One of the kelps that often washes up on the beaches of Vancouver Island, British Columbia is bull kelp (Nereocystis luetkeana). The large, diploid sporophytic stage of this species’ life cycle is the one that we typically see. The form of the kelp is characterized by a holdfast gripping a rock or some other type of anchor, and a long stipe topped by a round gas-filled bulb from which large blades or fronds are attached.
Bull kelp can grow extremely rapidly, and various accounts I have read give rates of over 6 cm per day. The kelp continues to grow until it reaches a length of 10 to 17 metres (some sources say up to 30 metres in length). With all that long line of the stipe and the very buoyant bulb, sometimes the object that the kelp is anchored to isn’t heavy enough and strong wave and wind action can bring the kelp, anchor and all to the shore.
I found these Bull Kelp stranded on the beach at Florencia Bay in Pacific Rim National Park Reserve. I was fascinated by how intricately these kelps were intertwined, a fine tangled mess.
It appears that anchor that they chose just wasn’t heavy enough. Perhaps there’s a lesson here…