When this article was originally published the author's first address was missed from the affiliation section. The correct affiliations are printed below:

E. Massutí: IEO – Centre Oceanogràfic de les Balears, PO Box 291, 07080 Palma de Mallorca, Spain; and UIB – Departament de Biologia, Campus Universitari, 07071 Palma de Mallorca, Spain. J. Moranta: CSIC-UIB, Institut Mediterrani d'Estudis Avançats, Miquel Marquès 21, 07190 Esporles, Spain. Correspondence to Enric Massutí: tel: +34 971401561; fax: +34 971404945; e-mail: [email protected]

We regret this error.