Red sea urchins an environmental red flag
June 12, 2008 · Updated 4:35 PM
It is likely that when Lewis and Clark reached the Columbia River in 1805, red sea urchins flourished in Washington waters that are still alive today.
Sea urchins easily live to be 100, and the largest ones, about eight inches in diameter, are likely to be about 200 years old, according to a pair of marine zoologists who have been studying the life span of the critters in connection with setting commercial harvests rules and limits.
The findings of Thomas Ebert of Oregon State University and John Southort at Lawrence Livermore National Laboratory in California, were published in Fishery Bulletin.
They measured traces of radioactive carbon incorporated into shells to confirm earlier estimates of sea urchin life span and said even the big ones showed no signs of deterioration. One born while Lewis and Clark were crossing the continent to the Pacific Ocean is as likely to live another year as a youngster, said Ebert, and the old ones produce more offspring. He credited their diet and lifestyle for their longevity. They rarely move more than a yard a day, and eat only seaweed.
On the other hand, they are the piece de resistance on the menu of sea otters, and a delicacy to Japanese and some Europeans who crack the shells open and eat the six skeins of golden-colored gonads both sexes contain.
It happens that the Washington Department of Fish and Wildlife currently is surveying the red sea urchin population to see how its doing.
Its pretty much the philosophy to be precautionary, said Morris Barker, marine resources director for WDFW. Wed rather have something to talk about than where the resource went.
I called Barker over my contention, based on talk with veteran fishers over many years, that we are treading on dangerous ground in the over-harvesting of many kinds of fish, bottom dwelling sea life, seaweed, kelp and the like. We do not know what effect the presence or absence of sea urchins, sea cucumbers, geoducks, etc., has on the health of the marine environment.
Do they contribute something to or take something out of the water that is necessary to the life cycles of some of their co-inhabitants? Did the harvesting of sea urchins and sea cucumbers, initiated in Puget Sound in 1971, contribute to the decline of the salmon, the disappearance of cod and rockfish? How long does it take for the harvested area to reseed or rejuvenate itself?
Barker conceded that the disappearance of what used to be vast beds of kelp and seaweed affected the life spans of many sea creatures who ate it or lived in it, but nobody has Godlike powers to know exactly whats going on.
There is co-management over various types of sea creatures among Fisheries, the Department of Natural Resources and treaty Indian tribes. There are strict rules for harvesting of geoducks to avoid destruction of eel grass beds. It could take 40 or 50 years, Barker said, for a dug out bed to recover. Poachers are common, but many are caught.
There is a license reduction program for red and green sea urchins, of which 1.6 million pounds were landed by state and treaty tribal fishers in the 1999-2001 biennium, and sea cucumbers, 1.1 million pounds catch in 1999-2001. Sea urchins grow on hard bottom and take about four years to grow the minimum size they can be taken, 4 to 5 1/4 inches.
Sea cucumbers reach harvestable size in about 16 months, according to Tom McMahon of the Washington Harvest Divers Assn. They grow everywhere and all but the guts are eaten. Asians dehydrate them, for use in treatment of diabetes or as a snack, battered and fried.
Seaweed harvest is limited to personal use only.
I hope results of the red sea urchin survey tell us to back off sucking up and selling everything saleable in our waters until we know each species place in the life of the ecosystem. Hood Canal already suffers from dead zones of low oxygen levels causing deaths and migrations of bottom dwellers.
Without action on our part, will Puget Sound become a Dead Sea and will we know why?
Adele Ferguson can be reached at P.O. Box 69, Hansville, WA. 98340.