Beachgoers may have noticed some glassy, sauerkraut-like stuff recently washing up.
Tunnell said the institute has recently received reports from fishermen and surfers getting the sauerkraut animal, also known as spaghetti bryozoan, stuck in their gear as it has appeared in large quantities along Texas beaches. Sauerkraut bryozoan is actually a group of filter-feeding polyps, Tunnell said. While it strongly resembles red algae, Gracillaria, there’s one unique way to tell them apart. “If you squeeze it and it goes limp on you, you know that it’s the bryozoan,” Tunnell said in a beachcombing video as he demonstrated. “It just popped like a gel-filled cell in there. If this was Gracillaria or some type of algae, you could press it but it would still stay stiff.”
Like algae, sauerkraut bryozoan can also have different colors, ranging from off-white to light green, and translucent to transparent. The colonies can grow up to 39 inches in length, according to the Texas Parks and Wildlife Department’s Quiet Invasion field guide. They can be found in the Gulf of Mexico or the Galveston Bay where they are considered invasive. Their native range is currently unknown, though they are widely distributed in warm temperate and tropical waters of the western Atlantic Ocean and the Caribbean.
Bushes of sauerkraut bryozoan can get entangled in fishing nets and shrimp trawls and affect navigation through hull fouling and fouling of submerged structures and industrial pipes, according to the field guide. The species can also compete with native species through overcrowding. Predators of sauerkraut bryozoan are fish, snails, bird and insects, Tunnell said. It’s unclear exactly why the animal is washing up in large quantities at the moment, but scientists at the Harte Research Institute said it could be due to water temperatures, bay to ocean currents, or something else not being monitored.
While they might be a nuisance to beachgoers, they are also ephemeral, Tunnell said. “It seems bad right now but this is a natural process and eventually this will dry up and this stuff will become part of the ecosystem,” he said. “Just know it’s temporary. This is not changing anything for beachgoers coming to the beach. Give it a few weeks and this will be gone and we’ll have something else washing up.”