The counts made during the visits in February and September 1991 confirm the importance of the island as a wintering area and stop over site for the waders during their northward and southward migration.

Grey-tailed tattlers (Heteroscelus brevipes), grey plovers (Pluvialis squatarola), whimbrels (Numenius phaeopus), and common redshanks (Tringa totanus) constitute the largest numbers recorded.

The preliminary entomological survey of Bansaan Island revealed a total of 16 species representing 6 orders and 16 families of insects.

Leafminers, leaf beetles, loopers and leaftiers are pests on mangrove trees: Pongamia pinnata, Osbornia octodonta, Terminalia catappa, Excoecaria agallocha, Sonneratia caseolaris, and Lumnitzera littorea.

Based on the paleontological analyses of three selected samples, it showed a list of known microfossils identified as common in nearshore or shallow environment, typical in coral reef areas.