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Beach Walks with Dr. Joe It’s Baby Pink Barnacle Time By Dr. Joe Richardson About 10 years ago I first noticed strange, large, pink barnacles growing on the North Beach jetty rocks. Although I had studied, conducted research and led field trips along the jetty for many years prior to this, I had never seen these strange big barnacles before. About the same time I started seeing them here, a marine scientist in Louisiana also reported seeing strange, large, pink barnacles for the first time. Soon reports from Florida and South Carolina also appeared. We all knew these were barnacles that we had not seen previously around here. Eventually it was determined that these giant pink barnacles were native to the tropical Pacific Ocean. The assumption is that this species was transported through the Panama Canal and introduced into the Atlantic Ocean, perhaps attached on a ship. Although this giant pink barnacle is an invasive species, I don’t think it is 26 TYBEE BEACHCOMBER | JULY 2017 going to cause ecological problems around here. Shortly after finding it, I got interested in its growth and distribution, and received a grant to conduct field and lab research on its ecology. Using the North Beach jetty as my primary field study site, I was able to determine some interesting facets of its biology around here. Although our native barnacles (Ivory Barnacle and Striped Barnacle) grow mostly on the upper parts of the jetty, these giant pink barnacles grow predominately lower on the rocks among the Oysters. So they compete with our native Oysters for space to live. We know our Oysters are important in our marsh tidal creeks where they filter the water and form small reefs where other animals can attach and hide. So if these invasive competitors were to spread in the marsh ecosystem, they could present a problem. Although I looked, and others did also, I’ve never seen any of the giant pink barnacles anywhere other than along the open ocean beach (on jetties, pier pilings, old groins). In my lab experiments with lower salinity water, as found in the marsh creeks, the pink barnacles survived fine, so they are capable of living in the marsh areas, but for some reason, they don’t, at least around here. I also found that baby pink barnacles show up on the jetty during June and July, so during my Tybee Beach Ecology Trips the next few weeks, I’ll be examining those rocks closely. During the summer, they grow fast! Within a few weeks, they are bigger than our native barnacles. With field and lab studies, I found they could survive our average winter-time water temperature, but they didn’t grow much. But over the years I’ve found that a really cold snap during winter can wipe them out. So for a number of reasons, I don’t think they will become an ecological problem for us. So when beachcombing, if you come across a chunk of giant pink barnacles that have gotten knocked off a beachfront hard structure, realize that you just found an animal that actually belongs in the tropical Pacific Ocean. “You never know what you might find on Tybee’s beach!” Dr. Joe Richardson is a retired marine science professor with 35+ years of research and teaching experience along GA and the southeastern coast and Bahamas. Besides research, he conducts Tybee Beach Ecology Trips year round (www.TybeeBeachEcology.com) and frequently posts pictures of what they are finding on his Tybee Beach Ecology Trips Facebook page.


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