During the time I lived in Philadelphia, from 1989 through 1993, just across the Delaware River, the waterfront of Camden, New Jersey was undergoing a significant revitalization. One of the centerpieces of this effort was the New Jersey State Aquarium, which opened on February 29, 1992. The aquarium was owned and operated by the New Jersey Academy for the Aquatic Sciences and had a strong focus on education and conservation. Since they were a New Jersey institution, the displays exclusively featured fish from New Jersey, including, as we will discuss below, the Atlantic Sturgeon. I loved the aquarium but, it turns out, I was one of the very few who did.
During its first year of operation, the aquarium attracted 1.6 million visitors; most visitors were less than impressed. The fish were all brown and grey. There were no dolphin shows and no electric eels. Patrons didn’t care about the breeding habits of the slimly sculpin in the acidic waters of the Pinelands, and so they stayed home. Attendance plummeted to 400,000 in year two and, in an attempt to bring people back, the Disney-fication of the aquarium began apace. Today it is called the Adventure Aquarium and has a shark tunnel, a Kid Zone, a hammerhead shark and a 4D theater. So now it is effectively the same as every other aquarium in the country. I support any enterprise that gets people interested in science, even one that sells cotton candy next to the shark tank, but I do sort of mourn the old version.
My favorite part of the original aquarium was the tank with the Atlantic Sturgeon. If you are not familiar with it, here is a picture:
Sturgeon, in my opinion, are quite fascinating. There are 25 species of sturgeon, all of which inhabit the Northern Hemisphere, and they have been there for almost 200 million years. They swam with the dinosaurs. Their body shape and features, to me at least, evoke the feeling of being near something ancient and exotic.
Atlantic Sturgeon are an anadromous fish, which means that they live most of their lives in the ocean but, like many other fish such as shad or salmon, return to fresh water streams and/or brackish estuaries to breed. Their breeding grounds range from Florida to Maine, and include all major North Carolina rivers as well as the Albemarle-Pamlico Sound. Atlantic Sturgeon live about 60 years, can grow up to 14 feet in length, and can weigh over 800 pounds. They are bottom feeders and primarily feed on crustaceans. (To learn why this dietary choice makes the Atlantic Sturgeon vulnerable to ocean acidification, please read last week’s column, Kelp to the Rescue?).
In the late 1800’s, after lobster, sturgeon were the second most valuable seafood product on the east coast of the United States. While there was a small market for sturgeon meat, the value arose primarily from harvesting their eggs for caviar. Dare County North Carolina was known at this time as a center of commerce for sturgeon and caviar. Unfortunately, sturgeon can take up to 20 years to reach breeding age and reproduce slowly after that, so by about the year 1900 their populations had been devastated and the sturgeon industry disappeared almost as quickly as it arose.
Development in North Carolina and along the rest of the East Coast during the 1900s was not kind to the sturgeon populations that remained. The paths to their breeding grounds were blocked by dams, the gravel beds on which they deposited their eggs were covered with silt, and the concentration of dissolved oxygen, a parameter to which sturgeon are particularly sensitive, decreased due to fertilizer run-off and insufficient treatment of sewage.(1) Fishing for Atlantic Sturgeon was outlawed along the East Coast in 1992 in order to try to let the population recover, and the ban is scheduled to remain in place until 2038. A number of studies suggest that these measures are helping this “living fossil” to recover. I sure hope so, and I hope that there is still some room in the Adventure Aquarium for one of my old friends.
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1) Depletion of oxygen in waterways is a multi-step process. First, excess nitrates and phosphates are introduced into the water from fertilizer run-off from lawns and farms, as well as from the effluent of inadequate sewage treatment facilities. The phosphates and nitrates cause a dramatic increase in the amount of algae in the water. This is typically referred to as an algae bloom. Algae don’t live very long, so not long after the algae bloom there is an accumulation of dead algae on the bottom the waterbed. Dead algae are great food for bacteria. So when there are a lot of dead algae the bacteria population explodes. Bacteria need oxygen to exist and to eat. Therefore, as they chew their way through the algae smorgasbord, the concentration of oxygen in the water drops, to the detriment of all other species.http://chapelboro.com/columns/common-science/sturgeon-the-living-fossil
Here is a North Carolina history question: Which North Carolina counties were named in honor of women?