HEART DEFORMITIES IN INTENSIVELY FARMED FISH: Implications for aquaculture sustainability in a changing world

Farmed fish often display severe heart deviations including abnormal ventricle shape and coronary lesions.

This problem has increased in Nordic Atlantic salmon and rainbow trout and is likely due to intensified juvenile rearing regimes at elevated temperature.

Importantly, heart failure may explain rising adult mortality rates during stressful events such as delousing, transport, and harsh environmental conditions (warming and hypoxia). Indeed, our preliminary data show that fish dying after stressful interventions exhibit more cardiac deviations.

While rearing mortality is a monumental welfare concern, which constrain sustainable and profitable aquaculture development, the links between juvenile rearing conditions, heart pathophysiology and stress tolerance of the adult fish is largely unknown.

In this project, we apply protocols developed by our group to rear juvenile rainbow trout at cold (7°C) and warm (16°C) temperature to map cardiac morphology and pathophysiological traits through development and relate that to heart function and electrophysiological properties.

We will also examine how heart deviations in the adult fish affect resilience to temperature and hypoxia stress, as well as transport and handling, along with cardiovascular function. The project will improve farming practices, cut production losses and benefit fish welfare.

This boosts a sustainable, profitable, and environmentally resilient development of the aquaculture industry in a changing world.