Lakes
Reports from the Great Lakes Region
- If you seek a pleasant peninsula ...
- Fish in Great Lakes spawning research, but still no young
- Grapes of wrath
If you seek a pleasant peninsula ...
UP's Seney National Wildlife Refuge offers
abundant opportunities
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A gaggle of geese take flight over a serene body of water at the Seney National Wildlife Refuge in Michigan's Upper Peninsula. Photo by Erik McGregor |
Great Lakes residents have outdoor adventure accessible to them by simply getting in the car and driving. In a few hours they can be at a tranquil lake fishing for bass, wading into a productive trout stream or in a dense patch of wilderness.
For those who want to be away from it all and witness nature at its finest, Michigan’s Upper Peninsula may be the destination for them. Lured by a vision of vast stretching timber, swamps, rivers and lakes intertwined with wildlife few people have ever seen, outside a zoo or documentary, millions of people flock to the UP.
Visitors bring their family, boats, camping gear and all other equipment imaginable on their journey into the unknown. They also bring money with them, and lots of it. According to MSU Extension’s tourism team, an estimated $5.1 billion in 1996 was spent in the UP, thanks to tourists. Almost immediately after one crosses the bridge it becomes apparent that small towns near the Mighty Mack thrive on tourists.
Speeding across I-2, the main highway running east and west, you get a breathtaking view of the coastline with its randomly dispersed, uninhabited islands offshore. What you also see, even if you don’t want to, are the many signs designed to pinch a penny out of every traveler on the road.
The signs for pasties are the most unavoidable, almost outnumbering the visitors, followed by maple syrup, “up north” relics and, of course, motels upon motels. All along the southern shore vendors, shops and motels are desperately searching for the next passerby who might stop at their stand, store or motel to spend a few bucks.
For those who venture less than an hour from the bridge this is all they will see, a stretch of tourist towns. The gas stations and fast food joints aren’t out of reach for them, so they aren’t out of their comfort zone. But for us, we will pass all of this. We will go headlong into the less populated and commercialized UP.
The Mackinaw Bridge Authority reported that 4,755,886 vehicles crossed the bridge in 2000. For those who pass the tourist towns in search of something more secluded the trip could take eight hours or more. Fortunately for myself, and many others, the trip will not be that long. Just a couple of hours after crossing the bridge one can come to rest at the Seney National Wildlife Refuge (SNWR).
Located five miles south of Seney, Mich., the refuge is over 95,000 acres that is host to a multitude of wild attractions. Locally, SNWR is known as the Great Manistique Swamp because of the expansive swamps and bogs in the area. More than 100,000 visitors come to SNWR each year in search of a verity of wildlife and wilderness landscapes.
The refuge’s diverse landscape enables it to support many of the popular animals to which tourists are attracted. Some of the more sought after animal attractions include ducks, bald eagles, ospreys, loons (the largest reproductive population in the continental 48 states), trumpeter swans, otters, beavers, pine martens, black bears, moose and wolves. With so many of these species on the endangered or threatened species list it’s no surprise thousands of people are drawn to the area.
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With the arrival of people comes money, along with problems and concerns for the protection of wildlife and natural resources. Litter, illegal camping, hunting, fire and overexposure are all issues the refuge officials must address.
Tracy Casselman, Seney National Wildlife Refuge manager, oversees the refuge and decisions that relate to how much, or little, the public is allowed to utilize the area. Casselman became the manager of the refuge after he moved from New Jersey about a year ago. With Casselman’s transition came a new and different set of challenges than what he was accustomed to as the Deputy of Forsythe and Cape May National Refuge. Both the refuges in New Jersey are quite a bit smaller than SNWR (Cape May is 8,000 acres and Forsythe is 43,000 acres), but the number of tourists that visit the NJ refuges is much larger.
SNWR has up to 50,000 automobiles travel the auto tour route (open May 15–Oct. 15) in any given year, whereas New Jersey has up to 250,000 automobiles on its tour route. Casselman says, “The difference is night and day (between Michigan and New Jersey). There are more people in one county (of New Jersey) than the entire UP.” During a particular winter in New Jersey, one snowy owl increased the visitors by 500 percent for the month of December, he said.
“There is little or no vandalism in the refuge, only half- to a dozen incidents and a few game violations per year,” Casselman says.
Casselman doesn’t find things like beer parties and drugs in SNWR like he found in the New Jersey refuges. “Last year someone cut a lock to a trail and set up camp for the night,” he says. Still, Casselman and his staff must make what they call “compatibility determinations” on behalf of the wildlife.
The staff must assess every proposed human activity and determine if that will have a negative effect on the land or wildlife. As a result of compatibility determinations there is no camping, horseback riding or snowmobiles allowed on the refuge. Activities of that nature are not worth the impact on wildlife, Casselman says.
Other activities, like the autoroute, have been deemed acceptable. Casselman says, “Certainly there is an impact on the wildlife but it’s worth the tradeoff.” He continues, “The wildlife comes first, then the public uses, never the other way around.”
When a problem with the autoroute arises, there are certain measures that can be taken to eliminate them. For example, last year the autoroute was detoured because it came within twenty feet of a bald eagle’s nest.
Fish in Great Lakes spawning research,
but still no young
Researchers blame endocrine disruptors for population's inability to reproduce
There didn’t seem to be anything wrong chemically with the fish in some of the Michigan lakes.
Yet World Wildlife Foundation senior scientist Theo Colborn and other researchers never saw the fish populations spawn any young.
“The only reason young’uns were being produced was because we were stocking the lakes,” she says.
After some studies, the culprit turned out to be a chemical disrupting the hormones in the adult fish—not the direct effect associated with other “nasties” like PCBs or dioxins.
“These things don’t cause cancer and that’s why we thought they were safe,” Colborn says. “We were misled.”
Since 1962, with the publication of Rachel Carson’s “Silent Spring,” scientists have noted the major role of chemical pollutants in the environment.
But an outgrowth of research on the Great Lakes has connected them all—PCBs, dioxins, some flame retardants, plasticizers, even Carson’s most despised, DDT.
“Actually they didn’t know DDT was an endocrine disruptor until just recently,” Colborn says. “It is quite a powerful anti-androgen and we didn’t even know there were anti-androgen chemicals until about seven years ago.”
DDT and a growing list of other chemicals have all been found to be endocrine disruptors, a broad term that covers any chemical that interferes with an organism’s hormone system.
Endocrine disruptors first came to the attention of the public after Colborn authored the 1997 book “Our Stolen Future,” which helped her win the Rachel Carson Leadership Award.
The book was the result of Colborn’s work on a technical book on the subject and her experience in 1997 working on a team looking at the state of the Great Lakes.
Until then, Colborn said many of the chemicals had been thought to be safe since they didn’t cause cancer but evidence of birth defects caused the issue to be pursued.
“The individuals aren’t constructed the same way,” she says. “They don’t function the same way. You’ve got immune systems that don’t work the same way. You’ve got brains that don’t work the same way.”
The chemicals normally don’t affect adult individuals but even small concentrations during early developmental stages can cause birth defects.
In humans, such defects include childhood diabetes, childhood arthritis and autism, which has increased 100 percent in the last 30 years.
And much of the development in the study of the chemicals has remained where it started—in the Great Lakes, says Tracy Easthope, director of the environmental health project at the Ecology Center in Ann Arbor, Mich.
“The reason why the focus on the Great Lakes is because they have a long residence time, they stay around here because the lakes aren’t flushed out all that often,” she says. “It’s a particular ecosystem, it’s an interesting place to study them.”
Although several lists of endocrine disruptors exist, regulations are hard to put in place. The U.S. Environmental Protection Agency is working to come up with a system to test potential endocrine disruptors.
Current efforts are focused on verifying a list of assays, which could then be used to test a list of chemicals, EPA environmental scientist James Kariya says.
Such efforts would go a long way to solidifying what the problems are and how to deal with it since there is still no course of action to guide companies thought to be contributing.
Business public issue leader for Dow Chemical Mark Walton says Dow probably is creating endocrine disruptors but there is no way to know if the company is causing any problems.
“Dow produces a lot of chemicals,” he says. “And some of them might be on lists that some would suspect to be endocrine disruptors but there’s been no evidence that they are at the exposure levels you’d expect that we might emit from one of our plants.”
Grapes of wrath
Michigan grape growers keep a watchful eye
on the grape berry moth
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Without the use of pesticides, grape growers suffer serious damage to their crops. "The [grape] berry moth is one of our top four or five pests," said Rick Brown, a grape grower from Lawton, Mich. Photo by Rufus Isaacs |
“Did you catch any bugs yet? Are they flying?” are questions researchers in entomology (the study of all six legged creatures) get all the time. Now, it is Rick Brown of Lawton, Mich., who wants to know if there are any grape berry moths flying. This insect is not new to him. Brown has dedicated his life to the culture of juice grapes.
Michigan has around 12,000 acres of juice grapes, mainly in Berrien and Van Buren counties, in the southwest region of the state, where the proximity to Lake Michigan creates conditions that allow fruit production. Rolling vineyards meet the woods in this region favored by gusty winds and mild temperatures. The small hills appear combed by trellises where the vines rest and grow under the sun during the summer. Even in winter, when only snowmobiles can get nearby, the vineyards look healthy and clean, every row glistening in the sun.
Each year, around 70,000 tons of juice grapes are harvested, ranking Michigan the third grape producing state in the country, behind California and New York. These grapes go to the juice company Welch’s in Lawton, where trucks heavy with harvested grapes arrive throughout September and October to deliver their load. They are met by testing personnel, who sample each one-ton bin before the grapes are accepted.
When they’re not accepted
Growers like Brown must pass quality standards set up by the government and required by the company so that juice of good quality can be made. These include clarity, sugar content in the berries, adequate berry maturity and damage levels below a certain level.
In all cases, the grape berry moth plays a critical role: since not only is there a threshold of less than 0.5 percent of the berries’ weight in damaged grapes allowed per load, but also because the presence of the worms inside the berries induces diseases like botrytis and black rot, which diminish the sugar content of the sample. Any load that does not comply with U.S. Department of Agriculture standards will be rejected.
For Michigan grape growers, a rejected load for any of those reasons can only mean one thing: disaster. The grapes will usually be disposed of back in the vineyards, to decompose on the ground.
“I remember a whole vineyard that wasn’t even harvested,” says Brown. “The people at the company went in there and told the grower the grapes were too poor to be accepted.” Apparently, the grower had thought nature would do its job with his grapes and protect them from harm if he didn’t spray. It didn’t work.
 Photo by Natalie Botero-Garcés |
| What is a grape berry moth? Endopiza viteana, the moth’s Latin name, is classified in the Tortricidae Family, Order Lepidoptera (the same as all butterflies). In spite, or because, of its coloring, it is difficult to see grape berry moths on grapevines because they scarcely measure more than an inch and spend their days on the underside of leaves. This insect is a native of eastern North America, where it remains the single most important pest of cultivated grapes. Since it can only feed on grapes, the moth evolved in woods where wild grapevines grow on trees. After the logging trend of the past century and today’s urban sprawl, wild grapes are also found on roadsides and hedges, near houses and barns, and on electricity cables, growing wherever they can find physical support. Some people use wild grapes like ivy is used, to cover garden hedges and decorate backyards. In spring, the bloom decorates the vines, and later the appearance of berries creates a Mediterranean look that can be called romantic. |
Brown is a third generation grape grower. His grandfather started growing grapes in 1923. Rick Brown tends to some 170 acres, half of which are his or his relatives’ grapes and the other half are leased. He has seen advances in equipment, such as improved mechanical harvesters that provide a more uniform and cost-effective harvest. He has seen trends shift, from a demand for fresh market grapes to more processed grapes, and has had to replant and change accordingly.
“The [grape] berry moth is one of our top four or five pests,” he says. “If you didn’t do anything to control it, you’d lose the whole crop.” And although there is no record in Michigan of the grape berry moth losses, he suspects that it would probably be high. Even assuming a conservative 10 percent reduction in yield to grape berry moth and the associated diseases, this pest would cost the Michigan grape industry $1.8 million per year.
Berry Moth’s Courting Ritual
In this romantic setting, among grape leaves and tiny clusters of flowers, researchers believe boy meets girl, girl likes boy, for the grape berry moth.
Or not quite like that: with this moth, the female chooses. In a particularly interesting sexual behavior, female moths emerging from their cocoons do not need to look for males because they possess a special “sexual weapon”—a pheromone they use to attract them.
Pheromones are chemicals emitted by insects in order to communicate with members of their species, in this case, to communicate sexual availability and location. The female releases pheromone by exposing a gland she has on the tip of her abdomen. The wind helps carry the pheromone away, much like a wisp of smoke, to be encountered by a lucky male or maybe more. Male moths follow the “plume” back to its source and find the female. After a few courtship behaviors, mating then takes place.
Rufus Isaacs, an entomologist at MSU, likens the pheromone-finding episode to what happens with people at a bar. “In a bar full of odors, a woman wearing a particular perfume will attract men who like her scent. A man may smell many things at a bar, but will follow the perfume until he meets the woman who wears it,” says Isaacs.
Capturing and Taming the Moth
The importance of the fact that female grape berry moths attract males with a scent did not escape researchers, who in 1954 were able to synthesize the pheromone in the laboratory and test it in the field. Rubber lures that were soaked in this man-made sex pheromone are used today as bait to attract males into traps lined with a sticky substance to capture them.
It is through this trapping system that the first appearance of the moth can be detected.
“We put these traps in vineyards before April 20, which is the earliest we have seen this moth come out. Once we have caught the first male, we can monitor the moth’s presence and have an indication of when to start taking preventive measures,” says Keith Mason, a technician at MSU’s Small Fruit Entomology Laboratory, who is in charge of conducting pesticide experiments, among others, in Michigan vineyards.
Management of grape berry moths involves pesticide applications, typically an organophosphate or carbamate. While insecticides often are the most effective and inexpensive method of controlling insect pests, there are some unintended consequences of their use. The long-term environmental impacts of pesticides are of greater and greater concern to the public and regulators. Residues on agricultural workers and in food are driving a reexamination of chemical use in food crops. New regulations by the U.S. Environmental Protection Agency have reduced the number of effective chemicals available to growers, and increased restrictions on remaining products.
“The government is taking away chemicals that do a good job and are safe to use and leaving us with the problem,” says Brown. To him, environmentalists are too removed from the real situation. “Meanwhile, other countries ship in their product and they are not subjected to the same regulations we are,” he continues, “which allows them to compete with a cheaper international product. What can we do?”
Growers must use the few available pesticides in the most efficient manner. Spraying too little may mean a pest outbreak, but spraying too much can fuel development of a critical problem in agriculture, that of resistance in insects.
First Moth Sighting
Finding the first moth is important for growers because they need to plan their management schedule for the growing season. But decisions, most of them depending on the weather, are not taken in the same way. Some growers will spray if they believe (mainly through hearsay) that grape berry moths will cause damage before harvest. Others, like Bryan Cronenwett of Lawton, spray according to what they see in their vineyards, tailoring their spray program to their scouting for damage.
“There is a lot of damage on that end,” he signals at a vineyard edge right next to very dark and lush woods. The first row of trees presents a drastic contrast with the organized rows of vines. They tower over them and bring shade in the summer and fallen leaves in the fall. Over the branches, wild grape grows and thrives, pulling the trees down by their sheer weight.
These wild habitats near vineyards are cited as responsible for grape berry moth damage in grapes. Researchers in New York and Ontario established a few years ago that proximity to woods is a risk factor for infestation by grape berry moth in a vineyard. Typically, edges of vineyards that border woods show four to 10 times more damage than any other place in the vineyard. However, one thing that boggled New York scientists is how so much damage can be found at a vineyard edge where few moths are caught. Their guess was females were flying in from the woods, where there are wild grapes, and laying their eggs on the vineyard grapes. Because males are attracted to the trap, but females are laying the eggs, so few grape berry moths were caught in the woods or at the vineyard edge.
MSU’s Small Fruit Entomology Laboratory have come up with a different theory. Work carried out by a graduate student showed the height at which the traps are placed could be more relevant than thought before. In studies during 1999, traps were hung at the edge of woods at four heights: five, 10, 20 and 30 feet above the ground. The idea was the moths were flying higher to reach wild grapes climbing on trees, sometimes higher than 50 feet. About 70 percent of the moths caught during that summer were caught at 30 feet high, compared to only 6 percent of the moths caught at five feet.
Trap Height Solved
Further research on height effect was conducted to assess the moth’s distribution in the woods and in the vineyard. In 2000, by testing with traps at different positions ranging from inside the vineyard to inside the woods, it became clear that moths are found in different areas at different times of the season, which means traps should be deployed accordingly.
In the early stages of the growing season, there are more grape berry moths inside the woods and at their edge than in the vineyard. Later in the season, more moths are caught in the vineyard than anywhere else. This would mean that the grape berry moth is probably coming out of the woods as the season progresses, where they end the season and cause the greatest damage.
In 2001, moths were monitored at all heights in the woods and vineyard. By looking only at the traps that are hung five feet above the ground, the moth population seems to be shifting from the woods into the vineyard during the growing season. But when other heights are considered, this population shift is no longer perceived, since more moths are found inside the woods throughout the whole season. However, inside the vineyard, there is a relative increase in moth numbers during the season that peaks around harvest.
This could mean that instead of a population shift, there is an expansion of the moths’ habitat, either because it needs new food sources, or because the vineyard grapes offer a new place to lay eggs and more food for the future larvae.
Information like this about grape berry moth biology and behavior is needed to improve management procedures, including better and more efficient use of pesticides. Mating disruption, the use of sprayed pheromones to confuse the males in their search for a female, will be challenging to use if the largest numbers of moths are inside woods where this practice is not allowed. Timing of insecticide applications may be done according to information from the traps by hanging them high in trees instead of near the ground. Resistance may be less of a concern since a continuous influx of moths from the woods would ensure susceptible genes are introduced into the vineyard, lessening the effect of insecticide selection pressure. This may not sound reassuring to growers, but to researchers, the delay of or avoidance of resistance is a benefit.
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Natalia Botero-Garcés is a Ph.D. student in Entomology. Her dissertation focuses on grape berry moths.
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