How strange to call this planet 'Earth' when quite clearly it is ocean. Arthur C. Clarke

Tuesday, September 20, 2016

Which Would a Whelk Want?

This summer I had the opportunity to mentor a high school student on a science project. She spent 10 weeks learning about the research process, building and running an experiment, and analyzing the results. Here is a quick summary of what we did. I say we, but she really did most of it.

Main question: Do dogwhelks use olfactory cues (smell) to detect prey?

Hypothesis: If dogwhelks are placed in a divided chamber, they will be more likely to move toward the side with a prey item.

Method: We built divided chambers and set them up under running filtered seawater. We randomly placed one mussel on one side of the divider. We then put one hungry dogwhelk on the opposite end of the chamber and recorded its movement until it crawled to one side of the divider.  We repeated this several dozen times.

The control trial is on the left, where we tested if the dogwhelks
are inherently predisposed to go on one side or the other. They 
were not, so we proceeded with the prey experiment. Once the 
dogwhelk crossed the red dotted line, we recorded which side
of the divider it was on.


Dogwhelks in position at the beginning of a trial.


Dogwhelks at the end of a trial.


Main result: Dogwhelks chose the side with the prey significantly more than the empty side. They seem to be using smell to find their food. 

Discussion: In today's warming and acidifying ocean, organisms' ability to use chemoreception is often altered. Dogwhelks are important predators in their habitat, and if they are going to have a tougher time finding or choosing their prey, their impact on the habitat will change, possibly changing the ecology of the prey community. For example, if dogwhelks stop eating their preferred species of prey, e.g. the blue mussel, this species may become more abundant and compete more with others. 

  

Thursday, June 2, 2016

PhD Candidacy

Last week I passed my qualifying exam and this week I gave the public seminar that is the last step to advancing to candidacy. Now all I have to do to get a PhD is finish analyzing my data, do one more experiment, and write everything into one cohesive thesis!



Monday, April 25, 2016

Quailties of a Successful Graduate Student

A few tips from a professor's talk at an American Fisheries Society conference.

Qualities of a successful graduate student:

1. Perseverance
2. Maintains a positive attitude
3. Excellent at communication
4. Has a strong work ethic
5. Takes initiative

I add:

6. Enjoys taking on seemingly impossible tasks
7. Never hopes to maintain a regular work schedule
8. Is comfortable periodically losing sanity
9. Enjoys flying by the seat of her pants and knows that control is not something to be grasped, ever.

If you are considering graduate school, please think about if you have or can learn these qualities!

Tuesday, April 19, 2016

OA experiment done!

I am happy to report that I successfully finished my ocean acidification experiment testing snail drilling behavior. This is extremely exciting as I had no idea if the experiment would work, and was going to treat this as practice for a real, better experiment down the line. But it worked so well, I don't think I'll need to do that!

Here are some final stats:

  • Number of snails I started with: 173
  • Number of snails that died: 13 (7.5%)
  • Number of snails that ate a mussel: 150 (86.7%)
  • Dates the experiment was running: Jan 14 through Mar 14
  • Number of days the experiment ran: 60
  • Shortest recorded feeding time for any one snail: 24 hours (feeding on a small mussel)
  • Longest recorded feeding time for any one snail: 246 hours, or 20.5 days (feeding on a large mussel)
The preliminary analysis shows that there was no effect of pH treatment on the snails' choices of which size mussel to eat. I have a lot more data exploration yet to do, so I'll provide any cool updates about results when I get them!!

A close of up the amazing pH probe
that precisely measured the pH in my 
treatments!


A close up of the backside of my snail bins. This is where
the treatment water entered the bin.


We used these CO2 tanks to acidify the
seawater for the low pH treatments.



This is how many boxes of glass bottles I used 
for water sampling. Each box contained 24 
bottles. There are 22 boxes. Yikes.


Here is my experiment being cleaned up! I was so happy!



Friday, February 26, 2016

OA Experiment Update

As of this morning, 123 snails have drilled and 13 have died. That means 78.6% are done! Now I'm just waiting until the remaining snails stop eating. Hopefully that is soon, but I'm not so sure because three more finished drilling this morning!

This is what a snail basket looks like when the snail has finished eating a mussel. The small 
mussel is open and empty. 

 Often, the snails drill a mussel and eat everything but the muscles and foot. You can see the 
posterior adductor muscle below the borehole in this small mussel.

This is a posterior view of the eaten small mussel. You can clearly see
the white posterior adductor muscle! That is the main muscle that holds 
the two valves (shells) of the mussel together.

These are the computers that control the pH of my treatments.


Sunday, February 14, 2016

Mussel foot

Did you know mussels have feet? This is one of my favorite photos from my experiment:


The mussel's foot is that long, skinny dark red/brown organ coming out of the mussel. The snail is under it, drilling into it to eat it. I like to think the mussel is trying to reach up and move away to escape from the snail, but I'm really not sure why its foot is out like that. Plus, it wouldn't even work since the snail is stuck on it. When I touched the foot, it retracted immediately. It's unusual for the foot to be out all the way like that, so I had to take a photo! 

If you are curious, the preliminary results from my experiment are showing no effect of pH treatment on the number or size of mussels drilled. But, it's still going, so who knows what the final results will be! 

Friday, January 22, 2016

First Ocean Acidification Experiment

I am excited to be running my very own ocean acidification experiment!

For the last two months I have been planning and executing an experiment testing the feeding behaviors and abilities of Nucella dogwhelk snails from different sites in different pH treatments. To my great satisfaction, everything has been working according to plan. As a result of this experiment, I will witness sunrise outside every day for at least 14 days straight! Hooray!

Thanks sooo much to the volunteers who have helped me every step of the way. You guys are super great!

Enjoy these pictures of the process!

Pre-experiment holding tank.

The experimental setup. Snails are in the baskets in
bins covered with acrylic sheets weighted with cinder blocks.

Experimental bin.
The marine lab when I get there in the morning.

Snail in a basket. It fell on its back and is trying to right itself.

Snails in baskets. The snail on the right is drilling that mussel!

A snail in a basket drilling a mussel.

Filling bottles with water samples to measure pH.

We even do it all in the rain!

Snail drilling a mussel.

Snails resting on the underside of the lid.

The little mussel was eaten by that snail!

This snail has its proboscis through the hole it drilled in the
right valve of this mussel. Since the mussel is open, you can see
the snail's proboscis on the inside!

Sunrise during sampling.