HONOLULU — Postmortem exams show at least two of three Hawaiian monk seals found on Kauai last year died after they were caught in fishing nets.
The National Oceanic and Atmospheric Administration determined the seals likely drowned after becoming entangled in gillnets, KITV-TV reported Wednesday.
The agency used lab tests and information from law enforcement to analyze the deaths of the animals discovered in September, November and December.
One of the three seals was severely decomposed, causing difficulty in determining an exact cause of death.
The state Department of Land and Natural Resources said the majority of fishers in Hawaii practice safe fishing, but some gillnet fishers and others “fish recklessly, with devastating impact on native and endangered species.”
The NOAA Fisheries website describes a gillnet as “a wall of netting that hangs in the water column, typically made of monofilament or multifilament nylon.”
“Marine mammals entangled in set gillnets can drown while those entangled in drift gillnets can drag gear for miles as they migrate and forage, leading to extreme fatigue,” the agency’s site said.
The Hawaii Division Aquatic Resources website includes legal requirements for gillnet use. Unlawful use includes leaving nets unattended without visual inspection every two hours, leaving nets in the water for more than four hours in a 24-hour period and failing to release or remove undersized, illegal or unwanted catch.
Hawaii Division of Conservation and Resources Enforcement officers have increased patrols to look for contact between monk seals and gillnets.
“We are in discussions regarding how best to ensure seals and turtles are protected given ongoing drownings in lay nets,” land and natural resources department Chair Suzanne Case said.