An environmentally-sustainable, integrated, co-culture system for dulse and abalone production

A co-culture system is described in which both red abalone (Haliotis rufescens) and a red seaweed, dulse (Palmaria mollis), are grown together in the same culture system. Dulse provides food for the abalone and improves water quality by removal of excreted ammonia. The system can be balanced by determining the effects of light intensity on dulse production and comparing these rates with dulse consumption by abalone of different sizes. In addition, uptake of ammonia by dulse under different light intensities can be balanced against excretion rates of abalone of different sizes. Dulse production rather than ammonia uptake is the limiting factor for rearing abalone in this system. An estimated 21–31 times more area is required for dulse production to meet abalone food requirements compared to that required for removal of excreted ammonia. Dulse production rates and light utilization efficiencies are high compared with those of other marine plants, such as kelp, and comparable to those of the most productive terrestrial crops. The availability of high, year-round light intensities is a key factor in determining the economic commercial value of such co-culture systems.