Turtles of Puhi Bay.

Last weekend Maryruth and I dove the shallow reef at Puhi Bay, to the northwest of our usual Hilo Bay diving spot. Puhi Bay has the distinction of being next to the Hilo sewage treatment outflow. Fortunately for the reef, the freshwater outflow from the mauka rains constantly flushes any pollution. There is so much freshwater entering Puhi Bay this time of year that the halocline extends from 5 feet to 10 feet depth at entry-- millions of gallons! The coral reef looks healthy and very diverse from about 12 to 28 feet depth, with large varieties of fish, many varieties of coral, and even the rare black brittle stars. There was red-brown silt beyond about 30 feet, then sand.

One of the nine sea turtles we saw on the 50 minute dive had fibropapillomatosis, a benign tumor skin condition caused by herpesvirus in turtles. Though there's always some virus in the water around where green sea turtles live, some marine biologists feel that sewer runoff promotes these warty growths by activating the latent virus in the turtle's skin. Who knows? I will say that fibropapillomatosis around this island is rare even in Puhi Bay thus far this decade, though it's my non-expert opinion that it is seen more near the local sewage treatment plant than elsewhere.