Since 2011 we have been working diligently in False Creek at the Fishermans Wharf in Vancouver wrapping creosote pilings and making net panels which provide artificial spawning substrate for herring spawning and rearing habitat. Just like the Squamish estuary, native spawning substrate called eelgrass had been dredged away to increase the depth of navigation channels and anchorages that ensure the safe passage and moorage of boats.
Dr. Matsen and Douglas Swanston first began testing the effectiveness of Enviroliner wraps in False Creek to protect herring from spawning on creosote on the pilings. While this technique helps hatch out rates, it did not solve the problem. As the tide moved up and down the herring eggs were exposed to deleterious substances on the surface, such as oil and fuel in the marina, which kills many of the eggs. For this reason when installing new infrastructure, such as commercial wharfs and marinas we are recommending concrete or steeling pilings.
Streamkeeper and Marine Biologist Douglas Swanston hand-crafted the first mesh spawning panel that kept the eggs under the surface. This unique technique of habitat restoration helped restore the local herring spawning and rearing habitat, assisting the depleted herring stocks in the Howe Sound, Burrard Inlet and False Creek. Net panels in False Creek virtually have a 100% hatch out rate! We currently have 160 net panels at Fishermans Wharf during the spawning season, with the need to increase this every year as we have more fish returning than expected. The herring can tend to spawn on previously spawned out nets if there is no where else to go. Like algae on the nets, this double layer of spawn smothers the eggs that are already there. Additionally, we have nets out at the Government dock in Squamish to see if anything turns up there.
All our projects are facilitated 100% by volunteers. We use donations to buy new material needed for the restoration work we do, as well as to fund community engagement initiatives.
Herring Life Cycle
In a Pacific Herring life cycle there are five stages, i.e. fertilized egg, larvae, juvenile, fingerlings, and adult. Herring hatch out into the larvae within two to three weeks of deposition. However, they do not all hatch at the same time. Larvae spend their first summer in protected bays that we now call Marinas and Commercial Wharfs in urban areas. At approximately 10 weeks of age larvae begin to grow from juvenile fish to fingerlings, and are not sexually mature until they reach 2-3 years of age as an adult. In the adult stage of life at 3+ years herring live in schools with a mixed age structure of 2-17 years old. The higher age class is typically closer to 12 in Southeast Alaska, Central BC, and Southern BC. Some fish only live to be 7 years old. Herring can spawn multiple times in their life and as they mature they carry more eggs. A large single female adult herring can carry up to 200, 000 eggs!