On the last Monday of October, a pilot flying along the Outer Banks sighted an area of discolored water — actually, it was red — near Bodie Island. The local resident said that the “red tide” extended from Oregon Inlet south toward Buxton.
Red tide on Oct. 27, 2014, near Buxton. Photo by Woody Harris.
Scientists from the National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Coastal Ocean Science (NCCOS) based in Charleston, S.C., contacted First Flight High School’s (FFHS) Phytofinders and asked them to take water samples and ship them to NCCOS.
For the uninitiated — meaning those who do not read the Scotch Bonnet on a regular basis — the FFHS Phytofinders is a group of students under the direction of science teacher Katie Neller. They have been involved in NOAA’s Phytoplankton Monitoring Network, or PMN, since 2005. The network uses citizen volunteers to monitor marine phytoplankton in coastal waters, with special attention to species that cause harmful algal blooms that can cause human health problems.
Each week during the past eight school years, different groups of dedicated FFHS students have sampled their selected sites after school, examined those samples the following day, and reported their data online. During the 2014–2015 academic year, the Phytofinders are sampling the coastal waters at the U.S. Army Corps of Engineers’ Field Research Facility in Duck and at Jennette’s Pier in Nags Head.
Barnacle, rescued loggerhead sea turtle. Photo courtesy NC Aquarium at Roanoke Island.
After being contacted by NOAA, Neller and the Phytofinders collected water samples at Coquina Beach and shipped those samples to Steve Morton who leads the PMN. While waiting for Morton’s results, the N.C. Aquarium on Roanoke Island decided to postpone its release of Barnacle, a recently rehabilitated sea turtle, until the waters around Bodie Island cleared up or the discolored water was determined to be nontoxic.
Late that week, Morton determined that the red-colored water was caused by a bloom of Mesodinium rubrum, a ciliated protozoan common in coastal waters worldwide. Its body is comprised of two uneven lobes with a belt of cilia around its middle to help it move. Mesodinium is as an active swimmer under a microscope and can appear to jump — either away from predators or toward prey.
A bloom of Mesodinium rubrum, seen here under a microscope, caused this red tide. Image by Steve Morton.
Although this ciliate is a consumer, it maintains symbiotic* algae inside its body that keep it well fed! Massive blooms of Mesodinium can color the surrounding waters brick red or rusty brown. Although red in color, blooms of this species are usually nontoxic to humans and marine life.
Thanks to Katie Neller and the FFHS Phytofinders who did a great job to help NCCOS and PMN solve a mystery on North Carolina’s Outer Banks.
And another note: Barnacle was moved to the N.C. Aquarium at Pine Knoll Shores and released from that location on Nov. 4. Watch him race to the water here.
*Symbiosis – a close relationship between two different species
