[1] Marine Inst, Oranmore, County Galway, Ireland
[2] Univ Aberdeen, Inst Biol & Environm Sci, Tillydrone Ave, Aberdeen AB24 2TZ, Scotland
[3] Sea State Inc, POB 74, Vashon, WA 98070 USA
[4] Univ Cient Sur, Carrera Biol Marina, Panamer Sur Km 19, Lima, Peru
[5] ProDelphinus, Jose Galvez 780E, Lima 15074, Peru
[6] Univ Exeter, Ctr Ecol & Conservat, Penryn TR10 9FE, Cornwall, England