Larval Aquaculture Program Scales Quickly - AZA.org
Aquarium workers have long labored informally to breed some of the ornamental marine species that appear in their exhibits, from flashy, multicolored royal grammas to slender, electric blue neon gobies to horse-faced silvery lookdowns.
"They like to tinker with things and work with animals," said Barbara Bailey, the curator of husbandry and sustainability at New England Aquarium in Boston, Mass. "It's been happening behind the scenes in aquariums for years."
In late 2019, the Association of Zoos and Aquariums committed itself to identify and coordinate these ad hoc projects, believing that doing so could improve animal welfare while making specimen collection more sustainable. Under the new Aquatic Collections Sustainability Committee, AZA launched larval programs with a survey to its aquarium members to learn who was engaged in aquaculture, which species they were breeding, and how many individuals they produced. It also inquired which species AZA-accredited aquariums would want the programs to produce going forward.
"AZA has really helped us focus the program, provide a structure for it," said Bailey.
Initial results have been promising.
"The very first year we did three species that we were really comfortable with, and we sent them to only a couple of institutions," said Hap Fatzinger, director of the North Carolina Aquarium at Fort Fisher in Kure Beach, N.C., and chair of the Aquatic Collections Sustainability Committee. "We wanted to find out: Can we raise these (species) on demand? Can we ship them safely and effectively? What does that look like?"
In 2022, the larval programs expanded the number of species on offer to five and invited all AZA aquariums to consider buying from them rather than from the commercial suppliers who have long provided ornamental marine fish.
Dr. Megan Brown, AZA's director of population management strategy, said that revenue from the sales of these larval fish is returned to a committee administered "sustainability fund" and is used to reimburse the costs accrued by the production facilities and to help support related research and professional development opportunities.
Laura Abrams, senior aquarist at the National Aquarium in Baltimore, Md., for example, is analyzing the nutrition of brood stock at the institution in order to improve the animals' longevity and welfare and see how that affects the success of the offspring.
"A lot was learned in the first year―the pilot year―and now they can implement what they learned," said Brown. "They are learning even more here in the second year. They've just started breeding some of the species for this year. Everybody I have talked to has been very pleased with the results."
When AZA allowed all member aquariums to buy larval fish in 2022, institutions asked to buy about 2,700 fish. Fatzinger said all orders for three species were filled in full and on time. They were Atlantic spadefish from the North Carolina Aquarium at Pine Knoll Shores in Pine Knoll Shores, N.C.; lookdowns from the New England Aquarium and its longtime partner institution, Roger Williams University in Bristol, R.I.; and neon gobies from the National Aquarium. New England and Roger Williams University were late in delivering smallmouth grunts and copper sweepers because those species had late spawns.
"Some of the species that we felt really comfortable and confident with just didn't do their thing like we thought they would," said Fatzinger.
Smallmouth grunts usually are reliable, "bread-and-butter" breeders, he added, but marine biologists suspected that the New England Aquarium's brood stock had "aged out," so the Aquarium bought new wild stock for 2023. Copper sweepers are notoriously sensitive to being handled or moved, he continued, but may be adjusting to their surroundings because New England has had successful spawning events with that species.
This year, the program is continuing its rapid growth, with 23 of AZA's 68-member aquariums ordering a total of 4,646 fish, a jump of more than 70 percent from 2022. The Texas State Aquarium in Corpus Christi, Texas, placed the largest order, for more than 600 fish; Walt Disney's The Seas in Orlando, Fla., was next, requesting more than 550 fish.
The Atlantic bumper is the most-frequently ordered species, ahead of smallmouth grunts and yellowtail fusiliers. This year, ACSC added two aquariums to its list of producers: the North Carolina Aquarium at Fort Fisher which is breeding Atlantic bumpers and the Shedd Aquarium in Chicago, Ill., which is breeding yellowtail fusiliers.
Another critical learning opportunity involves how these larval fish are transported. After eggs hatch and the resulting larvae approach juvenile status in an aquaculture facility, fish are ready to be transported to their new homes. This is usually done by air, to minimize the time out of their environments. Monika Schmuck, sustainability manager at the New England Aquarium, said her facility purges fish—that is, skips one feeding—before they are transported "so they don't soil the water on the way there."
The fish, most of them only one or two inches long at this point, are then put in a watertight container of sterilized and oxygenated water, sealed, and handed to a cargo company for express delivery. Some aquariums prefer shipping animals by FedEx, while others request air cargo on a particular airline. Only two, Mystic Aquarium in Mystic, Conn., and Adventure Aquarium in Camden, N.J., have traveled to Boston and driven back with their fish, said Schmuck.
Brown, of the AZA, said there are good reasons to produce some ornamental marine species using aquaculture at aquariums rather than have those facilities collect animals themselves or rely on commercial suppliers. Lookdowns, for instance, are usually exhibited in big schools, so AZA members purchase large numbers of these animals. Managed breeding also may reduce morbidity or mortality of sensitive species that do not travel well.
"Rather than bringing them from the Bahamas to Seattle, you're only going from, say, San Francisco to Seattle," said Brown. "It's a much shorter trip. That's the idea."
The program also is preparing to adjust its breeding programs to meet the needs of AZA aquariums.
"The need for individual fish species might change over time," said Kylie Lev, a curator at the Steinhart Aquarium in San Francisco, Calif. "If we have a lot of orders for yellowtail fusiliers one year, maybe there is less of a demand the next year. We would need to pivot to a different species. Maybe even plan to rotate some of the species in and out every three to five years depending on facilities' needs."
Fulfilling the current flood of orders is a learning experience of its own.
"We collect shipping data and note best practices around shipping and larval production," said Lev, who is also co-lead, with Bailey, of the Larval Programs Working Group. "We figure out what is working and not working in terms of brood stock, diet, and management. There is a lot of data to process so it can be a useful tool for us to learn from."
[Related story: Solving Aquatic Sustainability]
Marine biologists and other researchers learned early the value of being able to identify eggs, which can be as little as 40 microns in diameter and broadcast spawned into the water column.
"They then basically float around until we catch them," said Schmuck, of the New England Aquarium. Other species' eggs sink and are harvested from the sand or other substrate.
Experienced aquarists can identify many eggs by sight.
"Pelagic eggs are usually rounder but they have all different sizes and some are more oval shaped," Schmuck said. "They all have different egg droplet colors and circumferences and many unique things."
Misidentifications are not unknown, leading some breeding programs to waste time and resources hatching and raising fish that aquariums have not requested. "Some facilities collected eggs without having any idea what species they were from," Fatzinger said. "Sometimes we raised 250 of a fish that nobody wants."
To address this, the larval program has asked AZA member aquariums to contribute to an online catalog of marine fish eggs that includes images, physical descriptions, and DNA code for each entry.
For all their success thus far, the larval programs will not make the collection of wild fish obsolete, nor are they meant to do so. "A certain amount of wild collection will always be necessary to sustain a species, whether by bringing in new genetics or improving brood stock," said Lev.
There also is the matter of sheer numbers of animals required. A single aquarium may have a thousand species of fish in a single giant ocean tank, Fatzinger pointed out, and that is too many for AZA members to breed.
"We still get the majority of our animals from the wild—either we collect them ourselves or commercial collectors provide animals to us—and that's not going to stop anytime soon," he said.
Hero Image: Lookdown Fish. Photo Credit: © Getty Images
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