False killer whales move around the Hawaiian Islands in pods and venture far offshore for food.
This dolphin species learned they can take fish off of deep-sea fishing lines. But in their quest for a tasty meal of tuna, some get caught in the process.
An ongoing National Oceanic and Atmospheric Administration survey aims to track a group of false killer whales about 575 miles southeast of Oʻahu. NOAA will use the results to inform updates to the current management area.
But as The Conversation found out, the month-long survey has not gone as planned due to 10-foot swells and 35 mph winds. Launching smaller boats from NOAA ship Oscar Elton Sette has been too risky.
"We wanted to collect biopsy samples. We especially wanted to deploy satellite tags where we can track the movements of animals and see if they are connected to the Hawaiʻi pelagic population that way," said Amanda Bradford, the chief scientist on the survey. "Unfortunately, those require good weather conditions, which we have basically not had at all since we've been out."
Bradford said the crew had to pivot and focus on another type of surveying.
In the first 21 days of their 30-day survey, researchers detected eight groups of pelagic false killer whales. Bradford said that's a high encounter rate.
"For seven of those, we've been collecting water for eDNA," Bradford said, referring to environmental DNA. "Basically we drive through locations where we heard or saw false killer whales, and we collect and then filter water from those locations. And this is new for us, so we don't know how successful we'll be, but if we are successful, we'll have a new tool for monitoring false killer whales."
She said one downside is that eDNA doesn't provide the same genetic resolution as tissue samples from biopsies.
The NOAA ship is set to return to Oʻahu on Wednesday.
This interview aired on The Conversation on May 21, 2024. The Conversation airs weekdays at 11 a.m. on HPR-1. Sophia McCullough adapted this story for the web.
