Solving impediments to the co-culture of seaweeds and shellfish

Start/End: September, 2017 to February, 2019

Aquaculture is one solution to the increasing global demand for marine products and the problem of overfishing. However, aquaculture operations themselves may be threatened by environmental stressors associated with humans impacts, like climate change, in the coming decades. Strategies to buffer aquaculture operation from stressors like increasing temperatures, ocean acidification, and hypoxia are needed.

One potential solution to address the impediment of environmental impacts on aquaculture production is through integrated multi-trophic aquaculture (IMTA), both in land- and field-based operations. For example, the direct linkage (i.e., co-culture) of seaweed and shellfish farming activities has the potential to capitalize on the buffering capacity of seaweeds to raise seawater pH and clean the water of animal waste products. The potential benefits of co-culture include promoting growth and shell calcification of farmed shellfish, especially during the vulnerable hatchery grow-out phase, and the enhancement of seaweed growth and nutrient content.

This project addresses an additional impediment to developing integrated shellfish-seaweed culture as a means to ensure sustainable aquaculture productivity into the future, namely through the design of integrated land-based systems themselves, including tests of the optimal recirculation rate to maximize the pH buffering (for shellfish) and nutrient subsidy (for seaweeds) benefits of integrated culture.

The overall goal of this project is to test the ability of IMTA to provide benefits for seaweed and shellfish culture compared to non-integrated operations. The current impediment addressed is the development of integrated systems for land-based seaweed tumble-culture paired with oyster and abalone culture during the initial grow-out phases.