“…Carpenter et al 1972, Bekheet & Syrett 1979, Price & Harrison 1988. For macroalgae, the current knowledge of urea utilisation is restricted to the ability of urea to sustain the growth of a number of seaweeds (Nasr et al 1968, Mohsen et al 1974, Adamich et al 1975, Hanisak 1979a, Probyn & Chapman 1983, Mairh et al 1999, Navarro-Angulo & Robledo 1999, Lotze & Schramm 2000 and the demonstrated uptake of urea by Chordaria flagelliformis (Probyn & Chapman 1982, 1983 but not by Ecklonia maxima (Probyn & McQuaid 1985). From the present study, it appears that urea is a seasonally important N source for 4 intertidal seaweeds in New Zealand, with the greatest contribution to overall N nutrition occurring in summer when ambient seawater N concentrations are minimal.…”