When I’m not educating K-12 grade students about ecology or natural history, part of my Sea Grant marine education internship at that UGA Marine Education Center and Aquarium includes assisting the aquarium curators in caring for the animals. I enjoy this part of my job so much that I decided to set up two tanks of my own.
The UGA Aquarium, part of Marine Extension and Georgia Sea Grant, has a collection permit through the Georgia Department of Natural Resources that allows us to collect native wildlife for the aquarium. During one of our routine collection trips in the Skidaway River, we found three echinoderms, or spiny-skinned sea creatures, including a sand dollar, a gray sea star and a purple-spined sea urchin. These animals are important to our teaching mission. Seeing a live animal up close teaches students about the behavior and anatomy of an animal they may never encounter in the wild.
I brought the new critters back to the aquarium and began my project. First, I needed tanks. Our curators Devin Dumont and Lisa Olenderski pointed me in the direction of the spare aquarium equipment. Two 10-gallon tanks with under-gravel filters made the cut.
Water used in the UGA Aquarium tanks is pumped from the Skidaway River, cleaned and treated. I treated the water for my tanks with minerals, conditioners and a treatment to facilitate good bacteria growth that digests animal waste. (These treatments are the same ones you can find at the pet store.)
I waited a day before putting the animals in the tank so I could test the water quality parameters again to ensure that my tank was ready. Once everything checked out, in went the critters!
I researched the echinoderms’ diet and found that the sand dollar and gray sea star both eat detritus and meat, while the purple-spined urchin usually eats algae and other plant material. I feed the animals different things depending on what’s available. I also intentionally vary their diet as an enrichment method. I give the animals time to digest their meal, but at the end of every feeding day I scoop the leftovers out. Too much food can cause toxic waste products to build up in the tank.
To help keep the tank clean, I gave the echinoderms some tidy roommates. Peppermint shrimp are commonly found offshore and are great at eating leftovers and built-up waste.
I tested the water quality two weeks after tank set-up and found that the waste products (nitrates, nitrites, and ammonia) were higher than I anticipated them to be. A simple way to remove these waste products is to remove and replace the water.
I continue to monitor both animal health and water quality on a regular basis. A tank change occurs about once every two weeks, as these systems don’t have internal filters and need frequent water changes to keep them healthy. I also regularly search for any new information about these species to provide them with the best environment and diet.
I have used these live animals in our Sea Star and Touch Tank programs for elementary school students. They’re often surprised by the dozens of moving tube feet that the sea star uses for locomotion. The sand dollar’s tiny moving hairs, called cilia, also amaze students. Most students are used to seeing dead sand dollars on the beach, which no longer have cilia and are usually bright white. It’s great having a live sand dollar to show them, so they can see the difference and won’t make the mistake of removing live sand dollars from the beach.
This project required all of the husbandry skills that I developed during my internship here at the UGA Aquarium. Saltwater aquariums are complicated and fascinating systems and I was able to experience the whole process. Setting up and maintaining two tanks independently is a skill I’ll use to move forward in my aquarium career.