Sable Island, a thin landmass located off the coast of Halifax, welcomes new technology this week as wildlife researchers begin a new pilot project. Known for having the world’s largest colony of grey seals, up to 400,000 of these cute creatures are born on Sable Island annually. Unfortunately, the island’s small size breeds competition for resources amongst the species living there, meaning only around 10 percent of these baby seals are able to survive beyond their first year of life. Researchers from the Woods Hole Oceanographic Institution in Massachusetts took a particular interest in this seal population, and developed this pilot project in an attempt to determine what allows these seals to survive.
The study, chaired by Dr. Michelle Shero, involves putting Fitbit-like devices around the bellies of these seals in order to measure their heart rate, physical activity, vitals, and location as they grow up. Fitbits are generally used by gym enthusiasts and habit trackers, but researchers are now seeing the much broader impact they can have on wildlife conservation. These seal monitors were invented by team member and engineer Ben Weiss, who explained his ideas to CBC in an interview last week. “The major challenge was just trying to both meet the needs of the seals and the researchers, if you will — trying to make this something that was minimally intrusive on the seal itself, while also making the features something that are going to be easy to put together in the field.” Issues to consider in designing these trackers were the dragging motion the seals use to get around, the weight of the seals (they triple their birth weight in the first 16 days of life!) and being able to withstand use in the ocean.
Furthermore, after being born, their mothers only show interest in them for about two to three weeks, before abandoning them to look after their own needs. During this time, the seals are nursed, but do not learn essential skills like hunting or swimming. Rather, they are left to navigate life by their own instincts, in a struggle against the 400,000 other infant seals who also have not learned how to dive or hunt yet. As described by Dr. Shero in a press conference, “the pups go from being nursed on land, to being suddenly weaned and having to transition to making a living in the ocean. They have to be able to hold their breath for long durations and slow their heart rate on dives so that they use their oxygen stores slowly.”
If they are able to survive their first year, most will go on to reach maturity at around six years of age, and those who reach adulthood can live from anywhere between 25–30 years! This project will specifically follow six seals, from about one-month of life onwards. The research team opted for a hands-off, non-invasive tracking system that would not inhibit seals from living their daily lives by getting in the way. Instead, they issued these seals each a 3D-printed backpack to hold the device in place, assisted by a few drops of non-toxic glue. Dr. Shero continued, saying “One thing that’s actually very fun about trying to measure aspects of animal health that humans also do is that we don’t have to completely reinvent the wheel to still make a big impact.”
