CODIUM ENTERS MAINE WATERS 



By Gareth W. Coffin, Fishery Technician and Alden P. Stickney, Fishery Biologist (Research) 

 Bureau of Commercial Fisheries Biological Laboratory, Boothbay Harbor, Maine 04538 



An exotic species of marine algae, Codium fragile 

 (Sur.) subsp. tomentosoides (Hariot) (fig. 1) was 

 found growing in Bootlibay Harbor, Maine, near the 

 Bureau of Commercial Fisheries Biological Labora- 

 tory on July 17, 1964. Although the species has 

 been established in the Long Island (N.Y.) and Cape 

 Cod regions for se\'eral years, this is its first record 

 from the Atlantic coast north of Cape Cod. In 

 many oyster producing areas, Codium grows luxu- 

 riantly on the oyster shells and is considered to be a 

 serious pest by the oyster growers. 



The specimens from Boothbay Harbor were all 

 collected within 400 m. of the Biological Laboratory 

 in a sheltered cove, and all but one were attached to 

 various objects just below the low tide .mark; the 

 single exception was unattached and entangled in 

 some fronds of rock weed (Ascophyllum nodosum). 

 Among the substrata to which Codium was attached 

 were stones. Modiolus modiolus shells, seaweeds, and 

 waterlogged timbers. Because Galtsoff' had re- 

 ported Codium from depths down to 12 m., SCl'BA 

 divers surveyed the same general area for subtidal 

 specimens. Their survey, as well as littoral surveys 

 in other parts of the harbor, yielded rio additional 

 specimens, although more were subsequently found 

 near the site of the original discovery. 



Table 1 summarizes the data on all plants col- 

 lected from July 20, 1964 to August 5, 196.5. Game- 

 tangia were found on plants only during July and 

 August. Nine specimens bearing gametangia were 

 examined histologically to determine their sex: five 

 bore mostly male, three bore mostly female, and one 



Note. — .Approved for publication .\pril 20. 1966. 



'P. S. Galtso£f in a manuscript on file at the Bureau ol Commercial 

 Fisheries Biological Laboratory, Woods Hole. Mass., first called attention 

 to Codium on Cape Cod in January 1962. 



had about equal numbers of male and female 

 gametangia. 



Growth in the Boothbay Harbor area appears to 

 be rapid even during-the cold part of the j-ear. For 

 example, plants collected in May 1965 apparently 

 had grown as much as 34 cm. in length since the 

 previous November when they were so small as to 

 be barely visible. 



Table 1.— Codium fragile var. tomentosoides collected in the 

 Boothbay Harbor area, 1964-65 



In the past 60 years, Codium fragile appears to 

 have spread widely throughout the world. Silva 

 (19.55) presumed its original center of distribution 

 to be the Pacific and Subantarctic regions, perhaps 

 in Japan. It appeared in Holland about 1900 (Van 

 Goor, 192.3) and spread to Denmark, Norway, 

 Sweden, England, and France (Silva, 1955). The 

 introduction of Codium in Cape Cod was described 

 by Wood (1962), as well as Galtsoff. No certain 

 evidence is available to explain the source of its 

 introduction in Long Island, N.Y., or that of its 

 recent appearance in Maine. One possible explana- 

 tion of the Maine introduction might be that the 



FISHERY BULLETIX : Vol. 66, No. 1 



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