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Monitoring and management of the invasive alga Undaria pinnatifida: Images

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Native Algae

Dictyoneuropsis/Dictyoneurum. When young, some native brown algae can look like juvenile Undaria. Note the small stipe and "rumpled" surface, both of which Undaria lacks.

Possibly Grateloupia doryphora. This is actually a red alga. Photo ID by Dr. Kathy Ann Miller.

Possibly Grateloupia doryphora. Close-up. Photo ID by Dr. Kathy Ann Miller.

Dictyoneuropsis/Dictyoneurum. Unlike Undaria, this adult has no prominent mid-rib, and no laterals.

Desmarestia sp. (top) and Undaria (bottom).


Watersipora sp. overgrowing Tubularia marina. Watersipora (dark red) is an introduced bryozoan commonly found in harbors.

Watersipora sp. overgrowing a red alga.

Multiple Melibe leonina on Undaria. Many (not pictured) were laying egg cases.

Pugettia producta. This large kelp crab is an important grazer of Undaria.

Pugettia producta. Coloration is often diet-induced, as shown by this crab on Undaria.

Pododesmus cepio. The abalone jingle, a bivalve, serves as the substrate for an Undaria holdfast. The orange organism is Botryllus schlosseri, a colonial tunicate (sea squirt).

Metridium sp. Anemones are common on some of the floating docks.

Stongylocentrotus purpuratus. This juvenile purple urchin was feeding on Undaria haptera (the root-like structures that anchor the alga to the substrate). The large, white structures on the urchin are some of the five "teeth" that are part of a complex jaw structure known as "Aristotlešs lantern".

Stongylocentrotus purpuratus. Small (1 cm) juvenile purple urchins were commonly found on Undaria at A tier in mid-March 2004.

Melibe leonina. This nudibranch captures prey with its large, frilled oral hood.

Likely Metridium senile, which has a gray-and-white form noted from Monterey harbor.

Likely another color morph of Metridium senile.

Likely Mopalia muscosa. This chiton (a mollusk) has been partially overgrown by Undaria, but the chiton was still mobile. Unable to attach to the dock itself (because the chiton moves), some Undaria haptera were knobbed and suspended above the margin of the chiton.

Melibe leonina. You can see the frilled oral hood on this particularly large individual that had been on Undaria


John Kyzivat holds up an Undaria found growing on debris next to the crane dock.

Diver at the surface looking for Undaria. Pete Harvey is one of several volunteer divers that remove Undaria from pier pilings, floating docks, and boat hulls.

Divers from the California Department of Fish and Game have also removed Undaria.

Volunteer diver surfacing with Undaria collected off of a pier piling.

These five women were visiting from Japan and staying in the Monterey-Salinas area for three weeks to study English and learn about volunteering in the United States. They stayed with host families and learned English from Alex Hulanicki under a non-profit program arranged by PeopleLink of Petaluma. In addition to removing Undaria, they also volunteered at the Boys and Girls Club in Seaside, cooked for the homeless at Dorothy's Kitchen in Salinas, and taught Japanese at Palma High School in Salinas.

Wakako and Mari display a very large adult Undaria and a data sheet.

Speaking in Japanese, Mr. Alex Hulanicki explained to our Japanese volunteers what to measure and record once the Undaria had been brought to the surface.

Chris Kleinke uses a scraping tool to remove small Undaria from the floating dock.


G and D tier at low tide.

Sunset in the Harbor.

Harbor Masteršs office.

H tier and the sea wall.
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