Coastal seascape variability in the intensifying East Australian Current Southern Extension

Coastal pelagic ecosystems are highly variable in space and time, with environmental conditions the distribution of biomass being driven by complex processes operating at multiple scales. The emergent properties these their interactive effects result dynamic mosaics referred to as “seascapes”. Mechanisms that link large-scale oceanographic ecological variability coastal environments remain poorly understood, despite importance for predicting how will respond climate change. Here we assessed seascape along path rapidly intensifying East Australian Current (EAC) Southern Extension southeast Australia, a hotspot ocean warming ecosystem tropicalisation. Using satellite situ measures temperature, salinity current velocity coupled contemporaneous measurements from nine boat-based active acoustic surveys five consecutive years, investigated relationships between physical environment (zooplankton fish) timescales. Survey periods were characterised high conditions, variation influenced meso-to-large scale occurring offshore, including position strength eddies. Intra-annual was often similar or greater magnitude inter-annual variability, suggesting important scales days weeks. Two categories identified (A) warmer, less saline water (B) cooler, more water, former indicating influence EAC on processes. Warmer waters also associated fewer, deeper dense biological aggregations. As continues warm penetrate further south, it is likely this have substantial activity ecosystems, potential reduction accessibility prey aggregations surface-feeding predators fisheries. These results highlight import role offshore driving region undergoing rapid oceanic