Effects of fish kills on fish consumers and other water-dependent fauna: exploring the potential effect of mass mortality of carp in Australia

Abstract

Although the effects of mass fish mortality (MFM) events on fish populations and water quality are frequently reported, the effects on consumers of fish and other water-dependent fauna are relatively poorly understood. Managing the effects of MFM events on other fauna is important when they occur in ecologically or culturally sensitive locations, or involve protected or significant species or ecosystems. Better understanding of the effects of such events on fish consumers and other water-dependent fauna would aid proactive management of predictable events, such as pest-fish biocontrol releases. We conducted a global literature review to synthesise the effects of unexpected MFM events on fish consumers and other water-dependent fauna in freshwater, estuarine and marine ecosystems. We then constructed two conceptual models distinguishing between the short-term (hours to weeks) and long-term (months to years) effects of such events, highlighting the importance of key factors in determining the magnitude of the response. Last, we used these models and relevant literature to explore the potential implications of the proposed release of cyprinid herpes virus 3 as a biological control agent for the invasive common carp (Cyprinus carpio) in Australia and develop recommendations to minimise adverse effects of carp mass mortality on food webs.