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A Bloom of a “Different” Color. Using satellite imagery to monitor coastal algae. Algal Blooms. Marine algae form the base of the ocean food chain Coastal nutrient rich waters support a range of algal species Population growth is influenced by many factors. Fish. Shrimp. Zooplankton.
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A Bloom of a “Different” Color Using satellite imagery to monitor coastal algae
Algal Blooms • Marine algae form the base of the ocean food chain • Coastal nutrient rich waters support a range of algal species • Population growth is influenced by many factors Fish Shrimp Zooplankton Marine Phytoplankton
What is our interest in the marine algae? How do they affect us?
National interest • Some species add DMS (dimethyl sulfide) to the atmosphere • Satellite algorithms track pockets of high cell counts • Do the algal cells alter the biogeochemical nature of the area over time? Coccolithophore Emiliania huxleyi
National interest cyanobacteria Trichodesmium • Important Nitrogen fixer in the oceans • Produces a neurotoxin that can be involved in fish kills and human illness • Detection by Wide Field-of-view Sensor (SeaWiFS)
Harmful Algal Blooms Many different algal species are responsible for HAB’s • The population of algal cells can increase rapidly • Some algae produce toxins that can endanger marine animals and humans • > 5000 species • < 5% are toxic
National interest • The water appears “red” in color – known as the red tide • Neurotoxin concentrates in shellfish, but can be released from algae through wave action • Fish kills, marine mammals may die, human concerns Dinoflagellate Karenia brevis May 25-Jun 1, 2003
National interest • Formation of ECOHAB agency for focused research on Harmful Algal Blooms • Provides greater understanding of algal cell transport, conditions for blooms, and toxicity differences between the species Cells caught in Gulf Stream fingers
Local Interest • State agencies in coastal zones monitor the cell counts, notify public of health concerns • Shellfish and fin fishing may be restricted • Citizen awareness is increased; action groups are formed
Worldwide Effects of HAB’s • Light penetration levels in water decrease altering photosynthesis rate • Algal blooms may be harmful to seagrass and coral reef ecosystems and the connected food webs • Shellfish may accumulate algal toxins by feeding on the toxic phytoplankton resulting in fish kills, marine mammal distress, human illness and possible death
Phycotoxins and their Effects • Compounds will bioconcentrate when ingested at lower trophic levels (algal toxins or phycotoxins are relatively chemically stable to heat and cold) • Can cause “lesions” on dermis of fish thus providing a path for infection • Produce symptoms that affect the nervous system and/or intestinal distress; some cardiovascular effects in marine animals and humans
Ciquatera Fish Poisoning Pantropical distribution Toxins accumulate in reef fish that may remain toxic for as long as two years 50,000 plus victims annually – many unreported incidents Gastrointestinal and neurological distress, rarely fatal Gambierdiscus taxicus Neurotoxic Shellfish Poison Less severe than CFP, but similar toxic affects Often bloomsdiscolor the water and kill fish Causes respiratory discomfort like allergies when cells rupture Economic impact huge when fisheries are closed Karenia brevis or G.breve Types of Toxicity
Paralytic Fish Poisoning Concentrate in mackerel on the food chain PSP is caused by a saxitoxin Can cause death in marine mammals and in humans World wide distribution – species below is tropical Pyrodinium bahamense Diarrhetic Shellfish Poison Symptoms similar to bacterial gastroenteritis Not fatal, recovery in three days Algal cells found in all coastal temperate waters Okadaic acid from species below caused problems in Japan Dinophysis sp. Types of Toxicity
Amnesic Shellfish Poison First recognized in 1987 on Prince Edward Island Caused 4 deaths and 100 acute cases from ingestion of blue mussels Neurotoxic domoic acid is produced by the diatom below Careful monitoring during bloom cycles – wide distribution of this species Nitzchia sp. Types of Toxicity Can we predict when or where the next algal bloom will occur?
What do you notice about the incidents of reported toxic outbreaks? How can the public become more aware of this problem? Frequency of HAB events
Reasons for Increase in HAB’s • Global climate change producing wider ranges for some species • Human contributions of increased nutrients and pollution in coastal waters • Subtle changes in local ecosystems that may allow exotic species to thrive if introduced • A more comprehensive monitoring and reporting system
Watch for the HAB’s Study proximity of shellfish beds and coastal rivers to high algal cell counts Interactive mapping on-line to examine satellite imagery for SST, winds and chlorophyll-a http://www.csc.noaa.gov/crs/habf/habmaps.html
Compare data using GIS What factors may influence the growth of G.breve?
Predict bloom or not? • Scientists agree that a combination of factors seem to cause algae to “bloom” in an area • Satellite technology helps to focus on global and local HAB problem spots • Prediction capabilities have increased, so the public can be informed earlier about fishing restrictions and health concerns
Improved Local Water Quality Better Economic Forecast for Fisheries Be a “Bloom” Watcher? Global awareness and travel precautions What will your role as a citizen of the 21st century be in the HAB issue?