Eco engineers

摘要

For the past 30 years, Jane Watson has witnessed one of the most extraordinary underwater transformations. Year after year, on the west coast of Vancouver Island in British Columbia, she has been diving at the same sites, watching areas known as 'seaurchin barrens' transform into beautiful forests of 2m-tall kelp. The difference between the two environments is striking.Watson is an ecologist at Vancouver Island University with a particular interest in kelp forests. Whenever she explores a sea urchin barren, she finds herself floating in a pink world due to the overwhelming presence of pink coralline algae. Invertebrates such as sea urchins, abalone, chitons and sea cucumbers, which thrive in the open, are all easy to see. "It's like being on a grassland because it is an exposed environment," Watson says. In stark contrast, diving among the waving brown kelp is like hiking in a forest teeming with juvenile fish.