PODCAST: Whales migrating to Hawaii face a number of threats — but not all are visible
HONOLULU (HawaiiNewsNow) - As February marks the peak of whale season in Hawaii, NOAA officials are reminding mariners and spectators to be extra vigilant as these majestic creatures enter Hawaiian waters.
Generally, scientists estimate that about 10,000 to 12,000 whales visit Hawaii each year to reach their breeding grounds.
And with more whales in our waters, the probability of boaters encountering these animals are much higher — meaning extra precautions must be taken.
Ed Lyman of NOAA’s Hawaiian Islands Humpback Whale National Marine Sanctuary joined HNN’s “Repairing Earth” podcast to discuss some of the risks that these mammals face, such as vessel contacts and entanglements.
Lyman said there have been five confirmed cases of vessel contacts so far this season with two resulting in response efforts.
He said these incidents can occur both ways: when a boat gets too close to whales or whales get too close to boats.
To prevent these close encounters, officials are asking mariners to move at 6 knots or less when within 400 yards of a whale. He added that by moving at a slower speed and having multiple eyes out on the water, boaters will be able to safely maneuver through these shared waters.
Besides vessel contacts, Lyman also coordinates NOAA’s large whale entanglement response.
So far this whale season, he said there have been two confirmed cases of entanglement with one warranting a response in which a trained crew removed entangled gear from a whale spotted off of Kona.
Entanglement can create life-threatening situations for whales, with fishing line and netting wrapping tightly around parts of their bodies.
“Some of the whales have dragged the gear from their feeding grounds,” Lyman said. “They have drag gear 2,000 plus nautical miles, straight line distance from places like the Bering Sea; some shrimp pot gear off of Wrangell, Alaska; trap gear, like a king crab from the Aleutians, have come down to the Hawaiian Islands.”
Lyman said about one third of entanglements are like these. Another third involves local gear and marine debris, and the rest can’t be traced back to its origin.
While these are some of the threats whales face, not all of them are visible.
“Climate change is probably the greatest threat that they face,” said Dr. Marc Lammers, a research ecologist at the sanctuary.
While it’s difficult to predict what exactly will happen to whales as a result of climate change, scientists predict that for many marine species there could be a gradual shift towards the poles.
“As waters warm at the lower latitudes and also at the higher latitudes, some of their prey may get pushed further to the north and our whales may have to work harder to find prey and maybe travel further north,” Lammers explains.
“Now, what that means in terms of their presence here in Hawaii is difficult to say. It could mean that there they may over time shift to a more sort of northerly latitudes, perhaps up the island chain, maybe even to the northwestern Hawaiian Islands. We just don’t know at this point.”
Through their research, Lammers and Lyman said that they have already seen how warming waters could potentially impact whale populations coming to Hawaii.
Around the 2014 to 2015 timeframe, Lammers said a strong marine heat wave took place in the Northeast Pacific affecting whale populations for several years.
“For about three years or so, we saw decreased whale numbers,” Lammers said.
Since that time, scientists said the numbers seem to have more or less recovered, but what has changed is an earlier peak to the whale season.
“We’ve been documenting that over the past several years, we’ve seen a trend towards generally an earlier end to the whale season,” Lammers said.
“So, where we used to have the peak of the season occur sort of late in February, even early-March, historically. Now, the peak seems to occur in early-February or mid-February.”
While Lammers said they don’t think this change is necessarily related to the marine heatwave that occurred several years ago, he said it could be related to long-term shifts in the ecosystem where the whales feed.
Similarly, Lyman said, “I don’t think we have all the answers there, but it’s very much related to food diets — that has a more direct impact to them.”
Click here to listen to more of the Repairing Earth podcast
Despite this, scientists are still hopeful.
“Humpback whales are actually quite adaptable,” Lammers said.
“That’s why they’ve been very successful to recovering from many years and decades of whaling — and so they’re resilient in that sense. But of course, that means they’re probably going to have to do some things differently.”
Lammers explains that while humpback whales tend to have “high site fidelity and tend to go back to where they’ve been to before and where they were born, they aren’t necessarily like salmon who have to go back there.”
Plus, there’s steps humans can take to lessen their impact on whales.
“We want to make sure that we’re as respectful as possible around them,” Lammers said.
“There are certain things that we don’t have much control over. For example, we can’t make the water cooler, you know, from climate change. But we can slow down and do other things, so that we don’t exacerbate some of the issues that they face.”
To report an entangled or injured whale or other marine animals in distress, call (888) 256-9840 or click here for more information.
For more on the conversation, listen to Episode 14 of Repairing Earth, “Hawaii’s Whale Season Is in Full Swing,” on the HNN website or anywhere you get your podcasts.
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