I don’t know about you, but to me, nothing is better than the smell and taste of a summer BBQ. Food just always seems to taste better on those warm, summer days. Don’t you think? Can’t you already smell it? Those burgers, hotdogs, and of course, the kelp. Wait, what? Well, okay, maybe most humans don’t drool at the first bite of some grade “A” kelp, but I can sure introduce you to someone who does. Please meet, the black turban snail.
This week in Biology 326, we hope to discover that I’m not the only one who eats way too much in warmer weather. Week 5’s experiments focus on asking the question, do warmer temperatures have an effect on black turban snail grazing rates? I feel this is an important question to ask because, as global warming is heating the oceans, due to factors like the burning of fossil fuels, we need to understand how grazing rates could change within intertidal ecosystems. Why? Graze too much kelp, and there may be nothing left to support other species. Graze too little, then kelp and other algae may grow uncontrolled, eventually suffocating an entire ecosystem.
To figure this out, we first tested how much the black turban snails would graze over a week by weighing pieces of kelp and placing them in several bottles. We then placed some bottles in room temperature water, with and without snails and the other bottles were placed in cooler seawater, also with and without snails. The bottles without snails were used to keep track of the natural growth or deterioration of kelp. However, we grossly underestimated the amount of rations we’d need for this summer feast. Only two days into the experiment, these hungry animals had gorged on most of the kelp. Luckily, a few brave students and TAs made it in on their day off to take the weights of kelp after grazing, so we could continue with the study.
Photos by Jeff Joss
Next, we looked at how snail activity changed in a variety of temperatures. We did this in three ways. We measured how many bites each snail took per minute, while snacking on a piece of kelp. Next, we calculated their blazing travel speed. Ok, just kidding. Sure, they were a bit slow to start, but once they broke out of their shells, they were the life of the party (sorry, can’t resist a bad pun or two). Finally, we then timed each snail’s righting time. “What’s righting time,” you ask? Well, believe it or not, we placed the snails upside down and timed how long it would take to turn themselves back over, a cruel trick, maybe. Though, this sadly reminded me of my own struggles of trying to stand up after feasting on too much food on those warm summer days, far too many times. After all, you can’t produce good data without a high number of samples. Eventually, it all worked out though, we ended up giving the snails a hand by pushing them near the wall of glass, where they could prop themselves up once again.
The one thing that kept running through my head during these tests was, “Yep! This is science, and I love it!”
For more facts on snails and global warming, check out: