No Such Thing as a Free Lunch

October-November 2006

This is an article from WaveLength Magazine, available in print in North America and globally on the web.
To download a pdf copy of the magazine click here: > DOWNLOAD

by Neil Schulman

Lingcod and rockfish habitat—vertical rocks and lots of kelp.

Ah, perfection. You paddle from your campsite to a nearby kelp bed, drop a handline, and hang out for a few minutes. Not too much later, you’re paddling back to camp with a sizeable rockfish for dinner. Life couldn’t be much better.

Actually it could—if you’d caught something else, because that rockfish could be older than your grandmother and may have been born before the 1898 Klondike Gold Rush. Rockfish grow very slowly, and make up for that with a very long lifespan. They also have a slow reproductive rate—some species don’t breed until they hit 40 years old, and they produce few offspring each year.

Don’t get me wrong—I like fish as much as anyone. I’m lousy at catching them, but I excel at the eating part. My friends have seen me pry urchins off the rocks and eat them as a mid-paddle snack. And the west coast of North America is a great place for kayak fishing—but it deserves a bit of care about what we fish for, and why.

TROUBLE IN PARADISE?

Kayak fishermen often fish in protected waters with kelp forests.

When I run down the list of common Pacific fish, especially those caught from kayaks—salmon, steelhead, rockfish, lingcod, flounder, halibut—two patterns emerge. Pacific halibut and flounder are doing well. Salmon stocks vary greatly, but many are doing well where they don’t have to contend with dams, fish farms and lost spawning habitat. But rockfish and lingcod are in serious decline, even though they don’t have to fight past dams. And unfortunately, these species may be the best for kayak fishing… or is that a clue in this fish mystery?

Rockfish have declined in California, Oregon, Washington and BC. Oregon is contemplating new Marine Reserves which will be closed to fishing. Washington has closed the rockfish fishery altogether. In BC, the Canadian government is developing new fishing restrictions for rockfish and lingcod for 2007. Of nine major rockfish species on the West Coast, five are known to be in decline, three lack any population data, and only one is stable. Except in Alaska, lingcod populations have been declining for 10 years. As a wake-up to a lot of paddlers, the Broken Group Islands, BC’s legendary sea kayaking destination, has been closed to fin-fishing. (Check the Department of Fisheries and Oceans’ website www.dfo-mpo.gc.ca for the many Rockfish Conservation Areas on the BC coast, mostly in Georgia Strait and Johnstone Strait.)

But why are these fish in decline? The answer to this mystery lies with two letters.

THE SECRET OF ‘R’ AND ‘K’

All organisms have their own ways of reproducing, but they generally fall into two strategies: R and K.

The R-strategy is lots of offspring, quickly cycled, with little parental attention. These species—frogs, crabs, barnacles, and fish such as herring and salmon—produce huge numbers of offspring and let them fend for themselves. Many will be eaten by predators, but if you produce enough, usually enough survive to ensure the next generation. The young mature quickly, and soon begin their own reproductive cycle. R-reproducing species tend to have boom-and bust cycles, but without major human interference or ecosystem damage, they can ride out the busts.

K-Reproducers are the opposite—they produce few offspring, which they carefully nurture to an adulthood that comes much later. The young tend to have higher survival rates, and instead of boom-and-bust patterns, their populations tend to be stable around the carrying capacity of their habitat. It’s a survival strategy based around a stable environment. But this is a double-edged evolutionary sword: if something does go wrong, the population won’t recover quickly, because there are fewer young and they won’t start producing their own for awhile (an average of 20-40 years for rockfish.) Humans are obviously K-reproducers, along with most large mammals, seabirds, and octopi. And you guessed it—so are rockfish and lingcod. (See endnote.)

While this salmon journeys thousands of miles, lingcod and rockfish just stay home, and are vulnerable as a result.

THE FACTS ABOUT ‘K’ FISH

Rockfish and lingcod are vulnerable to overfishing because of how the various aspects of K reproduction manifest themselves. For lingcod, it’s how they protect their small stash of eggs—they guard them. After the female lays eggs in undersea rocks, the male will stay nearby for about three months during summer, and chase off anything that might eat them. This means that they’re very susceptible to fishing pressures, especially the kind that kayak fishing can generate—dropping a line near some offshore rocks that look promising. Lingcod may snap at lures as a defensive reaction in protecting its eggs, or as a source of food for a hungry fish stuck in one place.

Rockfish are also sedentary fish. Unlike salmon, which migrate widely across the ocean following food and currents, rockfish tend to stay in very localized sites—particular kelp beds and offshore rocks. Again, these are prime places for recreational fishing, kayak fishing in particular. As a result, rockfish are very prone to localized depletion. This often happens around popular campsites. Kelp beds and rocks near a good campsite have probably been fished by native cultures for centuries, and by kayakers for decades. It will take a couple of decades before the next generation of rockfish produces any offspring, which means the population will need a long time to recover.

Rockfish also have swim bladders. When a rockfish is brought to the surface, the gases inside its swim bladder expand and the bladder balloons and bursts, sometimes being expelled through the mouth. Even when the fish appears unharmed and swims away, its swim bladder has been damaged and an infection will set in, killing it within a few weeks. Which means that once you bring one up, it will probably die, even if you let it go. So keep it and stop fishing.

IF YOU NEED ANOTHER REASON

In a world full of multi-national megacorporations, the rockfishing industry is a rare thing—an industry that’s largely small and locally owned. Half the boat captains are self-employed and live full-time in the mostly-rural coastal communities they fish from. Recreational fishing for rockfish and other nearshore species brought over $17 million into the economy of California alone, without adding BC, Oregon and Washington. So it makes sense for us to make sure these fish stay around.

WHAT YOU CAN DO

Decline of Rockfish species on the west coast of North America. Courtesy of US NOAA Fisheries (National Oceanic and Atmospheric Administration).

The easiest thing to do is to stick to fish that have healthy populations and can absorb the fishing pressures. This means species like salmon, especially north of the US-Canada border, pacific halibut and pacific flounder and black cod (sablefish). Lingcod populations in Alaska are still generally healthy. You can also stay away from fishing holes that get used repeatedly by others.

More critically, you can support the measures needed to stabilize these populations. Since rockfish and lingcod are generally sedentary, their core breeding areas can be easily protected as marine reserves. And you can watch what you buy at the store. Web sites like www.mbayaq.org/cr/seafoodwatch.asp can help you decide what’s best to eat for the health of the sea, and—when it comes to mercury and PCB levels—for your own health as well.
Somewhere beneath the waves, a century-old rockfish will thank you.

Note: The terms ‘R’ and ‘K’ come from two coefficients in the Verhulst Equation for Population Dynamics. In this equation, R stands for exponential growth, and K stands for the carrying capacity. Since reproductive strategies often follow these influences, the strategies themselves were named after the two coefficients (usually represented by lower case ‘r’ and upper case ‘K’).