It started with introducing a sub-species of Canadian goslings from Ontario more than 60 years ago, now Vancouver Island estuaries are paying the price.

Garreth Ashley, a wildlife biologist with Guardians of our Salish Estuaries, also know as GOOSE, recently made a presentation to the Regional District of Nanaimo board about the status of the interior goose population, which is pressuring the Island's estuaries.

"In the 1950s and 60s the provincial and federal government for the intent, and the good intent, of increasing hunting opportunities for wildlife viewing started transporting Canada geese from places like Guelph Ontario to the west coast of Canada," Ashley said. "They brought these geese in crates and a lot of them were actually goslings that didn't have parents that teach them how to migrate."

The geese feast on the edges of water channels, affecting vegetative cover. For native geese that migrate, the vegetation can recover, but for populations that stay year-round, increased feeding breaks sediment stabilization. This can turn a thin and deep water channel that serves as an effective salmon habitat into a shallow, broad channel that heats up in the summer and is ill-suited for fish species.

Several initiatives are underway between First Nations and the stewardship group to combat the feathered foes, which Ashley reports have been successful in reducing the population, with new record-low numbers at different sites in 2024.

These include installing eco-cultural fencing to deter non-native waterfowl, and transplanting Lyngbye's sedge grass to protected areas where naturally growing vegetative cover no longer exists. 

A major initiative is addling, which means shaking the eggs of the year-round geese, detaching the membrane from the shell wall, halting development. Another initiative is harvesting the meat. 

Nests have decreased from 75 to 16 in the Englishman River Estuary, and Little Qualicum River Estuary stabilizing at 10 nests for the last three years, with a previous peak of 35. The Nanoose Bay Estuary peaked at 17 nests, but had zero for the last three years.

(Nests recorded for Englishman River Estuary, and Little Qualicum River Estuary and Nanoose Bay Estuary from 2013-24. (GooSE))

Despite the success of the efforts, Ashley drew attention to a spike at the Englishman River Estuary in 2022, when it went from 31 nests to 34, before going down to 18 in 2023.

"I get a lot of people asking what that is. It speaks to the need for a regional approach to Canada goose mitigation. The City of Nanaimo, unfortunately, was doing nest surveys but not addling thoroughly."

As a result, maturing Canada geese that were tagged in Nanaimo were moving into freed-up space at the Englishman River Estuary.

"We had a slight spike a few years after our success with harvests because carrying capacity had been met in Nanaimo in their nesting areas, and those geese were moving north to find open territory." 

Since then, Ashley said the City of Nanaimo has increased its addling efforts, which he contributes to its new record-low number of 16 in 2024. 

"We do want to take a regional approach to Canada geese because they can fly about 1,200 kilometres a day so if every municipality isn't chipping in you don't get that kind of success that we're going for."

Following the presentation, Jessica Stanley, regional board member, said Cedar is dealing with the geese wiping out cabbage crops "like you would not believe."

"I have had complaints from farmers and obviously we have the Nanaimo estuary," Stanley said, asking how they could work with farmers to report nests and work with GOOSE. 

Ashley welcomed farmers to connected with the group, and said they would be happy to teach methods to dissuade the birds. He explained that the group is identifying new areas with populations that can be harvested after approval from the federal government, which he said is a "rigorous process" but "protecting agriculture is one of our primary concerns."

"We've heard horror stories, of you mentioned, with $10,000 worth of seedlings disappear overnight when a flock of geese land," Ashley said.

Vancouver Island has a native migratory subspecies, Branta canadensis fulva, also known as the Vancouver Canada goose, which nests on the northern part of the Island bi-annually.