Date of introduction and origin
Thalassiosira tealata was first detected in English waters at
Blakeney, Gloucestershire, in 1950 (Wallentinus in press). Its
origin is unknown. As it was not found in Atlantic plankton samples
prior to 1950 it is presumed to be an introduction. It has also
been found in Japanese waters (Takano 1980).
Method of introduction
The method of introduction is unknown, but ballast transport
cannot be ruled out and imported oysters have also been
hypothesised as a potential vector (Rincé & Paulmier 1986;
Wallentinus in press).
Reasons for success
Rate of spread and methods involved
It was found in English waters in 1950 and off Norway in 1968
(G.R. Hasle pers. comm. in Wallentinus in press). The method of
spread is unknown.
It is distributed from the English Channel to Norway
(Wallentinus in press).
Factors likely to influence spread and distribution
Effects on the environment
Effects on commercial interests
Control methods used and effectiveness
The sample containing Thalassiosira tealata was collected near
Blakeney, Gloucestershire from the river Severn in 1950, but not
examined at that time. Its presence in European waters was known
for some years (G.R. Hasle pers. comm.) but the species was not
described until 1980 by Takano.
Rincé, Y., & Paulmier, G. 1986. Donnée novelles sur la
distribution de la diatomée marine Coscinodiscus wailesii Gran
& Angst (Bacillariophyceae). Phycologia, 25: 73-79.
Takano, H. 1980. New and rare diatoms from Japanese marine
waters - V. Thalassiosira tealata sp. nov. Bulletin of the Tokai
Regional Fisheries Research Laboratory, 103, 55-63.
Wallentinus, I. In press. Status of introductions of
non-indigenous marine species to north Atlantic waters:
introductions and transfers of plants. ICES co-operative research
Prof. G.R. Hasle, University of Oslo.