We are still a fair ways away from 'Integrated Multi-Tropic...

We are still a fair ways away from 'Integrated Multi-Tropic Aquaculture' (IMTA). If you're not sure what this is, it's basically a way to look at the whole aquaculture production cycle and consider complimentary crops to reduce environmental impact and increase the productivity. Two of the main components for IMTA in salmon is the use of muscles/oysters and seaweed that feed on the salmon effluent runoff and improve the water quality.

Unfortunately, there are precisely zero examples of this working at scale anywhere in the world. However, from a research and theoretical perspective, it is very interesting.

I have recently posted about the Blue Economy Cooperative Research Centre. You can read their strategic plan and see where some of the future of aquaculture in Australia is heading: https://blueeconomycrc.com.au/wp-content/uploads/2021/07/BECRC_Strategic-Plan_2021_A4_e010721.pdf

The use of muscles/oysters as bottom feeders doesn't seem to be top priority. Tassal has been involved with some seaweed focused research, and we've even heard Mark Ryan talking about seaweed being the third pillar (salmon, prawns, and then .. ?). The Blue Economy CRC wrote the Seaweed Industry Blueprint which is a great read: https://blueeconomycrc.com.au/new-seaweed-industry-blueprint-highlights-the-potential-of-australian-seaweed/

The main priority for seaweed in Australia is the development of Asparagopsis taxiformis. This is an Australian native seaweed, that if you add to the diet (~2%) of livestock improves their feed conversion rate (~30%) while also massively reducing their carbon emissions (~60-90%). They reckon this could be a billion dollar industry. The initial research was funded by Meat and Livestock Australia, CSIRO and James Cook University. They have since then licensed it out to a US company for further development (Ergh.. typical myopic Australian institutions). And my understanding is that once that's ready to scale up, Tassal would be interested in being a producer and distributor. However, this is not IMTA as far as I am aware. IMTA would require a different species of seaweed - and not sure where the funding from Tassal in that research has ended up.