, DeRango EJ, Krüger O, Piedrahita P, Páez-Rosas D, Schwarz JF. More than the sum of its parts: individual behavioural phenotypes of a wild pinniped. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Páez-Rosas D, Torres J, Espinoza E, Marchetti A, Seim H, Riofrío-Lazo M. Declines and recovery in endangered Galapagos pinnipeds during the El Niño event. Sci Rep 2021; 11:8785. [PMID: 33888850 PMCID: PMC8075323 DOI: 10.1038/s41598-021-88350-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 04/07/2021] [Indexed: 11/09/2022] Open
Abstract
Currently, the Galapagos sea lion (GSL, Zalophus wollebaeki) and Galapagos fur seal (GFS, Arctocephalus galapagoensis) are among the most important endemic species for conservation in the Galapagos Archipelago. Both are classified as "Endangered" since their populations have undergone drastic declines over the last several decades. In this study we estimated the abundance of both otariids, and their population trends based using counts conducted between 2014 and 2018 in all their rookeries, and we analyzed the influence of environmental variability on pup production. The GSL population size in 2018 in the archipelago was estimated to be between 17,000 to 24,000 individuals and has increased at an average annual rate of 1% over the last five years after applying correction factors. The highest number of GSL counted in the archipelago was in 2014 followed by a population decline of 23.8% in 2015 that was associated with the El Niño event that occurred during that year. Following this event, the population increased mainly in the northern, central and southeastern rookeries. The GSL pup abundance showed a decreasing trend with the increase in intensity of the El Niño. The GFS population in 2018 was counted in 3,093 individuals and has increased at an annual rate of 3% from 2014 to 2018. A high number of GFS counted in 2014 was followed by a population decrease of 38% in 2015, mainly in the western rookeries. There was interannual population fluctuations and different growth trends among regions of the archipelago. GSL and GFS pup abundance has a strong decreasing tendency with the increase in the subthermocline temperature (ST) and the El Niño 1 + 2 index. Our results provide evidence that both species are highly vulnerable to periodic oceanographic-atmospheric events in the Galapagos Archipelago which impact prey abundance and the flow of energy in the unique Galapagos ecosystem.
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Affiliation(s)
- Diego Páez-Rosas
- Galapagos Science Center. Isla San Cristóbal, Universidad San Francisco de Quito, Islas Galápagos, Ecuador.
| | - Jorge Torres
- Departamento de Ecosistemas Marinos, Dirección Parque Nacional Galápagos, Islas Galápagos, Ecuador
| | - Eduardo Espinoza
- Departamento de Ecosistemas Marinos, Dirección Parque Nacional Galápagos, Islas Galápagos, Ecuador
| | - Adrian Marchetti
- Department of Marine Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Harvey Seim
- Department of Marine Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Marjorie Riofrío-Lazo
- Galapagos Science Center. Isla San Cristóbal, Universidad San Francisco de Quito, Islas Galápagos, Ecuador.
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Blakeway JA, Arnould JPY, Hoskins AJ, Martin-Cabrera P, Sutton GJ, Huckstadt LA, Costa DP, Páez-Rosas D, Villegas-Amtmann S. Influence of hunting strategy on foraging efficiency in Galapagos sea lions. PeerJ 2021; 9:e11206. [PMID: 33954042 PMCID: PMC8051337 DOI: 10.7717/peerj.11206] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 03/12/2021] [Indexed: 11/20/2022] Open
Abstract
The endangered Galapagos sea lion (GSL, Zalophus wollebaeki) exhibits a range of foraging strategies utilising various dive types including benthic, epipelagic and mesopelagic dives. In the present study, potential prey captures (PPC), prey energy consumption and energy expenditure in lactating adult female GSLs (n = 9) were examined to determine their foraging efficiency relative to the foraging strategy used. Individuals displayed four dive types: (a) epipelagic (<100 m; EP); or (b) mesopelagic (>100 m; MP) with a characteristic V-shape or U-shape diving profile; and (c) shallow benthic (<100 m; SB) or (d) deep benthic (>100 m; DB) with square or flat-bottom dive profiles. These dive types varied in the number of PPC, assumed prey types, and the energy expended. Prey items and their energetic value were assumed from previous GSL diet studies in combination with common habitat and depth ranges of the prey. In comparison to pelagic dives occurring at similar depths, when diving benthically, GSLs had both higher prey energy consumption and foraging energy expenditure whereas PPC rate was lower. Foraging efficiency varied across dive types, with benthic dives being more profitable than pelagic dives. Three foraging trip strategies were identified and varied relative to prey energy consumed, energy expended, and dive behaviour. Foraging efficiency did not significantly vary among the foraging trip strategies suggesting that, while individuals may diverge into different foraging habitats, they are optimal within them. These findings indicate that these three strategies will have different sensitivities to habitat-specific fluctuations due to environmental change.
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Affiliation(s)
- Jessica-Anne Blakeway
- School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia
| | - John P Y Arnould
- School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia
| | | | | | - Grace J Sutton
- School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia
| | - Luis A Huckstadt
- Department of Ecology & Evolutionary Biology, University of California, Santa Cruz, CA, United States of America
| | - Daniel P Costa
- Department of Ecology & Evolutionary Biology, University of California, Santa Cruz, United States of America
| | - Diego Páez-Rosas
- Universidad San Francisco de Quito and Galapagos Science Center, Islas Galápagos, Ecuador.,Dirección Parque Nacional Galápagos, Oficina Técnica Operativa San Cristóbal, Islas Galápagos, Ecuador
| | - Stella Villegas-Amtmann
- Department of Ecology & Evolutionary Biology, University of California, Santa Cruz, CA, United States of America
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Walsh JT, Kovaka K, Vaca E, Weisberg DS, Weisberg M. The effects of human exposure on Galápagos sea lion behavior. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Justin T. Walsh
- J. T. Walsh (https://orcid.org/0000-0001-9989-7089), Dept of Biology, Univ. of Pennsylvania, Philadelphia, PA, USA
| | - Karen Kovaka
- K. Kovaka, Dept of Philosophy, Virginia Tech, Blacksburg, VA, USA
| | - Ernesto Vaca
- E. Vaca, San Cristóbal Association of Naturalist Guides, San Cristóbal, Ecuador
| | - Deena Skolnick Weisberg
- D. S. Weisberg, Dept of Psychological and Brain Sciences, Villanova Univ., Villanova, PA, USA
| | - Michael Weisberg
- M. Weisberg (https://orcid.org/0000-0002-3944-1167) ✉ , Dept of Philosophy, Univ. of Pennsylvania, Philadelphia, PA, USA
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Hernandez JA, Yoak AJ, Walden HS, Thompson N, Zuniga D, Criollo R, Duque V, Cruz M. Dog overpopulation on Santa Cruz Island, Galapagos 2018. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Jorge A. Hernandez
- College of Veterinary Medicine University of Florida Gainesville Florida USA
- College of Public Health and Health Professions University of Florida Gainesville Florida USA
- Center for Latin American Studies University of Florida Gainesville Florida USA
| | | | - Heather S. Walden
- College of Veterinary Medicine University of Florida Gainesville Florida USA
| | - Nina Thompson
- College of Veterinary Medicine University of Florida Gainesville Florida USA
| | - Daniela Zuniga
- College of Public Health and Health Professions University of Florida Gainesville Florida USA
| | - Rita Criollo
- Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos Santa Cruz Galápagos Ecuador
| | - Viviana Duque
- Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos Santa Cruz Galápagos Ecuador
| | - Marilyn Cruz
- Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos Santa Cruz Galápagos Ecuador
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EVALUATION OF THE OPHTHALMIC DISEASE AND HISTOPATHOLOGIC EFFECTS DUE TO THE OCULAR TREMATODE PHILOPHTHALMUS ZALOPHI ON JUVENILE GALAPAGOS SEA LIONS ( ZALOPHUS WOLLEBAEKI). J Zoo Wildl Med 2019; 49:581-590. [PMID: 30212353 DOI: 10.1638/2017-0096.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The Galapagos sea lion ( Zalophus wollebaeki) is an otariid species endemic to the Galapagos archipelago and is currently listed as endangered. The ocular trematode Philophthalmus zalophi was recently reported to affect the survival of juvenile Galapagos sea lions on Santa Cruz Island, resulting in marked ophthalmic changes. This study evaluated the ophthalmic disease and histopathologic effects of P. zalophi on juvenile Galapagos sea lions in the largest rookery located on San Cristóbal Island. Twenty juvenile Galapagos sea lions (10 male and 10 female) were evaluated among five sites in the rookery El Malecón. Ophthalmic examination, including fluorescein staining and evaluation of the adnexa, cornea, and sclera, were performed on each eye. The presence, number, and location of ocular parasites were determined, and parasites were collected for identification. Conjunctival biopsy was performed on 11 animals: 2 that lacked parasites and gross lesions and 9 with both parasites and gross lesions. All parasites collected were confirmed as P. zalophi and identified in 80% (16/20) of the study animals and 70% (28/40) of the examined eyes. Philophthalmus zalophi was most frequently found attached to the nictitating membrane but also located on the palpebral conjunctiva or cornea. The most common clinical signs were varying degrees of conjunctival hyperemia (28/40 eyes), most frequently of the nictitating membrane and mucoid ocular discharge (12/40 eyes). The number of parasites was significantly associated with the degree of conjunctival hyperemia ( P < 0.001). Histopathology of conjunctival biopsies revealed organized lymphoid follicles and lymphoplasmacytic infiltrates. The histopathologic changes and gross lesions were likely due to the parasite's attachment to the conjunctiva. This study provides additional details of P. zalophi infection in juvenile Galapagos sea lions. Further research is warranted to detail the life cycle of this parasite, transmission to sea lions, and potential treatment protocols.
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DeRango EJ, Schwarz JF, Kalberer S, Piedrahita P, Páez-Rosas D, Krüger O. Intrinsic and maternal traits influence personality during early life in Galápagos sea lion, Zalophus wollebaeki, pups. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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δ13C and δ15N values in pup whiskers as a proxy for the trophic behavior of Galapagos sea lion females. Mamm Biol 2019. [DOI: 10.1016/j.mambio.2019.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Páez-Rosas D, Villegas-Amtmann S, Costa D. Intraspecific variation in feeding strategies of Galapagos sea lions: A case of trophic specialization. PLoS One 2017; 12:e0185165. [PMID: 29059188 PMCID: PMC5653192 DOI: 10.1371/journal.pone.0185165] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/07/2017] [Indexed: 12/05/2022] Open
Abstract
The trophic behavior of marine predators varies according to the level of competition to which they are exposed. In general, populations that inhabit lower productivity systems face a strong intraspecific competition, which contributes to the development of different foraging strategies to maximize nutritional efficiency. Given the high trophic flexibility of Zalophus wollebaeki, this species is considered appropriate for the analysis of such behavior. Furthermore, this trophic flexibility has allowed them to persist in a seemingly marginal ecosystem. In this study, we used a comparative analysis of variables (diet and dive behavior) related to Z. wollebaeki trophic niche plasticity to better understand their foraging ecology, using techniques such scat analysis, satellite telemetry and complementarily an isotopic analysis. Scat analysis revealed intra-population variation in their diet, represented by prey from different environments (epipelagic and benthic). These results are supported by the animals’ locations at sea and diving profiles. Global Positioning System (GPS) and time-depth recorder (TDR) records showed the existence of two groups, with differing feeding areas and diving behavior. Also the δ15N values showed differences in the trophic level at which the species fed. These results constitute a relevant finding in the evolutionary behavior of the species, showing that Z. wollebaeki has developed a high degree of foraging flexibility, thus increasing its survival rate in an ecosystem that is highly demanding in terms of resource availability.
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Affiliation(s)
- Diego Páez-Rosas
- Universidad San Francisco de Quito (USFQ) and Galapagos Science Center, Galápagos, Ecuador
- Dirección Parque Nacional Galápagos, Unidad Técnica Operativa San Cristóbal, Galápagos, Ecuador
- * E-mail:
| | - Stella Villegas-Amtmann
- Department of Ecology and Evolutionary Biology, University of California at Santa Cruz, Santa Cruz, United States of America
| | - Daniel Costa
- Department of Ecology and Evolutionary Biology, University of California at Santa Cruz, Santa Cruz, United States of America
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