Necropsy findings into what caused the death of a monk seal pup found over the weekend in Waimanalo were inconclusive, the National Oceanic and Atmospheric Administration's National Marine Fisheries Service announced today.

RW18, nicknamed "Hoku," was born in May on the north shore of O'ahu.

The carcass was relatively decomposed, so drowning or another cause of death could neither be ruled out nor confirmed, officials said. Some samples were taken for analysis for pathogens or toxins. The seal appeared to have been in "good body condition" when it died, NOAA said.

"Over forty volunteers watched over the pup from sun up to sun down for six weeks while it was being reared on the beach by its mother," said David Schofield, marine mammal response coordinator. "Understandably, a lot of dedicated volunteers are very saddened by the loss. With so few monk seals remaining in the Hawaiian Islands, we can't afford to lose even one."

A volunteer located the seal's carcass after hearing about it from area fishermen and reported it to the state Department of Land and Natural Resource's Division of Conservation and Resources Enforcement. State and federal enforcement officials are investigating.

"While the evidence doesn't conclude the seal was drowned, we want to remind people of the existing state laws regarding use of gill nets, which are intended to protect marine mammals," said Laura H. Thielen, DLNR chairperson.

Thielen added, "O'ahu DOCARE has pulled over a mile and a half of illegal gill nets out of O'ahu waters in the last year. We ask that people register their nets, make sure they check them within the required time limits, and respect the "no-lay" net zones."

"Hoku" and its mother were carefully monitored by volunteers for the seal's six-week nursing period. NOAA relocated the seal to Manana (Rabbit) Island after it weaned to give it a chance to be near adult seals known to frequent the area and to mature away from human disturbance. It continued to be monitored daily by a volunteer who watches seals on the island with his spotting scope from Makai Pier.

Unauthorized public visitation to Manana Island is prohibited under state law. This offshore island is managed by DLNR as a wildlife sanctuary. It is inhabited by colonies of seabirds and monk seals, including young seals that have been weaned.

DLNR officers recently caught and cited for trespassing two men who landed on Manana Island by surfboards, and disturbed monk seals on the island, according to Thielen.

Anyone with information on Hoku's death seal or any other information about a suspected marine mammal protection violation can call NOAA's Office of Law Enforcement at 1-800-853-1964 and/or DOCARE at 587-0077. The public is also asked to report any seal or other marine mammal that appear in need of assistance to NOAA's marine mammal hotline at 1-888-256-9840.