"Several types of life forms form the food web. Green plants that can make their own food through photosynthesis are the web's producers. They form the bottom of the chain. Animals that get food from other animals and plants are consumers. Decomposers feed off dead plants and animals because decomposers cannot make their own food. Every member in the food web is a predator, prey or both. For instance, one predator may become the prey for another predator.
Extinctions and Disruptions
If one species in the food web ceases to exist, one or more members in the rest of the chain could cease to exist too."
https://education.seattlepi.com/happens-something-food-chain-goes-extinct-4656.html
"The food chains of the world’s oceans are at risk of collapse due to the release of greenhouse gases, overfishing and localised pollution, a stark new analysis shows.
A study of 632 published experiments of the world’s oceans, from tropical to arctic waters, spanning coral reefs and the open seas, found that climate change is whittling away the diversity and abundance of marine species."
https://www.theguardian.com/environment/2015/oct/13/marine-food-chains-at-risk-of-collapse-extensive-study-of-worlds-oceans-reveals
The Entire Food Chain Has Started Collapsing, Scientists Warn
https://www.msn.com/en-us/news/technology/the-entire-food-chain-has-started-collapsing-scientists-warn/ar-AA11ShFu