As a diver, the question of whether we should eat fish and seafood or not comes up so frequently. The fish in the ocean are what we want to see, they are the primary reason for us to go diving. We are amongst the few people in the world who actually get to see what is happening, and we have the saying “fish are friends,” so should we really be eating seafood? Ultimately, I always come back to the same thing, I am ok with it if it is sustainable, but how do you know if what you buy from the supermarket is sustainable?

Here in Iceland, we are lucky to have some of the healthiest fisheries in the world, even today 1 in every 7 cod dishes served across the world comes from Iceland. But even living in a country with apparently sustainable and managed quotas, I still question myself on the sustainability of mass fishing and the bycatch and impact these fisheries have.

Now as a diver, we have the opportunity to harvest from the ocean ourselves, and no matter what you think of that, it is very commonly done around the world. So I wanted to write an article to openly discuss the ethics and controversies, and share a few of my own experiences.

Every time I go into the water planning to bring something home, I try to hold myself to a simple standard. I take what I will eat, in the quantity I actually need, and nothing more. If I am diving for my own dinner, that means one meal, not a freezer full, not a bag to sell or trade, not a trophy to photograph and discard. This sounds obvious when stated plainly, but it is astonishing how often it gets ignored, even by people who consider themselves conservation-minded divers. The moment you start taking more than you can eat, whether out of habit, ego, or the simple thrill of a good day underwater, you have crossed from provisioning into something closer to extraction.

This is where I draw a hard line for myself. Scuba diving for food is, in my view, entirely defensible when the diver is selecting a single meal for themselves or their household. It becomes indefensible the instant it shifts toward commercial volume or toward hunting purely for the sake of hunting. An animal that is killed and not eaten is, to me, the clearest possible failure of the whole exercise. It does not matter whether that animal is a fish, a scallop, a lobster, or anything else that lives in salt water. If it is not going to end up on a plate, it should not be taken from the reef, the seabed, or the water column at all. That rule sounds severe written out like this, but underwater it is the only thing that keeps a good practice from sliding into a bad one.

So much of the conversation about ocean harvesting gets tangled up in arguments about methods, scuba versus freediving, spears versus hands, nets versus lines, when the far more important variable is intent. A method can be sustainable in one person's hands and destructive in another's. The gear does not make the ethics. The diver does.

People often assume freediving is inherently the more ethical choice, and scuba the more exploitative one, largely because freediving looks harder and scuba looks like it gives you an unfair advantage over the fish. I understand the instinct, but I think it misreads the actual issue. Scuba does give you more time on the bottom, more range, and less physical strain than a breath-hold dive, and that additional capability can absolutely be misused. A diver with a full tank and an afternoon to spare can clear a patch of reef in a way a freediver simply cannot, because the freediver is limited by lungs and by the discomfort of repeated deep breath holds.

But that additional capability is not, by itself, unsustainable. What matters is what the diver chooses to do with it. If I go down on scuba with the specific intention of finding one meal worth of scallops, and I surface once I have that meal, the extra bottom time changes nothing about the impact on the population. I could have spent that same hour searching rather than immediately grabbing the first legal-sized animal I found, which if anything makes for a more selective, lower-impact harvest than a rushed freediving grab under time pressure. The tank is a tool that removes the clock. Whether removing the clock leads to more selectiveness or more greed depends entirely on the person holding the mesh bag.

Freediving carries its own romance, and I love it for what it is, a quieter, more physically demanding way to move through the water. But I would resist the idea that it is automatically the more sustainable method. A freediver who spears every fish they see within legal size, regardless of whether they intend to eat all of it, is doing more damage than a scuba diver who takes one carefully chosen animal and stops. The credit for sustainability belongs to restraint and selection, not to which piece of equipment is strapped to your back.

There is also a physical honesty to freediving that I think gets romanticized past the point of usefulness. Holding your breath and dropping to depth on a single lungful of air is genuinely difficult, and that difficulty can feel like it should translate into some kind of moral high ground. But difficulty and sustainability are not the same axis. A freediver who has trained for years and can comfortably spend two minutes at depth has, in practical terms, almost as much capability to take animals as a scuba diver on a short dive, just compressed into repeated breath-hold dives rather than one long one. The two methods converge on the same outcome once you account for a skilled practitioner. What never converges automatically, regardless of method, is restraint. That has to be chosen every single time, on every single dive, by the person doing the diving.

Some of the most memorable days of harvesting in my life happened in the West Fjords of Iceland, hand diving for scallops in cold, clear water that made my fingers ache within minutes. There is no spear involved in that kind of diving, no gun, nothing that looks aggressive. You simply swim along the bottom, scanning the sediment for the telltale shape of a scallop shell, and when you find one of a size worth taking, you pick it up by hand.

What struck me about that experience, beyond the cold and the silence of those fjords, was how naturally the method enforced restraint. Hand diving for scallops is slow. You cannot cover much ground quickly, and you cannot take more than you can carry and process afterward, since each scallop has to be opened by hand later. That slowness is not a limitation to be engineered away. It is, in effect, a built-in sustainability mechanism. The method matches the pace of a person gathering a meal, not a person running an operation.

When choosing to hand dive for scallops, you immediately become selective about what you catch: you do not touch or take anything else, and you do not disturb the seabed or indiscriminately lift every creature the way a commercial vessel would. There is so little impact on the seabed compared to commercial, indiscriminate fishing. There surely is no better or more sustainable way to catch your seafood.

The other experience that shaped how I think about all of this happened while I was living in Mexico and spending a lot of time in the water along the reef, spearfishing lionfish. Lionfish are not native to the Caribbean or the Gulf of Mexico. They arrived from the Indo-Pacific, almost certainly through the aquarium trade, and they have since spread across a huge stretch of the western Atlantic with no natural predators and a reproductive rate that is frankly alarming. A single female can release tens of thousands of eggs at a time, repeatedly, year round, and the fish grow quickly, eat almost anything that fits in their mouths, and have venomous spines that most native predators have no instinct to avoid.

Spearing lionfish feels different from any other kind of harvesting I see done, because in that particular case, taking more was actually the more responsible choice, not less. The usual logic of restraint — take one meal, leave the rest — gets flipped on its head when the animal in question is actively displacing native fish populations and degrading reef ecosystems by eating juvenile fish and invertebrates that reef fish communities depend on. Removing lionfish, within reason and always with the intention of eating what you take, supports the reef rather than depleting it. I ate an enormous amount of lionfish during that period of my life, prepared in every way I could think of — ceviche, grilled whole, fried in tacos — because the entire point of the exercise was consumption paired with population control, not selective restraint for its own sake.

Scuba, freediving, and hand diving are the methods I know best from personal experience, but they are far from the only ways people harvest food from the ocean, and it is worth placing a few others in the same sustainability frame.

Hook and line fishing, done from shore or from a small boat, is in many ways the oldest and in some respects the most naturally self-limiting method there is. A single line can only take one fish at a time, which builds in a kind of pacing that mirrors the slowness of hand diving. The sustainability risk with hook and line comes less from the method itself and more from bycatch and from what happens to a fish that is caught but not wanted, whether it gets released properly or left to die on a hook it should never have taken.

Pole spears and Hawaiian slings, used mostly by freedivers, sit very close to spearguns in terms of selectivity, since the diver has to be close enough to the fish to see exactly what they are aiming at before releasing. That closeness is itself a sustainability feature, because it makes it very hard to take an animal by accident or to harvest indiscriminately at range.

Traps and pots, used for animals like lobster and crab, introduce a different set of concerns entirely, since they can keep working and catching animals even after a fisher has left the area, sometimes for weeks if a trap is lost. A trap does not know when the person who set it has already gotten their meal. This is why responsible trap fishing depends so heavily on regulation, escape mechanisms for undersized animals, and traps being checked and retrieved regularly rather than abandoned.

Gleaning and foraging along the shoreline, gathering mussels, seaweed, or other intertidal food by hand at low tide, might be the gentlest method of all, in that it requires no equipment beyond a bucket and does not touch the water column or seabed the way diving does. It carries its own risk of overharvesting a small area if too many people converge on the same stretch of coast, but for an individual gathering a single meal, it is about as low impact as ocean harvesting gets.

Net fishing, whether cast nets used by individuals or larger commercial nets, is where the sustainability picture gets genuinely difficult, because nets by design are far less selective than a spear, a hook, or a hand. A net does not know or care what swims into it, and bycatch — unwanted fish, turtles, and other animals caught alongside the target species — remains one of the most serious problems in ocean harvesting worldwide. None of this means net fishing cannot be done responsibly, but it requires much more deliberate design, smaller mesh regulation, exclusion devices, and careful timing, to approach the selectiveness that spearfishing or hand diving offer almost automatically.

What ties all of this together, for me, is that sustainability in ocean harvesting is decided far more by the person than by the tool. Scuba tanks, spearguns, hand baskets, fishing lines, and traps are all simply ways of reaching food that lives somewhere other than dry land. None of them are inherently virtuous or inherently harmful. What matters is whether the person using them is taking a single meal or an unlimited haul, whether every animal taken is actually going to be eaten, and whether the harvester understands enough about the specific place they are diving or fishing to know if that particular population can bear the loss.

I think about this every time I clip a mesh bag to my weight belt before a dive, whether I am in the cold silence of an Icelandic fjord looking for scallops or in the warm water off a Mexican reef looking for lionfish. The ocean will give you what you need, but only if you are honest with yourself about what you actually need, and only if you stop asking once you have it.