Sunday, January 11, 2015

Chesapeake Bay Dead Zones and Mass Mortality Events Worldwide

Thousands of birds in five U.S. states, Italy, and Sweden...
Tens of thousands of devil crabs in the United Kingdom...
Millions of fish in several U.S. states, Brazil, and New Zealand...

Biologists with the U.S. Geological Survey say "this happens every year, to numerous species, all around the globe."

Physicist Dr. Michio Kaku says maybe the birds were disorientated by something -- fireworks, thunder, lightning -- and there must have been a pathogen that took out the "bottom feeder" fish.

UPDATE: Stephanie Carlson, UC Berkeley
"Overall, disease was the primary culprit, accounting for 26 percent of the mass die-offs. Direct effects tied to humans, such as environmental contamination, caused 19 percent of the mass kills. Biotoxicity triggered by events such as algae blooms accounted for a significant proportion of deaths, and processes directly influenced by climate — including weather extremes, thermal stress, oxygen stress or starvation — collectively contributed to about 25 percent of mass mortality events. The most severe events were those with multiple causes, the study found."

Baltimore Sun:
HELSINKI, Finland -- Along the seacoast here, vacationing families keep their dogs away from the water some summers. If the animals drink it, they could die.

Along the sugar-sand beaches of Florida's Panhandle, the bodies of 115 dead dolphins wash up. In California's Monterey Bay, more than 400 sea lions die after agonizing seizures.

And along the Pocomoke River of Maryland's Eastern Shore, people who find themselves surrounded by dying fish develop strange symptoms: rashes, breathing trouble and memory lapses.

These scary episodes can be traced to an emerging family of seaborne pests known to scientists as harmful algae blooms. Their outbreaks are in the midst of a worldwide upsurge. They force closings of shellfish beds; kill fish, seabirds and marine mammals; and bring on human sickness -- and, in rare cases, death.

In 1997, after a 450-mile-long algae bloom ruined summer along parts of the Baltic Sea coast from Poland to Finland, thousands of Finns signed petitions demanding a government promise that the outbreaks would never happen again. "People wanted to turn it off, like a faucet," says Tapani Kohonen, former director of an international commission that oversees Baltic water quality. "But of course no one can promise that."

Scientists don't know how to stop the blooms. In most cases, they're not sure how they start. And debate often rages over whether nutrient pollution plays a role in any individual outbreak.

But most top experts suspect that today's excesses of nitrogen and phosphorus in coastal waters play a key role in the worldwide toxic algae epidemic.

"There are few other causes, other than climate change, that could be responsible for such widespread increases," wrote a panel of scientists headed by University of Maryland ecologist Donald Boesch.

Algae need fertilizer to grow, so it makes sense that more nutrients would trigger more blooms, some of which could be harmful. But the natural world is seldom simple, and so far, "There are few definitive data that really allow us to say that there's a universal relationship between harmful algal blooms and increased nutrients," says Kevin Sellner of the National Oceanic and Atmospheric Administration.

The health threat posed by poisonous algae has been known since about A.D. 100, when the Japanese observed that people were dying from eating the flesh of the puffer fish, which accumulates a toxic algae called fugu. The poison gave the fish its name in Japan, where it is prized as a potentially deadly delicacy.

For about 1,800 years, only three toxic algae were known to exist worldwide, according to marine toxicologist Daniel Baden, director of marine sciences at the University of North Carolina Wilmington. But in the past 50 years, about 50 new species of dangerous algae have been discovered, with reports of toxic outbreaks doubling in the past 30 years.

The blooms now threaten virtually every coastal state, says Donald Anderson, a senior scientist at the Woods Hole Oceanographic Institution in Massachusetts and the director of a nationwide initiative to track marine toxins. Between 1988 and 1997, toxic algae blooms cost the U.S. economy roughly $1 billion in lost seafood sales.

The United States' most troublesome algae-borne illness is paralytic shellfish poisoning, caused by a group of algae found off Northern California, the Pacific Northwest and New England. The poison has forced Alaskan officials to forbid shellfish harvesting. Almost every year, some Alaskans ignore the ban and die. But these outbreaks happen in relatively clean waters, and there's no obvious link to nutrient pollution, Anderson says.

Sometimes the link between harmful algae blooms and nutrients is strong. Pfiesteria piscicida, the microorganism responsible for 1997's fish kills and human illnesses on some Lower Eastern Shore rivers, is a prime example. In lab tests, Pfiesteria multiplies rapidly in nutrient-rich water.

In other situations, the cause-and-effect relationship is indirect. Some algae blooms, such as Florida's red tide, might occur naturally but last longer or grow larger because of nutrient pollution from land.

Red tide has been reported occasionally along the southwestern Florida shore since the days of the Spanish explorers. In the past 50 years, it has appeared about 40 times, and some outbreaks last a year or more.

The algae releases a nerve poison that kills fish, birds and marine mammals and can leave people gasping for breath. Florida was hard-hit last year with three outbreaks suspected of killing dolphins, sea turtles and manatees. And red tides have spread to the Carolinas and the entire Gulf of Mexico coast.

The blooms that crop up in the Baltic Sea turn its waters the opaque yellow-green of pea soup. After the disastrous blooms of 1997, when the algae grew so thick that sailors mistook large clumps of it for rocks, Finland's largest newspaper began including a toxic algae forecast in its summer weather reports.

The algae attacks the liver and causes potentially fatal hemorrhaging. "It seems as if increasing nutrients give us more toxic strains, but we don't understand why," says Kirste Lahti, a microbiologist with the Finnish Environmental Institute.

Some scientists suspect that nutrients might merely set the stage for other human-generated changes. In the Bay of Bengal near Bangladesh, former University of Maryland researcher Rita Colwell has tracked a clear correlation between higher-than-normal water temperatures and outbreaks of deadly cholera, a disease linked to algae blooms. Colwell believes high nutrient levels merely load the gun; it's warm water that pulls the trigger.

Ted Smayda, an oceanographer at the University of Rhode Island, says he's convinced that the link between nutrients and harmful algae is as strong as the smoking-and-cancer link. But Smayda says research into harmful algae blooms is in its infancy and proving the connection "is like looking for a needle in a haystack."

Chesapeake Bay and Baltimore Harbor Fish Kills

2014: "Dead fish were seen floating off Fells Point in the city and beyond the Patapsco's mouth at Cox's Point in Essex and near Bodkin Point in northern Anne Arundel County, according to Jay Apperson, a spokesman for the Maryland Department of the Environment.

State investigators estimated the kill at "up to 1,000" fish, mainly Atlantic menhaden, said Apperson. But others said the number seemed higher. Educators with the Chesapeake Bay Foundation and the Living Classrooms Foundation also reported seeing dead or dying shad in Baltimore harbor."

2012: "State investigators estimated there were 10,000 fish floating in Stoney Creek in northern Anne Arundel County and in its tributaries, Back Cove, Beehive Cove and Nabbs Creek, according to Samantha Kappalman, spokeswoman for the Maryland Department of the Environment. She emailed that "several thousand," mostly menhaden, were bunched up by the Fort Smallwood Road bridge.

Stoney Creek is just a few miles from Marley Creek, where authorities reported last week finding 100,000 dead fish amid a massive "mahogany tide," or algae bloom that's suffocating fish throughout this portion of the Chesapeake Bay.

Fed by nitrogen and phosphorus in sewage, fertilizer and pet waste running into the water, tiny aquatic plants "bloom" in mass quantities, turning the water brown, then die back, producing a stench and consuming the oxygen that fish need to breathe.

Scientists suspect this year's algae blooms came earlier and grew thicker because of the extra dose of nutrients and sediment that flooded into the bay last summer from Tropical Storm Lee, turning the water the color of malted milk for weeks afterward.

The situation may have been aggravated more recently by a sewer line break in Baltimore County, which spilled an estimated 50 million gallons of untreated sewage into the lower Patapsco River. Though the spill was halted promptly, it took until this week for bacteria levels to decline enough for health officials to say it was OK to touch the water downriver."

2011: "An estimated 2 million fish have been reported dead from the Bay Bridge south to Tangier Sound, according to the Maryland Department of the Environment, which investigates fish kills. The dead fish are primarily adult spot, with some juvenile croakers.

Agency spokeswoman Dawn Stoltzfus said bay water quality appears acceptable, and biologists believe 'cold-water stress' the likely cause of the fish kill. Spot are susceptible to colder water, she said, and normally leave the upper bay by now. Water temperatures plummeted in late December to near-record lows for that time of year, about 36 degrees.

While summer fish kills have become a regular occurrence, winter-related kills happen less frequently. Twenty million spot died in 1976 and again in 1980, said Rudy Lukacovic, DNR's fish kill investigator for 23 years. Both of those kills ranged from Baltimore Harbor to Solomons.

2009: "At least 3,000 fish have recently died in Baltimore's harbor, likely as a result of an algae bloom that sent a foul odor into surrounding neighborhoods, a Maryland Department of the Environment spokeswoman said Tuesday. The dead fish, primarily menhaden, were mostly congregated around the Domino Sugar plant in Locust Point, MDE spokeswoman Dawn Stoltzfus said.

Dissolved oxygen levels in the water had dropped to 3 milligrams per liter at the surface and as low as 0.2 milligrams per liter below the surface, she said. Even 3 milligrams per liter would create stressful conditions for fish, Stoltzfus added.

The harbor tends to get a large bloom of the algae, Prorocentrum minimum, this time of year, and higher water temperatures might have triggered a sudden die-off, Stoltzfus said."

2007: "The stink - and the dead fish - are the result of an algae bloom, or a "brown tide." State environmental officials have been investigating the fish kill since Sunday.

The nutrient-rich harbor had a recent large bloom of microscopic algae that turned the water rust brown, said Charles Poukish, environmental program manager for Maryland Department of the Environment. When water exceeded 70 degrees last weekend, the algae died. As the algae decomposed, it depleted the oxygen on the surface of the water, causing at least 7,000 fish to die, Poukish said.

The water will return to normal through tidal flushing and wind, which helps reoxygenate the water. But with an overabundance of nitrogen and phosphorous in water, conditions are ripe for another algae bloom, Poukish said."

2003: "At least once a day, Eileen McLellan gets a phone call from a homeowner along the Chester River, wondering about the dead fish washing up under the dock or the funny color of the algae or just the strange smell of the water.

Around the Chesapeake Bay, zones of low dissolved oxygen are increasingly found far beyond the deep waters of the main channel. They're now reaching tributaries, where residents have rarely seen so much algae and so few crabs and fish.

While oxygen levels typically decline each summer, recent surveys by the U.S. Environmental Protection Agency's Chesapeake Bay Program and the National Oceanic and Atmospheric Administration have found record areas of the bay almost devoid of oxygen and aquatic life."

1999: "An estimated 1 million dead fish were discovered yesterday in the lower Pocomoke River and one of its creeks. State officials believe it is the largest fish kill in Chesapeake Bay tributaries in a decade.

"The fish were all crammed, crowded into a small creek," said David Goshorn, a biologist with the department. "With the warm temperatures, the algae increases and it's very easy for large numbers of fish to consume all the oxygen and essentially suffocate themselves."

Since late June, fish kills have been confirmed in more than a dozen Maryland waterways and Baltimore's Inner Harbor. Earlier this month, after an estimated 200,000 yellow perch, menhaden and other small fish died in tributaries of the Magothy and Patapsco Rivers, state officials predicted an extended drought would result in more fish kills.

Jack Howard, a Shelltown waterman who assisted the state throughout the 1997 Pfiesteria piscicida scare, vividly recalls how the toxic microbe forced the closing of three waterways back then -- the Pocomoke and Chicamacomico rivers, and Kings Creek.

1996: "Anything but a rare organism, Pfiesteria has scores of toxic cousins that appear to be multiplying around the globe, mainly as algae but sometimes as zooplankton and, most conspicuously, as red and brown tides. In the Chesapeake Bay, heavy inflows of freshwater this year already have led to record blooms of algae.

"I haven't seen anything like it," said Lawrence W. Harding Jr., an oceanographer with the University of Maryland who has been conducting aerial surveys of algae blooms in the bay since 1989. The algae blooms stretched to the Atlantic Ocean. Record freshwater flows early this year coupled with snowmelt "loaded the bay up with nutrients," Harding said, producing some of the earliest and most extensive algae blooms he's seen.

"When we first began flying in March, we had red tides [algae] in and around the Bay Bridge and up toward the Patapsco River," he recalled. During spring, the midbay was clogged all the way to the Virginia capes with brownish blooms, he said.

Studies of the deadly blooms are accelerating, if only because the tiny killers have been found to harbor poisons 1,000 times more toxic than cyanide, strong enough to kill humans."

More information:
» EU Times: Birds and Fish are now Dying all Around the World (2011)
» ThinkProgress: 6 Ways Climate Change Threw The Animal World Into Disarray This Year

No comments: