What does ocean acidification mean for the future of sea life?
Photo by Li Fei
Despite pandemic shutdowns, carbon dioxide emissions surged in 2020 and entered the Earth’s atmosphere to further accelerate global warming. While 50% of this gas remained in the atmosphere, natural water cycles dumped 25% into the ocean, causing pH levels to increase dramatically. Over the past 250 years, surface ocean water acidity has increased by 30%. If CO2 emissions continue to progress at their current rate, the seas could become 150% more acidic by the turn of the century.
While rising pH levels do spell doom for most aquatic life, some species are adapting to live in a warmer, more acidic environment. While their survival is inspiring, their evolution will inevitably alter predator-prey dynamics and the ocean’s future, overall.
Food Chain Disruptions
Since ocean life is a key part of the food chain, any increase or decrease in the abundance of one species will affect the others. Inevitably, this ripple effect will cause major disruptions to the entire food chain.
Already, humans have seen these impacts as heat waves in animals — which are directly linked to climate change — kill whales, coral, krill shellfish and other marine life. These animals play key roles in the ocean’s food web, so their deaths are detrimental to other species.
Animals that have adapted to rising pH levels don’t offer much hope, either. While these species might survive more temperature increases, their predators or prey may not, which can tip the scales and even cause some species to go extinct.
Algae Blooms
Five years ago, unusual blooms of toxic algae sprouted up along the West Coast. This warm weather variety covered shallow seabeds and became a home for pH adaptable marine species like triplefin, which are notoriously unfussy about shelter.
However, many other fish species weren’t able to adapt to the shallow algae because it was less nutritious and couldn’t provide suitable shelter or a place to reproduce. Therefore, even if marine life were able to survive increasing ocean acidification and rising temperatures, they may not outlive the resulting algae blooms and food shortages.
Marine life that has a chance of surviving somewhere elsewhere may also leave the area rather than stay and accept their fate. While doing so mat preserve their species, it may put others at risk, especially those lower down the food chain.
Lack of Biodiversity
Acidification and adaptation, alike, can also lead to a decrease in marine biodiversity. As climate change accelerates and the waters grow warmer, more species will become endangered and go extinct. Then, food shortages and rapidly expanding fish populations will kill off even more species, which can permanently damage the ocean’s biodiversity.
Unfortunately, areas with dense biodiversity suffered the most when heat waves swept through their waters. Here, coral reefs, kelp forests and seagrass withered, with their prey following close behind.
Of course, even species that can adapt will ultimately inhibit their ecosystem’s biodiversity. As their population count soars, other species’ will fall, thereby turning predators into prey and vice versa.
Living with the Consequences
A healthy ocean is essential to the planet’s overall health and human survival. However, temperatures and pH levels will likely continue to rise over the next few years as humans struggle to combat climate change. Until then, fish populations will keep shrinking and food will become more scarce — for people and marine life.
Those that can’t adapt will die and those who can will live to see another day. Meanwhile, the seafood industry and its millions of fishmongers will reap what they have sown — a smaller and smaller harvest. Even those who only catch shellfish and crustaceans will experience shortages as acidification impacts the shells and sensory organs.
Meanwhile, the effects of rising pH levels will ripple through both land and marine ecosystems in ways scientists can’t even begin to comprehend. So, unless humans are willing to change their ways and minimize emissions, they’ll have to live with these rather sobering consequences.
Author Bio:
Jane is the editor-in-chief and founder of Environment.co. She is passionate about helping people understand the importance of sustainability and actionable steps to live a greener lifestyle.
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