as we were afraid of bringing along a highly 

 destructive fungus causing so-called "oyster 

 shell-disease." Because of Korringa's assurance, 

 however, we were quite certain we would elimi- 

 nate this and any similar dangers. 



The small shipment of European oysters was 

 later divided into two parts, one taken to the 

 U.S. Bureau of Commercial Fisheries Laboratory 

 at Boothbay Harbor, Maine, where some of the 

 oysters were suspended off the dock, the other 

 part kept in Milford Harbor, remaining there 

 under the observation of my associates and me 

 for several years. Not in a single instance did I, 

 other members of Milford Laboratory, or John B. 

 Glude, Director of the U.S. Bureau of Com- 

 mercial Fisheries Laboratory at Boothbay Harbor, 

 or his colleagues, notice or report to me the 

 presence ofCodium on the oyster shells. There- 

 fore, considering the chemical treatment that was 

 given the oysters before they were placed in 

 open American waters and because of the results 

 of our long-term observations of these oysters 

 at both Milford and Boothbay Harbor, it is im- 

 probable that Cocfium was brought into the waters 

 of New England "on the backs of the European 

 oysters." 



There are several much more plausible ex- 

 planations as to the way Codium was intro- 

 duced to our Atlantic coast. In my opinion, it was 

 brought into our waters during World War IL 

 At that time, to avoid being torpedoed by German 

 submarines along the open Long Island coast, 

 many freighters coming from Europe to the 

 port of New York traveled through the well- 

 protected inside passage — Long Island Sound. 

 At times, these vessels were so numerous that 

 many of them had to be anchored in Long Island 

 Sound for several weeks before they could be 

 unloaded at New York piers. I was then engaged 

 in the study of plankton of Long Island Sound — 

 in relation to propagation of oysters — running, 

 sometimes, 14-h sampling series from a small 

 boat. Several of our collecting stations were then 

 located on the Bridgeport and New Haven oyster 

 beds where seed oysters were dredged each fall 

 and planted on cultivated beds of Long Island, 

 Rhode Island, Massachusetts, and even Maine 

 (Loosanoflf 1966). 



To avoid the wind and heavy wave action we 

 would usually position our boat on the lee side 

 of anchored freighters. Often we were so close 

 to those vessels that we could converse with 



members of their crews. Many of these ships 

 were of European registry and, because of the 

 war, most of them were not able to undergo 

 proper bottom cleaning for several years. As a 

 result of this neglect, the ship bottoms were 

 covered with heavy layers of marine fouling 

 organisms. Sometimes such layers, as had been 

 reported by Woods Hole investigators, were as 

 much as 2, or even 3, feet thick (Woods Hole 

 Oceanographic Institution 1952). The fouling 

 mass was composed of many forms, including 

 mussels, tunicates, and, no doubt, a variety of 

 other organisms. The Codium was also present 

 and sometimes clearly visible. While the 

 freighters were riding at anchor, frequently large 

 chunks of the fouling mass broke off and fell to 

 the bottom of the Sound. We witnessed this 

 phenomenon on numerous occasions. 



Thus, it appears logical that C. fragile gained 

 entrance into the waters of eastern United States 

 from the bottoms of European freighters during 

 World War II. This possibility, however, seems 

 to be ignored; the blame is placed instead, 

 directly or indirectly, on a small, properly 

 handled shipment of European oysters which 

 was brought from Holland to Milford in 1949 

 (Quinn 1971). 



It may be mentioned, in conclusion, that, as 

 originally planned, the European oysters planted 

 in Boothbay Harbor not only survived in the new 

 environment but reproduced under a new set of 

 ecological conditions and became firmly estab- 

 lished within a large area (Welch 1966). There- 

 fore, these excellent "immigrants" may soon 

 become the second commercial shellfish crop of 

 Maine. Secondly, Codium, although a nuisance 

 and a highly undesirable invader in some respects, 

 and for introduction of which we claim no 

 "credit," may be a welcome addition to localized 

 biosystems by providing extensive, rich-in-food, 

 protective nursery areas to the advanced larval 

 stage and juveniles of many fishes and of such 

 important species of commercial invertebrates as 

 the American lobster, //omarj/s americanus, and 

 the blue crab, Callinectes sapidus. 



I wish to thank John B. Glude for reading 

 this manuscript and offering constructive 

 suggestions. 



Literature Cited 



LOOSANOFF, V. L. 



1951. European oyster, O. edulis, in the waters of the 

 United States. (Abstr.) Anat. Rec. 111:542. 



217 



