Focusing on Micro Life
Yesterday, all the middle school students had a chance to explore the macro organisms in the coastal habitat of Sandy Beach Park. Today, 6th grade students will turn their attention to the micro creatures floating undetected in the seawater that surrounds us: plankton. Tiny animal plankton (zooplankton) eat plant plankton (phytoplankton) and are eaten by other zooplankton. Some animal plankton (holoplankton) are plankton their whole lives such as copepods and pteropods. Other plankton (meroplankton) are only plankton when they are larvae then develop into adult forms (fish, crabs, oysters, etc...).
To obtain the plankton for the lab, I went down to the Ala Wai boat harbor last night and conducted a plankton tow from a dock. I attached a tow line to a plankton net, a funnel shaped, very fine-meshed net connected to a plastic bottle. When I towed the plankton net through the water for awhile, I got a concentrated sample of plankton in the bottle. I even shined a flashlight at the opening of the net while it was in the water in order to attract more plankton. Once the bottle was emptied into a bucket of seawater, I was ready for class this morning!
I participate in plankton outreach with a local marine education group, Kahi Kai ('one ocean' in Hawaiian), and so Kahi Kai's co-founder and University of Hawai'i scientist Anuschka Faucci helped facilitate today's lab. She brought some novel tools to help us observe and record plankton. These tools for mobile microscopy are called Cell Scopes and were developed by a lab at UC Berkeley. The Cell Scope contains powerful optics and easily connects to an iPhone or iPad in order to document the plankton. Kind of like iMicroscopes! Scientist Raphael Ritson-Williams of Hawai'i Institute of Marine Biology's Gates Lab also joined us and assisted students with slide preparation and plankton identification.
The Big Picture (of little Plankton)
Students were really excited to use the Cell Scopes to take pictures and video of the plankton. Many students commented that they did not realize there were so many little creatures in ocean water. A few students remarked that they have swallowed seawater and asked: "Have I drank plankton?" We all marveled at the diversity of the unique forms and appendages of the plankton, from the spiky-headed crab larvae to the delicately tentacled jellyfish. "It was surprising that such little creatures can eat, move, and grow just like us!" a student named Jack told me. Remember, we depend on plankton for about half of the oxygen we breathe and plankton are the base of marine food chains. Our plankton study also relates to our ongoing investigation of climate change, as this global issue threatens these tiny life forms and all the ecosystems they support.