#12: Weir are you? Part One...

Fishing weirs have been used in North America as a means capturing many different fish species for thousands of years. In Boston's Back Bay, remnants of fishing weirs thought to be about 2000 years old have been uncovered during various construction projects. Today, fishing weirs are still a widely used means of fishing in many parts of the world. In British Columbia, salmon is the target fish, while in Nova Scotia, weirs are used to catch shad.

A typical Bay of Fundy weir. Photo: www.brunswick.ca/Learn-About-Sardines/

In simple terms, a weir is a fish trap made of a series of wooden stakes with twine stretched between each stake to catch fish, but water is allowed to pass through freely. Weirs are built in tidal areas, so they are a perfect and efficient match for the Bay of Fundy! In most of the Bay, the target fish is herring (although flounder and mackeral are targeted in other parts of the Bay). Herring move to the surface and inshore at night. The weirs have a  "fence" that direct the herring into opening of the weir, where the fish begin to swim in a circular or figure-8 pattern which always directs them away from the opening. Unable to exit, the fish are eventually collected from the weir using a purse seine which draws fish to the surface and collects them into a condensed group when the net is pulled tighter (or pursed).

You can get in, but the chances of getting out are slim. Photo: http://www.gma.org/herring/default.asp

Herring is an important commercial fishery in the Bay of Fundy and is sold in many different forms. Herring can be consumed fresh, but can also be smoked and sold as Kippers. In the Atlantic, sardines sold in cans are simply a small herring. In addition, herring is used for bait for other commercial fisheries, such as crab and lobster, as well as being used in feed for pets, livestock, aquarium and aquaculture fish. Even the scales of herring (called "pearl essence") have been found useful by both the paint and cosmetic industries.

On occasion, cetaceans might enter the weir (here in the Bay of Fundy, it's usually harbor porpoise) and feed on the schooling herring. However, just like how the herring cannot find their way out once entering the weir, cetaceans can also find themselves in the same predicament. In 1991, the Grand Manan Whale and Seabird Research Station (GMWSRS) began a  harbor porpoise release program  to assist local fisherman with the safe release of porpoise found in their weirs. Since the start of the program, they have successfully released over 700 porpoise from the weirs around Grand Manan!

The GMWSRS Harbor Porpoise Release Program Team successfully releasing a harbor porpoise. 
Photo: www.gmwsrs.info/conservation/hprp/

On Saturday August 25th, GMWSRS received a call about a large whale (based on the description, possibly a right whale mom and calf pair) that was spotted in a herring weir on the western side of Grand Manan Island. On this particular day we were not on the water running our usual surveys in the Bay. Since the location of the weir made it much easier for us to respond from our port of Lubec than for other vessels out in the Bay to respond, we were asked to confirm and document the presence of an animal in the weir, and to identify the species. We decided to take our faster research boat, Callisto, since it was late in the day and and she could make the 13 mile trip in half the time the Nereid could. As I set out on the Callisto with Marianna and Meagan, I began to wonder about all the possible things that could be in the weir. Could it be a really large minke whale? Maybe even a basking shark? I figured it could also be humpback whale, since it had happened before... but I also knew of a couple past cases where right whales had entered weirs. As we cleared West Quoddy on that gorgeous Saturday afternoon I wondered.....could we actually be heading to a right whale entrapped in a weir?


Stay tuned for Part 2....


  1. What a cliff hanger! I'm on the edge of my seat, I hope you post the second one soon! ;)

    1. As you wish! We're glad to report a happy ending :)