When you take a walk along rocky beaches and lose your balance, it hurts when you fall. The barnacles that cover all the rocks are hard and pointy. At first glance, you wouldn’t assume that they are animals. But they are! They are inside the hard exterior!
Barnacles are arthropods and are actually more closely related to crabs than other animals like mussels! They are very important in the intertidal zone where you can find them. They cover a lot of the space available for other organisms, so they “control” the presence and abundance of other organisms and competition! So if barnacles are affected negatively by climate change factors such as temperature and salinity, then the entire intertidal ecosystem structure can change!
This is why climate change is a serious issue that must be tackled to protect ecosystems and biodiversity! The oceans will get warmer and will get less salty. This will make it difficult for marine organisms to live.
Because of how dangerous climate change is, I wanted to take a look at how temperature and salinity affected barnacles. In order to survive, barnacles must eat like all of us. Therefore, I looked at their feeding rate in response to the stress of different temperatures and salinities. It’s like how right before a big test, humans get too stressed to even think about food! Would barnacles react the same? I wanted to find out.
So the question is: how do barnacles even eat? Especially when they look like shell structures! Well, they have legs called CIRRI! They beat as a cirral fan to bring in food particles from the seawater. The cirri trap food and eventually bring it closer to their mouths. They are filter suspension feeders!
Keeping that in mind, I exposed barnacles to 3 different levels of temperatures and 3 different levels of salinities (INSTANT ocean sea salt was very helpful here!), and counted how many times they flicked their cirri in 1 minute. Sounds simple enough.
Boom! The results were definitely interesting! Less salty water made them feed slower! This means that with climate change making the ocean less salty and more fresh, barnacles might not be successful in being able to EAT! Cold temperatures led to barely any feeding at all! Warmer temperatures actually made them eat faster, because of increased metabolic activity.
However… what if they were in warmer temperatures for longer periods of time? Would they still succeed in feeding? Is that a chance we are willing to take by letting climate change continue its course without trying to fix it? NO! Climate change also makes things super cold in winters while keeping it hot in the summers! So probability of survival via finding food? Not that high.
My little experiment proves that they are going to be affected by climate change and we need to do something to keep the ecosystem in balance! Barnacles are strong and can tolerate a lot of stress but the combined effects of different stressors will eventually run them down! Protect the barnacles and their right to use cirri! It’s cirri-ous!
For some fun facts about barnacles and romance, check out this video:
Here is some information on climate change:
https://www.theglobeandmail.com/canada/article-report-on-climate-change-shows-canada-warming-at-twice-the-rate-of/
Want to learn more about stress and barnacles? Check out this quick link:
https://www.ncbi.nlm.nih.gov/pubmed/26615725
BIOL 326: Experimental biology of invertebrates 