Figure 1

Map of the sampling sites. (A) Locations of Niue Island and Rarotonga, Cook Islands in the South Pacific Ocean. (B) Sampling sites at Niue Island (1. Avatele Beach, 2. Tamakautoge Beach). (C) Sampling sites Rarotonga, Cook Islands (3. Black Rock, 4. Sheraton Passage, 5. Papua Passage, 6. Queen’s Residence, 7. Titikaveka and 8. Muri Lagoon).