This study was financed by the Estonian Science Foundation (Grants 4468 and 5809) and by Tartu University (TBGBO0553). The research permits used are as follows: DOFAW Kauai (February 24, 1999); Kauai Division of State Parks, K19082 (February 11, 2002) and K26156 (January 15, 2003); DOFAW Permit No. 69 (April 1, 2002); DOFAW Hawaii Permit No. 17867 (May 16, 2003); DOFAW Maui (May 30, 2003); TNCH Molokai (May 23, 2003); TNCH Oahu 2002, 2003.