There is provided herein a method of treating a poikilothermic organism, such as marine bivalves, in a decreasing temperature environment which method comprises exposing the organism to a source of eicosapentaenoic acid (EPA) at temperatures of from 18° C. to about 12° C., and then exposing the organism to a source of docosahexaenoic acid (DHA) at temperatures of from about 11° C. to about 5° C. There is also provided herein a method of just conducting the first or second exposing step without the other, and also a method of using a decrease in temperature to catalyze the organism to produce EPA and/or DHA and/or non-methylene-interrupted fatty acids (NMIs).
