From the Archives: Barnacle Investigation

While I'm on vacation, I'm reposting some popular posts from last year.

Today's post was originally published August 1, 2010.

Here in Massachusetts, our library system runs a summer reading program meant to promote reading during the summer months. Students log the hours they spend reading, receive prizes, and attend various programs at their town libraries (each town puts their own particular spin on the programming). This year's theme is "Go Green," so Miss Lisa at Rochester's Joseph H. Plumb Memorial Library invited me to facilitate a program last Wednesday. I was happy to share my love of the ocean, particularly the Rocky Intertidal Zone with kids from our town.

The investigation is one you can do with your children or students if you live near the ocean. On the East Coast of North America we have a kind of barnacle called an acorn barnacle. When we were in the UK, I did some tide pool exploration with my son and they had the same barnacles, so my British readers can participate, too! On the Pacific Coast and as far away as Malaysia, there's a kind of barnacle called Goose barnacles (or stalked barnacles). I'm told these will work, as well, though I have never tried it myself.

You can do this right on the beach or bring the barnacle rock home to complete the investigation. PLEASE remember to return the rock to the ocean as soon as possible. DO NOT kill them by keeping them at home. If I keep them at home more than overnight, I place a small aerator in the water to provide oxygen. I've kept them this way for a weekend, but always return them after a weekend.

Here's what you need:
Access to a Rocky Beach during low tide
A small rock with barnacles on it
A container large enough to hold the rock with barnacles, plus enough room to cover it with water
Ocean water
A hand lens (magnifying glass) is useful but not necessary
blank paper and pencils (if you plan to record observations)
Resources to consult after the investigation (see suggestions that follow)
Procedure:

1. Take the barnacle rock out of water for 2-3 hours. (This simulates low tide). If you've just collected it during low tide, it has likely been out of water for some amount of time already.
2. Ask your kids/students to examine the barnacles closely.  Provide hand lenses for this purpose. Have them choose one individual barnacle to draw large and in as much detail as possible. They can label these drawings "Barnacle Out of Water." Older students (third grade and up) can draw a top view of the barnacle and a side view of the barnacle. (Think of the barnacle as a little volcano- a top view would be if you flew over the volcano and looked down, a side view would be if you stood at a distance and drew it). They can also use words to describe what they see.  Note: All of this could be done orally, but I strongly encourage you to ask kids to at least draw what they see. Drawing forces them to look more closely and notice more details.
3. Ask the kids to write down (or share) any questions they have. Here are some of the kids working a the library:

4. Place the barnacle rock in the container and cover it with ocean water. Wait patiently for something to happen. This can take as long as 15 minutes, but may only take a few minutes. Here's one of ours:

5. At some point, the kids will see something come out of the barnacle. Many may call it a "tongue." Encourage them to look even more closely to notice the details and draw them on a new drawing (or drawings) titled "Barnacle in Water." Have kids talk to each other and suggest ideas about what is happening. For kids younger than 8, this may take as little as 5 minutes. Kids 8 and up will probably need 15 or 20 minutes to complete their drawings. 
6. Once they've looked closely and noticed as much detail as possible, share some scientific renditions of what they've been observing.
7. My two favorite sources for these line drawings are:

This one is quite complex and is best for older students

(sophisticated/ motivated 4th graders or older)

SPOILER ALERT: What follows is a brief explanation of what you will observe. Even though grown-ups may think they're too old for this kind of investigation, I encourage you to participate right along with your kids/students. That is, don't read about what you will see before you actually see it. Try to make some inferences of your own before reading any further. I have done this investigation with hundreds of adults in my science workshops for teachers and graduate courses for teachers in training and the adults are always wowed and impressed. Quite frankly, it's fun! If you're a classroom teacher and like to be well prepared, go ahead and try it out before you do it in a classroom, but don't read the scientific explanation before you see it  for yourself. Enough said!

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Barnacles are Arthropods, that is, animals with jointed legs and a hard exoskeleton. They are related to crabs, shrimp, and lobsters. Unlike other arthropods, barnacles are cemented down to one place, typically a rock or piling, but also on the bottoms of boats and even whales. Inside that hard limestone exoskeleton, they are on their heads, upside down. The feathery appendages you see coming out of the shell are their legs "kicking" food into their mouths (they filter the water to catch microscopic plants and animals called plankton). When you took the rock out of the water, it simulated low tide- a time when the barnacles are exposed to sun and air and therefore sealed up tight. When the tide comes back in, bringing a fresh batch of plankton, the barnacles begin feeding.

I encourage you to use one of the resources mentioned above to get a sense of what the animal is like inside the exoskeleton. Barnacles have a mouth, stomach, intestine, and anus, so kids can compare barnacle anatomy with their own anatomy to make a further connection. Who knew those tiny white barnacles that cut your feet at the beach could have something in common with you?

Here's a video :

In case your older kids' interests take you further...
Most barnacles are hermaphrodites (they have both male and female sex organs). One reason they crowd so close together on rocks is so they can procreate- a barnacle can not reproduce by itself. One barnacle sends a long tube-like penis over to fertilize a nearby barnacle.
You can see that in this video (they are also feeding):



Goose Barnacles sticking their legs out (video from Malaysia)



If you're really interested, there are lots more videos on the internet and specifically at YouTube. I chose the ones that seemed the best to me. To find more, google "barnacles feeding."

Ok, time for truth telling everyone... Did you read past the spoiler alert before trying this out? What do you think of this investigation? Did anyone do it as written? How did it go? Are the directions clear? If you didn't do it, will you? If not, why not? Your responses will help me decide what kind of activities to post in the future.

Top 10 Ways to Promote Science Inquiry

About a month ago, I promised to post my suggestions for guiding children in their science investigations.

Here are my suggestions, in no particular order:

1. Join in the fun. There's nothing like modeling the behavior you wish to instill to get kids motivated. This isn't "learning" science from a textbook. This is "doing" science. Get your feet wet or your hands dirty. When I was preparing to go out and draw the caterpillars, my daughter (age 5) couldn't wait to get started. My son (age 8) opted not to participate. That is, until he saw the two of us heading out with our pens, hand-lenses, and colored pencils. "Oh... magnifying glasses!" he said. He quickly changed his mind and joined us. I had to insist he come in when it was dinner time.
2. Provide basic materials to enhance observations. For small items, this includes magnifying glasses (hand lenses). For birds or far-off objects, binoculars will do the trick. A bug house or butterfly house is also nice, if you have it. Large jars with holes in the lids will also work for most insects. In addition, a decent set of colored pencils and a notebook chosen for the developmental stage of your child is good. For younger kids, this might be a notebook with blank space at the top for drawing with large-ruled lines below. For older kids, this might be all blank pages (like my son chose) or lined pages. (See examples here.) 
3. Teach kids how to use the tools properly. Practice this before an investigation is to start. Once the novelty of a hand lens wears off, kids are less likely to hold it up to their eyes and make silly faces. (Though that can be fun, too). In a classroom setting, however, it's best to get the silliness out of the way so the more serious work of science can begin. Let them be silly for a few minutes, then indicate when it's time to work.
4. Maintain your sense of wonder. Listen to your children/students talk. Remember what it was like to be a kid, awestruck by natural phenomena. Listen for possible investigations.
5. Slow down and pay attention. Instead of rushing from commitment to commitment, take a few minutes to notice your environment. Is the moon out tonight? Are there any flowers still in bloom?
6. Spend time in nature. This is an extension of above. You can't pay attention to nature without being outside. City dwellers... paying attention to the nighttime sky is a great way to connect with nature's cycles. Or, how about those plants growing up in the cracks of the pavement? Or maybe the birds on a wire above your head. What can you learn by observing them?
7. Share what you're doing with others. Talk about what you've noticed. People are interested in natural phenomena, even if they forget to stop and notice it themselves. Ask if they've noticed the same things as you. Listen to, and learn from, each other.
8. Help kids ask questions and seek answers to their questions. This is the beginning of any scientific investigation. When scientists set-up experiments, they are looking for answers to their questions.  
9. Remember that not every question will lead to an investigation. If that were true, we'd never do anything but investigate (for those of us who have young children, anyway. There's a steady stream of questions from young kids). But, saying, "I wonder..." keep kids thinking in this way even after they pass through the early years. I'd even go so far as to say that it helps keep us grown-ups "young."
10. Know your limits. Learn to recognize when you can continue an investigation without knowing the outcome and when you need to seek more information. For example, I knew enough about the first caterpillars we were investigating (Swallowtails, by the way! Still no changes.) to move the caterpillars into our butterfly house. Once we found the woolly bear caterpillar, however, I recognized that I did not know enough specifics about woolly bears to move it into the butterfly house. As a naturalist, I do not want to harm any animal I'm observing.  I did some quick research before giving my daughter the go ahead. 

Bonus idea for teachers:

Plan ahead. This is especially important for classroom teachers who have a room of 20 or more kids to organize. Having good lesson plans decreases behavior issues. If you don't know what the kids should be doing, how will they? Along these same lines, have good procedures in place. Model the behaviors you want kids to demonstrate. Practice them right from the beginning of the year. Assign jobs such as Materials Manager, Recorder, etc.

Here are two of my favorite books for those of you who want to learn more. Both books are useful for parents and teachers, though Rachel Carson is especially good for parents and Ellen Doris is especially good for teachers.

(I use this book in the graduate level science methods course I teach called "Science in the Elementary Schools: Teaching with Evidence").

Have any of you tried doing investigations with your children/students since you read my posts about the caterpillars? Will you try one now? How helpful was this information?

Caterpillar Investigation, Part 2

Yesterday, I posted about the caterpillars that appeared on our parsley a little over a week ago. I also told you I'd provide updates regarding any changes.

Here's a quick photo update.
Taken the first day we officially observed them- last Wednesday, September 22nd. This was the largest caterpillar at the time.

Taken two days later on, September 24th.

And here' s one taken today, September 27th:

My how they've grown in just 5 days! Nearly doubled in size!

Our primary question is: Will the caterpillars change into butterflies? And, if they do, how long will the process take? My daughter has already connected our observations to The Very Hungry Caterpillar by Eric Carle. In it, a fictional caterpillar eats lots of food (not all of it "real" caterpillar food) and then changes into a beautiful butterfly.

What do you think will happen? What questions do you have?