The aquaculture industry faces many challenges to expansion, including ma ximizing yield in limited spaces, addressing environmental impacts, and developing culture protocols for new and emerging products. One solution to these challenges is Integrated Multi-Trophic Aquaculture (IMTA), where species with complementary ecosystem functions from different trophic levels are farmed in proximity to each other. We tested the performance of US west coast venus clams (Chione spp.) when suspended and grown out in the presence of seaweed (Gracilaria spp.and Ulva spp.), and both seaweed and the California sea cucumber (Parastichopus californicus ). We ran a controlled aquarium experiment (March to August 2021) to understand underlying mechanisms, and a field experiment using a FLUPSY in San Diego Bay (June-Dec 2021; Fig. 1).
Over the 6-month aquarium experiment, clam mortality was highest in the clam-seaweed treatments compared to the others (Fig. 2), while growth rate (weight, length, height) did not differ between treatments (Fig. 3). Prel iminary summer data from the bay growout trials reveal that mortality was also highest in the clam-seaweed treatment, lowest in the three species treatment, and the clam only treatment experienced the highest clam growth rates. The findings of this study will inform west coast clam aquaculture efforts which are of rapidly growing interest, and shed light on potential environmental drivers of observed patterns.