By Dr Vanessa Pirotta

07 June 2018 - 15:00

Adult and baby killer whale swimming in the ocean
'As a whale swam to the surface to breathe, we opened the drone’s petri dish and flew it through the whale snot.' Photo ©

skeeze licensed under CC0 1.0 and adapted from the original.

The collection of whale snot in Australia requires approval from a university animal ethics committee, a scientific licence and a qualified Civil Aviation Safety Association drone pilot. 

How do you conduct a health check-up for an animal that is 80,000 kilograms bigger than your average pet? According to PhD candidate Vanessa Pirotta, the answer is drones.

What does whale snot look like?

You have probably seen whale snot before, and you didn't even know it. Whale snot is that visible plume of spray rising from a whale's blowhole. It looks just like water but it contains biological information such as DNA, hormones and bacteria, which scientists can collect to provide a check-up of a whale's health.

How do scientists usually collect whale snot?

Collecting health information from whales without having to hurt them can include collecting whale skin (sometimes left over on the ocean surface), whale poo or whale snot. Current methods to collect whale snot involve using a pole with a petri dish held over a whale’s blowhole. However, this can be dangerous as a whale could easily flip a small boat. It can also be difficult to collect when a whale is swimming.

In the past, scientists conducted health assessments on whales that had either stranded, in which case their health was compromised, or from those deliberately killed (hunted).

What do you do differently? 

To make collecting whale snot easier and safer, I collaborated with drone expert Alastair Smith from Heliguy Scientific in my PhD to design and develop custom-built, waterproof drones with petri dishes to fly through whale snot and collect bacteria.

We headed offshore in a boat to the humpback whale highway off Sydney, Australia. This is a known migratory corridor humpback whales swim along as they pass Sydney during their annual northern migration to their breeding grounds off Queensland. Once we spotted a whale or pod (two or more whales), we launched the drone into the air and flew it over to the whale or pod, 200 metres or more away from the boat. When in position, we used the drone’s camera to see when the whale was likely to surface. As a whale swam to the surface to breathe, we opened the drone’s petri dish and flew it through the whale snot. Immediately after, we shut the petri dish to minimise contamination of the sample as the drone flew back to the research vessel.

What do you do with whale snot after you collect it? 

In the lab, I swabbed the petri dishes using sterile cotton tips to collect the whale snot. It looked like small droplets of water. We then used forensic techniques to identify the types of bacteria living in the whale lungs. We also used next-generation sequencing to provide a library of the types of bacteria found in our samples. Then, we compared our samples with sea water and air samples also collected off the coast of Sydney, and were able to show that our drone was indeed collecting whale snot. This was great news.

I was also able to compare our findings with similar studies conducted in the Northern Hemisphere, and found some overlap in the types of bacteria found in the snot of other whale populations. We can use this information to help inform the health of stranded or sick whales. We can compare lung samples of sick or stranded whales to those of healthy ones, to look for overlap or differences in bacterial communities.

What can you do with the information you gain from whale snot? 

The initial step is to build a picture on the types of bacteria collected from these samples. This informs scientists of the types of bacteria we may expect to find in whale lungs (baseline information). Any changes or variability in bacteria found in whale lungs may provide an early indication of changes in whale health over time. Further sampling may also lead to virus detection, which we have been able to identify in the snot of humpback whales in the same population.

Collecting samples over consecutive years (long-term sampling) may help inform changes in whale population health overtime. The more we sample from whales, the better picture we build to learn more about their health. At the same time, we are also learning more about ocean health by sampling microbes living in our marine environment. For example, these whales could potentially be carrying microbes from Antarctica and transporting them as they migrate to Australia. In the future, it would be great to adapt this method to learn more about the health of threatened whale species, such as northern and southern right whales.

Watch Vanessa's presentation at the FameLab International Final live today (7 June 2018) and see more FameLab talks on YouTube.

Follow Vanessa on Twitter @VanessaPirotta

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