What ancient underwater food webs can tell us about the future of climate change

What a tangled web we weave. When it comes to the impact of the climate crisis on marine food webs, it seems we don’t know the half of it. That’s according to a new study from the University of Nevada, Las Vegas (UNLV), which compared ancient and modern ocean ecosystems in an attempt to understand how to make them healthier and more resilient.

Some scientists argue that food webs in the oceans have changed very little in the past 540 million years. However, a team of UNLV researchers has revealed that some ancient food webs were actually very different from today’s.

The study, published in the latest edition of the journal Frontiers in Ecology and Evolution, used fossils to reconstruct four different marine food webs from the days when dinosaurs roamed the earth more than 65 million years ago. The food webs were also compared to a food web reconstructed from a modern Jamaican reef. The outcome? The four ancient food webs varied greatly from one another, and the youngest was not the most similar to the coral reefs of Jamaica today.

The researchers say the findings indicate major changes in the structure of marine ecosystems since they first evolved, and that when considering conservation and restoration plans, human-caused deterioration of these structures over time can affect the ability to repair imbalances and prevent the extinction of the species that live within them.

“Learning how food webs work is very important for conservation because it helps scientists predict how ecosystems will respond to climate change,” said study co-author Carrie Tyler, a marine conservation paleobiologist and assistant professor in the department of geosciences UNLV.

“There is an interconnectedness and dependency between each member, meaning that when a stressor affects one species, it will eventually affect the rest of the network,” she said. “If a species is removed from the structure, the function in the food web may no longer be fulfilled because of the missing piece.”

Tyler said this can make it difficult to reintroduce species down the road because their functions may no longer fit into the structure. “Using paleontology in this way can help us understand what we should save and how to save it, giving us another way to look at conservation efforts.”

Added Roxanne Banker, a UNLV postdoctoral researcher working with Tyler, “By studying these structures over time, we can find ways to foster more resilient communities now and in the future.”

conclusions

• Climate change and altered ocean ecosystems due to human activity are of increasing concern. “No pristine ecosystems—those unspoiled by human activity—are left on the planet,” Tyler said.
• Community stability in oceanic ecosystem structures is determined by the species within it, what role they play in energy movement, how these functions interact with each other, and how strongly animals at the top of the food chain affect the rest of the food web. . Researchers are looking at how these systems respond to crises and whether or not species and functions can survive these stressors.
• New UNLV research can help researchers identify the long-term effects of biological invasion — such as the introduction of new species and/or predators, as well as other environmental disturbances — to determine how we can better help ocean ecosystems recover from damage . .
• By looking at things on a longer time scale, we can develop a more specific understanding of how human activity has affected ecosystems, which can help us approach restoration and conservation efforts more effectively.