Earlier this month, divers from the Vancouver Aquarium’s Howe Sound Research Program extended the reach of their research to McNab Creek – an unchartered area for this team. Their exploration resulted in the discovery of flourishing marine life, including a seabed nursery area filled with juvenile scallops, juvenile spot prawns, and abundant larval herring at two adjacent reefs on the west side of the estuary. While it is easy to spot silvery juvenile herring, the larval stages are translucent and are usually missed by divers, unless the abundance is dramatic. This was the case in the vicinity of McNab Creek.
Newly settled spot prawns must have refuge under dense perennial seaweed of a particular type in Howe Sound. In this case, it was sea colander kelp, a large perennial kelp that grows on deeper rocky reefs, where the water is cool enough for growing young prawns. It was right over the top of this prawn nursery that the huge aggregation of larval herring was milling. Just slightly west of this pinnacle at a shoreline promontory, small pink scallops were observed in abundance. This scallop species can release its hold on rocks and swim away from potential predators.
The McNab Valley on the west side of Howe Sound is very gently sloped, and so it was among the earliest areas to be logged. More recently, almost all of the second growth forest has also been logged. The survival of these nursery areas, despite the extensive logging, is remarkable, and the fact they are flourishing today makes them a significant part of the overall health of the Howe Sound ecosystem. Additional footage of McNab Creek Estuary can be found at this video link, courtesy of John Buchanan of Squamish.
The Vancouver Aquarium’s Howe Sound Research Program is one of five dedicated Aquarium research Programs committed to advancing scientific knowledge and conservation planning. Incepted in 1981, the Howe Sound Research Program has conducted both targeted field research and long-term monitoring of habitats and animals in Howe Sound, a roughly 30 by 20 km body of water spanning from Vancouver to Squamish. Exploration of this “living laboratory” has led to research breakthroughs, the identification of conservation issues, and new discoveries of marine life. Program researchers will be sending updates from the field – via AquaBlog – as new discoveries are made.