Ecosystems are our keys to existence

Last Modified: Friday, October 25, 2013 at 3:32 p.m.

The snow has come to my little spot in Canada and fishing has become more difficult. It's tough to get motivated in the morning when you have to shovel snow out of your boat before going out to lift your nets. But the elements are always with us, so there's nothing to be done about it.

The cold weather has an added benefit — it brings more fish. I have always thought the fish swim and eat when the water cools off in anticipation of “the big dark.” The lake, 260 miles long and 20-50 miles wide, will soon freeze over completely, and that ice will soon be covered with snow. There will be nothing but blackness in the water for months on end.

The fish, being coldblooded, will barely be able to move. In order to survive the big dark, they need to eat now. Swimming to find food, they get caught in our nets.

My family has fished this lake for more than 100 years, starting with my great-grandfather, who came here from Iceland seeking a better life. I have fished Lake Winnipeg for 30 years, and the lake has been good to me.

But the lake is threatened now. A few weeks ago, the zebra mussel was discovered in two nearby harbors, and biologists came to the harbor where my fish plant is situated to test for the invasive species.

This is big news here.

The Winnipeg Free Press reported: “ 'We still don't know how Lake Winnipeg became infested,' said Laureen Janusz, a fisheries biologist with Manitoba Conservation and Water Stewardship. She said zebra mussels could have drifted as microscopic larvae along the Red River into Manitoba or could have attached themselves to a boat operated in infested water.

“Officials are uncertain how well the mollusc will thrive in Lake Winnipeg or other Manitoba water bodies, and they're keen on containing it. If it thrives, it could contribute to the growth of green-algae blooms on the lake, curb production of certain fish species and foul beaches. Because of their ability to attach to solid objects, they can clog water-treatment-plant intake pipes and effluent-discharge pipes.

“Zebra mussels look like small clams with a yellowish or brownish D-shaped shell that has dark- and light-coloured stripes. They can grow up to two inches long but are generally less than one inch in length. Given the size of those found so far, they could have been in Manitoba for up to a year.

“The molluscs can multiply rapidly. 'It's my understanding that an adult zebra mussel can produce up to a million eggs a year,' Janusz said.

“Though certain Manitoba fish and waterfowl would be natural predators, it's unknown whether they would be able to control an infestation in Lake Winnipeg. Eradication techniques, such as the introduction of species that would feed on or otherwise kill the mussels, come with environmental risks of their own. 'If they (zebra mussels) become established in Lake Winnipeg, given the size of the lake, at this point I don't believe there is a lot that can be done,' Janusz said.”

My beloved Lake Winnipeg is threatened, but it's been threatened in the past. Twenty-five years ago, the striped bass appeared. For two years, wherever we set our nets, they were loaded with striped bass. Walleye, our bread and butter, was ominously absent. But the walleye rebounded, and now the striped bass occupies a small niche in the ecosystem of the lake.

Fifteen years ago, my friend Mike caught the first rainbow smelt. Shaped like a bullet with sharp teeth, it is a fierce predator of the walleye fry. Curious about this strange-looking fish, Mike took it to the authorities, who identified it.

“We didn't expect them to show up for another 16 years,” the biologist said then. They knew they were coming — it was only a matter of time.

The rainbow smelt emulated the striped bass, and while it looked like they were growing exponentially in numbers, they soon found only a small spot in this very productive body of water.

The carp was introduced to the lake in my grandfather's day, and it doesn't pose a threat to the lake. But zebra mussels?

The news isn't all bad. One threat to the lake is eutrophication due to nutrient overloading. In short, because of too many nutrients in the lake, mainly phosphorous, algae grows unchecked. It then dies and sinks to the bottom, where it decays, using up the oxygen. A lake with no oxygen on the bottom will soon be a dead lake.

The zebra mussel will remove nutrients from the lake, and in my opinion, it will not die. But more nutrients mean more fish, and fewer nutrients mean less fish, so my job here might get a little tougher. Beats a dead lake, though.

What does any of this have to do with Hendersonville or North Carolina?

As the world grows smaller every year, we need, as the species on top of the food chain, to better understand the ramifications of what we do to our little blue dot. That's one reason why the education of our children is of paramount importance.

Everything we do matters. The elements will always be with us, but we will not survive a big dark. We need to better understand the ecosystems on this planet and how they all relate to each other.

Invasive species will continue to enter new areas previously untouched. It's just a matter of time. We should know that for millions of years we were an invasive species. We spread from Africa all over the planet. And now we're everywhere.


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