Figure 1.

Bull kelp wrack at St Clair Beach, New Zealand. (a) Photograph of a detached, beach-cast bull kelp specimen at St Clair Beach in March 2009 (not one of the rafts that formed the focus of this study). Bull kelp specimens are frequently deposited on St Clair Beach in southeastern New Zealand, but generally show no signs of lengthy oceanic drifting. For example, this specimen is estimated to have spent only a short period adrift, owing to complete absence of goose barnacles (Lepas sp.) that rapidly colonize buoyant objects at sea. (b) One of the six bull kelp wrack specimens of subantarctic origin. Encrustations of Lepas sp. of various sizes are visible on the holdfast and stipes of the bull kelp. (Photograph taken at St Clair Beach on 26 February 2009.) Scale bars, (a) 500 mm and (b) 50 mm.