Boom-bust like dynamics of invasive black bullhead (Ameiurus melas) in Lake Sava (Serbia)

Abstract

The life-history traits and population dynamics of the black bullhead Ameiurus melas (Rafinesque) were studied monthly from August 2009 to December 2012 in Lake Sava in Belgrade (Serbia). This period included a mass mortality event in May 2011 and subsequent population recovery during 2012. Available evidence suggests the mass mortality was caused by European catfish virus that only affected the black bullhead. Changes in key life-history traits and the recovery potential (increase in catch-per-unit-effort, doubling of young-of-the-year to adult ratio, earlier maturation and increased fecundity) following the mass mortality event suggest population resilience typical of a recurring boom-bust pattern and demonstrate the species' capacity to recover rapidly and re-establish following disturbance. Repeated systematic mass removals of both juveniles and adults (using fyke nets) will be required if future fishery management measures aimed at limiting the population size are to be effective.