Emission fluxes for a range of C8–C15 volatile organic compounds (VOCs) were determined from the seaweed Fucus spiralis (spiral wrack) and an adjacent sand surface during low tide on the coastline of Mace Head, Ireland. These two surface types, assessed using dynamic flux chamber systems, are typical of the Mace Head inter-tidal zone. A range of n-alkanes and oxygenates were routinely identified in the measurement of chamber air. Examination of the odd/even n-alkane ratios and use of the carbon preference index (CPI) suggested a biogenic source for these compounds (CPIs >2 in for all samples). Fluxes of n-pentadecane, the most predominant n-alkane, ranged from 0.2 to 5.1μgm−2h−1 (0.9–24nmolm−2h−1), while oxygenates such as nonanal and decanal had fluxes ranging from