DO NOW! Can algae just be helpful in the ecosystem, just be harmful, or can it be both? Explain your answer.

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 Marine Phytoplankton Zooplankton Shrimp Fish Fish

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 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) cyanobacteria Trichodesmium

Harmful Algal Blooms The population of algal cells can increase rapidly Some algae produce toxins that can endanger marine animals and humans > 5000 species < 5% are toxic Many different algal species are responsible for HAB’s

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

Toxins 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

Types of HAB’s/Toxicity Brown/red tide Amnesic Shellfish Poisoning Diarrhetic Shellfish Poisoning Neurotoxic Shellfish Poisoning Paralytic Shellfish Poisoning Ciguatera Fish Poisoning Harmful Cyanobacterial Blooms

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

Types of Toxicity 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 blooms discolor 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. Can we predict when or where the next algal bloom will occur?

Study proximity of shellfish beds and coastal rivers to high algal cell counts Watch for the HAB’s Interactive mapping on-line to examine satellite imagery for SST, winds and chlorophyll-a /crs/habf/habmaps.html

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