According to research, around 70% of the world's oceans could be suffocating from a lack of oxygen as a result of climate change, potentially impacting marine ecosystems worldwide by 2080. The mid-ocean depths that support many fisheries worldwide are losing oxygen at unnatural rates and already lose oxygen at a critical threshold in 2021.
Vocabulary
impact | /im-pakt/ n. the effect that a person, event, or situation has in someone or something. ex: The impact of climate change on aquatic animals is devastating. |
occur | /uh-kur/ v. to happen, often without being planned; to exist or be present in a particular place or group of people ex: The decline of oxygen content in water, will occur throughout the world's oceans. |
depths | /depth/ n. the quality of being deep; deepness. Ex: The ocean's middle depths are from about 200 to 1,000 meters deep. |
potential | /puh-ten-shuhl/ adj. capable of being or becoming: Ex: …a potential danger to humans. |
manifest | /man-uh-fest/ adj. readily perceived by the eye or the understanding; Ex: That may manifest in significant impacts on the ocean's ability to sustain important fisheries |
Comprehension Questions
What do oceans carry for aquatic animals?
What is deoxygenation?
What are the ocean’s middle depths?
What do rising temperatures lead to?
What does humanity currently changing?
The new study is the first to use climate models to predict how and when deoxygenation, which is the reduction of dissolved oxygen content in water, will occur throughout the world's oceans outside its natural variability.
It finds that significant, potentially irreversible deoxygenation of the ocean's middle depths that support much of the world's fished species began occurring in 2021, likely affecting fisheries worldwide. The new models predict that deoxygenation is expected to begin affecting all zones of the ocean by 2080.
The results were published in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.
The ocean's middle depths (from about 200 to 1,000 meters deep), called mesopelagic zones, will be the first zones to lose significant amounts of oxygen due to climate change, the new study finds. Globally, the mesopelagic zone is home to many of the world's commercially fished species, making the new finding a potential harbinger of economic hardship, seafood shortages, and environmental disruption.
Rising temperatures lead to warmer waters that can hold less dissolved oxygen, which creates less circulation between the ocean's layers. The middle layer of the ocean is particularly vulnerable to deoxygenation because it is not enriched with oxygen by the atmosphere and photosynthesis like the top layer, and the most decomposition of algae -- a process that consumes oxygen -- occurs in this layer.
"Humanity is currently changing the metabolic state of the largest ecosystem on the planet, with really unknown consequences for marine ecosystems," he said. "That may manifest in significant impacts on the ocean's ability to sustain important fisheries."
Source:
American Geophysical Union. "Climate change has likely begun to suffocate the world’s fisheries." ScienceDaily. ScienceDaily, 1 February 2022. <www.sciencedaily.com/releases/2022/02/220201161050.htm>.