Tuesday, July 25, 2017

Twinkle Twinkle Little Star

During the summer of 2014 we saw it happening right before our eyes. Sea stars were dying off from a mysterious wasting syndrome and it was effecting every species of sea stars. The ochre star (Pisaster ochraceus), the most abundant of the sea stars along the BC coastline started to show signs of decay until they totally disappeared. Unfortunately the disease wasn't isolated to our coastline and soon millions of sea stars along the whole west coast of North America from Alaska to California died off. Although there have been similar events during the 70's, 80's and 90's they all seem to be the direct result of warmer ocean temperatures. 

Earlier this year I was paddling around Trial Island and noticed several tiny ochre stars no more than a couple inches across. I was pleasantly surprised and wondered if the sea star populations were making a comeback? This past weekend I was on Thetis Island which is located a few miles off Chemainus, BC and while there I spent some time beach combing during the very low tides of less than 1 foot. Approximately 3 to 4 feet below the high water mark I started spotting that familiar deep purple of ochre stars in every nook and cranny of the rocky terrain. Along a stretch of coastline less than 1000 feet I estimated that there were several hundred ochre stars that were about 7 to 9 inches across and they all looked very healthy. There also was a very good population of leather stars (Dermasterias imbricata) and a few large pink sea stars (Pisaster brevispinus).

Only time will tell if global warming will increase the regularity of warmer ocean temperatures and what effect it will have on the sea stars. It's a wonderful story of the sea stars recovery and hopefully the next die off event won't be permanent.  

Ochre sea stars

Leather sea star

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