William WL Cheung for The Conversation
Restaurant menus on Canada’s west coast will soon see an influx of squid and sardine dishes, while the popular sockeye salmon will make a slow release. Turns out climate change might have something to do with it.
Restaurants update their menus all the time and this often goes unnoticed by diners. These changes are driven by culinary trends, consumer preferences, and many environmental and socio-economic factors that affect ingredient availability. According to a recent study published by my research team, we can now add climate change to this list.
We have found that as ocean temperatures rise, many marine fish and crustaceans leave their traditional habitats towards the North and South Poles in search of cooler waters. This movement of fish stocks is affecting the availability of seafood catches, forcing chefs to rewrite the menus of seafood restaurants on Canada’s west coast.
Climate change affects our oceans and fisheries
The latest report from the United Nations Intergovernmental Panel on Climate Change has confirmed that climate change is impacting the ocean, fish stocks and fisheries through ocean warming, ice loss from sea, ocean acidification, heat waves, ocean deoxygenation and other extreme weather events.
The impacts of ecological changes induced by global warming are also observed in our fisheries. Global fish catches are increasingly dominated by species that prefer warmer waters.
We applied an index called “mean catch temperature” to measure these changes in fish species caught along the west coast of Canada and found that catches of warmer water species in this region increased by 1961 to 2016.
Link seafood on menus to climate change
But how exactly do these changes in fishing catches dictate the food that appears on our plates? My co-author John-Paul Ng and I decided to tackle this issue ourselves by focusing our efforts on the west coast of Canada and the United States where many restaurants serve seafood.
We looked at current restaurant menus in these areas, as well as menus – some dating back to the 19th century – taken from the historical archives of local town halls and museums.
After reviewing 362 menus, we used an approach similar to the one we developed to study fisheries catches and calculated an “average restaurant seafood temperature”. This index represents the average preferred temperature of all seafood species appearing on the sampled menus of restaurants in a city during a given period. This index is a tool that helps us assess whether our restaurants serve more or less hot and cold water seafood.
We have found that the average preferred water temperature of fish and shellfish that were on our menu has dropped from 9 degrees Celsius to 14 degrees Celsius in recent times (2019-21) during the period 1961-90.
This increase in preferred water temperature of fish on restaurant menus is linked to changes in seawater temperature and temperature-related changes in the composition of fish species caught during the same time period. .
More calamari and sardine dishes
Warming oceans are beginning to change the variety of seafood available.
Driven by warmer ocean temperatures in the northeast Pacific Ocean, the Humboldt squid – a large species of predatory squid that inhabits the eastern Pacific Ocean – is now making more frequent appearances on restaurant menus. Vancouver’s current restaurants.
British Columbia once had a commercially important Pacific sardine fishery, which was a common seafood restaurant. After the collapse of the fishery in the mid-1940s, fish rarely appeared on the menus of our sampled restaurants.
According to research by colleagues in fisheries research and our team at the Institute of Oceans and Fisheries, sardines, which prefer warmer waters, will soon be making a comeback on Canada’s west coast. We expect more sardine dishes to start appearing on restaurant menus here.
Responding to changes in seafood availability
Globalization and diversification of cuisines have brought a wider range of seafood options to coastal cities such as Vancouver and Los Angeles. Imported and farmed seafood are increasingly common ingredients on menus.
As climate change continues to alter the distribution of species in ocean waters, we predict that climate-induced changes in restaurant seafood menus will become even more pronounced.
Our restaurant menu study highlights the widespread impacts of climate change on our food system. In cases where alternative seafood ingredients are available and consumer preferences are flexible, the impacts on our social, economic and cultural well-being may be limited. However, substantial negative consequences are likely to be felt by many vulnerable communities that lack the capacity to adapt to such changes.
Global and local actions to support both climate change adaptation and mitigation are essential if we want the ocean to continue to provide food to people around the world who depend on it for their nutritional security.
(The author is a professor and director at the Institute of Oceans and Fisheries at the University of British Columbia.)