Cohen Stewart, Blake Harper, Jayde Couper, Sarah J. Bury, Amandine Sabadel
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引用次数: 0
Abstract
It is well established that non-native fish can become invasive and outcompete and displace native fish populations. However, little research has explored the potential benefits that non-native fish may provide to native fish populations. To address this information gap, we examined how the availability of non-native perch (Perca fluviatilis) as prey could benefit populations of the endemic longfin eel (Anguilla dieffenbachii) and the native shortfin eel (Anguilla australis) in two neighbouring open-water wetlands in the Rakatu-Redcliff wetland complex in the Southland region of Aotearoa New Zealand. The Redcliff wetland fish community comprised native fish only, while the Rakatu wetland comprised native fish and non-native perch. We compared the size, condition, population density, population size structure and diet of eels in these wetlands. While eels were not necessarily larger or better conditioned in Rakatu wetland, their population density was three times higher than the Redcliff wetland, with young-of-the-year perch comprising ca. 40% of their diet. Furthermore, juvenile eel density was four times lower in Redcliff wetland, suggesting that cannibalism may occur at this site to support the existing eel population. Based on our findings, we suggest that freshwater managers consider the predator–prey dynamics of both native and non-native fish before removing non-native species, to avoid unintended negative consequences for native predatory fish species.
期刊介绍:
Ecology of Freshwater Fish publishes original contributions on all aspects of fish ecology in freshwater environments, including lakes, reservoirs, rivers, and streams. Manuscripts involving ecologically-oriented studies of behavior, conservation, development, genetics, life history, physiology, and host-parasite interactions are welcomed. Studies involving population ecology and community ecology are also of interest, as are evolutionary approaches including studies of population biology, evolutionary ecology, behavioral ecology, and historical ecology. Papers addressing the life stages of anadromous and catadromous species in estuaries and inshore coastal zones are considered if they contribute to the general understanding of freshwater fish ecology. Theoretical and modeling studies are suitable if they generate testable hypotheses, as are those with implications for fisheries. Manuscripts presenting analyses of published data are considered if they produce novel conclusions or syntheses. The journal publishes articles, fresh perspectives, and reviews and, occasionally, the proceedings of conferences and symposia.