The author begins to address one of your questions in the article, although I would like to see this subject treated in a little bit more depth.
"Even the best land-based farms pollute, sending nitrogen into our waterways, so we use our kelp to capture that nitrogen, turn it into liquid fertilizers, and send it back to organic farmers to grow their wonderful vegetables. When the nitrogen then runs back into Long Island Sound, we capture it again."
It seems like, at least in theory, these types of farms can also help limit the damage caused by land-based human activity to coastal ecosystems.
"Even the best land-based farms pollute, sending nitrogen into our waterways, so we use our kelp to capture that nitrogen, turn it into liquid fertilizers, and send it back to organic farmers to grow their wonderful vegetables. When the nitrogen then runs back into Long Island Sound, we capture it again."
It seems like, at least in theory, these types of farms can also help limit the damage caused by land-based human activity to coastal ecosystems.