Thursday, May 16, 2013

Cholla Bay the Soft Sediment Intertidal


Before I got here, I thought intertidal zones were only the rocky kind. Yesterday I learned that is not the case. The soft sediment was like mud squishy underneath my feet (thank goodness for scuba booties!)Because the sediment is so soft the bi-valves are able anchor themselves down into it, staying moist while everything at the surface begins to dry. Fiddler crabs also dig into the sediment to create a little home while the water is gone. They borrow a little hole for themselves pushing out the mud in the shape of little balls. It was interesting to see how some of the fiddler crab holes only had a few balls by it while others looked like the crab had been working all day. The octopus stays hidden from the elements by squishing down and hiding into any little place it can find. We found two different ones hidden inside of Black Murex shells. The second one was squished down so far we didn't even realize it was there when we first picked it up. The little limpets use a strong muscle to grasp tightly onto the surface of something (rock, a clam, etc.) It creates super glue like seal hold in a little bit of water between them and their shell. This allows them to stay alive while the tide is out.

            Overall I think my favorite critter we saw that day was the octopus. When we were handling it, it moved very quickly trying to compress itself into anything. It tried the bottom of the bucket, but we were still able to find him. On land they are wobbly walkers using their tentacles to pull themselves towards the water, but once in the water they are able to swim quickly to find a new hiding spot. 

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