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Forage fish, the basic feedstock of the oceans, the fish that other fish eat, are declining in number, threatening the Atlantic economy.CHARLY TRIBALLEAU/AFP/Getty Images

Dan Boyce is a research scientist at the Bedford Institute of Oceanography in Dartmouth, an adjunct professor at Dalhousie University and a master of fine arts candidate at the University of King’s College.

I doubt you give much thought to herring, mackerel, capelin and other small ocean fish collectively known as forage fish. You’d be hard-pressed to see them on the menu at your local restaurant. Yet, despite their anonymity, these small ocean creatures have been called the most important fish in the sea and touch your life in many unseen ways.

As their name suggests, these fish provide the food – or forage that sustains marine ecosystems, fisheries and people. They’re eaten by almost everything bigger, from cod and tuna, to whales, seabirds and sharks.

If you eat pretty much anything – including farmed meat and seafood, wild-caught seafood and fruits and vegetables – it’s possible it was raised on, captured using or fertilized with forage fish. The fish are vital to the culture and traditions of many coastal communities and are among the most nutritious and affordable sources of ocean protein.

This widespread and foundational importance of forage fish is also why a recent downturn in their numbers off of Canada’s East Coast is so concerning. Our once-plentiful populations are declining and fisheries are starting to close, threatening lucrative industries and causing socioeconomic impacts that will ripple through communities and societies.

Oceana Canada recently released its sixth annual Fishery Audit that tracks the performance of Canada’s 227 managed fish stocks. The audit assigns stocks into four sustainability categories: healthy, cautious (harvesting should be reduced to promote rebuilding), critical (serious harm is occurring) or uncertain (data is insufficient to assess their status).

Canada has 17 forage fish stocks dominated by herring, mackerel, capelin and sardines. Of these, only one (6 per cent) is considered healthy, far lower than the proportion of healthy non-forage stocks (27 per cent). On the other hand, more than a quarter of forage fish stocks (29 per cent) are in the critical zone, double the proportion of non-forage stocks.

These sustainability concerns around forage fish are not vague future problems – they have already arrived in Atlantic Canada. Two forage fisheries, one for spring herring in the southern Gulf of St. Lawrence and another for mackerel Atlantic-wide – were abruptly closed this year. A third major fishery, for herring on the Scotian Shelf and Bay of Fundy, is one of Canada’s oldest and largest and appears to be on the verge of closure.

While the Oceana audit lists the status of Newfoundland’s two capelin fisheries as uncertain, scientists and conservation groups fear they have already collapsed and are deep in the critical zone.

Such fishery closures are a drastic, last-ditch effort to rebuild depleted fish populations. As people familiar with the 1992 Atlantic cod fishery closure know well, the closures can last for years or even decades.

It’s perhaps not surprising, then, that the fallout from this year’s mackerel closure was immediate.

Fishermen and fishing-industry organizations worried that the closures would lead to bait shortages that would harm fisheries throughout Atlantic Canada. For instance, the lucrative lobster fishery was valued at $3.2-billion in 2021 and accounted for 41 per cent of the value of all Atlantic fisheries. It relies almost entirely on mackerel and herring to bait its traps. So do fisheries for crabs, tuna, cod and so on.

Yet despite the recent fishery closures and potentially dire consequences, the Oceana audit also indicated that few of Canada’s forage fish stocks have recovery plans with adequate timelines and targets to rebuild depleted populations to healthy levels. The audit listed 41 per cent of forage fish stocks as uncertain. But even though we are fishing those stocks, sometimes intensively, we don’t have enough information to determine their status.

We must do better.

Forage fisheries rank among Canada’s oldest and largest. The landed catch of Atlantic herring alone far outstrips that of any other species in our history. Forage fish are a linchpin of healthy marine ecosystems, driving the production of larger species and supporting fisheries.

Because of this, forage fish are more valuable when left in the water. The economic benefit provided by forage fish has been estimated to be a staggering US$18.7-billion a year worldwide, more than three times higher than their direct catch value.

We must recognize and aggressively protect forage fish stocks. This could be achieved on many fronts. One is improved monitoring and assessment for the 41 per cent of stocks classified as uncertain.

There is also climate change, which is a large and growing driver of fish population change. Yet few forage fisheries consider climate-change impacts when making management decisions. The science tells us that incorporating climate change and ecosystem factors into fish management improves outcomes and reduces uncertainty.

But few depleted forage fish stocks have clear recovery plans with specific timelines and targets to rebuild populations. They need them.

Lastly, because forage fish fluctuate hugely in abundance and form massive schools at predictable locations, they are especially vulnerable to overfishing. Fishing quotas must be set with extreme caution to prevent this from happening.

The critical importance of forage fish combined with their eroded sustainability is creating a looming crisis. It’s time to prioritize vulnerable forage fish populations to improve their sustainability and rebuild them. In short, we must protect forage fish to protect ourselves.

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