COW OF THE SEA! That is what our local Green Sea Urchin was called this week during a talk on the habits and status of this curious Echinoderm. We find them wedged in crevices, or under rocks, but they move about on those numerous spines and tube feet to feed on kelp and other sea algae. The speaker was Amanda Leland who is doing research at the Darling Marine Laboratory here in Maine. In her words, "the urchin industry is decimated". During the late 1980s urchin harvesting began in earnest, and peaked around 1993. By 1999, there were not enough urchins to harvest in Casco Bay. What has happened is that the urchins are not coming back naturally. Their primary predator, the Jonah Crab, is increasing in numbers while the Cod (also a predator) is still struggling to survive.
Efforts are being made to reintroduce the Sea Urchin in hopes of achieving a restoration of these primary herbivores, with limited success. Though urchin provided a good economic return for divers in the past, there is little concern for their absence among the public. Lobstermen (who didnt harvest them) consider urchin a pest since they have been known to chew their lines causing trap loss and venture into traps for the fish bait. The roe of urchin, popular in other cultures, is not sought here. There is little concern for the plight of the urchin.
I did clear up a misconception during this talk. As most of you know, urchins have been harvested in the winter by divers. It was during the cold seasons that their roe developed and achieved commercial value. I had always wondered why the harvested urchins, when opened, all had "eggs" yellowish clusters that almost filled the inside of the tests. Why didnt the males (since they are either male OR female) look different or empty when cracked open? I now understand that what is sought for the diet of the Japanese (and others) are the gonads, or sex organs which when developed look alike in both sexes. They can be distinguished under a microscope.
I also learned that the urchins scientific name, Strongylocentrotus droehbachiensis, not only described the "strong center" (try cracking one open sometime) but derives its specie name from a town in Norway, Droehbach (which I couldnt find on the map!). Incidentally, I believe that name is the longest to be used for a plant or animal in scientific nomenclature. It is a mouth full!!
Those of us who enjoy discovering the diversity of sea life on our shores have cause for concern regarding the Sea Urchin. As for me, I am going to eat more crabs and encourage others to substitute Crab for Lobster rolls. I shall be more cautious in observing these spiny echinoderms, and think twice before dissecting out its intricate tooth structure, Aristotles Lantern. Diversity of our species is an important aspect of nature. Lets consider the urchin
Photo credit: MARINE LIFE OF THE NORTH ATLANTIC
by Andrew J. Martinez.
Drawing: by yours truly. How many of the creatures can you identify?
Ó 9/15/02 Ronnie