Understanding and predicting the impacts of environmental change on biological systems are key tasks facing researchers today. This requires good data. Unfortunately long-term biological data-sets are uncommon for aquatic systems and animals such as large-bodied fishes are unsuitable for experimentation. Aquatic biochronologies, generated from time-dependent information recorded in fish otoliths that are archived in their millions worldwide, can provide valuable long-term data-sets that facilitate the development of ecological and evolutionary insights into marine and freshwater environments.

South east Australian waters support both unique biodiversity and major commercial fisheries, but the region and its natural resources are increasingly being exposed to rapid oceanic warming. Here I present the results of a large-scale project investigating the environmental drivers of fish growth and recruitment variation using a data-set of unprecedented spatial, temporal and biological coverage. Over 30 otolith and catch-based growth and recruitment time series, up to 100 years in length, from across nearly 3000km of ocean have been analysed. Long-term growth and recruitment patterns for many species display temporal synchrony, pointing to universal ecosystem drivers. Directional trends are indicative of warming (via direct and indirect pathways) either promoting or inhibiting growth, whilst quasi decadal oscillations re-emphasise the importance of zonal westerly winds in driving recruitment and system productivity variation. Within species, significant growth plasticity exists that may confer some resilience on species faced with climatic change. Together, these results highlight the valuable information stored within otoliths and their potential to provide unprecedented levels of spatial and temporal detail in aquatic environments.