My potential sources will most likely be the Chesapeake Bay Journal and the Chesapeake Bay Foundation. These two sources have have allowed me to find out about invasive species in the Chesapeake Bay, the Potomac River, and other nearby waterways and tributaries of the Chesapeake Bay. I will also look into other sources that can assist me in furthering my knowledge about non-native species that are invading the United States.
Th Chesapeak Bay Journal is a monthly publication and covers environmental issues that affect the Chesapeake Bay. The Journal write articles and blogs concerning the plight of the Bay due to pollution and invasive species in the Bay. The Chesapeake Bay Foundation educates the general public, school administrators, teaches, and students regarding the Chesapeake Bay. They advocate on the behalf of the Bay by implementing solutions to improve the health of the Bay. The Chesapeake Bay Foundation litigates non-compliance of the laws and regulations that affects the Bay and restores the Bay through water quality improvements and the help of volunteers to clean up the Bay.
Wednesday, October 31, 2012
Wednesday, October 24, 2012
Purple Loosestrife
The purple loosestrife is a non-native plant that is known for its invasion of wetlands. "A beautiful flower but very aggressive invader, Purple Loosestrife is a perennial weed native to Europe and Asia that was introduced to the U.S. in the 1880s" (Fryberger 1). This plant is prevalent throughout most of the United States. "The purple loosestrife have gotten out of control in the continental US, and are taking over and choking out native species and altering the habitats" (Gaskins 1).
Purple loosestrife poses a dangerous threat to wetlands because of its prolific ability to reproduce. "The loosestrife have risen in both number and extent to which they alter the habitat they live in, and though it might seem that they would only impact other competing native plant species, they also have become enough of a problem where they also are hurting animal species, especially specialized wetland birds" (Gaskins 1). It threatens native plant species by crowding them out and by competing for sunlight and water. When purple loosestrife replace native plants, they destroy the habitats of animal and insects that depend on native species for food and shelter. Animals such as duck, muskrat, and geese have seen a decline in their populations due to the proliferation of the purple loosestrife. The denseness of this plant impedes water flow and requires costly management efforts. Scientists have found a natural predator of the purple loosestrife to control its growth. The Galerucella beetle feed on the leaf, bud, and stem of loosestrife plants and prevents the plant from reproducing.
There is a segment of society that treasure purple loosestrife and do not want this plant to be eradicated because of what they perceive as the benefits that purple loosestrife provides. Purple loosestrife contains astringent chemicals called tannins and salicarin. Astringent chemicals may help reduce diarrhea and inflammation. Salicarin might also assist in fighting bacteria, or bugs, n the intestine. Purple loosestrife are popularly used in ornamental decorations and in gardens.
Gaskins, Lindsay. Purple Loosestrife - Beautiful Killer. Duke University, 25 September
2010. Web. 24 October 2012
Fryberger, Kevin. A Beauty and a Beast. Stewardship Chronicles, 15 August 2011. Web.
29 October 2012.
Though I support maintaining control of the spread of purple loosestrife, I do not support the elimination of this plant. I understand the concerns of those who are concerned about the negative effects this plant has on other species of plants and on animal habitat. But I also understand the feelings of those who value what they consider are the benefits of purple loosestrife. This plant makes beautiful ornamental displays and decorations. They add a unique flair to gardens with their wonderful purple color that accents any arrangement. They also have what appears to be promising medicinal uses. Purple loosestrife is an invasive species that does serve a useful purpose.
Works Cited
Fryberger, Kevin. A Beauty and a Beast. Stewardship Chronicles, 15 August 2011. Web.
29 October 2012.
Wednesday, October 17, 2012
Mute Swans
Mute swans are an invasive species that have been present in the Chesapeake Bay area since the 1930s. They are the largest birds that are inhabitants of this area. Mute swans have a lifespan of about 12 years and adult birds have a six feet wing span. They were imported from Eurasia to populate residential ponds and parks. Mute swans are year-round inhabitants in creeks, lakes, rivers inland ponds, and streams. Their population has increased 1,271percent since 1986. They feed throughout the year which does not allow for grass beds to recouperate.
Mute Swan
Mute swans are a species that threatens waterfowl, crops, underwater grasses, and even humans. When these birds decimate available grasses, they move to feed on and damage agricultural crops. Mute swans are very aggressive and territorial. Their behavior even threatens human and displaces other birds. “Wildlife professionals have many critical and immediate problems to address, including habitat loss and fragmentation, invasive species, pollution, global climate change, energy development, emerging diseases, and human-wildlife conflict“ (Hutchins 2).
Mute Swans
Conflicts and court battles with animal rights groups have made it difficult to reduce the population of mute swans. Though saving animal species from being uprooted and/or eliminated is a noble cause, some invasive species must be controlled for the betterment of native ecosystems. It is important that there are conservation methods that control non-native species to prevent the loss of habitat which adversely affects native species. “The consequences for inaction on selected introduced species will be the loss of more native species and alteration of habitats“ (Hutchins 2).
The mute swan is a beautiful and attractive bird. People enjoy feeding them and these birds supplement their diet by receiving food from others. They give the public the opportunity to get up close to nature. But there is a down side to mute swans, which is an invasive species, inhabiting the areas of native species. Mute swans are ferocious eaters of grasses and crowd out other species by reducing the food supply of other birds including migratory birds. They are aggressive and they displace other bird species. Mute swans are known to be aggressive towards humans and there are two recorded incidences of them causing deaths of human beings. The negative effects mute swans have on the environment, other species, and the lives of humans warrant a concerted effort to control their numbers and prevent further destruction of the ecosystems in which they inhabit.
Works Cited
Hutchins, Michael. Non-native Mute Swans Must Go. The Wildlife Society Blog, 14
May 2009. Web. 17 October 2012.
Mute Swan
Mute swans are a species that threatens waterfowl, crops, underwater grasses, and even humans. When these birds decimate available grasses, they move to feed on and damage agricultural crops. Mute swans are very aggressive and territorial. Their behavior even threatens human and displaces other birds. “Wildlife professionals have many critical and immediate problems to address, including habitat loss and fragmentation, invasive species, pollution, global climate change, energy development, emerging diseases, and human-wildlife conflict“ (Hutchins 2).
Mute Swans
Conflicts and court battles with animal rights groups have made it difficult to reduce the population of mute swans. Though saving animal species from being uprooted and/or eliminated is a noble cause, some invasive species must be controlled for the betterment of native ecosystems. It is important that there are conservation methods that control non-native species to prevent the loss of habitat which adversely affects native species. “The consequences for inaction on selected introduced species will be the loss of more native species and alteration of habitats“ (Hutchins 2).
The mute swan is a beautiful and attractive bird. People enjoy feeding them and these birds supplement their diet by receiving food from others. They give the public the opportunity to get up close to nature. But there is a down side to mute swans, which is an invasive species, inhabiting the areas of native species. Mute swans are ferocious eaters of grasses and crowd out other species by reducing the food supply of other birds including migratory birds. They are aggressive and they displace other bird species. Mute swans are known to be aggressive towards humans and there are two recorded incidences of them causing deaths of human beings. The negative effects mute swans have on the environment, other species, and the lives of humans warrant a concerted effort to control their numbers and prevent further destruction of the ecosystems in which they inhabit.
Works Cited
Hutchins, Michael. Non-native Mute Swans Must Go. The Wildlife Society Blog, 14
May 2009. Web. 17 October 2012.
Wednesday, October 10, 2012
Intersex Fish
Biologists, over the past ten years, have been investigating fish kills in the Potomac River Basin . What the biologists found out was that male fish had female eggs in their testes. “For the past decade, they have worked to unravel the story of what’s causing “intersex” fish, a phenomenon that has turned up in 100 percent of smallmouth bass sampled in some areas of the Shenandoah and in 50 - 75 percent of those tested at a number of other sites in the Potomac basin” (Blankenship 1).
Outside the watershed, in less polluted areas, intersex abnormalities are seen in no more than 10 - 15 percent of smallmouth bass. The presence of characteristics of both sexes in a single organism is called intersex. Vitellogenin, which is normally found in the blood of female fish, is a precursor of egg yolk and has also been found in male fish. Research has shown that discharges from wastewater treatment facilities are linked to intersex fish. “Meanwhile, the severity of the intersex abnormality - such as more eggs in a male fish’s testes - was generally higher in samples taken from areas with significant wastewater discharges, basins with large amounts of agricultural land and areas with high densities of agricultural animals or poultry houses” (Blankenship 1). Long term exposure to pollutants is what is seen to be the cause of the pronounced female characteristics found in male fish.
“Intersex is caused by endocrine disruptors, which affect the hormone systems in fish, animals and humans. They are found in products intended to have biological effects, such as hormones or other feed supplements fed to livestock, or medicines taken by humans” (Blankenship 2). Although intersex characteristics have been found mainly in smallmouth and largemouth bass, it is occasionally found in other species. There are suspicions that chemicals are causing intersex and are resulting in the suppression of the immune systems of fish. This leads to fish kills due to fish being more susceptible to disease.
Though more research is needed to find the cause of intersex. I believe it is obvious that runoff from wastewater treatment plants and farm chemicals are causing intersex in fish. Fish with intersex characteristics are mainly found near wastewater facilities and near farming areas. Research should also delve into what can be done to decrease the exposure of chemicals to fish and other species.
Blankenship, Karl. Intersex fish linked to areas with high ag, wastewater runoff.
Chesapeake Bay Journal, October 2012. Web, 10 October 2012.
Smallmouth Bass
Outside the watershed, in less polluted areas, intersex abnormalities are seen in no more than 10 - 15 percent of smallmouth bass. The presence of characteristics of both sexes in a single organism is called intersex. Vitellogenin, which is normally found in the blood of female fish, is a precursor of egg yolk and has also been found in male fish. Research has shown that discharges from wastewater treatment facilities are linked to intersex fish. “Meanwhile, the severity of the intersex abnormality - such as more eggs in a male fish’s testes - was generally higher in samples taken from areas with significant wastewater discharges, basins with large amounts of agricultural land and areas with high densities of agricultural animals or poultry houses” (Blankenship 1). Long term exposure to pollutants is what is seen to be the cause of the pronounced female characteristics found in male fish.
“Intersex is caused by endocrine disruptors, which affect the hormone systems in fish, animals and humans. They are found in products intended to have biological effects, such as hormones or other feed supplements fed to livestock, or medicines taken by humans” (Blankenship 2). Although intersex characteristics have been found mainly in smallmouth and largemouth bass, it is occasionally found in other species. There are suspicions that chemicals are causing intersex and are resulting in the suppression of the immune systems of fish. This leads to fish kills due to fish being more susceptible to disease.
Largemouth Bass
Though more research is needed to find the cause of intersex. I believe it is obvious that runoff from wastewater treatment plants and farm chemicals are causing intersex in fish. Fish with intersex characteristics are mainly found near wastewater facilities and near farming areas. Research should also delve into what can be done to decrease the exposure of chemicals to fish and other species.
Works Cited
Chesapeake Bay Journal, October 2012. Web, 10 October 2012.
Wednesday, October 3, 2012
Zebra Mussels
The zebra mussels showed up in the summer of 2010 near Port Deposit, MD, a few miles from the mouth of the Susquehanna River. In the summer of 2011, someone found a single mussel nearby in the Sassafras River. It is believed that it is not the only mussel in the Sassafras River since for the last decade zebra mussels have been working themselves downstream. “Biologists in the Bay region have long been concerned about the arrival of the species, a native of the Caspian Sea, because of its ability to mushroom into huge populations, crowd out native mussel species and alter ecosystems" (Blankenship 1).
Because zebra mussels are a fresh water species, biologists believe that it is unlikely that they will gain a foothold in the Chesapeake Bay. But since these mussels can attach themselves to the bottom of boats, to motors, and trailers, they can be transported to waterways such as rivers, lakes, and reservoirs where they can thrive. In regards to mussels spreading in the Bay, biologists are concerned about the high river flows in the spring and summer reducing the salinity of the Bay which can result in the zebra mussels gaining strength there.
“Named for the striped pattern of their shells, zebra mussels are thought to have arrived in the Great Lakes in 1988 in the ballast water holds of ships from Europe" (Blankenship 2). Their dense colonies can block water intake pipes and cause major problems for industrial and municipal water uses. Zebra mussels have been blamed for causing billions of dollars in damages nationwide.
In 1991, these mussels arrived in the tidal basin of the Hudson River. One zebra mussel, while feeding on algae, can filter as much as a gallon of water per day. Their filtering can reduce the populations of some algae species and promote the increase of other algae species. They have caused the reduction in dissolved oxygen levels in the water faster than the oxygen levels could be replaced. Zebra mussels in some places, due to there large populations, have reduced the supply of food for fish causing a fall in the fish population. Native mussel populations have nearly been wiped out in some areas because of competition with zebra mussels.
Fortunately for the Chesapeake Bay and its tributaries, zebra mussels are not widespread. But it is important that users of these waterways are educated about prevention measures to make sure that they do not unintentionally transport mussels from place to place.
This story points out how zebra mussels can easily be transported from one waterway to another. They then can be transported by unsuspecting boaters and fishermen who may not know what to look for or the dangers that invasive species can present. That’s why it is important that there are regular educational programs directed to the public, especially to those who boat and fish in areas where invasive species are present or may be gaining a foothold. Only then we all can be knowledgeable about the impact that invasive species can have on the ecosystem.
Works Cited
Blankenship, Karl. Zebra Mussels slowly spreading into Chesapeake Tributaries.
Chesapeake Bay Journal, December 2011. Web. 3 October 2012.
Because zebra mussels are a fresh water species, biologists believe that it is unlikely that they will gain a foothold in the Chesapeake Bay. But since these mussels can attach themselves to the bottom of boats, to motors, and trailers, they can be transported to waterways such as rivers, lakes, and reservoirs where they can thrive. In regards to mussels spreading in the Bay, biologists are concerned about the high river flows in the spring and summer reducing the salinity of the Bay which can result in the zebra mussels gaining strength there.
“Named for the striped pattern of their shells, zebra mussels are thought to have arrived in the Great Lakes in 1988 in the ballast water holds of ships from Europe" (Blankenship 2). Their dense colonies can block water intake pipes and cause major problems for industrial and municipal water uses. Zebra mussels have been blamed for causing billions of dollars in damages nationwide.
In 1991, these mussels arrived in the tidal basin of the Hudson River. One zebra mussel, while feeding on algae, can filter as much as a gallon of water per day. Their filtering can reduce the populations of some algae species and promote the increase of other algae species. They have caused the reduction in dissolved oxygen levels in the water faster than the oxygen levels could be replaced. Zebra mussels in some places, due to there large populations, have reduced the supply of food for fish causing a fall in the fish population. Native mussel populations have nearly been wiped out in some areas because of competition with zebra mussels.
Fortunately for the Chesapeake Bay and its tributaries, zebra mussels are not widespread. But it is important that users of these waterways are educated about prevention measures to make sure that they do not unintentionally transport mussels from place to place.
This story points out how zebra mussels can easily be transported from one waterway to another. They then can be transported by unsuspecting boaters and fishermen who may not know what to look for or the dangers that invasive species can present. That’s why it is important that there are regular educational programs directed to the public, especially to those who boat and fish in areas where invasive species are present or may be gaining a foothold. Only then we all can be knowledgeable about the impact that invasive species can have on the ecosystem.
Works Cited
Blankenship, Karl. Zebra Mussels slowly spreading into Chesapeake Tributaries.
Chesapeake Bay Journal, December 2011. Web. 3 October 2012.
Phragmites - An Invasive Species of Grass
Phragmites is an invasive species of grass that can grow up to 18 feet tall. It was introduced to North America from the ballast of ships by English colonists. While phragmites can be bad for wildlife and other plant species, it prevents erosion in marsh lands where they exist because it holds and builds soil. “Over the last three decades, the invasive plant has multiplied perhaps 10 fold to cover roughly 100,000 acres or about 10 percent of Maryland marshes, according to an estimate by the Maryland Department of Natural Resources” (Pelton 2). Phragmites have also spread across other states such as Virginia and Pennsylvania.
It is known as Dr. Jekyll and Mr. Hyde by scientists because of its good and bad qualities. Though phragmites protect shorelines, scientists would prefer the prevalence of native grasses in the marshes. The reason is that phragmites are a poor habitat for fish, birds, and animals. Also, a toxin is emitted from its roots that kills and crowds out other grasses that are the habitat for wildfowl and other animals. “
"The Maryland Department of Natural Resources, with help from the U.S. Fish and Wildlife Service, spends about $30,000 a year spraying an herbicide (glyphosate, the active ingredient in Round Up) from helicopters onto selected stands of phragmites that are monopolizing the landscape in important wildlife areas" (Pelton 2). Glyphosate is also used by other states to control phragmites. The problem with using glyphosate is that planes are used to spray the phragmites and there is a danger that the chemical could drift to other areas and wipe out endangered plants. Also, spraying glyphosate is making farming more difficult because it is creating weeds that are herbicide-resistant.
Works Cited
Pelton, Tom. The Jekyll and Hyde of the Marsh. Chesapeake Bay Foundation, 27
September 2012. Web. 3 October 2012.
It is known as Dr. Jekyll and Mr. Hyde by scientists because of its good and bad qualities. Though phragmites protect shorelines, scientists would prefer the prevalence of native grasses in the marshes. The reason is that phragmites are a poor habitat for fish, birds, and animals. Also, a toxin is emitted from its roots that kills and crowds out other grasses that are the habitat for wildfowl and other animals. “
The prevalence of phragmites in Virginia has sufficiently been controlled through programs to prevent and reduce their spread. Though phragmites are good at preventing erosion, there are native grasses that can do as good a job. Native grasses that have been displaced by phragmites are better at providing habitat for animals and birds that live in the marshes. The control of phramites is also good for the environment in that less glyphosate will be sprayed and thus other grasses will not be killed and less farmers will have to deal with herbicide-resistant weeds.
Works Cited
Pelton, Tom. The Jekyll and Hyde of the Marsh. Chesapeake Bay Foundation, 27
September 2012. Web. 3 October 2012.
Subscribe to:
Posts (Atom)