I am also strongly reassured that XSS is a solved problem when using content security, and climate change has been solved by mass reforestation efforts.
The difficult part of a technical solution is not inventing it (although those are rightfully hard problems); the real challenge is in driving adoption of the solution.
The industry will push back on this solution for a broad range of reasons:
1. Cost - what is the cost of both the supplement and the labour required to administer it, or the differential on unfortified vs. fortified feeds.
2. Marketing - how will you communicate to folks that they should do this?
3. Customer Satisfication - does the supplement meaningfully affect any of the metrics for customer satisfaction (flavour, texture, etc of the meat).
4. Availability - retooling and spinning up the aquaculture required to produce the supplements
5. Viability - what is the ecological impact of the proposed seaweed solution, and is it a net positive.
I spent a chunk of my career as a researcher, developing protoypes and proof of concept stuff. One of the greatest things of that time in my career was developing something to 80% and throwing it over the fence, which let me ignore all of that hard work and call my project a win. One of the worst things is that out of that multi-year period of experimentation almost none of the work I did actually yielded unique products or improvements (although the tools I built did drive improvements to address issues and flaws found).
Assuming that you did the research, your work was definitely successful in finding a solution. You have not solved the problem, and the hard work is very much ahead.