Heat Waves Reach Deep Ocean Floor, Scientists Say

Intense waves in the ocean. Credit: Frantzou Fleurine / Wikimedia Commons / Public Domain

Scientists have discovered that vital marine species are suffering serious losses due to heat waves in the ocean’s depths. These heat waves, which are often referred to as “bottom marine heat waves,” last for a longer period of time than surface heat waves and have a catastrophic impact on marine ecosystems.

The impact of spikes in surface water temperature on marine ecosystems is already well-known. The phenomenon of “the blob,” which occurred from 2013 to 2016 in the Pacific Ocean along the North American coastline, caused the deaths of 1 million seabirds due to the severe impact on their main food source, fish.

However, a recent study has revealed that similar heat waves are occurring in deeper waters, with significant impacts on marine life. Lobster and cod, among other key species, are particularly vulnerable to the effects of these heat waves.

Longer and Intense Waves

The research team, whose findings were published on March 13 in the journal Nature Communications, has warned that the longer duration of these heat waves in deeper waters means that the damage to marine ecosystems is likely to be even more severe than that caused by surface heat waves.

The study, which was conducted by researchers at the University of Tasmania’s Institute for Marine and Antarctic Studies, analyzed data from 1950 to 2019 and found that bottom marine heat waves are becoming more frequent and intense.

The researchers also found that these heat waves can have cascading effects on the marine ecosystem, with impacts on multiple species and food chains. For example, a decline in lobster populations due to bottom marine heat waves could have a knock-on effect on other species that prey on lobsters, such as fish and octopuses.

Carbon Emissions Leading to Heat Waves

The team used computer models to predict the future impact of these heat waves on marine ecosystems. They found that if carbon emissions continue to rise at their current rate, bottom marine heat waves will become more frequent and intense, with severe consequences for marine biodiversity and fisheries.

The study’s lead author, Dr. Eric Oliver, has emphasized the urgent need to reduce carbon emissions to prevent further damage to the world’s oceans. He stated that “bottom marine heat waves are a clear warning sign that we need to take urgent action on climate change. We need to drastically reduce our carbon emissions to limit the impacts of these heat waves on marine ecosystems.”

The findings of the study are particularly significant given the key role that oceans play in regulating the Earth’s climate. It is imperative that immediate action be taken to safeguard the health of our oceans and the biodiversity that they sustain in light of the ongoing worldwide struggle to deal with the effects of climate change.

Effects of Global Warming on Oceans

The impact of global warming on the ocean has been significant, with the ocean absorbing about 90% of the excess heat. According to NASA, this has led to an increase of approximately 1.8 degrees Fahrenheit (1 degree Celsius) over the past century. The rise in temperature has resulted in a 50% increase in surface marine heat waves over the past decade.

Marine heatwaves have increased in frequency by 50% in the past 10 years.

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However, until recently, scientists had limited information on how the ocean depths were responding to these temperature fluctuations. To gain a better understanding of this phenomenon, researchers used existing measurements to simulate atmospheric conditions and ocean currents, filling in gaps in their knowledge of seafloor ecosystems.