environment human impacts

Good intentions sometimes lead to unfortunate outcomes

4 ways humans harm the environment (when they are trying to help)

There’s no question that human activities impact the natural environment. Some human activities have devastating consequences on the environment, while others have the sole purpose of improving or restoring the environment. Unfortunately, the latter occasionally has negative results, despite having positive intentions.

Humans negatively impact the environment in many ways: pollutants from industrial plants dumped into waterways, cutting down entire sections of forest, and prolific burning of fossil fuels resulting in global climate change are just a few examples. In the Good, the Bad, and the Ugly of human impacts on the environment, these things would certainly fall into the “Ugly”. However, there are times when humans have good intentions, but our attempts to help the environment actually hurt it. Here are 4 times human attempts to improve the environment back fired.

1) Osborne Tire Reef - In the 1970’s, over 2 million old tires were sunk to the sea floor off the coast of Fort Lauderdale, Florida to create an artificial reef. Seem like a dumb idea already? Well, on the surface, the plan wasn’t that bad. Many sea creatures like mussels, barnacles, and tube worms need solid structure to attach to. These organisms can help build the base of a food web to feed larger organisms like fish. Not to mention, many fish like having structure to hide in or around. You may be thinking that the tires would leach chemicals into the water, but that actually wasn’t the problem. The problem was the tires were tethered together and anchored to the bottom with steel clips attached to concrete blocks. The clips corroded allowing the tires to break free, eventually smashing into natural reefs during storms. Oops.

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Fig. 1 Osborne Tire Reef: Some of the tires that were sunk off the coast of Fort Lauderdale, FL. Even the tires that didn’t break away and cause further damage weren’t terribly successful at attracting marine life. Photo credit: Navy Combat Camera Dive Ex-East - https://commons.wikimedia.org/w/index.php?curid=7639120

2) Feeding wild animals – They’re so cute, you just can’t help but be generous and give them a bit of your food. But feeding wild animals is never a good idea, for several reasons. For starters, “people food” could be bad for them. Ducks and geese fed white bread, crackers, popcorn, and the like have been linked to a wing defect called angel wing (Figure 2) [1]. Feeding wild animals also reduces their natural fear of humans which can increase the likelihood of vehicle-animal collisions when the animals spend more time near humans trying to get food.

image alt text Fig. 2 Duck with “angel wings”: Young ducks and geese fed large amounts of “people food” may suffer developmental defects such as “angel wings.”Photo credit: Cengland0 - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=4936599

3) Nature Clean-Ups – Beach clean-ups that pick up human litter like plastic, metal containers, etc. are a good thing. However, there are times when volunteers accidentally remove some natural materials that are important for the ecosystem. For example, removing leaf litter from stream bottoms or thorn bushes growing along a river bank is bad for the riverine ecosystem. Bacteria decompose that leaf litter, insects eat those bacteria, and fish eat those insects. That leaf litter is actually an essential part of the river ecosystem’s food web. Likewise, the plants growing along a river bank filter out pollutants from reaching the water while providing shelter for other organisms like birds. Just because these bushes are unsightly and a nuisance to humans doesn’t mean the rest of Mother Nature sees it that way.

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Fig. 3 Navy Beach Clean Up: Okinawa, Japan. To be clear, picking up trash on the beach is a very good thing. However, removing natural materials from an ecosystem (though unsightly) is usually not. Never leave the beach empty handed. Photo credit: US Navy USS Blue Ridge

4) Biocontrol agents gone wrong – When an invasive species starts wreaking havoc on an ecosystem because it has no natural predators to keep its population in check, it may seem like a good idea to introduce a predator to control it. Unfortunately, this doesn’t always work out so well. A famous example in ecological text books is the introduction of the cane toad into Australia. It was introduced to combat the cane beetle that was devastating the sugar cane crop. This failed miserably as the toads were unable to eat many of the beetles. They did, however, thrive by feeding on other insect species and harmed potential predators of the toad with toxins they could emit from their skin. Generally speaking, vertebrates are a bad choice for biological control agents because they usually do not specialize on a specific target species. Therefore, they will impact other aspects of the ecosystem. Since this mistake almost 100 years ago, scientists have recognized the risks of introducing biological control agents and now conduct rigorous testing before releasing any biocontrol agents into the wild [2].

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Fig. 4 Cane Toad: The cane toad introduced to Australia. Photo credit: Froggydarb, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1552230


This isn’t to say that we should stop trying to help the environment. People who care about the environment and take action to help are incredibly valuable. Even within the categories presented above, there are many cases where ecosystem clean ups or biocontrol agents have been very successful. The important idea here is to learn from our past mistakes to avoid repeating them. The trick is to remove our human biases as much as possible when determining what is good or bad for the natural world. This is challenging to do, but it is essential that reality take precedence over human desires, opinions, or emotions. Good science is the key to maximizing our positive impacts and minimizing our negative impacts on the place we all call home.


[1] Smith, K. Angel wing in captive-reared waterfowl. J Wildl Rehab 1997. 20:3–5.

[2] McEvoy, Peter B.. 1996. Host Specificity and Biological Pest Control”. Bioscience 46 (6). [American Institute of Biological Sciences, Oxford University Press]: 401–5. doi:10.2307/1312873.

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