Getting a grasp on the marine life thriving in our waters

Biologists are the kind of people who have to wash their hands before they go to the bathroom as well as after. Take last Friday, for example. Vic asked me to bring a selection of marine invertebrates to show to his natural history class. That’s how I found myself lying on my belly on a wooden dock in Huntington Harbour, fishing around bare-handed under the dock for disgusting, slimy things. Talk about needing to wash your hands. Yuck.

Vic wanted at least one example from every major phylum of marine invertebrates. Between the dried and preserved specimens that I have for the classes I teach and specimens provided by Laura Bandy and Bob Adams from the Bolsa Chica Conservancy collection and the Southern California Marine Institute, we had everything from sponges to tunicates.

Echinoderms (sea stars, sea urchins, sand dollars and sea cucumbers) were well represented with dried specimens. For mollusks, we had a large collection of shells from local beaches plus preserved squid and sea hares.

But Vic wanted some live invertebrates as well. I visited a bait and tackle store in Seal Beach, where I picked up some lugworms to represent annelids and some Oregon ghost shrimp to represent the arthropods.

I put the 8-inch-long lugworms in a dish of seawater so the students could see how their many parapodia, or legs, move. The female ghost shrimp obligingly swam in her dish of water, fanning the egg masses that she carried on her belly. But neither the ghost shrimp nor the annelids were native to Southern California, so instead of releasing them at the end of class, I turned them over to Bandy to be used to feed fish in the aquaria at the Southern California Marine Institute.

For me, the biggest surprise was seeing how broad a spectrum of sea plants and invertebrates could be found in a few square inches on the side of a dock. These growths are considered fouling organisms and are scraped off periodically anyway, so I didn’t feel bad about taking a few specimens. I plucked one each of the three different types of marine algae or seaweed, finding representatives of green, brown and red algae. Each one of the four-inch-long plants had an entire microecosystem that came with it.

When we put the algae under a dissecting microscope, we found a mass of tiny white nudibranch eggs that were laid in a characteristic whorl. We found an anemone that was only a quarter of an inch across. And we saw plenty of copepods and isopods dashing about. These tiny arthropods are near the bottom of the food chain and are part of the plankton that supports the vast array of life in the ocean.

Between Bandy’s dock samples from Terminal Island and mine from Huntington Harbour, we had five different species of tunicates. Taylor’s colonial tunicates are tiny animals, each one about the size of the tip of a pencil. These bright orange dots live in colonies that are one to three inches across. You can see them at low tide growing on rocks or mussels. Most of the tunicates, or sea squirts, were a couple of inches long with two tubes. Water goes in one tube and squirts out the other. Vic says that of all the marine invertebrates, they are the ones most closely related to vertebrates. Like us, they have a notochord during embryonic life.

Sponges are the least evolved of the marine invertebrates. They are simple organisms with two layers of cells. Water flows through pores that permeate the tissue. The water brings in plankton, which are captured and digested by specialized cells on the inside of the sponge. I brought a natural bath sponge as an example. I also had a small living sponge that I collected from under the dock. This species of encrusting sponge is called a breadcrumb sponge. You can see some fairly large ones off the walkbridge at Bolsa Chica. Just look for the yellow blobs on the bottom. About the only things that eat adult sponges are nudibranches, but lots of marine critters feed on larval sponges.

One of the most obscure phyla is the Bryozoans, or moss animals. The most easily observed species is called kelp lace, a lacy white net that is tightly attached to kelp. You can see it on kelp that has washed up on the beach. Other encrusting bryozoans grow on mussels and other mollusks.

People are always asking what this and that strange animal is good for. One answer is that everything has its proper place in the ecosystem. Things eat and are in turn eaten. But with Byrozoans there is a more directly relevant answer. One species of Bryozoan harbors a species of bacteria that produces a class of chemicals called bryostatins. The chemical class is macrocyclic lactones, but you can live a long and happy life without knowing that.

The key point is that bryostatins are potent anti-cancer compounds. The National Cancer Institute is actively recruiting patients with solid tumors that have proven resistant to other types of chemotherapy for Phase I clinical trials. For more information, see https://www.clinicaltrials.gov/ show/NCT00003993.

Bryostatins are also being investigated as a treatment for Alzheimer’s disease and as memory enhancers. You never know what strange and valuable things you’ll find in the sea. That’s assuming that we don’t pollute them into extinction first.