Black liquor and the hangover effect: fish assemblage recovery dynamics following a pulse disturbance.

摘要: Anthropogenic perturbations impact aquatic systems causing wide-ranging responses, from assemblage restructuring to recovery. Previous studies indicate the duration and intensity of disturbances play a role in dynamics In August 2011, Pearl River, United States, was subjected weak black liquor spill paper mill which resulted substantial loss fish large stretch main channel. We quantified resilience recovery structure impacted area following event. compared downstream (impacted) assemblages upstream (unimpacted) determine initial impacts on structure. Additionally, we incorporated historic collections (1988–2011) examine across broad temporal scales. Based NMDS, sites generally showed similar sample periods with exception 2 months postdischarge, where visually differed. Multivariate analysis variance (PERMANOVA) indicated significant seasonal variation among samples, but found no interaction between unimpacted discharge However, multivariate dispersion (MVDISP) greater These results suggest that disturbance represent time period stochasticity regard dynamics, this followed by rapid term dynamic “hangover effect” as it represents frame cessation perturbation assemblage's return predisturbance conditions. The availability proximity tributaries refugia, were not affected disturbance, well abiotic parameters likely played This study only demonstrates an system, further value continuous, long-term, data enhance our understanding dynamics.