Hey everyone, In my last research round, I discussed how climate change affects organisms environments, changes their habitats and sometimes forces them to relocate. For this research round, I'll be exploring the effects the climate change has on the food chain and how this can cause loss of food, effects on food wed b processes and threaten some organisms into extinction.
Our globe, which is warming at an unprecedented rate creates unbalance on our planet. As I explained in my previous research this can mean ice melting and glaciers recessing excessively and the snow accumulation not being able to replace the amount lost each years leading to more recessions and ice loss (1). More recently, I explained how climate change and global warming more specifically is causing certain organisms to relocate into new areas due to lack of resources and loss of habitat. Not only does climate change create issues for organisms habitat but also creates difficulties for the organisms to find food which poses another threat to their survival.
Since climate is curtailed environmental influence to most organisms I can impact immensely the way an organism lives and produce possible threats to the organism if changed. Food-wise, this can mean that certain plants may be unable to grow a season due to hotter temperatures and little to no water. With a lack of the plant in the area, the animals who use this plant as their primary food source won't be able to eat, may have to relocate or possibly starve to death(2). For example, pandas and koalas who solemnly rely on one main food to feed them, for pandas bamboo and for koalas eucalyptus. Scientists predict that climate change will wipe out a lot of bamboo which means a shortage of food and habitat for the pandas. With pandas only relying on bamboo to feed them this could mean that there'll be a decrease in the panda population as the bears will struggle to survive unless they manage to adapt to eating other food(3,4). This will also be a similar case with koalas where there have been reports of droughts causing less eucalyptus to grow as well as climate inched changes can cause less nutritional quality and moisture content of leaves(5). (Keeping in mind that loss of these plants can be from other reasons i.e. deforestation)
Now it's not this simple, there are many more factors to be considered when discussing how climate change affects food sources for organisms. For some organisms, climate change can cause a disruption in what they eat now this may not be directly like the panda example but further down the food chain. When one species is in abundance or few this causes a ripple effect to the food web it's a part of (2,6). Looking at this image here will hopefully explain better what I mean.
Here's an arctic food chain (not a food web). The first example is if one year there was a reduction of copepods due to higher acidification in the ocean. This means that there is less food for the arctic cod to eat which leads to less arctic cod. For the seals who are hunting these fish will have difficulties finding food which could decrease their chance of survival and also fewer seal pups could be born effecting the polar bear (7). Now, this could be looked at differently if there was an abundance of one of the species.
These concepts can become more complex when looking at food webs like the one above for the polar bear. As you can see the polar bear is relying on many different aspects to produce its food. And if one where to be altered this causes a ripple effect both up and down the line. For instance, ice algae which thrive on the ice are reduced due to melting ice this will cause fewer zooplankton which is then eaten by arctic cod, which are eaten by seals and other marine mammals. Then the seals are eaten by the polar bears so if there is a decline in ice algae, it'll correlate to a decline in polar bear populations (2,8)
Here's a more complex food web of the Arctic. When looking at the web, in some way most of the organisms are linked by their predators or prey along the lines. Imagine if one of the species where to be taken out of the food web for example the Arctic fox, this would cause the Eider duck to increase in population as their predator is gone the benthic fish which is eaten by the eider duck to possibly decrease in population as there are more Eider duck hunting them than normally(9). Now what I'm trying to get at here is that there is a balance to these ecosystems and food webs. When an element is changed, this can rupture the whole system as they're all linked. So in this case when climate changes and creates irregularity this can affect not just the organism that's experiencing it force hand but all the others that rely on the organism. (Now you can see with climate change but there are a lot more factors as well depending on the ecosystem like deforestation, fishing etc.
This is another concept different from what I've been explaining above that also derived partly from climate change.
Bioaccumulation: "The accumulation of a substance, such as a toxic chemical, in various tissues of a living organism. Bioaccumulation takes place within an organism when the rate of intake of a substance is greater than the rate of excretion or metabolic transformation of that substance."
In brief, this means that a chemical that enters an organism from the pollutant either being long-lived,m mobile, soluble in fats or biologically active (10). Where one organism obtains it through one way or another then when its even by its predator the chemical is now in the predator's system and passed up the food chain. Now bioaccumulation can bee is seen in different ways depending on the instance, it is, after all, a essential process for the growth and nurturing of organisms like us when we'll bioaccumulate vitamins (A)(D) and amino acids. But in other cases its a way for organisms to pass along harmful chemicals they have in their system (10,11). Related to bioaccumulation is
Biomagnification: "the concentration of toxins in an organism as a result of its ingesting other plants or animals in which the toxins are more widely disbursed."
So over time in the image, you can see the chemical contaminant in the species increases as it goes higher up into food chain affecting all the species involved in the chain. Now this concept is more related to pollution from greenhouse gases and other chemicals, however, I believe I'd be the nice bit to add this research round.
There you go, if you have any question, suggestions, and comments please let me know. Thanks for reading!
(8) http://www.acia.uaf.edu/pages/overview.html (page66)