A new study is suggesting there may be a link between smaller freshwater fish sizes and deforestation due to the decrease in the amount of leaves present in fish habitats. Leaves have become a vital food source for fish. This study focuses primarily on young fish, a year old or younger, and shows that without the leaf food source, fish do not grow as big and fewer will reach adulthood.
The study’s lead author, Andrew Tanentzap from the University of Cambridge’s Department of Plant Sciences, explains the importance of this plant source by stating, “We found fish that had almost 70% of their biomass made from carbon that came from trees and leaves instead of aquatic food chain sources.”
He added that “While plankton raised on algal carbon is more nutritious, organic carbon from trees washed into lakes is a hugely important food source for freshwater fish, bolstering their diet to ensure good size and strength”. It has been show in the study’s findings that areas with the most zooplankton had the largest, fattest fish.
In areas where there is more dissolved forest matter, there is more bacteria—and more bacteria equals more zooplankton. The team of scientists from Canada and the UK collected data from eight points around Daisy Lake, Canada, which had varying levels of tree cover. This location is part of the boreal ecosystem due to boreal regions being the main focus of the study.
However, the scientist believe that these results would likely be the same in any other environment and point to the effects these result could have on freshwater fish as a food source for humans. The loss of forest is damaging aquatic food chains of which many humans are a part of thus deforestation could have bigger implications then many realize.