Harvesting Smaller and Smaller Wild Foods
Tuesday, January 20th, 2009
A new study lays out the idea and the evidence that wild harvested fish, animals and plants are becoming adaptive to aggressive harvesting by humans. So adaptive in fact that the species are maturing at smaller sizes and at earlier ages. These rapid mini-evolutionary changes are so alarming that the researchers behind the study warn of “imperil[ing] populations, industries, and ecosystems.”
Human consumption of food stuffs, animals included, is reaching such an imbalance that animals are growing smaller, literally. Size and weights are reduced by 20%, and females are reaching reproductive maturity at younger ages by 25%. That may not seem like such a big idea, but if you are 6 feet tall or 72 inches, if you lost 20% of your height, you’d be a tad shy of 4 feet 10 inches tall. That’s a big difference. Additionally, females having offspring at younger ages usually results in smaller broods in the younger years, leading to a net loss in offspring overall. When smaller animals breed, the resulting offspring will be smaller as well, further reducing the stock size.
The study looked at the food-gathering practices for a number of species, and found that the species that humans found the tastiest have proved the quickest adapters. Not out of anything but necessity, mind you. When a species loses more of its adult population, younger fish will naturally try to fill the procreative gap. In the case of more than 20 species, those natural (yet anthropogenic) changes are occurring at rates that are more than double the rate that other not-so-aggressively harvested species are changing.
This is disturbing news. Not only from the affected species point of view, but from a human standpoint, the food we rely on to feed the six plus billion of us is going to be getting smaller. Smaller food means less food. This burgeoning population know as the human population will be needing more food, not less. These findings are also proof that common fisheries practices that only allow the largest animals to be harvested is a faulty method that is ensuring that smaller representatives of the species will be the only adults left to create the next generations.
mammals, food, wild harvest, fish, animals, plants, adapt, evolution, population, reproduction
