The introduction of exotic species into freshwater ecosystems is one of the most important factors changing aquatic biodiversity, but we have limited to predict the ecological consequences on native communities. Using a combination of field surveys, field mesocosm experiments, and laboratory studies, we have shown that the invasive predator, Bythotrephes, has variable impact (Strecker et al. 2006, Strecker & Arnott 2008) that is driven by interactions with native predators (Jokela et al. 2017, 2011), light (Jokela et al. 2013), and behavioural adaptation of prey species (Hasnain and Arnott 2019). Working with the Great Lakes invader, Hemimysis anomola, we documented a predation impact on cladoceran zooplankton (Sinclair et al. 2016) and found that it changed the energy flow of near-shore food webs when occurring at high densities (Yuille et al. 2012). Recently, we have focused our efforts on factors that influence establishment success of novel species, conducting experiments to tease apart the relative influence of propagule size, number, condition, and diversity (Sinclair and Arnott 2016, 2017). We are also interested in how the impact of non-native species on communities and ecosystem function is altered in the presence of additional stressors, such as nutrients (Sinclair and Arnott 2015), calcium, and salinity resulting from road salt application. 

Hemimysis anomola - the bloody red shrimp

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