A cross-border science collaboration has yielded a global database that will help researchers understand how climate change is affecting ocean predators like the albacore tuna — which also happens to be an important food source for people around the world.
"Climate change is shifting where species can live, and the pace of change is most intense in the ocean," says Stephanie Green, associate professor in the Department of Biological Sciences and Canada Research Chair in Aquatic Global Change Ecology and Conservation.
"Our big questions are where will marine species go, and what will it mean for communities that rely on the fisheries they support?"
To tackle these questions, researchers at the University of Alberta are collaborating with colleagues in the United States to discover how top predators will respond to climate extremes and changing prey over the coming decades.
Wind and currents in the Pacific Ocean make the west coast of Canada and the United States an attractive feeding ground for migrating predators like tuna where they support lucrative fisheries, and also a hotbed of climate impacts.
The team honed in on albacore tuna, a torpedo-shaped predator known to eat hundreds of different species around the world and whose harvest is regulated by a treaty between the United States and Canada.
Diverse diet — but similar traits
The buffet of prey albacore consume makes it tough for scientists to predict where their populations will go as climate change worsens. To address this challenge, the science team shone a different light on the snacking habits of this ocean predator by looking at the common characteristics or traits of the foods they eat.
"Just like we choose foods based on what we like — be it a salty pretzel or sweet, crunchy apple — ocean predators make decisions based on the characteristics of the prey they are faced with," says Green.
To figure out what traits are important to ocean predators, the researchers created a database categorizing more than 30 traits including fat and protein content, shape, colour, size, and behaviours that make ocean species potentially tasty to predators, including albacore tuna.
"Our goal is to better understand when and where the most desirable prey will be found as the climate changes," says Green.
