Have we damaged marine life too much for it to recover?
A recent study casts doubt on the notion that ocean ecosystems have undergone little change over millions of years, leading scientists to rethink conservation strategies and public policy.
What a complicated web we spin. We apparently didn't know half of what the climate crisis has done to the marine food webs.
A recent UNLV study compared ancient and contemporary ocean ecosystems in an effort to learn how to improve their health and resilience.
Ancient underwater food webs can tell us about the future of climate change
CHANDAN KHANNA/AFP via Getty Images
Oceanic food webs, according to some scientists, haven't changed all that much in the last 540 million years, as per ScienceDaily.
Researchers from UNLV have discovered that some ancient food webs were actually very dissimilar from modern ones.
The study, which was published in the most recent issue of the journal Frontiers in Ecology and Evolution, used fossils to recreate four different marine food webs from the time more than 65 million years ago when dinosaurs ruled the earth.
The food webs were also contrasted with one that was recreated from a contemporary Jamaican reef.
The four prehistoric food webs were very different from one another, and the youngest one did not resemble the coral reefs found today in Jamaica the most.
Since they first evolved, marine ecosystems have undergone significant structural changes, according to researchers.
When considering conservation and restoration plans, damage to these structures over time caused by humans can impact the capacity to correct imbalances and prevent the extinction of the species living there.
According to study co-author Carrie Tyler, a marine conservation paleobiologist and assistant professor in the UNLV department of geoscience, understanding how food webs function is crucial for conservation because it aids scientists in predicting how ecosystems will react to climate change.
Researchers examined how much energy is transferred from phytoplankton, a type of single-celled algae, to the small animals that consume it (zooplankton).
According to the study, warming by 4°C resulted in up to a 56% reduction in energy transfer in the plankton food webs.
Warmer temperatures raise the metabolic cost of growth, which results in a less effective food chain and, ultimately, a decrease in biomass.
Professor Gabriel Yvon-Durocher of the Environment and Sustainability Institute at Exeter's Penryn Campus in Cornwall said, "These findings shed light on an underappreciated consequence of global warming."
The base of the food webs that support freshwater and marine ecosystems on which humans depend is made up of phytoplankton and zooplankton.
The consequences could be severe, according to Professor Mark Trimmer of the Queen Mary University of London, if the effects we observe in this experiment are also present in natural ecosystems.
Larger animals at the top of food chains, which rely on energy transferred from lower down the food chain, could be severely impacted. More study is required.
According to Dr. Diego Barneche, of the Australian Institute of Marine Science and the Oceans Institute at the University of Western Australia, only about 10% of the energy produced on one level of a food web is transferred to the next level.
This occurs because organisms spend a lot of energy performing various tasks throughout their lifetimes, and only a small portion of this energy is stored in biomass that is consumed by predators.
Warmer temperatures may cause metabolism to accelerate more quickly than growth, which lowers the amount of energy available to predators higher up in the food chain.
