CERCA project aims to bring herring back to Cowichan Bay

It was a cold and rainy evening when 10 Cowichan Estuary Restoration and Conservation Association volunteers met at the Fisherman’s Wharf in Cowichan Bay on Jan. 3 to initiate CERCA’s herring recovery project in this part of the Salish Sea.

The work was timed to take advantage of a very low tide of 0.4 metres at 9:30 p.m., chosen to wrap a whopping total of 28 pilings under the sheltered wharf.

Historically, herring had spawned in abundance in numerous places along the shorelines and estuaries of the Salish Sea including the Cowichan Estuary. But those numbers plummeted in the mid-20th century as a result of industrial pollution and incompatible use of estuaries and shoreline habitat that killed herring eggs before they had a chance to hatch. Spawning habitat in Cowichan Bay and the Salish Sea at large has become scarce due to the man-caused disappearance of seagrass and kelp beds constituting prime spawning habitat in the past.

CERCA has been anxiously waiting for this moment, making use of the very low tide and the alleged peak spawning period by herring of the Salish sea between January and February.

The test pilings will be monitored as of the end of January hoping that herring will like their new spawning habitat. If successful we intend to search for additional suitable sites using the same technique, wrapping creosoted dock pilings with UV-resistant landscaping material that prevents creosote from destroying the herring eggs. This method has been successfully employed by the Squamish Streamkeepers Association since 1977 in the Howe Sound Region and Vancouver’s False Creek docks, resulting in an astounding hatching success and recovery of sizable herring populations for the benefit of the entire marine food chain.

We will report on the progress of the project.

The recovery of herring populations is considered key to the rebound of local salmon populations, which in turn will encourage marine mammals such as dolphins and whales to return as has happened already in Howe Sound.

CERCA gratefully acknowledges the financial support of the project by Sidney Anglers.

Dr. Goetz Schuerholz is the chair of CERCA.