Haptophytes of the Nervion River estuary, northern Spain

The meso-macrotidal Nervion River estuary in northern Spain was sampled monthly from March to September 2002 and 2003 to study species composition and abundance of haptophytes in the phytoplankton. From natural samples and uni-algal cultures, 17 haptophyte species were identified using light and electron microscopy. The species were found across a wide range of temperatures and salinities. The most frequently occurring haptophytes in the estuary were species of the genus Chrysochromulina; however, Isochrysis galbana reached highest abundances. Chrysochromulina lanceolata and Phaeocystis globosa were occasionally present at high abundances. Another bloom-forming species, Prymnesium parvum, was recorded only once. Of the genera identified, eight species belonged to Chrysochromulina, two to Prymnesium and the rest of the genera were represented by one species only. The majority of the species were recorded for the first time in the Cantabrian Sea and one of them for the first time in the Atlantic Ocean.