Written by Brittany Visona and Kaitlin Yehle
“One man’s trash is another man’s treasure.” It’s a phrase that accurately summarizes the relationship between Ocean Wise Marine Mammal researchers and whale poop.
Yes, poop, feces, excrement, waste… whatever you like to call it. It might not be glamorous, but for researchers looking to protect at-risk whale species, poop is liquid gold. By collecting fecal samples, researchers are able to examine the underlying variables contributing to the overall health of individuals and the population – all whilst using a non-invasive research technique.
Poop contains a variety of biological and chemical signatures that provide a snapshot of an animal’s current condition. Prey fragments, in addition to isotopes (chemical signatures left in an animal’s tissues from the prey it ingests), help to assess diet, while toxins provide insight on the level of contaminants in their system. Fecal hormones can reveal the physiological stress the animal may be facing, and indicate what environmental factors may be to blame. Hormone concentrations in poop also serve as an early indicator of pregnancy. All of these factors can be linked to a specific individual as each fecal sample contains trace amounts of DNA that allows researchers to determine an individual’s gender and identity, making it possible to monitor the health of individuals and populations over time. Because of the valuable information it holds, finding a fecal sample out in the field is much the same as hitting a scientific “jackpot”.
We know what you must be thinking: what does whale poop even look like? When found on the surface of the water, it is often mucousy or has a frothy appearance. It might be a bunch of tiny bits dispersing in the water, or more gelatinous and clumped together. It can be all sorts of colours; from all shades of brown, to greens, yellows, oranges, and even beige or grey. Sometimes it has a very similar appearance to marine algae. When researchers are unsure whether a sample is actually whale poop or just algae, that’s when they have to conduct a sniff test! As one would expect, whale poop has either a fishy or dog-poop-like aroma, or some combination of the two. Yes, you read that right, we told you it wasn’t glamorous!
As for finding whale feces, there are several ways researchers track down samples. Because whale poop can float for a period of time, if you know what to look for you can spot (and even smell) samples at or near the surface from the bow of a slow-moving vessel – the main protocol implemented by Ocean Wise’s fecal team. Researchers at the University of Washington utilize trained dogs to help with this task. Motivated with the reward of a ball, their “poop-sniffing” dogs are able to locate samples from greater distances behind the whales. Although our fecal team does not have a dog, they do have drones! Working alongside the fecal team, Ocean Wise’s photogrammetry team has a bird’s-eye view of defecating whales. Once noticed, the team radios to the fecal team, 200-300 metres behind the whales, and alerts them about the precious sample’s whereabouts.
Once located, the team can collect poop near the surface using a small bucket which ensures the entire sample, including the fine particles, are collected. However, if it’s sinking, the team will use a very fine-mesh dipping net to collect as much of the sample as possible. Onboard the vessel, samples are put in a centrifuge to remove excess seawater and then are immediately frozen. Samples collected in the field are then brought back to the lab where our Ocean Wise genetics team individually identifies each sample using DNA genotyping (read more about this process here) before other analyses are performed.
Since 2018, Ocean Wise’s fecal team, led by MSc student Kaitlin Yehle, has collected fecal samples from both the endangered southern resident and threatened northern resident killer whale populations. The study looks to evaluate the concentration of steroid and thyroid hormone metabolites present in northern and southern resident fecal samples as indicators of disturbance-related and nutritional stress, respectively. Examining relative concentrations of the two can provide insight into the type of environmental stressors these populations are experiencing, which is key in determining their overall health.
With one more year of sampling left to do in 2020, we are itching to hear the team’s findings and answer some burning questions: What threats are contributing to stress in resident killer whales? Are southern residents under greater stress than northern residents? And if so, why? Stay tuned for updates later this year!
Ocean Wise’s fecal hormone study is part of a collaborative project with Fisheries and Ocean’s Canada (DFO) and is funded by DFO’s Oceans Protection Plan.
If you are interested in our scientific publications, please visit the Marine Mammal Research Program’s website, https://research.ocean.org/program/marine-mammals.