Researchers at the University of British Columbia are taking to the skies in an effort to better understand the ocean.
As a part of their latest efforts, aerial drones have been put to work tracking jellyfish clusters in stunning new detail as they become more widespread. Scientists hope these new sky-high techniques will elevate our understanding of these mysterious creatures, including their impact on species like salmon that compete with them for food sources.
UBC Hakai Professor in Oceanography, Brian Hunt says in at least one BC study, up to 95% of herring larvae were reportedly eaten by jellyfish. He believes that could “hugely” impact the ecology of this area.
“Jellyfish can compete with some species of salmon for food. They can also affect herring. Herring spawn in springtime and while jellyfish generally don’t bloom at that time, with warming ocean conditions the jellyfish could be starting to proliferate earlier in the season,” says Hunt.
Video courtesy UBC
Traditionally, researchers have used boats and cameras on small aircraft to observe marine life. However, Faculty of Science undergraduate student Jessica Schaub that’s an expensive way to get mediocre imagery.
“Drones are much more cost-effective and they can fly low, close to the surface, and produce high-quality images. We used them to zoom in and out to capture details or overall patterns,” says Schaub.
Thanks to the use of drones, Schaub says for the first time they’re getting very clear and detailed pictures of how jellyfish clusters move, how they behave when freshwater from rivers enters the system, and how they use ocean currents to stay together.
“But what’s really exciting is we obtained good estimates of the total mass of jellyfish aggregations in the area – 60 to 120 tonnes of wet weight. That’s a huge amount and it provides a starting point for further studies on jellyfish energy demands and their effect on the local food web.”
New details with new data
According to Professor Hunt a marked increase in the number of moon jellyfish in 2015 and 2016 has been observed. That period of time also stood out for the number of warm-water gelatinous plankton groups, including sea squirts, that they found.
“In 2017 we saw a decrease in jellyfish around Calvert Island, though warm-water pyrosomes—tube-like animals—were abundant. Remember, 2015 was when we saw the warm-water “blob” on the B.C. coast, and this was followed by an El Nino event in 2016. These combined events may explain the increase in jellyfish numbers that we saw in those years, while the cooler waters in 2017 may have had a negative effect on their biomass,” says Hunt.
These latest techniques will eventually be combined with underwater photography in an effort to form a complete picture of how jellyfish clusters are impacting local environments as ocean temperatures continue to change.
[INTERVIEW: UBC Professor and researcher Brian Hunt talks with David Zura about the impact drone technology is having on research and what new methods, like submersibles, may be around the corner]