off-site impacts affecting water fall 2012, lecture 8
TRANSCRIPT
Off-Site Impacts Affecting Water
Fall 2012 , Lecture 8
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Areas Affected• Many factors influence water quality in rivers, lakes, estuaries,
seas, and oceans
• An estuary is a place where fresh water from a river mixes with ocean water The water is brackish, meaning it has a salinity between that of fresh water
(very low salinity) and the open ocean (about 35,000 parts per million salt)
• A sea is a large body of saline water that may be connected with an ocean, like the Mediterranean Sea, or may be a large saline lake that, like the Caspian Sea, lacks a natural outlet
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Previously Encountered Factors• Some of these factors we have encountered
previously Agricultural runoff
• Sediment due to erosion
• Fertilizers
• Pesticides
Deforestation, often leading to sediment erosion
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Storm Water Runoff Storm water runoff, particularly from urban to suburban regions
• May include fertilizers applied to lawns and gardens, and pet and wildlife waste
• Also include pollutants like motor oil, gasoline, antifreeze, power steering fluids, and tire residue from roads
• Household hazardous wastes like insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids
• Can also include debris carried into drainage networks and streams Examples: plastic bags, six-pack rings, bottles, and cigarette butts - washed
into waterbodies can choke, suffocate, or disable aquatic life like ducks, fish, turtles, and birds
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Effect of Stormwater Runoff • Polluted stormwater often affects drinking water
sources
• This, in turn, can affect human health and increase drinking water treatment costs
• Bacteria and other pathogens can wash into swimming areas and create health hazards, often making beach closures necessary
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What is Pollution? • A very useful definition of pollution is , “something
in the wrong place at the wrong time in the wrong quantity” (from Holdgate, M.W. 1979. A Perspective of Environmental Pollution. New York: Cambridge University Press. 278 pp.)
• The word pollution is derived from the Latin term polluere, which means to soil or defile
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Non-Point Source Pollution• Most of the discussion of pollution in this
lecture involves non-point source pollution, a very difficult source of pollution to clean up
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Effect of Pollution in Water• One of the most important effects of pollution in
waterbodies is called eutrophication
• Eutrophication is a word which comes from Greek: eutrophia—healthy, adequate nutrition, development
• Although this is the word origin, it is really applied incorrectly - a more correct term would be hypertrophication – excessive nutrients
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Eutrophication definition• The addition of artificial or natural substances,
such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system
• It is sometimes called nutrient pollution, and involves Holdgate’s “wrong quantity” definition of pollution
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Eutrophication Caused Problems• Nitrogen and phosphorus are nutrients that plants need to grow
• Problems occur when an excess amount of these nutrients are delivered to a water body, which causes an excessive growth of algae, clouding the water
• This leads to more serious problems Hypoxia - low levels of dissolved oxygen as the algae decomposes,
defined as dissolved oxygen ≤ 2.0 mg l-1
Anoxia – Near zero oxygen levels, defined as dissolved oxygen <0.2 mg l-1
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Dissolved Oxygen (DO)• Dissolved oxygen is critical to the survival of
aquatic life
• The amount of dissolved oxygen needed before aquatic organisms are stressed, or even die, varies from species to species
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Nutrient Sources
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• Nutrients are carried from the land by rivers as a result of weathering of rocks and soil in the watershed
• These nutrients enter estuaries and the ocean
• In estuaries, they can also come from the ocean due to mixing of water currents
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Anthropogenic Nutrients: Coastal Zone• Anthropogenic nutrients are mainly related to people living on
and in the coastal zone because human-related impacts are much greater than natural inputs
• More people living in the coastal zone means more nutrients entering our coastal waters From wastewater treatment facilities Runoff from land in urban areas during rains From farming in the coastal zone Pet and wildlife waste also contributes
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Anthropogenic Nutrients: Upstream Sources
• Upstream sources impact water bodies as well
• It’s important to focus on the coastal zone, and on upstream sources of nutrients
• Eutrophication can happen in lakes, streams, estuaries, or in portions of the ocean
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Estuarine Research• Most research is done in estuaries or bays
• Estuaries are of particular interest because of their use for recreational and commercial fishing
• These are supported because estuaries are typically full of fish populations, being among the most biodiverse regions on earth
• Since eutrophication can cause low dissolved oxygen which kills fish, fisheries are in danger from nutrient pollution
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Sandlake Estuary Video
• Sandlake Estuary, Tillamook County, Oregon showing the large biodiversity typical of estuaries
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Initial Eutrophication• Green masses of algae growing on a pond, a lake, or in an
embayment, are the first signs of eutrophication
• The layer of algae blocks light that is needed for seagrasses to grow
• Seagrasses are plants that grow in shallow waters
• They live rooted at the bottom of the pond or in shallow coastal areas and in extreme cases the lack of light will kill them
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Eutrophication Graphic
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Algae on Ponds
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Duckweed• Photo caption: “Duckweed and
filamentous algae are predominant in this photo. Too much of both for any pond which can cause fatally low dissolved oxygen levels causing fish loss.”
• Duckweed is a tiny plant with little leaflets and roots, which can literally cover an entire pond.
• It is commonly transferred from pond to pond by waterfowl
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Dr. Suzanne Bricker• She is a physical Scientist and Manager
of NOAA's National Estuarine Eutrophication Assessment, National Centers for Coastal Ocean Science
• She was the lead scientist in the U.S. National Estuarine Eutrophication Assessment study (NEEA), which provided a integrated framework for eutrophication assessment and carried out a comprehensive overview of 141 estuaries in the United States
• Slides 22-35 are based on the NEEA assessments, and there are links on the additional information page to this work
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Eutrophication Locations• Eutrophication is not limited to ponds or lakes
– it can also occur is estuaries, more open coastal waters, and even in the deep ocean
• In coastal areas, algae blooms can appear red or brown in color.
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Stinky Beach• In some areas, floating algae will wash up on a beach
and really smell as it decays making the beach an undesirable place to go.
• Some estuaries have a place called “stinky beach,” that is very characteristic thing with those decaying algal mats
• These things may make the water body look murky and smell unhealthy
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Economic Harm• Toxic algal blooms can decrease fishing
success and can cause losses of tourism
• They can also decrease real estate values
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NEEA Estuary Reports• Starting in the early 1990’s, NOAA’s National Estuarine Eutrophication
Assessment division conducted a national study of eutrophication • They looked at 141 estuaries, measuring nutrient levels in the estuaries,
and trying to determine the source of the nutrients• NEEA reported more than half of those estuaries had significant nutrient-
related problems• The report also suggested that conditions in most estuaries were at risk of
becoming worse in the future due to expected increases in population in coastal areas
• An updated report was issued in 2007, that looked at conditions in the early 2000s and how things had changed since the early 1990s
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Data Agglomeration • NEEA relied on local experts who monitor the 141
estuaries to provide data • These investigators take measurements of algae,
dissolved oxygen, and seagrasses, as well as other things, several times a year in their particular, or specific, estuary
• By looking at the changes that occur over time, those scientists can examine how the estuary is doing and whether things are changing in an undesirable way
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2007 Report Conclusions• Overall, the U.S. is holding the line against further
eutrophication problems
• There were improvements in some estuaries, which is good news, but in about an equal number of estuaries conditions have worsened since the early 1990s.
• However, there are regional trends which differ from the national trend
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Least Impacted Estuaries• The U.S. was divided into five regions - the North Atlantic,
Mid-Atlantic, South Atlantic, Gulf of Mexico, and the Pacific Coast
• The least impacted estuaries, nationally speaking, occurred or are located in the North Atlantic region, which includes the coastline from Cape Cod to Maine
• These systems are different from most other regions: They have fewer people living in the watershed The tidal range is very high, so there is very good mixing with the
ocean for most of the systems that occur there
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Most Impacted Estuaries• The most impacted systems we found were in the
Middle Atlantic, from Cape Cod down to Chesapeake Bay
• The Middle Atlantic region has probably the highest density of people living in the region
• Many of the estuaries in the Middle Atlantic have a smaller tidal range and poor mixing with the ocean
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Source of Problems• Human activities that impacted the systems
include: Agriculture including both the use of fertilizers
and animal operations Wastewater treatment plant effluent Urban/suburban runoff
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Global Eutrophication• NEEA also found that eutrophication is not just a
problem in the United States• It impacts estuaries on a global level – consequences:
Loss of seagrasses Loss of fish habitat Low levels of dissolved oxygen Longer-lasting or first-time blooms of nuisance or toxic
algal
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Global Cooperation• Chinese and European scientists have worked with NEEA, and
NEEA learned that there are serious problems with eutrophication in estuaries and coastal water bodies in both places
• By sharing NEEA methods and learning from scientists in other places about management measures that have been successful in reducing eutrophication, NEEA is trying to improve management techniques
• Eutrophication is a global problem and everyone can benefit from working together
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Shellfish• One way to reduce algal growth within a water body
is to have large populations of oysters or clams• In Chesapeake Bay, there used to be very large,
thriving populations of oysters which filtered the water body and kept the Chesapeake Bay waters clearer
• When those oysters died, Chesapeake Bay started having problems, in addition to the fact that there were more nutrients entering the system
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Shellfish Farming• Shellfish farming or encouraging natural
populations can be used for natural water filtration even though the nutrient load is not actually reduced
Seasonal Variation in Estuaries• Many estuaries receive varying amounts of
freshwater inputs seasonally This can be due to terrestrial wet/dry seasons It can also be due to high inputs of snowmelt
waters in spring, especially after a winter with heavy snowfall
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Snowmaggedon• The February 5–6, 2010 North American blizzard, also known
as "Snowmaggedon", was a Category 3 ("Major") nor'easter and severe weather event
• Most crippling was the widespread 20 to 35 in (50 to 90 cm) of snow dropped across southern Pennsylvania, the Eastern Panhandle of West Virginia, northern Virginia, Washington, D.C., Maryland, Delaware, and southern New Jersey
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Snowmaggedon Photos
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In Pittsburgh, over 20 inches (51 cm) of snow fell causing numerous power lines and tree branches to buckle.
19th Street in Dupont Circle, Washington D.C., Northwest, where ~24" of snow had fallen on February 6th by day's end.
Eastern U.S.
Satellite Image
• North American blizzard of 2010, imaged by NASA's Aqua satellite on February 5, 2010
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Four Nor’easters• Snowmaggedon was the second of four nor'easters during the
2009-2010 winter that brought heavy snow to enough of the Northeast's population to be numerically recognized by NOAA's NESIS intensity rating
• The first and third of these systems, the December 2009 Nor'easter and the February 9–10, 2010 North American blizzard, respectively, combined with this event to bring the snowiest winter on record to much of the Mid-Atlantic
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Three Nor’easters in 12 Days• Snowmaggedon was the second of three major Mid-Atlantic
snowstorms that occurred over a 12-day period
• Each subsequent storm focused its heaviest snow slightly farther north: the January 30, 2010 storm (not recognized by NESIS) dropped more than a foot of snow across Virginia and the lower Chesapeake Bay region, while the February 9–10, 2010 North American blizzard bulls-eyed the Maryland-Pennsylvania border with as much as 28 inches
Chesapeake Bay, 2009-2010• In 2010, river flow to the Chesapeake Bay was above average
in winter (November and December 2009, January 2010) and March, and lower than average in late spring (April, May) and summer (June-September)
• Above average flow in winter coincides with the significant amount of snow that the Chesapeake watershed received during December 2009 and January-February 2010
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Increased River flow effect• As river flow
increases the amount of nutrients entering the Chesapeake Bay
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March 2010 Bloom• The nutrients
fuel phytoplankton growth and subsequent algae blooms
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Production of Hypoxia• Phytoplankton eventually die and sink to deeper water where
bacteria consume the dead phytoplankton in a process that consumes oxygen, leading to potentially hypoxic or anoxic conditions
• An increase in fresh water entering Chesapeake Bay from its surrounding rivers also reduces the amount of oxygen that can be mixed into deeper waters
• The water from the rivers tends to flow on top of the salty water because fresh water is lighter than brackish water
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Density Stratification• This “layering” of water is an example of stratification, due to
density
• It prevents mixing between the fresher water on top and the saltier water on the bottom
• The only source of oxygen for deeper waters is from the surface water (where phytoplankton grow and produce oxygen and where oxygen from the atmosphere mixes into the water)
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Reduced Mixing• Stratification of the water reduces mixing of
oxygen into deeper waters
• This makes it more likely for anoxia and hypoxia to develop in the deeper waters
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Early Hypoxia/Anoxia Maximum• The flow into Chesapeake Bay in 2010 appears to have
affected summer conditions by shifting the intensity of low dissolved oxygen conditions to earlier in the summer
• Higher flow in winter and March led to an early maximum of anoxia and hypoxia in late June because an especially large and dense phytoplankton bloom developed in March in the mid to upper Bay
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Thermal Stratification• Water above 4P C is less dense than colder water, due to
thermal expansion
• The high early spring flow combined with hot temperatures in early summer led to strong stratification in June
• The impact of the high winter and March flow would likely be complete by the end of June because the effects of strong March river flow only last for 90-120 days
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Low River Flow• Extremely low river flow
from April to July led to less nutrients entering the Bay (which slowed the growth of phytoplankton) and reduced stratification later in the summer, allowing the bottom waters to be mixed with oxygen-rich surface water
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June Maximum• The winds in August blew from the southeast most
frequently, a direction of wind that favors the mixing of oxygen from surface water and the atmosphere into deeper waters to relieve low dissolved oxygen conditions
• As a result of all these processes, hypoxia was reduced and the anoxia disappeared in late summer
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2010 June Maximum
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• In 2010, the largest volume of anoxia and hypoxic waters occurred in late June
• This map shows the late June bottom minimum DO for Chesapeake Bay
• A very large amount of anoxia occurred in late June, the second highest amount on record
Late Summer Reduction• After March, the flow and nutrients
slowed down, with below average amounts from April through August
• Anoxia cannot be sustained at high levels throughout the summer without new nutrients coming into the Bay
• By the end of August, the volume of anoxia was smaller, and by late September, anoxia was completely gone
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Change in Pattern• Thus, the Snowmaggedon and other severe
Nor’easter events of 2010 drastically changed the usual pattern of anoxia and hypoxia in Chesapeake Bay
• This has a profound effect on the ecological cycles
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Climate Change?• Were the Nor’easter events related to climate change?
• Present day climate science cannot say with certainty if a particular event is due to climate change
• Statistical analyses reveals far more frequent “maximum” events
• Many scientists feel the large deviation of the maximum events from the norm are a very likely indicator of the influence of climate change
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Chesapeake Bay Video
55• NASA video about satellite monitoring of Chesapeake Bay
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Tampa Bay, Florida
• Between 1950 and 1980, half of the acres of seagrass beds in Tampa Bay were lost as a result of the murkiness of the water due to algae blooms
• Starting in the 1980s, local officials worked on various actions to reduce nutrients that would then reduce those algal blooms
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Treatment of Tampa Bay Problems• Wastewater treatment plants were required to
provide advanced treatment.
• Stormwater discharges were regulated
• The phosphate industry changed their practices to reduce fertilizer spills at port facilities from which fertilizer products were shipped
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Tampa Bay Success• The combination of these actions reduced
nutrient loads resulting in less algal growth and the waters cleared up
• Seagrasses started growing again By 2004, researchers observed the highest level of
seagrass acreage since 1950
HAB• HAB stands for Harmful Algal Bloom
• A number of different organisms can cause HAB’s – examples: Red Tide - Karenia brevis Brown Tide - Aureoumbra lagunensis Takayama tuberculata Peridinium quinquecorne Noctiluca scintillans Prymnesium parvum
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Red Tide• Off the west coast of
Florida, Karenia brevis, a marine dinoflagellate common in Gulf of Mexico waters, is the organism responsible for Florida red tide, as well as red tide in Texas
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Brevetoxins• K. brevis is a microscopic, single-celled, photosynthetic organism
that can bloom frequently along Florida coastal waters
• Cells have two flagella that allow them to move through the water in a spinning motion.
• K. brevis naturally produces a suite of potent neurotoxins collectively called brevetoxins, which cause gastrointestinal and neurological problems in other organisms and are responsible for large die-offs of marine organisms and seabirds
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Safety• Oysters clams, mussels, whelks and scallops can
accumulate red tide toxins in their tissues
• People that eat oysters or other shellfish containing red tide toxins may become seriously ill with neurotoxic shellfish poisoning (NSP)
• Once a red tide appears to be over, toxins can remain in the oysters for weeks to months
Red Tide Timeline
• The diagram illustrates known occurrences of Red Tide in Florida going back to 1844
• In recent years, Red Tide has been a nearly annual occurrence, particularly for the period October through March
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Current Red Tide Status• The Florida Fish and Wildlife Conservation
Commission maintains a website at http://myfwc.com/research/redtide/events/status/statewide/ which lists current Red Tide outbreaks
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Red Tide Photo• The photo shows Red Tide
associated with outflow from the Caloosahatchee River flowing into the Gulf of Mexico on October 12, 2012
• Rick Bartleson, research scientist for the Sanibel-Captiva Conservation Foundation, said the bloom started about a month ago off Sarasota and has been slowly moving south toward Lee County
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Cause of Current Red Tide• There are two reasons for the current outbreak:
Runoff from the Caloosahatchee River due to recent heavy rains Water releases into the Caloosahatchee River by the Army Corps
of Engineers from Lake Okeechobee, in response to the rapid increase in lake level following Tropical Storm Isaac (fro 12 to nearly 16’ a.s.l.)
• The increase in discharge rate carries increased nutrients levels
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Google Earth link• The following link is to
a Google Earth map of K. brevis
• GE-10-12-12.kmz
• The photo is a static image of the web site image
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Brown Tides• Aureoumbra lagunensis causes Brown tides, which
occur naturally and can be common in waters with high salinity
• The brown tide algae have been noted from Florida to Maine on the east coast and throughout coastal areas of the Gulf of Mexico, but July, 2012 is the first time FWC has documented a bloom of the algae in state waters, in the Indian River Lagoon
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Brown Tide Consequences• Brown tide organisms are nontoxic and there are no known
human health concerns
• Shellfish and fish kills can occur during blooms due to brown tides production of mucus that can prevent shellfish from feeding
• A sustained bloom could impact shellfish populations in the northern Indian River Lagoon
• Fish kills can occur when the algae deplete oxygen from the water
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Takayama tuberculata• On July 5, 2011, Takayama tuberculata blooms were observed
at Vanderbilt Beach and Naples Pier
• Takayama tuberculata blooms have been documented along Collier County annually since 2008
• High concentrations of T. tuberculata can deplete dissolved oxygen and discolor the water red to brown
• Whether T. tuberculata blooms in Florida produce toxins is undetermined
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Takayama tuberculata Fish Kills• On July 18, 2011 fish kills associated with low dissolved
oxygen concentrations were reported at Clam Pass and Vanderbilt Beach
• Many aquatic species washed up, dead or dying, onto the county's beaches
• Beachgoers were warned by to exercise caution due to the "large number of stressed and dying animals in the surf zone that could cause injury if stepped on."
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Nurse Sharks in Shallow Water• Local residents and
county officials were surprised to see the variety of creatures that normally do not appear in the shallows, such as lobsters and nurse sharks
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Peridinium quinquecorne• Peridinium quinquecorne can be found year-round in many
brackish and estuarine waters in Florida because it can tolerate temperatures from 16 to 38ºC (60-100ºF) and survive in a wide range of salinities (11 to more than 32 parts per thousand)
• When Peridinium quinquecorne occurs in blooms, it can cause discoloration, from red to brown
• Although the organism is not toxic, it can cause fish kills as the result of anoxia
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Peridinium quinquecorne Blooms• Blooms of Peridinium quinquecorne have occurred
alongshore of southwest Florida from late summer to early fall since 2005
• In June 2010, water samples collected southern Lee and northern Collier counties indicated a bloom of P. quinquecorne extending from southern Sanibel Island down to Seagate
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Noctiluca scintillans• Noctiluca scintillans bloom
offshore of Walton county on Feb. 19, 2011
• It is a large, bloom-forming dinoflagellate and is nontoxic
• No fish kills or other adverse effects were reported in February or March as a result of the bloom in northwest Florida.
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Noctiluca scintillans Fish Kills• Blooms have been linked to
massive fish and marine invertebrate kills from the toxic levels of ammonia that accumulate in surrounding waters
• A pocket of air inside the cell wall allows this algal species to float
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Prymnesium parvum• Prymnesium parvum, also known as golden
algae, is a naturally occurring microscopic member of the phytoplankton community
• It has been found in brackish waters worldwide and has been noted in Florida waters since 2005
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Prymnesium parvum Toxicity• It is a known toxin producer and has caused large-scale fish
kills in other parts of the United States and the world
• It can cause ecological and economic harm particularly to aquaculture industries
• In Florida, fish kills caused by P. parvum have been localized to small ponds in residential areas and golf courses and the Intracoastal Waterway
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Types of Toxins• P. parvum can produce allelopathic compounds,
chemicals that inhibit growth in another species of plant, that give the cells a competitive advantage over other phytoplankton and grazers
• P. parvum also produces an ichthyotoxin, or fish toxin, called prymnesin, which affects gill-breathing organisms by rupturing gill membranes
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Florida West Coast, Fall 2001• In fall 2001, the SeaWiFS images showed an
extensive red tide off Florida's central west coast, near Charlotte Harbor
• The waters containing this red tide migrated to the south along the coast
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Nutrient Transport• Winter storms caused large amounts of fresh water to
drain from the Everglades into Florida Bight (the curve in the shoreline from the Keys north to Everglades National Park on the mainland), carrying high levels of nutrients such as silicate, phosphorus, and nitrogen to the sea
• These caused a bloom of the microscopic marine plants known as diatoms in the same patch
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Diatom Bloom• The diatom bloom turned the water dark and the "black water" patch re-circulated for several months in a slow clockwise motion off southwest Florida in the Florida Bight
• Slowly, the dark water drifted farther south and toward the Florida Keys
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Photo Caption: NASA's Terra satellite acquired this image of a red tide bloom along Florida's west coast December 22, 2001
Florida Bay, Early 2002• A patch of "black water" spanning over 60 miles in diameter
formed off SW Florida and contributed to severe coral reef stress and death in the Florida Keys, according to results published from research funded by NASA, the U.S. Environmental Protection Agency and the National Oceanic and Atmospheric Administration (NOAA)
• The "black water" contained a high abundance of toxic and non-toxic microscopic plants
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Florida Bay • True color
(brightness enhanced 20%) MODIS/Terra image from February 17, 2002, shows black water in Florida Bay
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Florida Bay Video Animation• SeaWiFS Image of
Blackwater
• True color date Jan. 9, 2002
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Florida Bay False-Color Video Animation
• SeaWiFS Image of Blackwater, date Jan. 9, 2002
• False color visualization showing chlorophyll
• Reds and oranges represent high concentrations of chlorophyll
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On-Site Studies in Florida Bay• Chuanmin Hu and colleagues at USF Institute for Marine
Remote Sensing examined data collected by divers from the dark water area in the Florida Keys
• They discovered a 70 percent decrease in stony coral cover, a 40 percent reduction of coral species, and a near-elimination of sponge colonies at two reef sites after the dark water passed
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Florida Bay Dead Zone• They concluded that the coral reef ecosystem had been
stressed by a red tide of algal blooms and toxins contained in the dark water
• Recent evidence also points to these phytoplankton blooms being fed by increased nutrient input from agricultural and urban run-off
• This is an example of what oceanographers call a “dead zone”
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