Island group mapping and replanting ocean forests

Rachelle Stein-Wotten

Sounder News

Monday, June 17 2013

Years ago, plying through Gabriola’s waters by boat meant maneuvering through dense stretches of bull kelp.

While some areas like Drumbeg and Gabriola Passage still have rich kelp canopies, the algae remains conspicuously absent in other areas.

Its disappearance has alarmed a group of Gabriolans and spurred them into action to save the keystone plant species by replanting kelp beds in Gabriola’s waters.

Help the Kelp began in 2009. Ken Capon, Michael Mehta took several boat trips, distributing strands of tiny kelp covered with sporophytes – the reproductive components of kelp – by tying them to string wrapped around rocks.

Now, Michael (see right), who has a PhD in environmental science, is leading a team to begin mapping the entire island this summer to learn where bull kelp are healthy and where the group has the best chances of further replanting efforts taking hold.

“We realize the ecosystems have declined so dramatically that it’s not simply enough to observe or catalogue or map them ... we need to do direct intervention.

“Kelp forests are like the lungs of the ocean,” Michael said. “They take up a tremendous amount of carbon, so they play a role in climate change mitigation; they provide a lot of carbon and nutrients and minerals” and act as a nursery for forage fish, which are food sources for other fish such as salmon as well as marine mammals.

“It’s important that we re-establish the balance that’s been lost; if we don’t, we risk losing a lot.”

Globally, kelp face numerous threats.

Michael said much of the decline appears to be due to ocean acidification and rising water temperatures.

The population of sea urchins, which eat kelp, has been expanding rapidly. While diving in the north end, Michael has seen “thousands” of urchins in under 30 minutes.

Adding to the problem, the wolf eel – a voracious urchin predator – has been overfished.

Outboard motors and trolling boats can also wreak havoc on a kelp bed, slicing through an entire canopy, severing the stipe, or stem, and causing the whole plant to die. 

Last week, Michael watched from the shore as a barge plowed through a kelp forest that Help the Kelp had replanted.

“We need to figure out how to make aware to boaters that they shouldn’t be going through bull kelp canopies, they shouldn’t be fishing in them.” During the group’s replanting phase he would like to see areas protected and local governments to lobby companies like CSPAN and BC Ferries to stay 1,000 metres away from shorelines. 

Much of the area the group will be replanting in will fall within Parks Canada’s proposed National Marine Conservation Area Reserve, particularly the south end of the island, and will help ensure activities such as shipping, fishing and tourism are ecologically sustainable. 

Michael said he hopes community groups will still be able to continue work in the NMCA.

Past efforts have concentrated replanting in the Whalebone area and Berry Point.

“We don’t know how successful those ... are,” Michael said. “We know from at least basic observation that it seems to be working, [but] we don’t know the extent to which it worked.”

Mapping will help determine that for future plantings. Afterwards, the group is planning on taking several planting approaches.

Along with the approach taken the first time, other methods planned are to anchor a rope to the sea floor wrapped with a spool of baby kelp full of sporophytes, the same method used by kelp farmers; attempt a “sori transplant”: snip leaves from healthy kelp plants around Gabriola, and put them in biodegradable mesh bags and attach them to the sea floor; create a sea urchin exclusion zone in which divers will take all sea urchins out of a designated area and move them elsewhere; and finally, reintroduce wolf eels, the most expensive proposition.

Mapping and monitoring equipment is expensive and the group is running completely on donations. Contact helpthekelp@hotmail.com to find out how to get involved and visit the group’s blog, www.helpthekelp.blogspot.ca, to follow the group’s work over the summer.