Sylvia Earle has been studying the oceans for 50 years. Now she's pushing an equivalent of the parks many people are familiar with on land. The natucal versions are called marine protected areas (MPAs). We do have man ysuch areas around islands and reefs, but Earle eants to extend the idea to "fencing off" critical areas on the high seas from exploitation. The Sargasso Sea - "the golden rain forest of the sea" - is her leading example. See others in the web pages at the title link.
COMMENT: This isn't an idea, it's an imperative. Conservationists are sometimes unrealistic about what can be accomplished, but we're reached the point where this HAS to be accomplished.