Waters off the shore of Denman Island turning Aquamarine with herring spawn (eggs and sperm) Tuesday afternoon.
A big week for biology and communities in Baynes Sound this week as we experienced a significant Pacific herring, (Clupea pallasii) spawn and seine fishery in the Sound and gill net fishery on the outside of Denman Island. We slipped out Tuesday afternoon to witness this biological marvel.
For the local marine environment, the herring spawn is like the Cherry blossoms, the true sign that spring is here. The spawn starts in northern California and makes it’s way northward to Alaska with the warming season and a giant pulse of biological productivity is associated with it. Warming water means more phytoplankton (microscopic drifting algae) and oyster growers in the sound are noting their oysters are fattening and growing again after the winter. Zooplankton, tiny floating marine animals and larvae are increasing and will provide food for all the higher levels of the food chain.
Small Pacific Herring, Bill Pennel photo
As an estimated 93 thousand tonnes of herring come into the shallows of the Georgia Strait this year they deposit and incredible biomass of eggs (roe) which will themselves provide an important food source. A single female may lay as many as 20,000 eggs in one spawn following ventral contact with submerged substrates. However, the juvenile survival rate is only about one resultant adult per ten thousand eggs, due to high predation by numerous other species. In a few weeks, the herring eggs will hatch and the resulting larvae will join the local zooplankton community and be a staple food source for many important marine species such as Pacific Salmon which are migrating out from the freshwater streams.
Whole migratory systems have evolved to follow this wave of productivity. Thousands of seabirds like the once endangered Brant Goose follow this productivity foraging on this bounty as they move northward back to their northern summer breeding ranges. Other species like Harlequin ducks, Scoters and the like, which have been wintering in the Baynes Sound/Denman/Hornby complex will fuel up on herring roe before leaving for their summer ranges in the interior. Big predators like wintering Stellar and California Sea Lions and Bald Eagles all congregate inshore for this event. For the next month the biological productivity of the Sound peaks.
almost the entire Canadian population of Harlequin ducks winters locally
Big predators like wintering Stellar and California Sea Lions and Bald Eagles all congregate inshore for this event. For the next month the biological productivity of the Sound peaks.
Loud California Sea Lions at the Fanny Bay Dock
If you are emotionally connected to the ocean (as we all should be) it is hard not to get excited about this event. The herring fishery which has been doing well in the last few years is a link to our communities as well. This is the last significant fishery to still operate in the Sound and is a tie to our cultural history of fisheries that were once a significant part of the Baynes Sound marine economy.
This is why we are excited to be a part of this year’s Brant Wildlife Nature Festival this year with local communities and the Nature’s Trust of BC. We are sponsoring a number of events related to the festival which you can find here.
So all the above was a good excuse to drop what we were doing for a couple hours on Tuesday afternoon, grabbing a couple practicum students who happened to be in the building and running north up the Sound to watch the Seine Fishery happening along the west shore of Denman Island. A collection of my photos follows and we hope that you will find some time to get out to the shoreline to see this spectacle for yourself. Check the Brant Festival Website for more on viewing opportunities and local Naturalist Dave Ingram has a great photo-essay on viewing the spawn. We’ll also try and post some updates when time allows.
Brian (Station Manager)
If you look close you can actually see herring swimming in the spawn as the water was actually turning white below the boat with milt (sperm).
The Seiner Western Ranger was holding with their Purse Seine having encircled a school of herring. You can see that they are already full of herring with the boat being loaded down to the scuppers already. While we watched two more Seiners one still empty came along to help. Here is link to Purse Seining on Wikipedia.
Skipper on the Western Ranger directing the show from a rigid hull inflatable on the far side of the seine. He was pretty cheery with a full boat, full net and no wind and little rain. He was dipping herring samples and gave us some for our public display tanks. Thanks!
Deckhand in Seine skiff standing by the cork line.
First Year Fisheries and Aquaculture practicum students Solomon and Chelsea lucked out on their first day of practicum and got to go watch the herring fishery up close. We’ll work them harder next week!
Further south, the Qualicum First Nation Seiner Qualicum Producer which calls Deep Bay home port was pumping fish from the end of the seine while tied to another vessel.
Note how deep these boats are in the water too.
Ocean cloud and Pachena Bay doing the same thing the lines visible going out from each were to the Power skiffs pulling boats apart so they can harvest from the seine net pulled between them.
The entire eastern side of the Sound along the Denman Shore was turning aquamarine even on such a grey day by the time we left.
Our new herring adapting to our local Baynes Sound habitat tank back at the Station.