Sweeping With the Fishes


Anyone who’s taken care of so much as a goldfish knows the routine: Feed the fish, clean the bowl, change the water. But overseeing the well-being of more than 10,000 sea creatures in about 1 million gallons of saltwater can be anything but routine.

“While a home aquarist might take care of only a few species, we have to worry about dozens if not hundreds at a time,” says Mark Loose, a 29-year-old professional aquarist--in other words, a fish caretaker--who works in the Southern California/Baja section of the Long Beach Aquarium of the Pacific. “It keeps us really, really busy. But it’s also a lot of fun.”

As he speaks, Loose is practically up to his elbows in fun in the aquarium’s food preparation room: shelling raw shrimp and chopping smelt. It’s almost like a scene from the fish market in San Pedro--where the aquarium purchases most of its food--except the customers here are cold-blooded and scaly.

This morning’s feeding is in the predator tank. On the menu are five pounds of squid, 10 pounds of smelt and four pounds of shrimp--enough to satisfy the tank’s approximately 400 aggressive fish, many of which have had to be weaned off live prey to accept today’s offerings. To keep appetites healthy--and keep the fish snapping up food so the water stays clean--they are given light meals four days a week; Mondays, Wednesdays and Fridays (including this day) feature heavier fare.


Frequently, the aquarium’s 15 full-time aquarists (all of whom are certified divers) and some of the roughly 100 volunteer caretakers literally immerse themselves in their work, donning scuba gear to feed the fish and clean the walls of the facility’s largest tanks.

Next to feeding, controlling unwanted algae growth is one of the biggest chores, especially in outdoor tanks that receive lots of sunlight. “You can spend an hour scrubbing just one section of a wall and by the time you’re done, algae is growing where you started,” Loose says. “It’s quite a job, and I have the muscles to prove it.”

To ease the workload, aquarists have enlisted yet another corps of volunteers: an army of algae-munching turban snails, sea hares and other herbivores.

While algae control is important for aesthetics, the biggest key to keeping the fish happy and healthy is water quality, said Kenneth Yates, chief of animal husbandry. A huge array of equipment, from filters and pumps to ozone generators, ultraviolet light (both of which are used to kill bacteria) and protein skimmers (contraptions that remove waste products from the water), is hidden behind the exhibits’ slick exterior. (Oh, and don’t forget the million-watt backup generator that is supposed to help keep the facility self-sufficient for a week if the utilities are knocked out.)


Depending on the exhibit, filtering all the water in a tank takes 30 to 90 minutes. In addition, water is tested daily for levels of salt, as well as deadly chemicals like ammonia (from waste or deteriorating food) that can build up rapidly, especially in new tanks.

Even if the tests are normal, water is changed regularly as a precaution. But if indicators are seriously off, caretakers quickly replace the tainted water with clean seawater, 250,000 gallons of which are barged in monthly from several miles off the coast.

In essence, each tank works like a miniature ecosystem. As the tanks become more established, water quality will generally improve, and that will let aquarists add more sensitive animals such as live corals and real plants like kelp and eel grass.

“The great thing about this place is that it’s constantly evolving,” Yates said. “It will always be a work-in-progress.”