Birds Canada calls on British Columbians to help identify dead seabirds during marine heat wave

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It’s a different kind of bird watching.

Birds Canada is asking British Columbians to help monitor dead seabirds found on coastlines to help scientists better understand how certain events, such as climate change and oil spills, affect seabird health.

While help is needed year-round, conservationists are particularly concerned this summer because of a Pacific marine heat wave that could cause mass mortality.

“These marine heat waves are killing bird populations, especially seabirds,” said David Bradley, B.C. director for Birds Canada.

Pacific marine heat waves usually begin when summer temperatures rise and the strong Pacific winds slow down, quickly warming the surface temperature of the water.

This particular marine heat wave began forming about 1,600 kilometres off the coast in May, but has moved east towards B.C. and Oregon in recent weeks. The affected area of the ocean is now about four million square kilometres, and surface temperatures have been up to 5C higher than normal in recent weeks.

Bradley, speaking to CBC’s On The Island on Tuesday, said increased ocean water temperatures prevent nutrient-rich cold water from rising to the surface, which can reduce the food supply and cause seabirds to starve.

A study published in July, based on research by Bradley and numerous other scientists along the Pacific coast from California to Alaska, looked at about 90,000 surveys of dead seabirds and found there were five mass die-offs (more than 500 kilometres in size, more than 10 carcasses per kilometre) between 2014 and 2019 in the northeastern Pacific and Bering seas.

Scientists linked warm ocean events to disease or starvation in these five situations.

“When the heat wave happens, it suppresses the upwelling of cold water, and that often leads to a reduction in the food supply, and that unfortunately leads to seabird deaths,” Bradley said.

Seabirds that breed in B.C. are of particular concern, including auklets, terns, gulls and ducks.

To contribute to seabird mortality research, all you have to do is walk the beach once a month and look for seabird carcasses along the shoreline after high tide. Volunteers receive a kit from Birds Canada that includes a field guide, gloves and metal tags.

The idea is to try to identify and tag the species so that it isn’t double counted and, if found again, to determine how long it was on the beach.

Beached Bird Survey participants are important all year round, but the current heatwave has created an acute need this summer.

Data from the US National Oceanic and Atmospheric Administration shows that some parts of the Pacific Ocean are experiencing a Category IV or “extreme” heat wave – the most severe level in the organisation’s ranking system.

As this year is predicted to be an El Niño year, this particular marine heat wave may take longer to cool down.

While it’s too early to predict the effects of El Niño, William Cheung, director of UBC’s Institute for Oceans and Fisheries, said it’s important to study what these conditions will do to our coasts.

“One of the predictions and projections that scientists have made is that […] with climate change, these heat waves will become more frequent and more intense in the future,” he said.

Wildlife rescues on the rise

The arrival of the marine heat wave in B.C. waters coincides with a heat wave in the south of the province, prompting a wildlife rescue group to warn of the risks to all animals.

Kimberly Stephens, hospital manager for the Wildlife Rescue Association of B.C., says there has been an increase in calls and admissions of animals affected by extreme temperatures.

She says some have heat exhaustion, others have been displaced by wildfires, or food and water resources have dried up due to heat and drought.

Stephens suggests people put out shallow water bowls for animals so they can drink without drowning, but advises not to leave out food.

“Some species are a little more sensitive to these environmental changes than others,” Stephens said in an interview.

As an example, she says bats are particularly sensitive to heat, as once their bodies reach a certain temperature, they go into heat stress, which lowers their chance of survival.

“For most of our birds and bats, of course, insects are a main part of their diet,” she says. “So, the decrease in the population of insects because of the extreme heat and the drought will also have an adverse effect on their on their well-being.”

More than 80 per cent of B.C. has reached Level 4 or 5 drought conditions, the highest rankings on the provincial scale.