Biological observations associated with the toxic phytoplankton bloom off the east coast

Dead sand eels (Ammodytes sp.) was caught by trawl or washed up on the beaches south of Farne Island, on May 24, 1968, about a fortnight after the first report of dying seabird. The two phenomena were most likely connected through the food chain, as many sea birds vomited sand eels and that same toxic material was present. Patients with symptoms of paralytic shellfish poisoning indicated that a bloom of a toxic dinoflagellate may have been involved. Though a large numbers of moribund mussels was observed on a shore survey May 28 and June 6 the concentration of Gonyaulax tamarensis and Prorocentrum micans, two species that have been associated with paralytic shellfish poisoning and 'red tide', were insignificant. However, a marked peak in the numbers of Gonyaulax tamarensis about May 17-19 indicate that this species was the source of the paralytic shellfish poisoning..