Important conservation work is happening at the Vancouver Aquarium – just not in the building. It’s actually happening on the rooftop. That’s where Aquarium biologists have been breeding and rearing Oregon spotted frogs (Rana pretiosa) for the third year in a row in hopes of bringing them back from the brink of extinction. As many as 23 egg masses of 600-1,200 eggs each were expected this year, and with the recent hatching of these egg masses, all but a few tadpoles will be released this week in different locations in the Fraser Valley to supplement wild populations.
The Oregon spotted frog is an endangered species in Canada. The species has vanished from 90 per cent of its range in British Columbia due to factors such as draining of wetlands, the conversion of agricultural land to housing and urban development, and the arrival of invasive species.
Two out of the four greenhouses on the Aquarium’s roof have been set aside for the project, which is part of a wider initiative spearheaded by the Oregon Spotted Frog Recovery Team, made up of members from provincial, federal and regional district agencies; First Nations; universities; and conservation organizations. Aquarium staff spent the early spring ensuring that the conditions were just right for Oregon spotted frog reproduction. It was a cool spring in Vancouver, so the water temperature was held at 7-9 ˚C in the frog habitats.
In most of the habitats, there were two males to every one female. Kris Rossing, one of the Aquarium biologists working on this initiative, says that’s because a female frog in the presence of two males, rather than just one male, is more likely to breed.
Kris says the biggest challenge in executing a conservation
project like this is the space and equipment needed to house enough adult
Oregon spotted frogs and their egg masses. This year, the Earth Rangers’ Bring Back the Wild program is
supporting the project at the Aquarium. The Vancouver Aquarium is also part of
a worldwide effort, along with other zoos and aquariums, to conserve other amphibian species under the Amphibian Ark (AArk) project.
Since 2007, Aquarium staff has been collecting Oregon spotted frog eggs to establish an aquarium-based assurance population. In 2010, Oregon spotted frogs were bred at the Aquarium for the first time ever in an aquarium environment.
Kris is proud of the Oregon spotted frog conservation work that has been going on since 2009 on the Aquarium rooftop. He says, “It really makes me feel good to be saving a species.”