Posted by DiverD on January 14, 2003 at 10:17:12:
In Reply to: Re: Boring Subject "Sea Urchin" posted by Steve on January 14, 2003 at 09:06:47:
Sorry for the confusion. What I guess I'm saying is there is more kelp now at Hagerty's and Flat Rock then when I was young, say around 1978 or so. I have vivid memories of swimming over barren rocks with nothing but urchins in sight. Its very different now. I was told that a group of divers spent years systematically removing the small bright purple urchins from that area and carrying them away. Maybe its just a rummor. As for otters I've never seen one. They were trapped nearly out of existence in the 19th century.
As for otters absence having little to do with urchin barrens, otters are apex predators at the top of thier food chain. Biologists have shown that removing such predators generally has unpredictable but often extreme and even disatrous effects on the ecosystems they once patrolled.
I don't buy the El Nino arguments becouse El Ninos have been recorded as being regularly occuring for over 500 years, with lots of mention of bad weather and bad fishing, but no mention in over 500 years of forever lost kelp. I would think a good el nino would be like a forest fire, Wiping out old growth and at the same time making way for new.
I really think it has most to do with the fact that the little bright purple urchins are not native, and cause major havoc like so often happens when non-native species are released into a different ecosytem.