A recently posted You-Tube video titled "Humpback whale gives our canoe a love tap!" shows a juvenile humpback whale off Maui surfacing unexpectedly near an outrigger canoe, then breaching nearby.
The film documents what scientists call a "surprise encounter," in which the people on the vessel apparently had no idea the whale was nearby until it surfaced alongside their boat.
As Hawai'i's whale population continues to increase, surprise encounters with whales are becoming more commonplace for all vessels operating in Maui County waters, including canoes, kayaks, fishing boats, shipping barges, snorkel and dinner cruise boats and whale watch vessels.
Pacific Whale Foundation’s “Be Whale Aware” program links research data gathered about Maui’s whales with practical advice to help vessels navigate safely around whales.
Photo: Pacific Whale Foundation
"It is simply a case of an increasing whale population," said Dr. Emmanuelle Martinez, senior research scientist at Pacific Whale Foundation. "The North Pacific humpback whale population has increased in size following the cessation of commercial whaling, with recent population estimates at approximately 23,000 individuals."
"Hawai'i is one of the primary breeding grounds for North Pacific humpbacks, with close to 60 percent of the population migrating here each winter to mate and give birth," Martinez noted. "The region between the islands of Maui, Molokai, Lana'i and Kaho'olawe hosts the highest densities of humpback whales in Hawai'i during the breeding season."
Pacific Whale Foundation's "Be Whale Aware" program links research data gathered about Maui's whales with practical advice to help vessels navigate safely around whales. The "Be Whale Aware" recommendations include traveling at a slow speed (15 knots or less), keeping a lookout at the helm at all times, and installing propeller guards or Whale Protection Devices on all vessels. All Pacific Whale Foundation vessels follow the "Be Whale Aware" guidelines, in addition to strictly obeying state and federal laws about vessel operation in the proximity of whales.
In 2006, Pacific Whale Foundation conducted a pioneering study looking at encounter rates between whales and vessels. The data showed that while the population of whales had increased three-fold in Ma'alaea Bay since 1990, the boat traffic actually had decreased 10 percent. More importantly, the study found that a vessel traveling at just five knots would encounter a whale within 300 yards for every nine miles traveled.
Then in 2011, Pacific Whale Foundation launched a new study to document the likelihood of surprise encounters with whales by vessels traveling off the coast of Maui.
From January through April, researchers stationed one observer on a total of 204 whale-watch cruises on five different vessels departing from Ma'alaea and Lahaina Harbors. As the vessels traveled, the observer conducted periodic scans to document the number of humpback whale groups detected for the first time at a distance less than 300 meters from the vessel, dubbed a "surprise encounter."
During these surveys, the observer recorded 2,464 whale sightings. Of all the sightings, 133 (3 percent) were classified as surprise encounters.
Using the data and scientific modeling programs, Pacific Whale Foundation's research team estimated there would be an 8.2 percent increase in the odds of a surprise encounter for each one knot increase in vessel speed. The Foundation's whale-watch vessels in the study traveled at an average speed of five knots. The researchers' model indicated that traveling at 15 knots instead of five knots would increase the odds of a surprise encounter two-and-two-tenths times.
"It's clear that reducing your speed will reduce the likelihood of a surprise encounter with a whale," said Dr. Martinez. "There are no speed limits for vessels in Hawai'i, but Pacific Whale Foundation recommends that vessels operate at 15 knots or less from December to May."
Pacific Whale Foundation will be continuing its research study this year on its dedicated 27-foot research vessel Ocean Protector. Line transects have been laid out within the four-island region. The team will be traveling along those transects at a varying speed, gathering data on pods encountered, with a particular interest on recording individuals that surface unexpectedly within a specific distance from the boat. They will also be plotting the distribution of all whales that are observed during the surveys.
"We want to determine the 'hot spots,' where it is especially important to keep a watchful eye for whales and to reduce vessel speed accordingly," said Dr. Martinez.
As part of the study, Pacific Whale Foundation researchers are photo-identifying individual whales and collecting data on pod composition, gender (when apparent) and age classes of individuals encountered.
"We want to understand whether some age-class, group types are more likely to surface unexpectedly around boats," said Dr. Martinez.
Once the study has been completed, Pacific Whale Foundation will share its findings with boaters through the "Be Whale Aware" program and will also provide the data to wildlife management officials at the National Marine Fisheries Service and the Hawaiian Islands Humpback Whale National Marine Sanctuary.
Pacific Whale Foundation's research programs and the operation of Ocean Protector are made possible through the revenues generated by the Foundation's whale watches and ocean eco-tours.
"We offer the only Maui whale watches and cruises that are owned by a bonafide nonprofit organization," noted Pacific Whale Foundation Executive Director Greg Kaufman. "We are thankful to our guests for choosing us and helping to fund this work."