Examinando por Autor "Harrod, Chris"

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    Ecological variation in invasive brown trout (Salmo trutta) within a remote coastal river catchment in northern Patagonia complicates estimates of invasion impact
    (John Wiley and Sons Inc, 2024-01) Bahamonde, Paulina Andrea; Chiang, Gustavo; Mancilla, Gabriela; Contador, Tamara; Quezada-Romegialli, Caudio; Munkittrick, Kelly Roland; Harrod, Chris
    Salmonids were first introduced into the Chilean fresh waters in the 1880s, and c. 140 years later, they are ubiquitous across Chilean rivers, especially in the southern pristine fresh waters. This study examined the brown trout (Salmo trutta) and native taxa ecology in two adjacent but contrasting rivers of Chilean Patagonia. During spring 2016 and spring–fall 2017 we examined the variation in benthic macroinvertebrate and fish community composition and characterized fish size structure, stomach contents, and stable isotopes (δ13C and δ15N) to understand population structure, fish diet, and trophic interactions between S. trutta and native taxa. The native Galaxias maculatus (puye) dominated the fish community (74% of abundance). S. trutta was less abundant (16% of survey catch) but dominated the fish community (over 53%) in terms of biomass. S. trutta showed distinct diets (stomach content analysis) in the two rivers, and individuals from the larger river were notably more piscivorous, consuming native fish with a relatively small body size (<100-mm total length). Native fishes were isotopically distinct from S. trutta, which showed a wider isotopic niche in the smaller river, indicating that their trophic role was more variable than in the larger river (piscivorous). This study provides data from the unstudied pristine coastal rivers in Patagonia and reveals that interactions between native and introduced species can vary at very local spatial scales. © 2023 Fisheries Society of the British Isles.
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    Evaluating food metrics of lanternfshes in waters of the southeastern Pacifc Ocean
    (2023-02) Cárcamo, Carolina; Espinoza, Pepe; Canales‑Cerro, Carlos; Curaz‑Leiva, · Stephanny; Guzman‑Castellanos, Ana Brisca; Quintanilla, Ivonne; Vargas, · Fernanda; Fernandoy, Francisco; Zuñiga, Mauricio; Galvez, Patricio; Vargas, Rene; Saavedra, · Álvaro; Harrod, Chris; Schultz, Eric T.; A. Klarian, Sebastian
    Using carbon and nitrogen stable isotope values, we analyzed the trophic position (TP) and the isotopic niche width of lanternfishes from three different areas in the Southern Pacific Ocean. Fishes from Perú had slightly higher δ13C values compared with fish from Chilean areas. In contrast, δ15N values increased with latitude (North to South). Myctophids TP differed between the three study areas (highest in Central Chile, lowest in Peru). Peruvian fishes had a smaller isotopic niche than the lanternfishes of those from Chile. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.