The West Coast boasts a year-round exploration season of forested trails and rugged shorelines that seem to never end. The dense-growth temperate rainforests are filled with tall trees covered in mosses and forest floors brimming with lush vegetation. The beaches are fiercely traversed by wild winds and beating waves. This is my home. Many West Coast locals happily spend their afternoons beachcombing with family or friends and exploring freely. As a child, I remember playing with washed-up bull kelp and goofing off with the large alien-like kelp bulbs all over the beaches, never really knowing what they were.
As an unscientific-minded individual, the term Nereocystis luetkeana rattles my brain. I’m not doubting my own intelligence, I just thrive in other areas of knowledge and literature—don’t we all? So, what is Nereocystis luetkeana? It’s bull kelp. In Greek, it means “a mermaids bladder.” I love that. I can see it now—a slimy, spherical bulb with long tresses of hair-like seaweed flowing through the currents of the sea, forming a forest in the oceans on the coast of the Pacific Northwest.
Bull kelp thrives in cold-water areas and loves places with a strong current, like the Strait of Georgia. Bull kelp is an annual kelp, which means it reproduces each year. The Slater Museum of Natural History website says that bull kelp can grow over 30 metres long, extending from the ocean floor all the way up to a buoyant hollow bulb at the water’s surface, and have a rapid growth rate.
Unfortunately, in recent years, many of the kelp beds in our local waters have disappeared, and I wanted to know why. Was it due to human influence?
I spoke with Jane Watson, a retired biology faculty member of Vancouver Island University who has a wealth of knowledge about kelp. I asked her why these underwater forests of “mermaid’s bladders” were so important, and what issues were causing their decline.
Healthy kelp forests are essential for the Pacific Ocean’s ecosystem to flourish and stay healthy. The extent of their importance is astounding. Watson informed me that bull kelp forests provide habitat and shelter for fish, protecting many sea creatures from storms. They change how water currents move and reduce erosion by retaining debris and sand. Bull kelp forests also create food webs. On a global scale, the Ocean Conservancy website says, “kelp forests can absorb and hold carbon which might otherwise end up contributing to rising global temperatures.”
I asked Watson what she thought was the reason behind kelp forest disappearances around Nanaimo, and what factors were contributing. “Death by a thousand cuts,” she said. For me to understand the possible reasons for kelp forest decline, she told me she first needed to fill me in on the process of bull kelp reproduction.
Bull kelp require clear, cool, nutrient-dense waters to survive, as sunlight needs to penetrate through the water for the reproduction phase. Watson gave me a rundown on bull kelp’s two-phase life cycle. It begins when adult kelp release spores into the water. These spores settle on the bottom of the ocean for the winter. During this time, they develop as either male or female microscopic gametophytes. The females produce eggs, and the males produce sperm. The sperm then find the eggs on the ocean floor, and—bang! By springtime, a sporophyte develops from the female egg, and kelp growth begins.
Rising water temperatures, or thermal pollution, directly affects kelp health. Watson told me that the kelp is not able to survive and reproduce in warming waters. This makes sense, as our oceans are warming due to climate change, and the reality is that many aquatic species can’t adapt.
“I believe something is affecting the reproduction on a microscopic level,” Watson said. “The Fraser River has been dumping silt into the waters, covering the microscopic male and female plants, or newly developing sporophytes, which will become the bull kelp plant we see on the ocean floor.”
The kelp’s reproduction cycle has been made difficult due to pollution. A report from University of California on the ecology and management of bull kelp stated that “[s]ewage discharge and nutrient runoff associated with agriculture could trigger phytoplankton blooms that significantly reduce water clarity.” Like humans, bull kelp need clean water and food to live. It’s no surprise that Nanaimo’s bull kelp forests are in major decline.
Brian Timmer is a master’s student at the University of Victoria. He works in the Spectral Remote Sensing Lab with the Hakai Institute doing coastal science research. “We use remote sensing drones to go out and monitor bull kelp forests. We can use technology to better monitor kelp in different areas, and see where we can help,” Timmer explained, to my amazement.
Timmer was a scuba diving instructor in Nanaimo before starting his undergraduate degree, and this is where he discovered his love for bull kelp. He shed some light as to why bull kelp in Nanaimo have had a particularly tough time, and frankly, it blew me away.
“Around ten years ago I would regularly dive in Nanoose and there were a lot of sites with really gorgeous healthy kelp beds, but when the marine heatwave—known as the ‘Blob’—came in 2014 to our coastline, the kelp suffered.”
He told me that this heatwave also contributed to sea star wasting syndrome, a disease that turns the sea stars to sludge and literally melts them away. It affected various species of sea stars along the entire West Coast from Alaska to Mexico.
“It was the largest disease-related die-off of a marine species, and it’s still happening,” Timmer said.
This is another crucial reason why the kelp isn’t surviving around Nanaimo. This heatwave has impacted the predator-prey ecosystem, which has consequently affected the bull kelp in our waters. To put it simply, sea urchins eat kelp and sea stars eat urchins, and when these populations become off-balance, the kelp suffers.
“Some of the bigger sea stars that would have eaten urchins were completely wiped out. There was a break in the food chain where now the sea urchins have nothing eating them and are exploding in population,” Timmer said. He told me that while Nanaimo has river otters, it does not have sea otters, which are another significant predator of the sea urchin.
So, death by a thousand cuts is an apt statement. As I grew up in Nanaimo, learning about the loss of kelp forests is devastating. Climate change is upon us. Water temperatures are rising, and our local habitats are suffering. In speaking with Jane Watson and Brian Timmer, I learned that this is a complex issue with many factors, and if one element in an ecosystem is disrupted, it affects the entire system.
On a more positive note, bull kelp is not declining across the entire West Coast, but only in some locations. Timmer told me that kelp in the Victoria area is flourishing, as the waters are cooler there and provide more current.
For more information, check out this short video of Jane Watson speaking on the importance of bull kelp in our waters.
