Enjoy this blog, originally posted Sept. 14, 2013.
The Fishes department sprang into action as soon as word came that field biologists from the Illinois Department of Natural Resources (IDNR) would soon be at Shedd’s doorstep with three large bighead carp they’d netted in the Humboldt Park lagoon. We had to prepare for the animals’ arrival!
Non-native silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis) are aggressively invading our local waters (although these three were put in the lagoon). By outcompeting the native fishes, they decimate aquatic ecosystems. Known collectively as Asian carp, they are regarded as “bad fish” around the Midwest. But luck was definitely on the side of the three individuals the IDNR caught that day, because as soon as they entered Shedd Aquarium, they were met with the same thoughtfulness, dedication and high level of care given to each of the animals that call Shedd home.
And they would need it.
Bruisers that bruise easily
Caring for these carp in an indoor habitat can be challenging. For all the images of Asian carp hurtling out of rivers, like flying baseball bats, and injuring fishermen and boaters, Shedd aquarists often think of these carp as “wussy” fish: They bruise easily, don’t handle being transported very well, are picky eaters and react to loud noises or sudden movements with a burst of swimming speed or even a leap out of the water (which can bruise them as well as anyone they hit).
Because we already house some of the invasive carp at Shedd in our At Home on the Great Lakes gallery, we knew what it would take to keep these new animals healthy and looking their best.
A small army of aquarists and animal health staff members met the IDNR biologists and the three massive carp on the loading dock with large rolling transports (think 300-gallon heavy-duty plastic containers on wheels) filled with cool water bubbling with pure oxygen. We used soft rubbery nets designed for some of our delicate sharks to one-by-one gently scoop the fish, each weighing around 50 pounds, out of the IDNR holding truck and into individual transports.
First stop: quarantine
The quarantine area was the bigheads’ first stop. It’s Shedd’s fish welcome center. Here, new arrivals are behind the scenes and away from the busy day-to-day activities of the rest of the building. The carp shared a 3,400-gallon reserve pool while they acclimated to a new environment. Because loud sounds or sudden movements could startle the fish, we took every precaution to keep it a “quiet zone.” Air stones in the water created a bubble “screen” at the surface to obscure movements above the pool. Signs were posted outside quarantine to ensure that people from other areas knew to not be too loud. Our gift shop employees even changed how they stocked a storeroom one level above the quarantine pool so as not to disturb the new fish.
Our three massive “girls” settled in well. (We don’t actually know their gender because there was no need for an in-depth veterinary exam and we can’t determine the sex of this species from external characteristics. We can only offer a “best guess” that such large fish might be females.)
Introduced into the Great Lakes (gallery, that is)
When the bigheads’ 60-day quarantine was up, and they were ready to meet their public, it took many people working together to make the move to the gallery happen smoothly and safely. Fishes staff members who knew the animals well lowered the quarantine pool level and, with the help of our veterinarians and vet techs, added a fish sedative to the water. Then each carp was gently lifted into a soft, smooth plastic sling that was moved into a larger hammock (another item made especially for our sharks) to be weighed and measured before going into a waiting water transport with oxygen. A quick elevator trip took the carp and support staff up to the gallery, where an aquarist was waiting to help them make a gentle transition to their new home. It all went well.
In a short time, the three carp went from “bad fish” to “our girls,” and they are just as tenderly cared for as the other animals at Shedd. Be sure to stop by and say hi to them in At Home on the Great Lakes. If these three can raise awareness about the issue of invasive species, this is as close as bighead carp will get to Lake Michigan.
—Eve Barrs, senior aquarist
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