Field Notes
U.S. Fish & Wildlife Service
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Non-native magnificent bryozoans (Pectinatella magnifica): increased occurrence in the Pacific NW?
Pacific Region, March 28, 2012
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Kayakers explore a P. magnifica bloom in Beaver Creek near Newport, Oregon.
Kayakers explore a P. magnifica bloom in Beaver Creek near Newport, Oregon. - Photo Credit: Barry McPherson
Football-sized P. magnifica pictured in the Columbia Slough in Portland, Oregon, where they continue to occur in late summers.
Football-sized P. magnifica pictured in the Columbia Slough in Portland, Oregon, where they continue to occur in late summers. - Photo Credit: Jeff Adams

Have you encountered huge gelatinous blobs floating in the water lately? That blob may in fact be a bryozoan. The population of non-native Magnificent bryozoans appears to be on the rise in the Pacific NW. They can only survive in warm waters, 60?F, so increasing occurrences could signal climate change is warming waterways and allowing more of these bryozoans to survive outside their native range.


The Pacific Region Aquatic Invasive Species Program at U.S. Fish and Wildlife Service has received increasing concerns in recent years. Worried citizens and scientists alike are reporting sightings of large summertime blooms of Pectinatella magnifica, also known as the Magnificent bryozoan. There are more than two dozen species of freshwater bryozoan, but this one is truly magnificent. Each gelatinous blob can reach seven feet in diameter and will turn a dark vibrant purple, with shiny white spots. These large gelatinous invertebrates have been called everything from “moss animals” to “dragon boogers,” and are commonly mistaken for amphibian egg masses when seen floating in the water. Each mass is built from hundreds of individual filter feeding zooids, which extend tentacles from the edge of the blob to pull food out of the water.

In late summer and early fall, as water temperatures reach their warmest, these blobs continue to grow, and can become so numerous, they form bryozoan blooms. One such bloom was located at Vancouver Lake, in Vancouver, Washington last summer. A research assistant with Washington State University’s aquatic ecology lab reported, “Users of the lake claim they’ve never seen these organisms prior to this year. They were seeing hundreds this summer. The specimen I saw was greater then 1 foot in diameter” – Joanne Breckenridge,
Research Associate, Aquatic Ecology Lab at WSU (Vancouver)
August 2011

A retired ODFW biologist outside of Newport, Oregon spotted another bloom last summer. “We saw a lot of this stuff underwater along the margins of Beaver Creek. I hear that these have shown up in September in past years.” – Barry McPherson, retired ODFW employee, Newport OR September 2011

Similar sightings by recreationalists, field biologists and the general public indicate that this bryozoan, which is actually native to waters east of the Mississippi River, is potentially becoming more abundant outside of its native range. And this has scientists worried and wondering why. They are worried because increases in filter feeding activity makes water clearer, permitting solar light to reach greater depths. This can allow more aquatic plants to grow and shift the natural balance of that habitat. When blooms are located in waterbodies with water outtake pipes they can clog those pipes, requiring 24-hour monitoring. Scientists think that if water temperatures rise due to climate change, Magnificent bryozoans may find more suitable habitat here. And once they are here in large numbers they can disperse rapidly. Small seedpods called statoblasts are all that remains after adult colonies decompose at the end of fall. Each seed has jagged hooks that easily attach to an unsuspecting mallard’s foot, bill, or feathers, who then flies the seedpod off to neighboring waters.

Natural resource managers are eager to learn more about the potential spread of these non-native bryozoans. Mapping their occurrence in the USGS Nonindigenous Aquatic Species database is a great way to decipher their movements. If you spot one of these creatures be sure to report it! http://nas.er.usgs.gov/

Contact Info: Theresa Thom, 503-736-4722, theresa_thom@fws.gov
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