"Once a systems engineering consultant, Brian Von Herzen now devotes his life to reversing global warming by restoring the primary production of oceans, using kelp and other seaweeds. Primary production is the creation of organic compounds from carbon dioxide through photosynthesis. ... The key technology involves marine permaculture arrays (MPAs), lightweight latticed structures roughly half a square mile in size, submerged 80 feet below sea level, to which kelp can attach. Attached buoys rise and fall with the waves, powering pumps that bring up colder, nutrient-rich waters from far below. Kelp soak up the nutrients and grow, establishing a trophic pyramid rich in plant and animal life.
Plants that are not consumed die off and drop into the deep sea, sequestering carbon for centuries in the form of dissolved carbon and carbonates. Floating kelp forests could sequester billions of tons of carbon dioxide, while providing food, feed, fertilizer, fiber, and biofuels to the world." -Marine Permaculture, Drawdown.org
"In just 57 hours after deployment, the system sparked plankton growth. Shortly thereafter, these blooms attracted various species of fish. Two weeks later, a 17-foot long whale shark was still circling the area feeding on plankton that had started blooming." -Marine Permaculture, ClimateFoundation.org

Does this mean we that we are now going to need a Oceans & Seas Permaculture sub-forum at permies?

Yes! Anyone familiar with the concept? Would be interested to hear more. Is there a marine/aquatic sub-forum at permies?

We have reforestation program for land. It would be cool to have it for the sea too. The scale wouldn't be at the home-scale though it seems, it would have to be at the farm/biz scale or even bigger at the government scale. I could see it increasing the amount fish in an area or maybe adding them where coastal cities dump their municipal sewer water into the sea.

Here are some Natural Marine Permaculture Arrays.
With the keystone species in each regions.
I wonder what the entire "guild" would look like.
I have read that some kelp forest have over 20 different species of kelp in it.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5751975/

I sincerely hope that we wouldn't destroy even more while tryıng to save.