Raising Reef Fish From Larvae, So Fewer Come From the Reef

Almost every marine fish in an American public aquarium started its life on a reef. A multi-year project funded by NOAA Sea Grant is trying to change that for more than 20 species, and the North Carolina Aquariums are three of the ten institutions doing the work.

The initiative is called Catalyzing Marine Finfish Aquaculture Through Public Aquariums. Its output is not a single breakthrough but a set of protocols: step-by-step methods for taking a marine fish from an egg the size of a pinhead to an adult an aquarium can put on display, for species nobody had managed to raise before.

Why is this hard?

Because of what a marine fish egg is. The eggs are often no larger than a pinhead, and they hatch into larvae that are barely developed, with no capacity to chase down anything substantial. Their first meals have to be live organisms close to invisible to the naked eye, cultured in quantity, at the right size, at the right moment. Miss that window and the whole cohort is gone.

This stage is the bottleneck in the entire field, and it is why freshwater fish have been bred commercially for decades while marine species have not. Everything downstream of it is comparatively ordinary animal husbandry.

The project’s answer is partly equipment. Teams use Modular Larval Rearing Systems, or MoLaRS, a set of inexpensive and customizable setups developed by Andrew Rhyne of Roger Williams University that let an aquarium trial a new species without dedicating a whole room to it. The species list runs to the ones aquariums most want and have had to buy wild, including neon gobies, Atlantic lookdowns and golden sweepers.

Who is actually doing it?

Ten institutions, deliberately not one. Researchers at the University of Massachusetts Boston, Roger Williams University and the New England Aquarium lead the work, with seven partner institutions alongside them, among them the North Carolina Aquariums at Pine Knoll Shores, Fort Fisher and on Roanoke Island, and Woods Hole Oceanographic Institution Sea Grant.

The structure has a name: a distributed production model. Rather than build one central hatchery, the project spreads specialized capacity across a geographic network, so each institution works on what its existing animals, water and staff suit it for. A public aquarium already holds adult broodstock of difficult species, already runs life support around the clock, and already employs people who watch those animals daily. The project treats that standing infrastructure as a research asset.

“By developing successful breeding and rearing protocols for new species, these aquariums serve as research and development hubs, reducing dependence on wild-caught animals and creating methods that commercial producers may be able to adapt for additional species,” said Rhyne, of Roger Williams University’s Center for Economic and Environmental Development.

Does this change anything outside the aquarium?

That is the claim, and it is made carefully. NOAA Sea Grant’s aquaculture manager, Chuck Weirich, said the project team “successfully developed hatchery production protocols for several marine finfish species” across seven aquariums, and that the work “offers potential applications to enhance the commercial production of ornamental finfish, as well as juvenile fish to stock commercial foodfish operations.”

Note the hedging in that sentence. Nobody is announcing a commercial industry. What exists is a set of methods, and a deliberate effort to hand them over: the group is producing open-source aquaculture guides for the species it studies, so that aquariums and commercial producers outside the partnership can repeat the results rather than rediscover them.

There is a conservation argument underneath it that is worth stating in its own right. “Working with a wide variety of species may help in the future when we may need to conserve populations through direct intervention,” said Michael Tlusty of the University of Massachusetts Boston. Knowing how to breed a fish before you need to is the difference between a rescue and a postmortem.

What about the fish currently on display?

The aquariums are not disowning them. The project’s own framing is that public aquariums source marine fish responsibly from wild populations, where collection is done ethically and in ways that keep the ecosystem healthy, and that aquaculture widens the menu rather than replacing it. The work advances the Association of Zoos and Aquariums’ Aquatic Collections Sustainability Initiative, and has already produced thousands of fish distributed to AZA-accredited institutions around the country.

That number is the most concrete result here. Protocols are promises; thousands of animals in other people’s habitats are evidence.

Can the public see any of this?

Yes, which is new. The collaboration has published an interactive story map called Breeding and Raising Fish for Aquariums, built from video, maps and behind-the-scenes photography, specifically so that the larval-rearing work that happens in back rooms is visible to people who will never be in one.

“Advancing aquaculture techniques is about more than raising fish, it’s about building a community,” said Barbara Bailey, vice president of animal care at the New England Aquarium. “By sharing knowledge, expertise, and experience across public aquariums, we can strengthen sustainable collections, expand our collective impact, and accelerate innovation.”

The North Carolina Aquariums’ announcement is here, and NOAA Sea Grant, which funds the initiative, is here. We covered the Florida Aquarium’s work spawning elkhorn coral, another case of an aquarium breeding what used to be collected, here.