The eastern oyster is one of the most iconic species in the Chesapeake Bay. For more than a century, oysters have been one of the area's most valuable commercial fisheries, and the filter-feeder continues to clean the waters and provide food and habitat to other animals. However, over-harvesting, disease and habitat loss have led to s severe drop in oyster populations. Scientists are working to manage harvests,establish sanctuaries, overcome the effects of disease, and restore reefs with hatchery-raised seed in an effort to restore this important bivalve.
You don't have to like eating this peculiar-looking shellfish to appreciate its vital role in the Chesapeake Bay ecosystem - and its importance to people who live around the Bay. Oysters are natural filter feeders. This means they feed by pumping water through their gills, trapping particles of food, as well as nutrients,suspended sediments and chemicals. In doing so, oysters help keep the water clean and clear for bay grasses and aquatic life. One oyster can filter more than 50 gallons of water in a single day.
As oysters grow, new larvae (or seed) settle on top of adults, forming layers of oysters that spread upward and outward. With their countless nooks and crannies, these reefs provide habitat to hundreds of diverse water creatures - from small fish and invertebrates seeking shelter to larger fish looking for food. Oysters do have a number of natural predators: (1) anemones, sea nettles, and other filter feeders eat oyster larvae, (2) flatworms and mud crabs feed on new spat, (3) blue crabs and some fish species eat older spat and first-year oysters, and (4) shorebirds feed on adult oysters that are exposed upon intertidal flats.
Since the late 19th century, the oyster industry - including the catch, sale, shucking, packing, and shipping of oysters - has contributed millions of dollars to the region's economy. Oysters have also added to the region's historical and cultural heritage, fueling countless bull and oyster roasts. Oysters have also inspired the unique design of boats in the area: the log canoe, the pungy, the bugeye, the skipjack, the deadrise and the scow.
The decline of the Chesapeake Bay's native oyster population can be attributed to several factors, including historic over-harvesting, disease and habitat loss. The severity of this decline is often illustrated in terms of its impact on water quality: in the late 19th century, the Bay's oysters could filter all of the water in the Bay in three or four days; today's oysters would take nearly a full year to filter the same amount of water.
In the 17th century, huge numbers of oysters lived in the Chesapeake Bay. European settlers reported enormous oyster reefs that thrust up from the Bay's bottom, posing hazardous navigation for their wooden ships. Colonists first used hand tongs to harvest oysters, but by the 1800s, oyster dredges were also in use. In the 1850s, more than 1.5 million bushels of oysters were harvested from the Bay each year. In the 1880's, the number jumped to 20 million bushels each year. At the turn of the 20th century, the Chesapeake Bay oyster fishery was one of the most important assets of the United States.
Over-harvesting, however, removed huge volumes of oysters from the Bay and led to the end of the Bay's healthy oyster reefs. Dredging for oysters has scraped the reefs away, and oyster beds are now limited to flat, thin layers of dead shell and live oysters spread over a wide surface of the Bay's bottom. These damaged habitats offer less surface area for reef-dwelling creatures to inhabit, and can easily be buried by a heavy wash of sediment, or dumping.
In 1949, scientists discovered Dermo in the Chespeake. MSX was discovered in the waters ten years later. Dermo, or Perkinsus marinus, is a parasite that usually infects oysters at the age of two years; it causes slow growth rates and death. MSX, or Haplosporidium nelsoni,also leads to oster death, but can infect oysters of all ages. Both diseases are contracted between May and October, and their prevalence can be affected by water temperature and salinity.
Overcoming the effects of Dermo and MSX has posed a challenge to oyster restoration in the Chesapeake Bay. It is estimated that by age three, 80 percent or more of a single oyster year class, in a high disease area (like the Virginia portion of the Bay) will die from disease. Over the past century, the watershed has experienced a change in land use, as urban, suburban, and agricultural areas have replaced forested lands. This has increased the amount of nutrients and sediments entering our rivers and streams, and has contributed to the poor water quality that affectslife in the Chespeake Bay. Excess nutrients, for instance, fuel the growth of algae blooms that create low-oxygen dead zones that restrain the growth of oyster larvae; while sediments can suffocate oysters and other shellfish. Also, poor water quality can cause stress that will make oysters more susceptible to disease.
Showing posts with label pollution. Show all posts
Showing posts with label pollution. Show all posts
Thursday, March 16, 2017
Wednesday, March 15, 2017
The Chesapeake Bay - Part 3
I love the Chesapeake Bay - it seems that it's always there, in my memories... I've been swimming in the Bay, I've fished and crabbed, clammed and oystered in it. I've been boating on it. Unless there's a big storm, it's very calm, compared to the ocean; but when it's windy, the chop, can just about kill you. People get lost in it, people die in it. It's just a smaller ocean that they're on....
In the 1970s, while I was in high school, it was discovered that the Chesapeake Bay contained one of Earth's first identified marine dead zones. The waters were so depleted of oxygen that they were unable to support life, which led to massive fish kills. It's estimated that, even today, the dead zones in the Bay kill up to 75,000 tons of clams and worms, which live on the bottom of the Bay, which weakens the base of the estuary's food chain, and robs the blue crab, in particular, of a primary food source. Crabs are occasionally seen massing on the shore to escape pockets of oxygen-depleted water, a behavior called a "crab jubilee." The hypoxia, or oxygen depletion, results in part from large blooms of algae, which are nourished by the runoff waters of residential, farm, and industrial waste throughout all the contributing watersheds. One report in 2010 criticized Amish farmers for having cows that "generate heaps of manure that easily washes into streams and creeks, and flows onward into the Chesapeake Bay." But farmers should not be singled out... everyone east of the eastern mountains contributes to the pollution of the Bay waters.
The runoff and pollution have many components that help contribute to the algae bloom, which is mainly fed by phosphorus and nitrogen. The algae prevents sunlight from reaching the bottom of the Bay while it's alive, and it de-oxygenates the Bay's water when it dies and rots. Another blocking of sunlight is caused by erosion and the runoff of sediments into the Bay, which, in turn, is caused by devegetation, construction, and the prevalence of pavement in urban and suburban areas. The resulting loss of aquatic vegetation has reduced the habitat for much of the Bay's aquatic life. Beds of eelgrass, the dominant variety in the southern portion of the Bay, have shrunk by more than half in the last 40 years. Over-harvesting of fish and shellfish, pollution, sedimentation, and disease have turned much of the Chesapeake's bottom into a muddy wasteland.
One particularly harmful source of toxicity is Pfiesteria piscicida, which affects both fish and humans. Pfiesteria caused a small regional panic in the late 1990s; a series of large blooms started killing large numbers of fish, and people who swam in the water developed mysterious rashes. Eventually, nutrient runoff from chicken farms was blamed for the algae growth, fish deaths, and human rashes.
Thanks to multiple state and national programs, the Chesapeake Bay improved slightly in terms of the overall health of its ecosytem in 2010. In 2008, it earned a rating of 28, out of 100; in 2010, it had a rating of 31. An estimate in 2006 from a "blue ribbon panel" of of watermen, ecologists, and scientists stated that the cleanup costs for the Bay would be about $15 billion - and that would be to get the Bay's rating up to only 70 of 100 points. One of the problems that compounds the difficulty of the Bay's recovery is that 100,000 new residents move to the Chesapeake Bay shore area each year. A report in 2008 in The Washington Post suggested that government administrators had overstated the progress of cleanup efforts to "preserve the flow of federal and state monies to the project." In January 2011, there were reports that millions of fish had died in the Bay; instead of an investigation, however, officials suggested that the kill was the result of extremely cold weather.
The latest report on the overall health of the Chesapeake Bay, in 2015, gave a total rating of 53 out of 100. In 2013, it had a rating of 45. With work and funding, we might be able to bring the Bay back to what it used to be....
In the 1970s, while I was in high school, it was discovered that the Chesapeake Bay contained one of Earth's first identified marine dead zones. The waters were so depleted of oxygen that they were unable to support life, which led to massive fish kills. It's estimated that, even today, the dead zones in the Bay kill up to 75,000 tons of clams and worms, which live on the bottom of the Bay, which weakens the base of the estuary's food chain, and robs the blue crab, in particular, of a primary food source. Crabs are occasionally seen massing on the shore to escape pockets of oxygen-depleted water, a behavior called a "crab jubilee." The hypoxia, or oxygen depletion, results in part from large blooms of algae, which are nourished by the runoff waters of residential, farm, and industrial waste throughout all the contributing watersheds. One report in 2010 criticized Amish farmers for having cows that "generate heaps of manure that easily washes into streams and creeks, and flows onward into the Chesapeake Bay." But farmers should not be singled out... everyone east of the eastern mountains contributes to the pollution of the Bay waters.
The runoff and pollution have many components that help contribute to the algae bloom, which is mainly fed by phosphorus and nitrogen. The algae prevents sunlight from reaching the bottom of the Bay while it's alive, and it de-oxygenates the Bay's water when it dies and rots. Another blocking of sunlight is caused by erosion and the runoff of sediments into the Bay, which, in turn, is caused by devegetation, construction, and the prevalence of pavement in urban and suburban areas. The resulting loss of aquatic vegetation has reduced the habitat for much of the Bay's aquatic life. Beds of eelgrass, the dominant variety in the southern portion of the Bay, have shrunk by more than half in the last 40 years. Over-harvesting of fish and shellfish, pollution, sedimentation, and disease have turned much of the Chesapeake's bottom into a muddy wasteland.
One particularly harmful source of toxicity is Pfiesteria piscicida, which affects both fish and humans. Pfiesteria caused a small regional panic in the late 1990s; a series of large blooms started killing large numbers of fish, and people who swam in the water developed mysterious rashes. Eventually, nutrient runoff from chicken farms was blamed for the algae growth, fish deaths, and human rashes.
Thanks to multiple state and national programs, the Chesapeake Bay improved slightly in terms of the overall health of its ecosytem in 2010. In 2008, it earned a rating of 28, out of 100; in 2010, it had a rating of 31. An estimate in 2006 from a "blue ribbon panel" of of watermen, ecologists, and scientists stated that the cleanup costs for the Bay would be about $15 billion - and that would be to get the Bay's rating up to only 70 of 100 points. One of the problems that compounds the difficulty of the Bay's recovery is that 100,000 new residents move to the Chesapeake Bay shore area each year. A report in 2008 in The Washington Post suggested that government administrators had overstated the progress of cleanup efforts to "preserve the flow of federal and state monies to the project." In January 2011, there were reports that millions of fish had died in the Bay; instead of an investigation, however, officials suggested that the kill was the result of extremely cold weather.
The latest report on the overall health of the Chesapeake Bay, in 2015, gave a total rating of 53 out of 100. In 2013, it had a rating of 45. With work and funding, we might be able to bring the Bay back to what it used to be....
Tuesday, March 14, 2017
The Chesapeake Bay - Part 2
I remember, as a child, riding the ferry across the Chesapeake Bay on our way to Chincoteague. When I was born, my father was in the US Navy, and we were stationed at Oceana, Virginia; then at Millington, Tennessee, then Corpus Christi, Texas. Dad retired from the Navy on my fifth birthday, and we moved to Gainesville, Florida. Anytime we visited Mom's home town, which was usually once or twice each year, we took the ferry from Norfolk to Cape Charles, Virginia. That happened until 1964, when I was 8 years old; in April of that year, the Chesapeake Bay Bridge-Tunnel opened. I was astonished that you could drive both over and under Chesapeake Bay and did not have to take the ferry. I can even tell you that we crossed the Bridge-Tunnel in my Uncle's brand new Jeep Wagoneer - my sister, Mom, and I in the back seat, and Aunt Ruth in the front passenger seat, with Uncle Claude driving. I remember seagulls flying alongside the car, and how scared I was when we entered the first of two tunnels. Now, 52 years later, I enjoy the scents of the salt water and the rhythmic beat of the tires across the joined slabs of the road bed - as well as the sight of the gulls flying beside the car. For me, the Chesapeake Bay has always meant that I was almost home...
The Chesapeake Bay is home to many fauna that either migrate to the area, or live there year round. There are over 300 species of fish and many shellfish and crab species. Some of these creatures include the Atlantic menhaden, the striped bass, the American eel, the eastern oyster, and the blue crab. Birds include ospreys, great blue herons, bald eagles, and peregrine falcons; the last two listed were threatened with extinction by DDT: their numbers plummeted, but have risen in recent years. The piping plover is a threatened species which inhabits the wetlands around the Bay.
Larger fish, like the Atlantic sturgeon, as well as several varieties of sharks, and stingrays visit the Chesapeake. The waters of Chesapeake Bay have long been regarded as one of the most important nursery areas for sharks along the east coast. Megafaunas like bull sharks, tiger sharks, scalloped hammerhead sharks, basking sharks, and manta rays are also known visitors. Bottlenose dolphins are also found in the Bay. The unconfirmed sightings of humpback whales seem to be proven, as four dead humpbacks have washed up recently along the Eastern Shore. The endangered North Atlantic right whale, as well as fin, minke, and sei whales have also been seen within and near the mouth of the Chesapeake. Loggerhead turtles are also known visitors in the Chesapeake.
The Bay is mostly known for its seafood production - especially blue crabs, clams and oysters. In the middle of the 20th century, the Bay supported 9,000 full-time watermen and their families. Today the Chesapeake is less productive than it used to be . This is due to runoff from urban areas along the western shore of the Bay, runoff from farms on the Eastern Shore and from the Susquehanna River watershed, over-harvesting of marine life, and the invasion of foreign species into the waters.
In the 19th century, the plentiful oyster harvests in the Chesapeake led to the development of the skipjack, the state boat of Maryland, which is the only remaining working boat type in the United States that is still under sail power. Other characteristic bay-area work boats include sail-powered boats such as the log canoe, the pungy, the bugeye, and the motorized Chesapeake Bay deadrise, the state boat of Virginia.
In contrast to harvesting the wild oyster, oyster farming is a growing industry in the Chesapeake Bay that helps maintain the estuary's productivity, as well as a natural effort for filtering the impurities, such as excess nutrients, from the water in an effort to reduce the effects of man-made pollution. The Chesapeake Bay Program is using oysters to reduce the amount of nitrogen compounds entering the Bay's waters. Oysters are hermaphroditic and will change gender at least once during their lifetime; they often begin life as a male, and end life as a female. There are numerous ways to cook and eat them (besides raw on the half-shell), as well as many recipes and sauces to accompany oyster dishes. According to Kendra Bailey Morris, of the National Public Radio in 2007, "The Chesapeake oyster - sometimes called Chesapeake white gold - has a flavor and texture that begs connoisseurs to come back and shuck just a few more."
The Chesapeake is also famous for its rockfish, a regional name for striped bass. Once on the verge of extinction, rockfish have made a significant comeback because of legislative action that placed a moratorium on rockfishing, which allowed the species to re-populate. Rockfish are now allowed to fished again, but only in strictly controlled and limited quantities.
Chincoteague Island, my maternal family home, was long famous for its oysters and clams. For many years, Campbell's Soup Company had an exclusive contract for the oysters and clams caught, or raised, in and around the island. For quite a few years only Chincoteague oysters and clams were used in Campbell's soup..... The island had problems with pollution, and our shellfish production took a huge dive. The waters are now cleaner, and our oysters and clams are being noticed again.
The Chesapeake Bay is home to many fauna that either migrate to the area, or live there year round. There are over 300 species of fish and many shellfish and crab species. Some of these creatures include the Atlantic menhaden, the striped bass, the American eel, the eastern oyster, and the blue crab. Birds include ospreys, great blue herons, bald eagles, and peregrine falcons; the last two listed were threatened with extinction by DDT: their numbers plummeted, but have risen in recent years. The piping plover is a threatened species which inhabits the wetlands around the Bay.
Larger fish, like the Atlantic sturgeon, as well as several varieties of sharks, and stingrays visit the Chesapeake. The waters of Chesapeake Bay have long been regarded as one of the most important nursery areas for sharks along the east coast. Megafaunas like bull sharks, tiger sharks, scalloped hammerhead sharks, basking sharks, and manta rays are also known visitors. Bottlenose dolphins are also found in the Bay. The unconfirmed sightings of humpback whales seem to be proven, as four dead humpbacks have washed up recently along the Eastern Shore. The endangered North Atlantic right whale, as well as fin, minke, and sei whales have also been seen within and near the mouth of the Chesapeake. Loggerhead turtles are also known visitors in the Chesapeake.
The Bay is mostly known for its seafood production - especially blue crabs, clams and oysters. In the middle of the 20th century, the Bay supported 9,000 full-time watermen and their families. Today the Chesapeake is less productive than it used to be . This is due to runoff from urban areas along the western shore of the Bay, runoff from farms on the Eastern Shore and from the Susquehanna River watershed, over-harvesting of marine life, and the invasion of foreign species into the waters.
In the 19th century, the plentiful oyster harvests in the Chesapeake led to the development of the skipjack, the state boat of Maryland, which is the only remaining working boat type in the United States that is still under sail power. Other characteristic bay-area work boats include sail-powered boats such as the log canoe, the pungy, the bugeye, and the motorized Chesapeake Bay deadrise, the state boat of Virginia.
In contrast to harvesting the wild oyster, oyster farming is a growing industry in the Chesapeake Bay that helps maintain the estuary's productivity, as well as a natural effort for filtering the impurities, such as excess nutrients, from the water in an effort to reduce the effects of man-made pollution. The Chesapeake Bay Program is using oysters to reduce the amount of nitrogen compounds entering the Bay's waters. Oysters are hermaphroditic and will change gender at least once during their lifetime; they often begin life as a male, and end life as a female. There are numerous ways to cook and eat them (besides raw on the half-shell), as well as many recipes and sauces to accompany oyster dishes. According to Kendra Bailey Morris, of the National Public Radio in 2007, "The Chesapeake oyster - sometimes called Chesapeake white gold - has a flavor and texture that begs connoisseurs to come back and shuck just a few more."
The Chesapeake is also famous for its rockfish, a regional name for striped bass. Once on the verge of extinction, rockfish have made a significant comeback because of legislative action that placed a moratorium on rockfishing, which allowed the species to re-populate. Rockfish are now allowed to fished again, but only in strictly controlled and limited quantities.
Chincoteague Island, my maternal family home, was long famous for its oysters and clams. For many years, Campbell's Soup Company had an exclusive contract for the oysters and clams caught, or raised, in and around the island. For quite a few years only Chincoteague oysters and clams were used in Campbell's soup..... The island had problems with pollution, and our shellfish production took a huge dive. The waters are now cleaner, and our oysters and clams are being noticed again.
Sunday, July 10, 2016
Camping Idiots
Wildfires everywhere! As I look out my window, I see smoke rising from behind the foothills - Mount Sanitas, to be specific. It's been in the sky since yesterday afternoon, when it was listed as a 100-acre fire. Now it's over 600 acres in size, has burned down three homes, and has more than 2,000 families evacuated. One of the three homes belonged to a first-responder. Property, personal possessions, and wildlife are being destroyed because of two idiots who went camping. They had a campfire burning for more than 48 hours, and when they left, they dumped a half-bucket of sand and rocks on top of the fire and left. They were sure that the fire was totally extinguished, with that half-pound of sand and gravel. It was not, and with the normal mountain breezes, the fire soon erupted and spread. One would think that two "good-ole boys" from Alabama would have more sense; but they sure as heck didn't. They were found at an evacuation center in Nederland. They have been arrested. Thanks to these guys, we have more heat, more pollution, the loss of habitat for many creatures, and multiple "Scenic Byways" are closed because of the fire. It will take a long time for this area to become "scenic" again! This fire is still totally uncontained because of swirling mountain winds.
Not only do we have the Cold Springs fire to the west of us, there's also the Beaver Creek fire in Routt County that is over 15,000 acres in size, and is growing.
Over by Golden and Morrison, west-bound Interstate 70 (near C-470) was closed down due to fire, and the Rooney Valley Soccer Complex and a local hazardous materials plant were evacuated.
Near Coaldale, the Hayden Path fire has caused a campground evacuation in Fremont County.
Not to mention the fire inside a scrap metal yard in Denver....
It reached 101 degrees (F) here this afternoon. We are in a continuing drought situation. The smoke and particles in the air do not help with my COPD. I just about choked to death walking the six blocks to the grocery store this morning....
Please be careful regarding fire danger anywhere in the world. Be safe. Don't be sorry. - That is all. -
Not only do we have the Cold Springs fire to the west of us, there's also the Beaver Creek fire in Routt County that is over 15,000 acres in size, and is growing.
Over by Golden and Morrison, west-bound Interstate 70 (near C-470) was closed down due to fire, and the Rooney Valley Soccer Complex and a local hazardous materials plant were evacuated.
Near Coaldale, the Hayden Path fire has caused a campground evacuation in Fremont County.
Not to mention the fire inside a scrap metal yard in Denver....
It reached 101 degrees (F) here this afternoon. We are in a continuing drought situation. The smoke and particles in the air do not help with my COPD. I just about choked to death walking the six blocks to the grocery store this morning....
Please be careful regarding fire danger anywhere in the world. Be safe. Don't be sorry. - That is all. -
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