There are many studies showing the importance of seagrass meadows along North Carolina’s coast. Those meadows provide habitat for fish, filter water, stabilize shorelines and provide protection from storms.
Now a new study shows another benefit.
Fish that live in seagrass meadows along the coast seem to be able to recover much faster from tropical cyclones.
That’s right. Just like people, fish populations return to the places where they live and resume their lives much faster after devastating storms if they have a supportive place and community to return to.
The study focused on Back Sound, which is about one mile from Harkers Island. The lagoon separates Shackleford Banks to the south from the mainland and Harkers Island to the north.
Researchers used data collected over a 10-year span. The team found there was no significant difference in the fish communities before and after a storm. Not only that, the data also showed there was little difference in fish communities during years the area was hit by a hurricane and years when no hurricane struck.
“I think the resilience of the fish communities depends on the integrity of the seagrass habitat,” said Y. Stacy Zhang, Ph.D., a marine ecologist and assistant professor at NC State. “It’s very much like humans who evacuate for a storm. Do they have a home to come back to afterwards?”
“If the human community is relatively intact, the population won’t change very much,” adds Zhang. “It’s the same with the fish population. It appears if the seagrass meadows aren’t damaged, the fish population recovers quickly.”
The study used data from a long-term trawl survey conducted by Dr. Joel Fodrie at UNC’s Institute of Marine Sciences. Fodrie’s team performed two-minute trawls through seagrass meadows in Back Sound.
Researchers trawled monthly at random locations and then documented how many fish they found and what types.
Zhang believes the long-term dataset, along with the frequency at which the data was collected, was key to the new study.
“The fact that we could analyze 10 years of data that stretched over multiple storms and multiple locations is important because it provided a variability of different strengths of storms, different fish communities and years when storms never hit,” said Zhang. “That’s a much better analysis than looking at the effects of a single storm.”
The unanswered question, however, is what happens to fish communities as climate change warms coastal waters and fuels stronger hurricanes.
“Because estuaries are such dynamic systems, it makes us think that the fish, seagrass, oysters and other organisms are adapted to withstand and live in a system that is highly variable,” adds Zhang.
“Since 2010, North Carolina has experienced more than 10 tropical storms and hurricanes, and we found that fishes in local seagrass meadows have been resistant to those major disturbances. We don’t know for sure, but that gives us hope that the seagrass communities may be able to withstand storms even with a changing climate.”
