Ocean conservation efforts: what is actually working

"Ocean conservation" covers everything from a beach clean-up to a treaty signed at the United Nations. They are not equivalent. Some efforts measurably rebuild marine life; others mostly move numbers around on a map.

This page sorts the main ocean conservation efforts by how much they actually change the pressure on marine animals, and where each one currently stands.

Which ocean conservation efforts work best?

The short version: protection only works when it is full protection, and protection is only half the job — the other half is taking less out of the water.

1. Fully protected marine reserves

Marine protected areas (MPAs) are the headline tool. Roughly 8-9% of the ocean sits inside some kind of MPA, but only around 3% is fully or highly protected — meaning extractive activity such as industrial fishing is actually banned rather than merely "managed" (Marine Protection Atlas; UNEP-WCMC).

That gap matters. A "protected" area that still permits bottom trawling is protection in name only, and several European MPAs have been documented as trawled more heavily than surrounding waters. Where protection is genuinely full and enforced, biomass inside reserves recovers, and the recovery spills over into adjacent fished waters.

What to look at when you hear an MPA announcement: is extraction banned, is the area enforced, and how big is it?

2. The High Seas Treaty (BBNJ)

Two thirds of the ocean lies beyond any national jurisdiction, and until recently there was no legal mechanism to create protected areas there at all. The BBNJ Agreement — the "High Seas Treaty", adopted at the UN in 2023 — creates one. It is the single biggest structural change in ocean governance in decades.

It is also not yet the finish line: the treaty needs ratification by enough states to enter into force, and then MPAs still have to be proposed, agreed and enforced. Treat it as a door that has been opened rather than a job completed.

3. Cutting fishing pressure and bycatch

Around 37% of assessed marine fish stocks are fished at biologically unsustainable levels, according to the FAO's State of World Fisheries and Aquaculture. Fishing is the dominant direct pressure on ocean wildlife — larger, at the level of animal populations, than plastic.

Bycatch is the part that most people never see. Hundreds of thousands of cetaceans, plus sea turtles, sharks and seabirds, are estimated to die in fishing gear every year. Gear changes work: pingers on gillnets, turtle excluder devices in trawls, weighted longlines and night-setting for seabirds all have measured reductions behind them. They are cheap relative to the problem and badly under-deployed.

Abandoned and lost fishing gear — "ghost gear" — keeps killing after it is discarded, and makes up a large share of the plastic mass in ocean garbage patches.

4. Restoration: reefs, mangroves, seagrass

Restoration projects for mangroves, seagrass meadows, oyster reefs and kelp forests deliver nursery habitat and carbon storage at the same time. The evidence is genuinely good, with one caveat: restoration cannot outrun ongoing pressure. Replanting a seagrass bed that is still being dredged or anchored over is a treadmill.

5. Demand-side change

Every conservation measure above is a way of managing how much marine life is removed from the ocean. Reducing the demand attacks the same number from the other end, and it is the one lever an individual controls directly. Roughly speaking: what is not ordered is not caught.

This is also where ocean conservation and animal ethics meet. Fish and other marine animals are the largest group of vertebrates killed by humans by a wide margin, and the evidence for fish sentience — nociception, learning, social behaviour — has strengthened considerably over the last two decades.

Ocean conservation efforts ranked by leverage

What this means if you want to help

1. Support full protection, not paper MPAs — the wording of a designation is the whole story.
2. Back bycatch-gear mandates, which are the cheapest measured lives-per-dollar intervention in the list.
3. Reduce the demand side. Leaving fish and other sea animals off the plate is the one ocean conservation effort that needs no treaty, no budget and no enforcement.