Acartia tonsa were found in the Tamar and Exe (http://jncc.defra.gov.uk/page-1706) when taking samples for experiments on eggs (See J.A. Lindley, P. Donkin, S.V. Evans, C.L. George, K.F. Uil.1999. Effects of 2 organochlorine compounds on hatching and viability of calanoid copepod eggs. J. exp. mar. Biol. Ecol. 242, 59-74). Sampling in the Exe from the pontoon at the Turf Locks Inn was April and October 1994 and May 1996 and in the Tamar at Cotehele Quay in June and July 1996.
