Garden Space Invaders

By Jill Hahn//Special To The Tab

 

If you're like me, you started thumbing through garden catalogs in the dark days of early February, ogling the lush photographs and dreaming of how all those perfect, blooming plants would look in your own yard. Of course, your yard was covered with 2 1/2 feet of rock-hard snow in early February, and there wasn't enough daylight to grow a mushroom. Sending photos of bright flowers and vivid fruit to New Englanders in February is like sending a frosty six-pack to a recovering alcoholic. Common sense might just go out the window. And the choices you make as you admire those glossy advertisements can have an impact far beyond the corners of your yard.

 

The 10 most unwanted

Here are the top 10 species of plants that are listed as unwanted by the Massachusetts Natural Heritage and Endangered Species Program:

·      Oriental bittersweet Celastrus orbiculata

·      Purple loosetrife Lythrum salicaria

·      Autumn olive Elaeagnus umbellate

·      Japanese, Morrow's, and Amur honesuckles Lonicera sp.

·      Multiflora rose Rosa multiflora

·      Norway maple Acer platanoides

·      Garlic mustard Alliaria petiolata

·      Shining and common buckthorns Rhamnus fragula, R. cathartica

·      Common reed Phragmites communis

·      Common and Japanese barberries Berberis vulgaris, B. thunbergii

 

Consider:

 

"Lonicera maackii [Amur honeysuckle]... produces masses of white flowers that mature to yellow followed by a profusion of 1/4" bright red fruit persisting into winter... adaptable to poor soils..." (Nature Hills Nursery) "This climbing Bittersweet Vine produces sunny yellow seed pods that give way to bright red, decorative berries... thrives in the poorest of soils. Songbirds love to gather around this attractive plant, and so will you!" (Michigan Bulb Company)

Wow, those plants sound great! But what the catalogs don't tell you is that these two species are on the Massachusetts Natural Heritage and Endangered Species Program's "Ten most unwanted invasive species" list, villains that threaten the wellbeing of the native plants and animals that have defined our natural landscape for millennia.

An invasive species is one that, once established, manages to spread in numbers and space to the exclusion of other plants. Alien invaders, those imported from other countries, tend to be especially damaging because the predators that might keep in check in their native habitat don't exist here.

If you look around your yard, you will likely find that most of the familiar plants that define your personal landscape are actually alien species. That rhododendron just bursting into bloom is as likely to hail from Japan as from North Carolina. The tulips came from Central Asia, the daffodils from the Mediterranean. Even the grass species growing in your lawn were introduced from Europe. Although they are not native to the U.S., most of these species are well-mannered and don't present a problem to the forests and meadows of New England. What sets such species as the honeysuckle and bittersweet apart is that they are not content to stay where they are put. The very attributes that make you want to buy them (thrive in the poorest of soils, attractive to birds) are what make them a threat.

Five key biologic traits characterize invasive species: 1) they produce large quantities of seeds; 2) they have effective dispersal mechanisms; 3) they are readily established; 4) they grow rapidly; and 5) they are effective competitors. The birds, for example, that flock to your bittersweet vine to eat its berries become dispersal agents that carry its seeds to your neighbor's yard, our woods and roadsides, the local Audubon preserve. Every manager of natural spaces in our state is currently waging war against spreading stands of alien invaders. When the diversity of native plants becomes overwhelmed by stands of a single, introduced species, it can cause the disappearance or extinction not just of those outcompeted plants, but of the animals that depended on them as well.

So what can you, the responsible gardener, do? Before you make an impulse buy from a garden catalog or center, do a little research. There are many sites online that can help you identify, and avoid, alien invaders (The New England Wildflower Society has a well-researched list, as well as a list of native alternatives, http://www.newfs.org/conserve/invasive.htm). To get you started, here are a few plants you should not buy:

Goutweed, or snow-in-winter (Aegopodium podagraria), a variegated, three-leaved groundcover that's almost impossible to pull out because it propagates by easily-fragmented runners; those non-native honeysuckles(Lonicera Morrowii, L. tatarica, L. Maackii, L. x bella & L. japonica);Porcelain Berry (Ampelopsis brevipedunculata); Yellow Flag Iris (Iris pseudacorus); Burning Bush (Euonymus alatus), that ever-popular large woody shrub that turns bright scarlet in autumn.

Be especially suspicious of plants touted as able to grow in all conditions, or as good for erosion control. Become familiar with the top 10 unwanted species and eradicate them ruthlessly whenever you see them. Some of them will be obvious weeds, while others hold pride of place in many local gardens. It hurts to look at your beautiful burning bush specimen as an alien enemy, but that shrub doesn't look so beautiful when it's monopolizing the understory of the local forest.

Now excuse me while I go dig up the prickly but lovely Japanese barberry bush that's screening my compost bin, and leap back into my losing battle with the Japanese knotweed that is marching its way up my backyard. Thank goodness I wasn't the one who decided that might be a nice ornamental plant and set it loose on an unsuspecting Newton.

Jill Hahn, a Newton Highlands resident, is a biologist, a writer, and a mom. All three roles contribute to her interest in environmental issues. She can be reached at jkkhahn@comcast.net.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

From Drought to Flood

By Nigel Pickering and Kate Bowditch//Special To The Tab

 

Last month in this column, the emphasis was on the spring drought, the effects of dry weather on the Charles River, and measures that homeowners could be taking to try to keep water on their own property. This month, the story seems to be the opposite, as many in Massachusetts have experienced the worst flooding in many decades. Yet the drought and the flood are really one and the same story: the natural environment and the human environment are bound together, each dependent on the other.

The storm systems that battered New England from May 9-15 dumped more than 15 inches of rain on some Massachusetts communities. In Newton, there was over 5.5 inches of rain in just three days. As of this writing, there has already been over 10 inches of rain in Newton this May. The historical average for the month is 3.3 inches.

The effects of a deluge such as the one in May are dramatic. Rainfall becomes runoff as soils are saturated, rivers swell to overtop their banks, and floodwaters cause millions of dollars in material damage. Fortunately, in this storm and flood, few lives were claimed. The Charles River never actually flooded, though many streets, parks and basements were inundated by runoff and rising groundwater.

Other river systems, and the communities in those watersheds, were hard hit, however, and more than a week after the rains stopped, there are still flooded sections of many towns. So what caused some areas to have more floods than others? Two factors that affect flooding are basin characteristics, and rainfall patterns. Both of these factors came into play in the last storm. Both the rainfall pattern and the local basin characteristics were extremely variable, causing some areas to have the worst flooding on record, while others had only moderate flooding.

The most important basin characteristic that impacts flooding in this area is 'basin storage.' Basin storage consists of rainwater that infiltrates into the soil or groundwater and runoff that fills wetlands, dams, or other man-made stormwater controls. Think of basin storage as holding capacity: it is the amount of water an area can hold before it runs out into the main river channel. An area with a lot of basin storage will not flood as fast as an area with little basin storage.

Rainfall distribution affects the local rainfall amount and intensity. Even in an area with a lot of basin storage, high intensity rainfall can overwhelm the infiltration capacity of the soil, stormwater conveyance structures and river channels, causing high flows and potential flooding.

This particular storm was not evenly distributed, causing large variations in both the rainfall volume and intensity. Radar estimates of the rainfall pattern in Massachusetts and surrounding areas show that northeastern Massachusetts had 8-16 inches of rainfall compared to about 4-8 inches in the Charles River watershed near Boston. Since the rain all fell in a period of about 5 days, not only were the amounts different, the intensities were also highly variable from one area to the other.

The resulting streamflows varied widely and can be measured by the 'return period' of the flow. For example, a 10-year return period is one that will occur, on average once in 10 years. The Charles River came within inches of flood stage but only reached a 2-year return period. In contrast, the return period for the Merrimack at Lowell was 40 years and the whole Ipswich River was over a 100-year return period.

Some of the muted streamflow response in the Charles might be attributed to the extensive area of wetlands in Cutler Park on the Newton/Needham border, and those on the Medfield/Millis border. In the late 1960s, Charles River Watershed Association (CRWA) was instrumental in working with the Army Corps of Engineers to permanently protect 8,103 acres of wetlands called the Charles River Natural Valley Storage Area. Riparian wetlands rapidly expand to store floodwaters then slowly release the water back to the river after the storm. This wetland storage project serves as a nationwide model for natural flood protection.

In urbanized areas, basin storage can be severely reduced, increasing flooding problems. Impervious surfaces like rooftops, driveways, parking lots and roads reduce evaporation, soil storage, and travel times. The double-edged effect of impervious surfaces is that is disconnects rainfall from ground water, thus creating more larger peaks and runoff volume (floods) while reducing recharge and base flow. The result is more storm flow with less base flow, that is, more of the wrong kind of water.

Perhaps not surprisingly, the same actions that CRWA encourages communities and homeowners to adopt to cope with drought will help reduce the impacts of flooding: reduce paved surfaces; let rainfall percolate into the ground; direct runoff to vegetated areas; keep water out of pipes; protect wetlands and open space; plant more trees. Global warming will likely cause more droughts, and more floods. We need to design our environment so we can live with both.

Nigel Pickering, PhD, Senior Engineer and Project Manager at CRWA, is a computer modeling and mapping expert. Kate Bowditch, MA, a Senior Environmental Scientist at CRWA, is a hydrologist. 

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

The step beyond recycling

By Eleanor Saunders//Special To The Tab

 

Three things are true about garbage today. First, the amount our cities and towns handle has more than tripled over the last fifty years, as product wastes increase dramatically and recycling recaptures only about 30 percent of what we throw away. Second, the manufacturers who feed this waste stream - packaging companies, the electronics and computer industry, textile and carpet producers to name a few - benefit from passing the financial responsibility for their discarded products onto our municipalities. Third, garbage collection and even recycling have become big business, dominated by national and multinational corporations that operate in the global marketplace and thrive on this very waste stream. Thus, rapidly increasing bills for garbage burden taxpayers, while manufacturers and waste management companies profit from the current way of doing business.

In addition, we are running out of sites for landfills. Few communities want to contend with landfill nuisance factors - odor, pests, and commercial traffic from dump trucks. Even fewer want to accept the risks associated with the hazardous leachates created when buried garbage breaks down. Despite new technologies and precautions, landfill leakages frequently occur, and the toxic metals, carcinogens, and endocrine disrupters in decomposing waste escape their safety nets. Incinerating garbage brings with it similar problems - heavy truck traffic to incinerator sites plus toxic residues concentrated in the ashy remains. And both these methods of disposal contribute to climate change by producing significant amounts of greenhouse gas, including one third of our methane emissions, a gas 20 times more potent than carbon dioxide.

Daunting as all of this sounds, you may be surprised to hear that there already is a tested approach which can significantly reduce these problems. However, it is an approach that requires us, the taxpayers, to exert a substantial amount of political will against the industries that profit from and lobby for the status quo. The approach is called Extended Producer Responsibility. It recognizes that we who are downstream of production cannot do much but try to cope with the amount and types of product waste that come our way. However, upstream, at factories, a great deal can be done through innovations in product design and manufacturing. EPR and its close policy relative Product Stewardship shift at least some responsibility for waste from municipalities to manufacturers and thereby promote a reduction of environmental impacts at all stages of a product's life-cycle.

Producers are free to design their own product take-back schemes and to select whatever means of recycling and reducing hazardous materials make most financial sense to them - so long as they meet agreed upon performance standards and timetables. The experience of European Union countries, Canada, and Australia since the1990s demonstrates how effective attacking waste problems from this end can be. And a whole array of solutions ranging from strict government regulations to voluntary agreements are there to be assessed for effectiveness and implementation in the U.S.

Here is one small example of what could happen if EPR policies were in place. Nationally, about 3 - 4 billion pounds of nylon carpeting are discarded each year, costing around $100 million dollars in hauling and disposal fees. As currently manufactured, much of this carpeting cannot be recycled and also contains hazardous dyes and materials. However, a commercially viable, environmentally sound carpet material already exists. Called nylon 6, it can be manufactured in eco-efficient ways, such that at the end of its useful life, old carpeting can be broken down and re-manufactured into high quality nylon 6 material, over and over again. Waste is effectively eliminated. Today, a few U.S. and Canadian companies produce nylon 6 carpeting made without hazardous chemical dyes and with special backing and adhesives, designed to facilitate the re-manufacturing process. Nylon 6 even has the potential for applications beyond carpeting. Its properties would allow it to be used in the automobile industry and in the manufacturing of plastic housings for electronic equipment, two more product categories which severely burden our municipal waste streams. The nylon 6 story is a perfect illustration of what ecologically sound redesign can produce, if there were enough carrots and sticks to motivate more corporations to invest in it.

When EPR initiatives were initially explored here in the 1990s, industry effectively blocked their passage. Yet, ironically, many of corporations opposing EPR in the U.S. have managed to comply with these regulations in Europe, Australia, and Canada. Even European governments with conservative political agendas have embraced EPR, because it reduces taxes by lowering waste disposal costs, while adhering to the principles of the marketplace as the source of solutions for society's problems. Government may set standards and timetables, but private industry is free to determine the most cost effective ways to meet them. Furthermore, there's no reason that U.S. government couldn't subsidize efforts toward environmentally sound redesign, just as it traditionally has subsidized companies for the environmentally damaging exploitation of virgin resources like oil, gas and timber.

But what about the impact on consumer prices of redesigning and retooling to meet EPR regulations? Won't buyers end up paying? It's true that individual items may cost a little more as a result. But now we all end up paying, whether we buy a product or not, because of the escalating cost of municipal waste disposal. An EPR legislative initiative for electronic waste is currently under development in New York City, and one has been passed in Maine. If EPR makes sense to you, perhaps it's time to let government officials know that you want Massachusetts to be another state in the forefront of EPR legislation.

Eleanor Saunders, PhD, is a clinical psychologist, who practiced in Newton for many years. She now lives in The Berkshires and is a student at the Center for Environmental Research and Conservation at Columbia University.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

The Inevitable Avian Flu

By Alissa Becker//Special To The Tab

 

When meteorologists broadcast that a noreaster is tearing towards New England, Star Markets become clogged with frenzied shoppers stocking up on peanut butter and Duct Tape. But when scientists warn that the waves of a bird flu epidemic are expected to crash on the shores of California this summer, the forecast is met with disbelief and apathy. This lack of fear is understandable. Often we spend years awaiting catastrophic events that never come to pass; Y2K, for example. However, bird flu is no empty threat.

There are many environmental factors increasing the likelihood that the avian influenza virus will spread to humans. Deforestation shrinks habitat for the animals which are the "reservoirs" for these viruses and increases opportunities for those animals to come into contact with human communities. As the numbers of domestically farmed birds increases, avian viruses that have infected farmed birds have significantly more opportunities to infect humans. The likelihood of a virus crossing over to humans is also increased by the very crowded conditions in which people and domestic fowl are found in developing countries, such as the Philippines, Indonesia, and China. Some local customs, such as consuming the blood of domesticated birds, cockfighting, and the widespread sale of pet birds, further increase the potential for the virus to move into the human population. The uncontrollable migration of wild birds from areas affected by the virus provides yet another avenue for the virus to spread around the world. Taken alone, none of these factors are cause for alarm, but together they bring us closer to a pandemic.

When a bird flu pandemic develops, within a year a third of the world's population would contract the virus. Up to 90 million Americans would fall ill, with nine million Americans requiring hospitalization in critical care units for respiratory distress. Between 200,000 and two million Americans would be expected to die. Laurie Garrett of the Council on Foreign Relations has stated that the only thing that could exact "a larger human death toll would be a thermonuclear war."

In some respects, the avian influenza virus and the HIV virus that causes AIDS are similar; both originated in non-human hosts. HIV began as a virus affecting species of monkeys before it mutated and became capable of infecting humans. Similarly, the avian influenza virus is normally limited to infecting birds, but on rare occasions it changes slightly so that it is able to infect humans. As both these viruses originated in animals, the human immune system lacks any exposure- and thus immunity- to them, so they can lead to human epidemics, with high mortality rates. (Other familiar, deadly diseases that originated in animals include Lyme disease, West Nile, dengue, and ebola.)

The avian influenza virus and the HIV virus are not alike in all respects. The most important distinction is that, while AIDS is an epidemic that will likely continue indefinitely, the avian flu is a pandemic that is expected to last only eighteen months. In this short period of time, however, avian flu will kill more people in its first twenty-five weeks than AIDS has killed in its first 25 years.

Most scientists agree that a pandemic is inevitable. The only thing that has kept the bird flu from spreading human-to-human is a protein on the virus' surface, which acts much like a key to open up cells for invasion. Currently the virus has a "protein key" which only unlocks birds' cells and a handful of unlucky humans' cells. To infect millions of humans and cause an epidemic, the virus needs only to change this one protein so that it fits into the "locks" of human cells. The virus could randomly mutate until it happens upon the right key, or it could acquire a protein key from the influenza virus that is already adapted to humans. With the high frequency of human-domestic fowl contact in Southeast Asia, the avian influenza virus is provided with many gene-altering encounters with the human influenza viruses.

Although the bird flu virus is currently rarely transmissible from birds to humans, once in possession of the proper protein, it will easily spread from human to human. Unlike HIV, which can only be spread through exchange of certain bodily fluids, the bird flu virus can be spread with a mere sneeze, cough, or handshake. Because symptoms take several days to develop, it is impossible for airports to screen for bird flu. People who don't know they are infected could board airplanes and spread the virus around the world in mere hours. When the virus becomes transmissible from human to human, there will be little to impede its spread.

A bird flu pandemic is inevitable, too, because avian influenza pandemics have occurred many times. In the past three hundred years, there have been ten reported avian influenza pandemics, about one every thirty years. The most lethal one occurred less than hundred years ago, in 1918. Although often overshadowed by World War I, this pandemic killed half a million Americans, more than the number of American fatalities in World War I, World War II, Korea, and Vietnam combined. The last bird flu pandemic occurred under 40 years ago in 1968, so the next one is slightly overdue.

The human population will always be plagued by diseases and pandemics will continue to kill millions. The seeds have been sown for another deadly avian influenza pandemic; right now, millions of avian influenza viruses are feverishly mutating and re-sequencing their genes in search of the perfect protein and waiting for this virus are myriads of unchecked entrances into the human population. We do not know exactly when this deadly virus will emerge, but we must prepare for its inevitable arrival.

For more information on avian flu visit www.fluwikie.com or read The Great Influenza by John M. Barry.

Alissa Becker is an AP Biology student in her third year at NNHS.

This article is archived at www.greendecade.org/tabarchive.asp

Read More...

Summary only...

Cute little baby animals - more than meets the eye!

By John Linehan/Special To The Tab

 

A visit to either the Franklin Park Zoo or Stone Zoo this summer will reveal lots of cute new faces. It has been an unusually productive year at Zoo New England's institutions. The "oohs" and "ahs" are audible while mothers shepherd their offspring and teach them the requisite skills for their lives ahead. It's easy to see that these mothers revel in their maternal roles and responsibilities.

There was a time, not long ago, when even good zoos produced offspring merely for the sake of attracting visitors. As good zoos evolved, under more enlightened leadership, the realities came into focus. Unchecked reproduction of some animals and non-reproduction by others was rapidly depleting genetic diversity and in other cases leading to over-production. Surplus animals sometimes ended-up in bad situations.

This has changed dramatically. With the aid of computer modeling programs, improved animal husbandry techniques and a wildlife conservation focus, accredited zoos across the country now manage much of their animal collections as if there were no ownership. Individual animals are paired for breeding based upon their genetic background. Animal transfers between zoos are planned and carried out with well-organized master plans designed to ensure the conservation of species. As we have established husbandry techniques for successful reproduction, we have also developed a wide variety of contraceptive techniques. Each species is different physically and behaviorally. Zoo veterinarians and keepers are continuously challenged by the diversity of species' biologies. The goal of the programs is to maintain the maximum genetic variability in each of these species and then to maintain stable populations that are in balance with the space and other resources of the zoos. Today, zoos are net wildlife producers, not consumers. While some of these efforts result in reintroduction programs, most are aimed at maintaining self-sustaining captive populations and safeguarding wild population.

Our growing Mexican wolf pups at Stone Zoo are part of a successful program to re-establish this species in Arizona, New Mexico and Mexico. We have red crowned cranes at Franklin Park Zoo, which now have offspring reintroduced and migrating in Asia. There are many others, such as gorillas, giraffe, jaguar, zebra. The existence of these animals supports wild populations through education and partnerships with other zoos and conservation organizations. The organization and cooperation required to plan and enact these complex programs is carried out mainly by zoo staff volunteering their time to make the programs work. Their tireless efforts are coordinated through the Association of Zoos and Aquariums and facilitated by a small group of population biologists.

 John Linehan is President and CEO of Zoo New England, the non-profit organization which manages our two state-owned zoos, Franklin Park Zoo in Dorchester and Stone Zoo in Stoneham. He serves on several committees of the Association of Zoos and Aquariums.

This article is archived at www.greendecade.org/tabarchive.asp

Read More...

Summary only...

Something's fishy

By Michelle Portman/Special To The Tab

 

You might want to get a membership to the New England Aquarium. There are fish there that chances are you'll never see in the wild. Not because they thrive in habitats far away, in exotic places and tropical climes, but because people have fished them to death. Another place you might be able to see these fish is served on a plate garnished with spices, herbs and lemon juice at dozens of popular restaurants. How is it that the fish we love to dine on are dead in the water (seas), yet always available for the right price at our neighborhood eatery?

It is clear that for at least the past decade, fisheries, especially those in New England, have been plagued by tragedy and controversy. Many commercial fish populations, such as cod, flounder and Atlantic salmon, have been culled to such an extent that it is questionable whether they will ever recovery.

Government has tried to step in with policies and regulations aimed at stabilizing and recovering fisheries. Ten years ago, the federal Magnuson-Stevens Fisheries Act, also called the Sustainable Fisheries Act (SFA), was signed into law. It resulted in a myriad of measures to regulate fishing activities- quotas by species, size limits, gear restrictions, seasonal fishing ground closures, etc. Yet these measures are controversial because of their effects on fishermen, the fishing industry and overall marine biodiversity.

A recent national report on ocean policy, funded by the Pew Trust, takes issue with policies promulgated by regional Fisheries Management Councils (8 in number). Too often, council decisions have emphasized short-term commodity production, i.e., focusing on maximizing catch, revenues and employment rather than sustaining natural systems that support wild fish populations and healthy ecosystems. Overall, they rely on scientific uncertainty to justify risk-prone management decisions rather than apply a precautionary approach. Particularly problematic are the adoption of short-sighted single species management techniques that neglect long-term goals for fisheries and ecosystems.

With all the threats to fish - loss of habitat, overfishing, declining ocean water quality and ineffective regulation - how is it that we are finding plenty of fish on the menu of our favorite restaurants? For the most part the answer is: aquaculture.

There are many different modes of aquaculture - for shell fish, for freshwater fish and seafood - making it difficult to generalize regarding its impacts. For most off-shore cultivation, thousands of fish live their short lives in crowded cages sunk below the surface in deep ocean waters. Negative effects involve the concentration of their waste products that causes eutrophication (nutrient overload) in surrounding waters. Also the density at which the fish are kept make them more susceptible to disease and parasites. (To sea lice, for example, a fish farm is an all-you-can-eat buffet.) Pesticides and antibiotics given to the fish soon find their way into the environment with deleterious impacts on marine water quality and habitat.

These substances don't make "farmed fish" any more healthy for the human consumer either. A recent news article on farmed fish in the UK, called Scottish farmed salmon "the most contaminated product on the supermarket shelves".

Another problem is that of escapees. Farm-hatched fish can escape into the wild and dilute the gene pool of healthier, "smarter" wild specimens, potentially impacting the capability of some species to spawn properly, to grow to adulthood and to be resistant to certain parasites and disease.

This past April, the U.S. Senate heard testimony on offshore aquaculture. A bill backed by the Bush administration is being debated that would expand, support and regulate large-scale fish farming in American coastal waters. Supporters argue fish farms would enhance fish production and reduce seasonal variations in availability. Opponents worry they would add cut-rate competition against existing ocean fishers, flooding the market with low-quality, low-price fish.

These debates leave the average fish-lover wondering whether off-shore and deep-sea cages are a sensible alternative to wisely managing our culling of wild ocean fish. Arguably, the solution lies with the consumer. People can refrain from eating species that are threatened. They can create a demand for certain products raised or fished sustainably. Many folks want to do the right thing when buying or ordering fish, but don't know how. Certainly, the different ways fish are raised and/or caught makes things confusing.

A full discussion of the most environmentally-friendly fish to consume is beyond the scope of this article, but why re-invent the wheel? When I buy fish at the market or order in a restaurant, I consult my Seafood Watch guide. This is a little folding card that I carry in my wallet. It is published by the Monterey Bay Aquarium. Regional and national pocket-sized guides can be downloaded from their Internet site: www.mbayaq.org/cr/seafoodwatch.asp. There is plenty of information on this site about how to be a wise fish consumer and plenty more on what's happening to fisheries and fish.

Remember, despite what we see on our menus, all is not well with our regional and global fisheries. For the sake of fish, and our appetites, precaution is advised.

Michelle Portman is a Ph.D. candidate studying marine conservation policy at UMass-Boston and she works as an environmental analyst.

This article is archived at www.greendecade.org/tabarchive.asp

Read More...

Summary only...

Learning to live with less water

By Kate Bowditch/ Special To The Tab

 

 

With the beauty of spring bursting into bloom, you may not have noticed, but Massachusetts is in a serious dry spell. With almost no spring rain, and no winter snowpack to provide spring melt, we are well out of our normal seasonal water cycle. According to the National Weather Service, this year we had the driest March on record in many parts of New England, and river flows in the Charles are as low as they have ever been at this time of year.

The most visible and immediate impacts of spring drought are in the river, where the usual spring flush is simply not happening. Fish and other aquatic species that rely on spring's high, fast flows are instead struggling in flow levels that are normal in July. Wetlands that are normally full of water in March and April are already drying out. For people who enjoy spring kayaking and fishing on the Charles, the low flows have had an obvious and dramatic impact, especially in the free-flowing sections of the river.

<!--[if gte vml 1]>

Low flow, spring 2006, Cheesecake Brook

<![endif]-->Hopefully, this spring drought will not last through the summer, and the stressed river, wetlands and urban forest will rebound. But climate change and development patterns are putting more and more stress on the water-based environment, and we will have to adapt our habits, practices and expectations accordingly. We need a built environment that protects resources, and is flexible enough to withstand change. Over time, that means reducing our reliance on traditional engineering such as curb and gutter, pipes and concrete channels, and embracing softer, greener infrastructure. Nature provides some of the best models for coping with changing weather and climate conditions, and we need to emulate as many of those models as possible.

The Charles River Watershed Association advocates for "keeping water local," and provides suggestions for managing water on sites of all sizes and uses, whether a parking lot, an industrial facility, or a single family home. The basic concept is to design a site so it works as if it were undeveloped. By approximating nature's own design and function we will protect not only the natural environment but our built environment as well.

Homes, and the local environment generally, can be made more resilient and better able to cope with less water. Think of each property as one small patch of land that needs to sustain itself with its own resources, and you will begin to see possibilities. Try to recharge most rainwater into the ground; direct runoff over vegetated areas to slow and clean the flows; allow water to pool and collect in low wet areas that are planted with wetland species; save rooftop runoff in a cistern or barrel system to use for outdoor watering needs; use native plants that are suited to a fluctuating climate and do not need to be watered.

A landscape that keeps rainfall on-site is good for our rivers, ponds and wetlands. It is beneficial to property owners and to communities when landscapes are designed to withstand dry periods as well as heavy rains, and with reduced need for fertilizer, pesticides and irrigation. There are many good sources of landscaping information, such as the fact sheets available on the EPA website: www.epa.gov/owow/nps/facts. Some people might consider improving or creating wetlands on their property, as suggested in a recent webcast series sponsored by the Izaak Walton League of America http://itre.ncsu.edu/cte/TechTransfer/Teleconferences/iwla2006.asp

Kate Bowditch, Senior Environmental Scientist and Project Manager at Charles River Watershed Association, is a hydrologist. She earned her MA in Geography/Water Resources Management from BU.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

A deadly poison in your yard?

By Gilbert Woolley/Special To The Tab

 

If you've been reading these pages recently, you've heard a lot about toxins; mercury in dental amalgam, tires loaded with heavy metals and toxins in pesticides and herbicides. These are all genuine toxins, but they don't have an immediate effect. There is one toxic present in many yards in Newton that does have immediate and also long-term effects. That toxic is arsenic, the spouse poisoner's favorite. If you have a deck, or anything made from wood in your yard that was built before 2004, it is almost certain to have been built with "Pressure Treated Lumber" which, until 2004 meant wood treated with CCA: Copper Chromated Arsenic. We are not talking about parts per million. A typical deck contains several ounces of arsenic, enough to kill the neighborhood. Even a playhouse contains enough arsenic to kill the family. The Pressure Treated Lumber now in the stores should be free from toxics.

When adding a deck to our house some 15 years ago on a hot summer's day, I developed a nasty rash on my face. I discovered that this was caused by the arsenic in the dust from sawing and sanding the CCA-treated wood sticking to my sweaty face. At that time I had no idea what Pressure Treated meant and the lumber store gave no warnings. Irritation of the skin is one immediate effect of arsenic, and inhaling dust can cause burning of the throat and lungs.

After rain, the CCA still bleeds out of our deck and is identifiable by a pale green deposit on the surface. The green is from the copper, but more arsenic than copper bleeds out. This arsenic can be absorbed through the skin and by children by sucking contaminated fingers. Children must be trained to wash their hands before eating after possible contact with CCA-treated wood. Animals kept in cages made from CCA-treated wood have become very sick. The most important warning is never to burn CCA-treated wood, indoors or outdoors. Some of the arsenic is released as a vapor, and the effects of inhaling arsenic over a period are very serious. The vapor also deposits a film of arsenic on the ground and on vegetation. The remainder of the arsenic is concentrated in the ash, and a teaspoon of ash is a fatal dose for an adult. Exposure to arsenic over time is suspected as causing cancer, particularly in young children.

The harmful effects of CCA are so undisputed that the Bush administration, usually skeptical about environmental and health hazards, signed on to an agreement between the U.S. Environmental Protection Agency and the lumber industry to stop shipment of CCA-treated lumber to retailers after Dec. 31, 2003. This agreement prevents additional CCA wood from entering the market place, but does nothing to address the millions of cubic feet of lumber already in the environment.

The US EPA recommends that CCA-treated wood which can be contacted by people should be coated every year with an oil-based varnish, such as polyurethane. Any time you see a green deposit on the surface of the varnish, it's time to repaint. Wear waterproof gloves whenever you may be in contact with CCA.

As decks and other pressure-treated lumber structures reach end of life, they will pass into the waste stream. There is no perfect solution to how to prevent the arsenic from passing into the atmosphere, groundwater and drinking water, but the worst possible scenario is that municipalities like Newton, that rely on incineration to dispose of wood, will ship the CCA-treated wood to an incinerator. People living downwind of the incinerator will be subject to large doses of arsenic and the ash will be highly toxic.

Until there is a practical method of extracting CCA from the wood, a properly lined landfill is the least harmful method of disposal, but the landfill should not be upgrade from a drinking water well and the adjacent groundwater must be monitored. Arsenic is said to become attached to soil particles so that any release to the environment should be slow.

At present, most jurisdictions in the U.S., including Massachusetts, do not classify CCA-treated lumber as hazardous and it can be disposed of in unlined landfills. Unless corrected, this is going to result in serious health problems in the future. The long-term problem is that millions of pounds of arsenic have been used to treat wood and if not controlled much of this will eventually be released into the environment. (The amount of arsenic used is known because there are records of arsenic imports and almost all is used in CCA-treated wood.)

NOTE. A major reason why action to limit use of CCA-treated wood was so long delayed and why so little attention is paid to the health hazards is that many doctors do not recognize the symptoms of low-level exposure to arsenic.

Gilbert Woolley is a retired engineer. He has been a very active member of the Sierra Club since 1971, and he served on the Sierra Club National Toxics Committee for six years.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

Dogwood anthracnose: deadly disease

By Bruce Wenning/Special To The Tab

 

Flowering dogwood, Cornus florida, is a native understory tree in the eastern United States. This tree has been popular for use in home landscapes for over fifty years. Part of its popularity is that it is a slow to moderate grower and can reach a height of thirty feet and a crown width of about twenty five feet at maturity.

Flowering dogwoods are highly prized for their white or pink leaf- like bracts, which are often mistaken for the actual flowers. The flowers are much smaller and less showy than the surrounding four bracts. The bracts and flowers are emerging just about now in the landscape. At the Mass Audubon sanctuary where I work there are close to fifty scattered through out the property, and you certainly get a sense that spring is here to stay when you see these trees in bloom.

The 50 that I see every day were once part of a population of 250 that ranged in age from thirty to seventy years old. Unfortunately, by the late 1980's the majority of this larger population had died or was weakened so severely by this new fungal pathogen that they were cut down, forever changing the landscape. The pathogen is dogwood anthracnose, Discula destructiva,. It was first discovered in the New York City area in 1979. By the late 1980's it had spread to Massachusetts and to other east coast states south of New York City. Dogwood anthracnose continues to spread throughout the natural range of this native tree.

According to U Mass plant pathologist Dan Gillman, there is controversy about the origin of this disease. Some researchers think it is an invasive, exotic pathogen introduced on nursery stock, perhaps from Asia. Others think it could be a weak pathogen that mutated and became more virulent as environmental conditions favored and enhanced it. In either case, it is a disease to be reckoned with. It will continue to spread in our woodlands and forests and threaten the existence of this prized native tree.

Most anthracnose fungi attack only leaves and rarely kill their hosts. However dogwood anthracnose attacks both leaf and woody tissue. It is more destructive than the anthracnose diseases of maple, oak, sycamore, and birches, to name a few. Most of the time dogwood anthracnose kills the host slowly. It causes leaf spots, leaf and shoot blight (wilting) and twig, stem, and trunk cankers. Cankers give older trees a bumpy and contorted look, and they will eventually kill the tree. When infected flowering dogwood is subjected to environmental stresses and drought, tree death occurs even faster. Trees that have lost several branches or are in a weakened condition try to fight off the disease by developing prolific sprouting of small, clustered branches called water sprouts, which are highly susceptible to infection, which produces the cankers.

Fungal spore development causing this disease is favored by cloudy, cool, humid, and wet weather that occurs mostly in spring and early summer. Leaf spotting, and twig and stem infection usually start in the shady lower branches where the microclimate is cooler and more humid, which is beneficial for spore development. Sun and wind cause leaves and stems to dry out faster in the upper portions of the tree, thereby disabling the fungus and minimizing infection.

The disease can be managed by following these suggestions.

·      Get a soil test to determine the proper amount of organic tree fertilizer needed to maintain tree health.

·      Mulch the root zone with two to three inches of bark mulch to keep roots cool and to conserve moisture to drought, especially young trees, which are most susceptible to drought.

·      Provide at least one inch of water once a week during dry spells or drought.

·      Water only the root zone, not the leaves; excess moisture can spread the fungus.

·      The best times to prune dogwood to minimize disease infection and spread is during dry weather. Timing is key; a dry spell of 48 hours-one week is best. The tree will be able to seal off the wound within 24 hours. The other time is in late winter, because when temperatures are below forty degrees (F) the fungus advances more slowly.

·      Consult a Massachusetts Certified Arborist to confirm if you need fungicidal sprays. Fungicides will not cure dogwood, only protect it until the fungus mutates to a more virulent form. If you use fungicides, skip applications during dry weather when anthracnose spores are less infective.

For more information about dogwood anthracnose and soil testing see: www.UMassGreenInfo.org.

Bruce Wenning is the grounds manager for the Mass Audubon Society Habitat sanctuary in Belmont and serves on the Board of the Ecological Landscaping Association. www.ecolandscaping.org.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

Taming the winter moth

By Joseph S. Elkinton/Special To The Tab

 

 

My laboratory at the University of Massachusetts in Amherst has embarked on an effort to control the winter moth, Operopthera brumata, a major new threat to our forests and shade trees. The winter moth is native to Europe and has recently invaded eastern Massachusetts and caused widespread defoliation of many kinds of deciduous trees, including all species of oak and maple. In addition, it represents a threat to blueberry and apple crops. Severe tree defoliation has occurred at sites near Cape Ann and throughout the South Shore and Cape Cod. It has probably been established in eastern Massachusetts for about a decade, but no one knows how it got here or exactly where it was first established. Until 2003, it was thought to be a native species, the fall cankerworm, Alsophila pometaria. Close examination of the adult females in December 2003 proved that it was neither fall cankerworm nor the Bruce spanworm, Operopthera bruceata,a native species that is very closely related to the winter moth. All three species are in the inch-worm family of moths that feed in early spring and then drop to ground in late May where they form earthen cocoons in the soil or forest litter. The adult winter moths emerge in November or December. The females have no wings. They climb the trunks of trees and produce a pheromone that attracts the winged males. After mating they lay eggs in bark crevices, which then hatch the following spring. Many people in eastern Massachusetts have been startled by the large numbers of male winter moths they have seen flying in early evening at Christmas time. This phenomenon accounts for the name winter moth.

We believe we have an excellent chance to use natural controls to prevent future defoliation by winter moth and to convert it to a non-pest status similar to that of the hundreds of native caterpillar species that exist in our forests without ever causing outbreaks. Invasions of winter moth have occurred at other sites in North America, namely Nova Scotia in the 1950s and in the Pacific Northwest in the 1970s. In each case, a decade-long outbreak has been successfully and permanently controlled by the introduction of a parasitic fly called Cyzenis albicans, from Europe, where it is one of the naturally occurring parasites of winter moth. In Nova Scotia, they first released C. albicansin 1954. High levels of parasitism did not occur until 1961, but after that winter moth retreated to low density where it has remained ever since.

One of the most attractive features about C. albicansis that it specializes on winter moth and does not attack any other species with the possible exception of Bruce spanworm. That means that C. albicanswill not have any unintended effects on other species and when it suppresses winter moth densities, it will suppress its own density as well. People will be unaware that this fly is present in their back yards just as they are unaware of the many native species of parasitic flies and wasps that attack native insects in their yards.

In April 2005, we received about 5,000 winter moth pupae shipped to us from Victoria BC by colleagues in the Canadian Forest Service. Many of these pupae were infested with C. albicans, and from this batch we obtained 832 adult flies of which about half were females. On May 4, 2005, we released 225 C. albicansat a site in Wompatuck State Park in Hingham, where we have collected data on parasitism of winter moth since 2004. The remaining flies were held in the laboratory to produce eggs for production of more flies for next year. Based on similar work in Nova Scotia, we do not expect to see much, if any, parasitism for several years, because the eggs laid by a few hundred released flies are dispersed among the millions of winter moths at this site.

We believe that our efforts to control winter moth by introducing C. albicansare almost guaranteed to work because the approach has already worked before at two other locations in North America. If so we will achieve permanent solution to the winter moth outbreak that will require no further expenditures once we get C. albicans established. However, in order for the introduction to work within a reasonable time frame (e.g. five years) we must invest sufficient funds to be able to release several thousand C. albicansfrom as many sites as possible each year. Otherwise it could be a decade or more before the parasitoid population catches up with the already huge winter moth population. Last year we estimated that there were approximately a quarter million winter moth eggs being laid in each tree. With several million trees infested, the estimated size of the winter moth population in eastern Massachusetts is several trillion!! It will take some years for a few thousand C. albicansto multiply sufficiently to catch up. As with any biological control project, we must release a sufficient number of parasitoids at each site in order to assure that the next generation of parasitoids are abundant enough to find mates. Luckily the Massachusetts state legislature is considering a bill to provide the necessary funding for this initiative.

Joseph S. Elkinton is Professor of Entomology in the Department of Plant, Soil and Insect Science, University of Massachusetts, Amherst, elkinton@ent.umass.edu, 413-545-4816.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

Artificial turf: Solution or problem?

By Gilbert Woolley/ Special To The Tab

 

Astroturf, the original brand of artificial turf, was used for the first time in 1968 in the

Houston Astrodome baseball stadium. Many indoor and some outdoor fields were

covered in Astroturf, but the surface was well described by a critic as "carpet on

concrete" and it fell out of favor.

 

In the early 21st century several brands of artificial turf have overcome some of

limitations of Astroturf and other early products.

 

Construction varies in detail, but the newer products try to produce a playing surface

that is close to that of natural turf. This is achieved by adding around an inch and a

half of a resilient material, sometimes mixed with sand, around the synthetic "grass

blades," which can be made of nylon, polyethylene or polypropylene (which in turn can

be made from recycled plastic. The resilient material is, typically, ground up waste

rubber from worn out tires, or in one case, the soles of athletic shoes.

It has been estimated that an average soccer or football field of artificial turf uses

45,000 recycled tires that might otherwise take up space in a landfill or an illegal waste

site. About 250 million scrap tires are generated in the US every year. Today 80

percent are ground up and recycled: 30 percent mixed with asphalt for highways; 30

percent mixed with plastics for molded products which do not need to have a good

appearance; and 15 percent are used for athletic surfaces, including artificial turf.

Artificial turf is low maintenance, and requires no herbicides, pesticides, or watering,

and no need for reseeding. The most important advantage, with respect to the

management of the field, is that it can be played on every day, winter and summer. It

doesn't get bald patches and doesn't get muddy when it rains.

 

Disadvantages are that, in summer, artificial turf gets much hotter than natural turf, but

this problem is not so critical in Massachusetts as some places. Also, dealing with

animal droppings and human "body fluids" is more difficult. On natural turf, there is

natural "treatment" from bacteria in the soil, but on artificial turf solids must be

frequently removed and the surface sanitized. The "sanitizer" must be harmless to the

skin of players.

 

The improved artificial turf has been widely accepted in the US but In Europe the

response has been mixed. FIFA, the international organization governing soccer has

approved Field Turf, one of the newer brands, for all games, except for World Cup

tournaments. (The English governing body for soccer approves it for practice but not

for league games while the Scottish Premier League banned artificial turf for

competition matches in 2005.)

 

The trade association of natural turf providers claims that ground up tires are

hazardous and supports this claim by pointing out that tires are banned from many

landfills. But, in fact, the reasons tires are banned from landfills is that they are a

breeding ground for mosquitoes, create a risk for serious fires that are hard to

extinguish, and that tires are unstable in landfills.

 

Of course, just because turf is "natural" does not mean it is environmentally harmless.

Large amounts of fertilizer, herbicides and pesticides are sometimes used to keep a

field in first class shape. Newton practices Integrated Pest Management, which

reduces the use of these products significantly, but maintaining the fields may still

require the use of materials that we would prefer to keep out of storm drains.

If gas or diesel powered machines are used for mowing, or to spread fertilizer, that

has environmental impact, as does the use of large quantities of water, usually

drinking quality, to keep the grass healthy.

 

It is most likely that, at end of life, the artificial turf may be too heavily soiled to be

economically recycled and will need to be disposed of in a landfill. This is where the

bulk of the material, the rubber, would have gone if not used for turf. But it is now in a

form much preferred by landfills to intact tires. The rubber will not be broken down by

microorganisms in the landfill or dissolved by water and will be there almost "forever",

like most of the inorganic materials that go into landfills today.

The existing playing field at Newton South High School, where there is interest in

using artificial turf, is large and not perfectly level.

 

It has bare spots, especially around the basketball court. It does become muddy in wet

weather. It is liberally covered with goose droppings. The geese use the area for

feeding. They dig in their beaks to extract worms and grubs. If the grass were

replaced by artificial turf, the geese would soon learn that there was nothing to eat in

the area.

 

This writer's opinion is that there are no heavy "environmental" issues involved, and

that the decision to use, or not use, artificial turf should be based on cost over (say) a

ten-year period. Suppliers claim a much longer life. It may be economical to use

artificial turf only in areas of heavy use like the basketball diamond.

 

Gilbert Woolley is a retired engineer. He has been a very active member of the Sierra

Club since 1971, and he served on the Sierra Club National Toxics Committee for six

years.

 

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

Hurricane man blows into town

By Lois Levin/ Special To The Tab

Those who braved the cold on Feb. 27 to hear MIT Professor Kerry Emanuel's
Environmental Speaker Series lecture at the Newton Library were captivated by his
clear presentation of complex scientific data from his climate modeling research.
Dr Emanuel's data shows that the intensity of
hurricanes in the Atlantic has grown dramatically -
doubled - in the past 30 years. This is due largely to
human activity. We have released enormous amounts
of greenhouse gases into the atmosphere by burning
oil and coal to create energy to power factories, heat
our homes and run our automobiles. We have
warmed the oceans, including the areas where
powerful storms are formed, and this translates
directly into more powerful hurricanes, with serious
consequences for coastal areas.
New England is highly vulnerable to hurricanes, which
have occurred at a remarkably steady rate for
centuries, averaging one every five years. As these
storms continue to grow more intense, they place us
at increasingly greater risk. Therefore, while we work
to address global warming, we must also empower
public agencies to plan for and cope with these
storms, which expose us to great physical danger and
financial risk. Insurance companies are already
refusing to provide coverage for storm damage in
many coastal areas.
The lecture, sponsored by the Green Decade Coaltion, will be aired on NewTV later
this spring.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

Frozen by uncertainty

By Eric Olson/ Special To The Tab

Global warming is upon us. Even the oil companies tell us so. BP, formerly known as
British Petroleum but now officially just "BP" (after spreading the rumor they wanted to
stand for "Beyond Petroleum") is running full-page ads in major newspapers
encouraging people to take the time to calculate their carbon footprint. The only
reason anyone would take the time is if they first believed there was some problem
with their carbon footprint, i.e., specifically carbon dioxide, the heat-trapping gas
formed whenever a fossil fuel is burned. Climate scientists have been fretting for a
couple of decades now that our species' emissions of billions of tons of CO2 per year
could warm up the planet, and both their models and their observations point clearly
now in that direction. So it is a great relief to see at least some of the major
beneficiaries of our carbon-intensive economy are finally encouraging consumers to
take note.

Let's say you do use the BP calculator or others like it to calculate your footprint. You
provide information on your household heating and air conditioning, your electricity
consumption, your mileage and miles driven, add in a plane trip or two, and don't
forget the hot water heater. What did you get? Between 15 and 20 tons per year? Are
you surprised that I guessed so close? It's not hard. Energy geeks all know that the
typical American house generates just over 13 tons annually, and we just add in 5 to
10 additional tons for transportation. Plane travel is especially costly by this measure.
Now what? This is the question of the decade. There is a great deal of uncertainty
about what if anything we can do on a personal level. Consider first the climate itself:
This is an unpredictable beast and has changed over the millennia all on its own.
There is a slim chance that it will either autocorrect (maybe more clouds will form and
will block the sun) or an act of God will save us at least temporarily (ash from large
volcanic eruptions also block the sun). A second rescue could come from our own
ingenuity: Surely we will come up with something - a cheap fuel from our own
garbage, cold fusion, vastly superior yet cheaper solar panels, etc. A third option is to
turn to the government and shout, "Make everyone suffer equally! Only then will I
accept sacrifice." Finally we could just be resigned to our fate. After all, maybe a
warmer world won't be so bad, really. We could just ride it out and send food to the
people suffering the worst consequences.

A hard-nosed economist, confronted with such uncertainty, might argue for a "wait but
watch closely" approach. If you act too soon, goes this reasoning, you may regret it
when some better option comes along. This sounds sensible, as does so much of
what economists say, but in light of the stakes involved (many species threatened with
extinction, 17% of the land area of Bangladesh to be lost with just a 1-meter rise in
sea level, hurricane intensity in the Atlantic up sharply over the past 30 years), a better
description of this response is "frozen by uncertainty". The deer-in-the-headlights
image comes to mind.

A middle ground is to do SOMETHING, even if it's small. Like get yourself down to
Swartz Hardware in Nonantum and check out their amazingly low prices on compact
fluorescent bulbs (full disclosure: I have no financial interest in that store). This could
be your Step One. Did you know that a single one of these twisty bulbs saves you
over $50 over its seven-year lifetime? Even if they still cost $10 they would be worth it,
but their cost is just a couple of bucks now, and the light quality has improved over
that of earlier versions.

As for Step Two, how about that $50 I just saved you, two lines back? Use that money
to support new renewable, clean electricity generation in New England. There's an
astonishing way to do this, and it gets your money multiplying all over the place.
Here's how it works: The government has already imposed a tiny clean power charge
on our utility bills. Look closely at your NStar bill and you'll see it. This money flows to
an entity called the Renewable Energy Trust Fund, which is charged with encouraging
new clean power (solar, wind, etc.) for the state. If you contribute $50 to support clean
power, the Trust fund will release an equivalent amount back to the City of Newton,
and the City has committed to spending this money on educational solar panel
displays on our public schools. (Oak Hill Middle School will be the first recipient, slated
for this summer.) Then the Trust releases a second $50 match, to support energy
efficiency projects in low-income housing in the state, wherever the need is greatest.
Finally, since this is a donation, you get a tax deduction for it, 100 percent of it. So you
can support new clean power, help put solar panels on a school, make a low-income
family a bit warmer next winter, get a tax deduction, and lo, it's free money to begin
with, because you bought the bulb at Swartz. Would you like to buy a second bulb?
To get going on this and join the growing throng of people voting with their pocket
books for renewable power, call the Mass Energy Consumers Alliance at 617-524-
3950 ext. 129, and ask to speak with Janna Cohen-Rosenthal. You may want to do
those other things - wait and watch closely, shout at the government, etc. - but the first
step is to crack through your own frozen uncertainty and support clean energy. One
lightbulb and one phone call at a time.

Eric J Olson, PhD, is Chairman of the Newton Citizens' Commission on Energy. He
teaches in the Sustainable International Development program, Heller School of
Social Policy & Management, Brandeis University.
This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...

The Dilution Effect

By Jill Hahn / Special To The Tab

 

Here’s a story about a blacklegged tick, a white-footed mouse, an unpleasant

bacterium, and how reducing biodiversity in our own backyards can literally make us

sick.

Lyme disease, which now accounts for about 90

percent of the vector-borne disease (spread by an

animal carrier) in the U.S., is caused by the

bacterium Borrelia burgdorferi, transmitted by the

bite of an infected blacklegged tick, Ixodes

scapularis. A new-born tick does not carry the

bacterium. In order to acquire the bacterium, the

larval tick must take its blood meal from an infected

animal. And here’s where the I. scapularislarvae are

the kind of eaters you wish your children were: they

are not picky. They will feed on a wide variety of

mammalian, bird, or even reptile hosts. The larva

takes one blood meal from the host it happens to

encounter, and then molts into its next stage, called

a nymph.

Most people contract Lyme disease from the nymphal stage of the blacklegged tick,

partly because the nymph is small and hard to spot, partly because it is active in June

and July, when we’re likely to be out enjoying the woods.

What determines whether the nymphal tick that just bit you is likely to give you Lyme

disease? Dr. Richard Ostfeld, senior scientist at the Institute of Ecosystem Studies

(Millbrook, NY), conducted a series of elegant, if messy, experiments to find out. Since

a nymph can only acquire B. burgdorferi during its larval meal, Dr. Ostfeld’s first task

was to determine whether feeding on different animals resulted in differing proportions

of infected nymphs. To do this, he and his colleagues trapped individuals from every

potentially important bird and mammal species in his study site in Duchess County,

NY. This list included deer, robins and other songbirds, white-footed mice, chipmunks,

raccoons, possums, skunks, shrews, and squirrels. The animals (deer excepted) were

caged for 72 hours. Any tick larvae attached to them fell off into pans of water under

the cages. They were collected (a dirty job, because more than just ticks dropped into

those pans during the 72 hours) and tested for the presence of the Lyme disease

bacteria.

Dr. Ostfeld discovered that over 90 percent of the ticks that fed on white-footed mice

tested positive for B. burgdorferi. 40-55 percent of the ticks from shrews or chipmunks

tested positive, and the proportion of positive ticks collected from the other species

ranged from around 15 percent to less than 2 percent. So the host species a larval tick

2

Photo courtesy of Frontiers in Ecology

and the Enivronment

White-footed mouse female

and pups

fed on dramatically affected whether the resulting nymph would be able to transmit

Lyme disease.

Since different species of animal have differing abilities to pass the Lyme disease

bacterium to the tick, this suggests that increased host biodiversity might lower the

prevalence of infected ticks. Dr. Ostfeld dubbed this hypothesis the Dilution Effect.

Ecologists know that, as you fragment forest into smaller and smaller pieces, the

number of animal species found in those forested "islands" declines. If the Dilution

Effect holds true, then the proportion of infected nymphal ticks should increase as

forest area goes down and biodiversity decreases. Dr. Ostfeld and his colleagues set

out to test that prediction.

They measured the density of nymphal ticks in forest fragments of different sizes

(ranging from less than two acres to almost 19 acres) by dragging drop cloths through

the forest and counting the number of nymphs collected. When Dr. Ostfeld tested the

ticks, he discovered that, as the Dilution Effect predicted, the proportion of ticks

infected with B. bergdorferi increased as the forested area decreased.

Why would this be? In the smaller forest fragments,

many potential host species disappeared. One

species, however, whose numbers conspicuously

explode as forest area decreases is the white-footed

mouse. White-footed mice, as Dr. Ostfeld had

already shown, are incredibly efficient at infecting

ticks with Lyme disease.

What does this mean for human health? Simply put,

biodiversity protects us from Lyme disease. If you go

hiking, say, in the White Mountains of New

Hampshire, and you get bitten by a blacklegged tick

nymph, you know that tick had a wide variety of

species from which it could have taken its larval

meal, and most of those wouldn’t be likely to infect it

with the Lyme disease bacterium. On the other

hand, if you’re out on a small plot of forested land in

your suburban hometown - especially if it’s smaller than about five acres - that nymph

that bit you most likely got its last meal from a white-footed mouse, and most likely did

contract the bacterium during that meal. So your chances of contracting Lyme disease

from a tick bite are much higher in the forest fragment near your house than in the

National Forest.

If those cute little white-footed mice are the problem, why not simply get rid of them?

Attempts to eradicate rodents to a level at which they can no longer transmit disease

are notoriously unsuccessful. Attempting to rid the woods of ticks is a similarly

Sisyphean task. There is another solution: let the Dilution Effect work for us by

changing the way we manage our landscape.

Dr. Ostfeld’s work has shown that the loss of biodiversity through the fragmentation of

our native forests has real health consequences. The Dilution Effect holds true for

Lyme disease and may play a role in other vector-borne diseases as well. It’s time to

3

stop thinking of biodiversity as something that would be nice to preserve, but of no

practical value. The next time a local interest in your community wants to break up an

existing parcel of forest into smaller pieces for the sake of development, think about

the health consequences, and think twice.

Jill Hahn, a Newton Highlands resident, is a biologist, a writer, and a mom. All three

roles contribute to her passion about environmental issues. She can be reached at

jkkhahn@comcast.net.

This article is archived at www.greendecade.org/tabarchive.asp.

Read More...

Summary only...