Your favourite seaside vacation spots may look a little different by the end of the century as climate change causes the blues and greens of the oceans to become more vibrant,
Scientists examining the effects of climate change on ocean ecosystems say they have developed a global model that simulates the growth of phytoplankton鈥攎icroorganisms that convert sunlight into chemical energy through photosynthesis, affecting the colour of the ocean surface.
Phytoplankton contain chlorophyll, a pigment which absorbs the blue portions of sunlight to produce carbon for photosynthesis. As a result, more green light is reflected back out into the ocean, giving algae-rich regions a greenish hue.
In other words, oceans that are rich in phytoplankton tend to look greener, whereas tropical waters with less phytoplankton take on an Instagram-worthy blue or turquoise hue.
The study suggests that, as temperatures rise, blue regions will become bluer, reflecting less phytoplankton. Greener regions, including waters near the poles, may turn deeper green, as warmer temperatures encourage more diverse phytoplankton to grow.
While this shift in colour may sound picturesque, it points to the significant impact climate change has had on our oceans.
鈥淧hytoplankton are the base of the food web鈥攍ess phytoplankton [means] less food for the rest of the marine ecosystem,鈥� study co-author Stephanie Dutkiewicz, , told CTVNews.ca in an email.
Dutkiewicz said oceans around the world are likely already changing in colour, but the changes are likely too small for us to detect with the naked eye. The study estimates that over 50 per cent of the world鈥檚 oceans will shift in colour by the year 2100.
Since the late 1990s, satellites have been taking continuous measurements of the ocean鈥檚 colour to determine the amount of chlorophyll鈥攁nd, in turn, phytoplankton鈥攊n an oceanic region. While chlorophyll levels could be altered by the effects of global warming, natural events such as El Niño can also cause an uptick in chlorophyll.
This study aimed to show how researchers can see a clear signal of climate change鈥檚 effect on phytoplankton by looking at measurements of reflected light alone鈥攕omething the research community has been advocating for.
鈥淲hat this study is trying to explain is that in parallel to measuring the amount of phytoplankton in the water, we should also be measuring the light coming from the water,鈥� Maycira Costa, , told CTV News.
鈥淚t鈥檚 an important variable that we should be tracking to understand changes in the ocean as a result of climate change.鈥�
Over the last two years, , where she installed a series of sensors on B.C. Ferries鈥� Queen of Oak Bay, which runs between Horseshoe Bay and Departure Bay. The sensors, which measure the colour of the water, work to calibrate satellite data in real time, providing information about the health of the Salish Sea.
The research was the first of its kind in Western Canada.
Costa hopes this latest report will reinforce the importance of understanding the effects of climate change on the world鈥檚 oceans, noting phytoplankton are 鈥渧ery important in the carbon cycle."
