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ENVS232 Marine Pollution > Harmful Algal Blooms (HABs) > Flashcards

Harmful Algal Blooms (HABs) Flashcards

1
Q

What are phytoplankton species that cause problems when in sufficient numbers called?

A

Harmful Algal Blooms (HABs)

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2
Q

Why do some phytoplankton species cause problems?

A

They can produce toxins and/or have physical structures that create problems for living organisms

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3
Q

How many algal species are associated with harmful algal blooms (HABs)?

A

Only a few dozen algal species are associated with HABs out of thousands of algal species.

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4
Q

What are most HAB species known for?

A

Most HAB species, such as Alexandrium and Pseudo-Nitzschia, are known for producing toxins.

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5
Q

How do HAB toxins affect the food chain?

A

HAB toxins can accumulate along the food chain and intoxicate higher trophic levels.

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6
Q

What are the direct effects of HAB toxins in the water?

A

HAB toxins released directly in the water can be toxic to fish, shellfish, and mammals.

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7
Q

Can HAB toxins be released into the atmosphere?

A

Yes, HAB toxins can also be released into the atmosphere

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8
Q

Where do harmful algal blooms (HABs) occur?

A

HABs occur worldwide in both freshwater and seawater.

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9
Q

What are the possible causes of the expansion of HABs?

A

Possible causes of HAB expansion include:
Natural dispersal by currents and storms
Shipping and transport
Shellfish translocation
Increased monitoring

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10
Q

How does natural dispersal contribute to the expansion of HABs?

A

Natural dispersal by currents and storms can spread HAB species to new areas

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11
Q

What human activities contribute to the spread of HABs?

A

Shipping, transport, and shellfish translocation are human activities that contribute to the spread of HABs

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12
Q

What role does increased monitoring play in the occurrence of HABs?

A

Increased monitoring may contribute to the perceived expansion of HABs by detecting them more frequently.

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13
Q

What functions can be affected by harmful algal bloom (HAB) toxins?

A

HAB toxins can affect both respiratory and nervous functions.

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14
Q

What has been widely documented as a consequence of HABs?

A

Deaths of fish, marine mammals, and sea birds have been widely documented

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15
Q

How can HABs affect humans?

A

HABs can have varied effects on humans, and in extreme cases, can lead to death through ingestion of contaminated seafood

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16
Q

What is the impact of harmful algal blooms (HABs) on ecosystems?

A

HABs cause strong disruptions to the entire ecosystem, affecting plankton, benthic communities, and predators

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17
Q

What are the effects of long-term exposure to HAB toxins?

A

Long-term exposure to HAB toxins can lead to:
Immunosuppression
Abnormal development
Tumors
Reduced growth
Physiological dysfunction and reproductive issues
Pathological effects

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18
Q

What is the main vector for human exposure to harmful algal bloom (HAB) toxins?

A

The main vector is through the consumption of affected fish and shellfish, such as mussels and clams.

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19
Q

What is another possible vector for exposure to HAB toxins?

A

Volatilization of toxins, such as brevetoxin from Karenia brevis, is another possible vector.

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20
Q

How often are persistent symptoms seen in cases of HAB toxin exposure?

A

Persistent symptoms are seen in 2-3% of cases.

21
Q

What measure is often taken to protect public health during HAB events?

A

Fishing activities are often closed until the toxins have diluted away.

22
Q

What percentage of unusual marine mortality events are associated with harmful algal blooms (HABs)?

A

More than 50% of unusual marine mortality events are associated with HABs.

23
Q

What happened near Cape Cod in 1987 due to HABs?

A

14 humpback whales died after feeding on mackerel that had high levels of saxitoxin (paralytic shellfish poisoning, PSP).

24
Q

What similar event occurred in 2003 related to HABs?

A

Another 12 whales died in a similar event in 2003.

25
Q

What happened to manatees in Florida in 1996 due to Karenia brevis (NSP)?

A

150 manatees were killed. Toxins were found in both their tissues and lungs, suggesting transfer through the food web and direct contact with aerosols.

26
Q

What happened to California sea lions in 1998 due to a local harmful algal bloom (HAB)?

A

400 California sea lions died along the central California coast.

27
Q

What happened to bottlenose dolphins in spring 2003?

A

107 bottlenose dolphins were found dead.

28
Q

Were there any concurrent blooms of Karenia brevis during this event?

A

No, there was no concurrent bloom of Karenia brevis.

29
Q

What was found in the stranded dolphins examined?

A

High levels of brevetoxin were measured in their tissues and stomach contents, as well as in their fish prey recovered from their stomachs.

30
Q

What does this event demonstrate about HAB toxins?

A

This event shows that lethal doses of toxins produced by HABs can be transferred through the food web and that marine mammal mortalities can occur in the absence of a bloom.

31
Q

What are the methods for detecting harmful algal blooms (HABs)?

A

Visual Inspection from Boats:

Description: Involves sampling, microscope use, and counting.
Pros: Precise.
Cons: Labor-intensive and poor resolution.
Satellite-Based Detection:

Description: Uses optical methods to detect HABs.
Pros: Can cover large areas.
Cons:
Poor resolution for small blooms.
Detection limits issues.
Does not detect early stages of blooms.
Interference from colored dissolved organic matter (CDOM) and cloud cover.

32
Q

What are some actions taken to directly reduce or suppress harmful algal blooms (HABs)?

A

Mechanical Methods:
Example: Use of clay particles.
Description: Clay particles are used to adsorb algal cells on their surface, causing them to sink.

33
Q

What are some potential approaches for controlling harmful algal blooms (HABs)?

A

Genetic Control:
Description: Involves engineering marine pests that do not produce toxins or developing bacteria strains targeting HABs.
Note: Genetic control methods have been successfully used on land but have not yet been implemented in the ocean.
Environmental Control:
Description: Involves techniques such as improving aeration and physically modifying residence time (e.g., dredging channels).
Challenges: Difficult to implement.
Ultrasonication:
Description: A new method with potential for application in the field.

34
Q

How is the occurrence of the next harmful algal bloom (HAB) predicted?

A

Cyst Counts in Sediment:

Description: Cyst counts in sediment are conducted and compared with the next bloom occurrence.
Development of Predictive Models:

Description: Models are being developed to predict the location and dates of upcoming blooms.
Importance: These models are crucial for management purposes.

35
Q

How is plankton typically divided into two types?

A

Phytoplankton:
Description: Photosynthetic cells.
Zooplankton:
Description: Animal-like plankton.

36
Q

What is mixoplankton?

A

Mixoplankton are planktonic organisms capable of both photosynthesis (phototrophy) and consuming prey (phagotrophy) simultaneously.

37
Q

Why is phytoplankton essential in marine ecosystems?

A

Produces Oxygen (O2):

Description: Phytoplankton contributes to approximately 50% of the Earth’s oxygen production through photosynthesis.
Regulates the Climate:

Description: Phytoplankton plays a role in regulating the climate by absorbing carbon dioxide (CO2) during photosynthesis, thus influencing the greenhouse effect.
Affects Element Cycles:

Description: Phytoplankton influences various element cycles, such as the carbon, nitrogen, and phosphorus cycles, through their metabolic activities.
Base of Marine Food Web:

Description: Phytoplankton forms the base of the marine food web, providing primary energy sources for higher trophic levels such as zooplankton, fish, and marine mammals.

38
Q

What factors control phytoplankton communities?

A

Abiotic Factors:

Environmental factors such as temperature, light, nutrients, and water chemistry.

Biotic Factors:

Biological factors including pathogens, grazers, and competitors influence phytoplankton communities.

39
Q

How do biotic interactions affect phytoplankton communities?

A

Some interactions, such as allelochemical interactions, sexual signals, and resource research, are mediated through the release of chemicals.

40
Q

What environmental factors shape plankton communities?

A

Despite its importance, the role of chemical communication in shaping plankton communities is poorly understood.

41
Q

What are allelochemical interactions?

A

Allelochemical interactions involve the release of compounds, known as allelochemicals, by a protist. These compounds inhibit other species in the environment.

42
Q

How do allelochemicals affect plankton communities?

A

Allelochemicals give a competitive advantage to the producer cell by inhibiting competing species.

43
Q

Impact on Plankton Communities

A

Allelochemical interactions can shape plankton communities by influencing species composition and abundance

44
Q

Where do blooms of the genus Alexandrium typically occur?

A

Blooms of the genus Alexandrium occur in estuaries and coastal areas.

44
Q

What contaminations can estuaries and coastal areas face, including those with Alexandrium blooms?

A

Estuaries and coastal areas can face various contaminations, including metal contaminations.

45
Q

What is the significance of copper (Cu) in estuaries and contaminated coastal waters?

A

Copper is a redox element that is essential and can be found in high concentrations in estuaries or contaminated coastal waters.

46
Q

What is the significance of copper (Cu) in microalgal physiology

A

Copper is an essential element, but high concentrations can impair microalgal physiology and sometimes increase phytoplankton toxicity.

47
Q

How does copper (Cu) affect the exudation of dissolved organic carbon and allelochemicals by A. minutum?

A

High concentrations of copper increase the exudation of dissolved organic carbon and allelochemicals by A. minutum.

ENVS232 Marine Pollution (24 decks)

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