Do non‐native invasive fish support elevated lamprey populations?

• Published in: Journal of Applied Ecology
• Main Authors: Inger, Richard, McDonald, Robbie A., Rogowski, David, Jackson, Andrew L., Parnell, Andrew, Jane Preston, S., Harrod, Chris, Goodwin, Claire, Griffiths, David, Dick, Jaimie T.A., Elwood, Robert W., Newton, Jason, Bearhop, Stuart
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2010
• Subjects: Brama; Pollan; Coregonus autumnalis
• Online Access: http://dx.doi.org/10.1111/j.1365-2664.2009.01761.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2664.2009.01761.x; https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2664.2009.01761.x

Summary 1. Managing populations of predators and their prey to achieve conservation or resource management goals is usually technically challenging and frequently socially controversial. This is true even in the simplest ecosystems but can be made much worse when predator–prey relationships are influenced by complex interactions, such as biological invasions, population trends or animal movements. 2. Lough Neagh in Northern Ireland is a European stronghold for pollan Coregonus autumnalis , a coregonine fish and for river lamprey Lampetra fluviatilis , which feeds parasitically as an adult. Both species are of high conservation importance. Lampreys are known to consume pollan but detailed knowledge of their interactions is scant. While pollan is well known to be a landlocked species in Ireland, the life cycle of normally anadromous river lamprey in Lough Neagh has been unclear. The Lough is also a highly perturbed ecosystem, supporting several invasive, non‐native fish species that have the potential to influence lamprey–pollan interactions. 3. We applied stable isotope techniques to resolve both the movement patterns of lamprey and trophic interactions in this complex community. Recognizing that stable isotope studies are often hampered by high‐levels of variability and uncertainty in the systems of interest, we employed novel Bayesian mixing models, which incorporate variability and uncertainty. 4. Stable isotope analyses identified trout Salmo trutta and non‐native bream Abramis brama as the main items in lamprey diet. Pollan only represented a major food source for lamprey between May and July. 5. Stable isotope ratios of carbon in tissues from 71 adult lamprey showed no evidence of marine carbon sources, strongly suggesting that Lough Neagh is host to a highly unusual, nonanadromous freshwater population. This finding marks out the Lough’s lamprey population as of particular scientific interest and enhances the conservation significance of this feature of the Lough. 6. Synthesis and applications. Our ...