The urchin plague strikes at the kelp's holdfasts their crucial attachments to the rock. 海胆们正在吃巨藻的固着器 把巨藻固定在石头上的重要装置
but each urchin has five teeth, which are self sharpening and are replaced every few months. 但是每只海胆有5个锋利的牙齿 而且每隔几个月就换牙
Urchins fell vast areas of kelp forest creating clearings know as urchin barrens 海胆吃掉了大片的海藻森林 把它们变成了不毛之地.