Wednesday, 7 September 2011

A whale sized breathalyser!

Why would anyone in their right mind want to breathaylse a whale? And what is about that heady cocktail of stale air and water that interests a  whale biologist?  To cut a long story short - HORMONES! That cocktail of stale air contains secrets about a whale's short term stress levels and a female's reproductive status. Cortisol is a steroid hormone produced by the adrenal gland in response to stress, and progesterone is a steroid hormone involved in pregnancy. Some very clever people at the Sea Mammal Research Unit (SMRU) and Mingan Island Cetacean Study (MICS) have been developing tests to detect trace levels of cortisol and progesterone in whale breath, and hope to measure stress responses to man made sounds and to detect which females in a population are pregnant.

So how do you breathaylse a whale? Believe me it's not easy, a lot of patience is required and you do need a whale sized breathalyser. The whale sized breathalyser is essentially a very, very, very clean (triple washed) ladies nylon stocking, in a quilters ring, attached to the end of a long, carbon fibre pole which can be placed above the whale's blow hole when it breathes. We call it "blow sampling". Below is a photographic guide to blow sampling.

Step 1. Find a whale and try and get down wind of it.
Step 2.  Place the whale breathalyser in the "blow", making sure there is no cross contamination from other whales.

Some people go to extremes to ensure that we get an excellent sample!

Ramp Style "Extreme" Blow Sampling to collect a Meduse quality sample.

Once collected, the quality of each blow sample is assessed and graded on a four point scale; 1 - Poor, 2 - Medium, 3 - High and 4 - Excellent. So for example the sample collected from Meduse (see the image above - Ramp Style "Extreme" Blow Sampling) would have been graded as  excellent because the breathalyser kit was placed right above the blow holes in the direct path of the blow. Each sample is then sealed with an inhibiting agent to prevent the natural biological breakdown of the hormones we are interested in, and sent back to the lab for analysis.

No comments:

Post a Comment