Featured Image Credit: Whit Welles via Wikimedia Commons
By Jessie Kittel
The 8,000 or so North Pacific Humpback whales that spend their winters hanging out in the Hawaiian Islands have broken a new record. Unfortunately, this is probably a record they could have done without. Up to this point in their breeding season, six humpback whale carcasses have washed up near the shores of various Hawaiian Islands. This is the most deaths ever recorded in one season on the islands, and it’s not even halfway finished.
The North Pacific Humpback Whale breeding season runs roughly from November to May. Before this year, the highest number of recorded whale deaths was five, during the 2013 season. In the recent past, the average number of whale deaths has usually stayed somewhere around three. However, three months into the 2016-2017 season and we’ve already doubled the average.
Many of the main islands have been witness to these whale carcasses. One was found on Kauai, two on Oahu, two on Maui, and one off Moloka’i. Not only are these dead whales rather gruesome to behold, they also attract sharks to the areas. Shark activity usually spurs public beach closures until the whale has been completely consumed, is broken down by wave action, or is towed away.
One whale that was located off of the windward side of Oahu was towed away at the National Oceanic and Atmospheric Administration’s discretion. NOAA stated, on khon2.com, that had they not taken action to remove the carcass, it would have likely washed up on a popular public beach that would have then been closed for the majority of the weekend.
While scientists aren’t certain what the cause of the increased mortality is in the area, they do, of course, have a few theories. Most of these theories are nutritionally founded.
Humpback whales travel just over 3,000 miles from their Alaskan feeding grounds to their Hawaiian breeding grounds. While in the Hawaiian Islands, they’re there for two reasons and two reasons alone: to mate and to give birth. While near the islands they are not known to feed much, if at all.
That means they get all of their nutrition while they’re in Alaska. They pack on the pounds while in the nutrient rich and productive Alaskan waters and then rely on those fat stores to support them on the journey to Hawaii, during the mating season, and on the return journey.
David Schofield, regional marine mammal response program coordinator, was quoted on Hawaii News Now, stating “It could be there was an early migration of whales and maybe some of them were not nutritionally capable of making that trip.”
Also notable, the 2015-16 season, saw the fewest total number of whales that made the journey in five years, as reported on Hawaii News Now.
It’s difficult to say what is causing these deaths however, the rapidly rising population size of the North Pacific population is likely partially at the root of this trend. More whales create increased competition for already dwindling prey availability in Alaska. While it is likely only a portion of the problem, one way to help combat this gruesome tragedy we’re witnessing in the Hawaiian Islands would be supporting fisheries sustainability in their feeding grounds.
If you see a dead or stranded whale, please call and report the sighting to the Marine Mammal Hotline at 888-256-9840.