Invasive Species of the Ottawa River
Dan Brunton is a highly regarded Ottawa naturalist and professional environmental consultant. I interviewed Dan about invasive species in the Ottawa River.
Q: Katharine Fletcher. Dan, what is your title and what are some of the projects you are most proud of?
A: Dan Brunton: I’m probably best described as a field ecologist providing independent ecological consulting services. I’ve been doing this for 30 year now and am most proud of never having worked as an agent for anyone. In other words, my professional role is not to be an advocate for a particular position but to conduct objective analyses to the best of my ability, be they the ecological implications of Interprovincial Crossing options (yes, I’m very pleased to be playing a significant role in that important and controversial project) or determining the status of Endangered ferns in western Canadian national parks.
Q: For years National Capital Region residents and others who care about the Ottawa River and its watershed have heard about invasive species such as zebra mussels. What is an invasive species?
A: It’s simply a plant or animal that is not naturally occurring in that place but which become established in a natural habitat and prospers at the expense of its native organisms. That’s why invasives are such a problem: they are the world’s second largest cause of loss of native biodiversity; they use up ever-larger amounts of natural resources that are already critically required by our ever-more stressed native flora and fauna.
Q: What invasive species (animals, plants) are of most concern along the Ottawa River and its watershed?
A: People (and I include aboriginal people in this). Our species has a habit of spreading out across various habitats, destroying the natural elements wherever it develops permanent populations and producing long-term landscape damage that is slow to recover. I’m only being partially tongue-in-cheek here, but we certainly behave like an invasive species and have for millennia. It would be hard to select a number one ‘wild’ bad guy because their impacts are not the same, but I’d put something most people don’t even know about right up there. Canary-grass (Phalaris arundinacea) is an agricultural grass that now dominates thousands of hectares of disturbed Ottawa River marshlands. It is much more ecologically intrusive – especially in the lower river valley – than the overly-publicized Purple Loosestrife. The jury is still out on the newly arrived Water Chestnut; if it does not do well in more acidic waters, like Purple Loosestrife and European Water-milfoil, it likely will only become a locally significant problem in the lower watershed. European Carp is a bad one, so is Zebra Mussels (another lower watershed threat) … the list goes on.
Q: Further to this, can invasive species be natives or are they all “hitchhikers” or else deliberately introduced?
A: Yes. Wild turkey was once native to a tiny portion of southwestern Ontario but is now being “reintroduced” hither and yon hundreds of kilometers beyond any hint of former occurrence as “a native Ontario species.” By that measure, we should be “re-introducing” bison and polar bears” in the Ottawa Valley. The success of a large, locally non-native organism like wild turkey is achieved through the expenditure of natural capital, to the detriment of native organisms which have depended on those resources for thousands of years.
Q: Is there a distinction between invasive species and species which suddenly start to “explode” in numbers to take advantage of a specific input/niche? I’m thinking of blue-green algae and its opportunistic flourishing due, I think, to an overabundance of nutrients?
A: Sure. Virtually all species are hard-wired to take advantage of opportunities. You can’t “blame” a white-tailed deer for surviving unnaturally milder winters, producing too many young and destroying native forest floor vegetation though over-browsing. It’s just being a deer. Under natural conditions something resets the clock – a nice little forest fire, an insect infestation, a large increase in predator populations, disease … what have you. Our artificial tinkering and abuse of natural systems, however, has damaged the function of so many of these natural world regulators and as a result, has degraded the controls and limits on ‘weedy’ species like deer (or blue-green algae, for that matter).
Q: Some invasives – zebra mussels may remain a good example – appear/seem to have spin-off beneficial effects. I’m thinking of water clarity, specifically in their case. But is this true?
A: “Beautiful” can be an ugly word in the natural world. It does not matter if Zebra Mussels makes a water body look ‘nice’ (assuming, for the sake of argument, that lake water as clear and sterile as a swimming pool does look ‘nice’). It’s all about whether things work. Give me an ugly old native Snapping Turtle any day to one of the much prettier non-native, pet-store refugee Red-eared Turtles that are showing up along the Ottawa River with alarming frequency these days. There usually is something in place to take advantage of changes in the natural world so it’s often not hard to see short-term winners even with the arrival of invasives. But if systems that have taken thousands of years to work the bugs out (or, quite literally, work the bugs in) become unbalanced, then we have a problem. It’s irrelevant how pretty it looks.
Q: Some invasives are escaped horticulturals. I’m thinking of the European frog-bit which was introduced in 1932 to Ottawa’s Arboretum at the Central Experimental Farm. By 1952, this aquatic was growing in the Ottawa River at Montreal Island. Can you comment on gardeners’ and others introduction of exotics into our gardens?
A: European Water-milfoil may have gotten into the Ottawa River as a horticultural escape too. And it’s not just the aquatic species that threaten our river. In a study I recently conducted of some 200 urban natural areas in the City of Ottawa (and isn’t it great that the City of Ottawa has 200 areas within its urban lands that could be so considered?) we determined that and escaped and/ or intentionally dumped horticultural weeds to be a significant problem in virtually every woodland adjacent to residential development. People, understandably, think it’s okay to dump leaves and garden material in the woods because it’s all green, right? Dead wrong. Periwinkle, Garlic-mustard, Goutweed, Jerusalem Artichoke … all sorts of invasive plants invade natural woodlands and degrade their ability to properly filter and manage surface water runoff that drains into our river and its tributaries.
Q: What can cottagers, river enthusiasts do about invasives?
A: Don’t mess with the natural habitat of your waterway. That means maintaining or restoring a natural filtering buffer between our artificial upland landscapes and the water. Don’t hard-surface and “enhance” river or stream banks. Obviously, don’t dump plant or animal material into any waterway. The bottom line is to keep conditions close to and within our waterways as natural as possible so we do contribute to artificial concentrations of nutrients or other destabilizing influences. Our marvellous river has a huge capacity to repair and restore itself … if we just get ourselves and our debris out of its way.
Q: Should we be looking out for specific invasive species and reporting them if we find them? If so, can you give us an Ontario and Quebec contact?
A: The natural resources ministries in Ontario and Quebec monitor such things as invasives but no-one has a dedicated “invasives hot-line” as such. Still, if someone thinks they have evidence of a new and potentially troublesome occurrence, call the Ottawa Riverkeeper’s toll-free hotline 1-888-9KEEPER. The Riverkeeper will deal with the issue directly or be able to direct it to the appropriate person(s) or agency.
Katharine Fletcher is a freelance writer based north of Quyon, Quebec. Her latest book is Capital Rambles: Exploring the National Capital Region – find this and her other guides at regional bookstores or at MEC.