BOSTON (July 2018) - As free-swimming North Atlantic right whales moved through the Atlantic Ocean, scientists with the Anderson Cabot Center for Ocean Life at the New England Aquarium were able to capture 100 blow samples from 46 whales. This is the first time ever that researchers have successfully quantified hormone levels in breath from large whales at sea - a very difficult feat because breath samples can often be contaminated or diluted with seawater. The work is significant because breath samples contain various biological markers such as hormone levels which scientists can use to study the whales' health.
A team of researchers at the Anderson Cabot Center recently published their findings in the journal, Scientific Reports, detailing the unique approach that they took using urea, an organic compound present in blood, as an indicator of sample dilution. The approach, used by doctors for humans, allowed the researchers to determine how much urea was concentrated within the blow and then correct for ocean water contamination to compare hormone levels in the whales.
"As a team, we wanted to push hormone detection work further to make it quantifiable and reliable science that other whale biologists could potentially draw on," said Elizabeth Burgess, the study's lead author. Previously, Anderson Cabot Center scientists have studied hormone levels by collecting scat samples which led to significant research on how whales respond to stress related activities by humans, physical injury, and reproductive capabilities. "For the first time, we don't have to wait around for these whales to poop," said Scott Kraus, vice president and senior science advisor.
This new non-invasive method, however, is an immediate way to test hormone levels. Unlike feces or blubber samples which accumulate hormones over time, the hormone content in blow may reflect more rapid and short-term acute responses to particular events or stressors. Most North Atlantic right whales are subject to frequent entanglement hazards and the risk of vessel strikes in the active fishing and transportation lanes along the Atlantic coast. The population is now estimated to be under 450.
"This study shows feasibility. Given the right conditions, you can get blow samples from large whales at sea and you can measure several hormones in these samples," said Rosalind Rolland, senior scientist who started the Marine Stress and Ocean Health program in 1999. For this work, the team spent up to 12-hour days on calm seas over eight days, using a long pole deployed from a boat to gather the samples.
The most pivotal whale in the study was Harmonia, a pregnant female (Whale #3101 in the Anderson Cabot Center's right whale catalog). The researchers collected two blow samples and one fecal sample, which meant that the scientists could compare the expected results from their documented fecal work and compare it to the blow results. Both types of samples had high progesterone levels characteristic of pregnancy.
Since 1980, the right whale team has developed a vast database of photos and biological information such as gender, age, calving history, and habitat use for each animal. "In order to build such a novel.
and unique approach, it's important to have a large record to test what works and what doesn't," Burgess said. "Our decades of work on the right whales made that possible."
In the future, scientists can use this technique to examine how whales respond to different disturbances - such as an entanglement, seismic blasting for oil and gas exploration, increased shipping traffic, and offshore wind energy development - by doing before and after measurements of stress hormones in blow. It will also help with monitoring the population's overall health and can be used on other whale species. "Getting information from these whales sets us up to really understand the health of these animals and the condition they experience," Burgess said.
"This project was a really classic example of extending into new, innovative technologies by leveraging decades of work done at the Aquarium," Burgess said. The team received funding for the study from the Office of Naval Research (ONR) Marine Mammals and Biology Program.
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IMAGES: Dropbox folder with 5 permit-marked photos inside: https://www.dropbox.com/sh/tkk8lkf9sswf09k/AABhLV-WAotCAJRWhNLHgDbfa?dl=0
Journal
Scientific Reports