Algae Quiz

Your answer: Not Harmful

Correct answer: Harmful

Harmful to underwater grasses, fish, crabs and oysters.

This is a bloom of the algae Prorocentrum minimum in Baltimore Harbor, also referred to as a “mahogany tide.” Typically seen in the spring, these blooms are not harmful to humans but have significant environmental impacts by limiting light that reaches bay grasses and leading to low oxygen levels when biomass decomposes.

For more information: 

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Prorocentrum.aspx

Your answer: Harmful

Correct answer: Harmful

Harmful to fish.

Blooms of the algae Karlodinium veneficum cause the water to turn a reddish brown, leading this to be another type of algae that is sometimes called a “mahogany tide.” While this algae is not harmful for humans, it is known as the “fish killer” algae, as it produces toxins that are lethal to fish.

The first photo is a Karlodinium bloom in Corsica River in 2005, and the second is of a bloom in St. Leonards Creek on the Patuxent in June, 2003, which was associated with a fish kill of silversides.

For more information: 

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Karlodinium-veneficum.aspx

 

Your answer: Not Harmful

Correct answer: Harmful

Harmful to fish.

Blooms of the algae Karlodinium veneficum cause the water to turn a reddish brown, leading this to be another type of algae that is sometimes called a “mahogany tide.” While this algae is not harmful for humans, it is known as the “fish killer” algae, as it produces toxins that are lethal to fish.

The first photo is a Karlodinium bloom in Corsica River in 2005, and the second is of a bloom in St. Leonards Creek on the Patuxent in June, 2003, which was associated with a fish kill of silversides.

For more information: 

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Karlodinium-veneficum.aspx

 

Your answer: Harmful

Correct answer: Harmful

Harmful to fish, crabs and oysters.

This is a bloom of the algae Aureococcus anophagefferns at Public Landing, in Maryland’s Coastal Bays, in 2006. Also referred to as a “brown tide,” these blooms can lead to significant ecosystem impacts, such as shellfish starvation and shading of seagrass beds. In Long Island, N.Y., blooms of the same species led to major declines in bay scallop populations.

For more information: 

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Brown-Tide.aspx

Your answer: Not Harmful

Correct answer: Harmful

Harmful to fish, crabs and oysters.

This is a bloom of the algae Aureococcus anophagefferns at Public Landing, in Maryland’s Coastal Bays, in 2006. Also referred to as a “brown tide,” these blooms can lead to significant ecosystem impacts, such as shellfish starvation and shading of seagrass beds. In Long Island, N.Y., blooms of the same species led to major declines in bay scallop populations.

For more information: 

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Brown-Tide.aspx

Your answer: Not Harmful

Correct answer: Not Harmful

This is a bloom of a green filamentous algae called Rhizoclonium in Mattawoman Creek on the Potomac River. The bloom was reported by a concerned citizen in August, 2005. Though the bloom is not harmful, large mats of filamentous algae can lead to low oxygen levels when they decompose.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Macroalgae.aspx

Your answer: Harmful

Correct answer: Not Harmful

This is a bloom of a green filamentous algae called Rhizoclonium in Mattawoman Creek on the Potomac River. The bloom was reported by a concerned citizen in August, 2005. Though the bloom is not harmful, large mats of filamentous algae can lead to low oxygen levels when they decompose.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Macroalgae.aspx

Your answer: Harmful

Correct answer: Unknown (Free point!)

This red discolored water occurred in 2014 in Sinapuxent Bay, Worcester County, near Assateague Island. Not to be confused with  a “red tide,” an algal bloom which occurs in Florida and can cause respiratory issues for beach goers, this was actually a rod-shaped bacteria bloom, and though DNR analyzed the site, scientists could not determine if it was harmful. Because it was unknown, DNR recommended no swimming in the area. 

The bloom resulted in a strong smell, likely due to hydrogen sulfur since bacteria blooms are associated with anaerobic, or no oxygen, conditions. The bloom naturally dissipated within a few days.

Your answer: Not Harmful

Correct answer: Unknown (Free point!)

This red discolored water occurred in 2014 in Sinapuxent Bay, Worcester County, near Assateague Island. Not to be confused with  a “red tide,” an algal bloom which occurs in Florida and can cause respiratory issues for beach goers, this was actually a rod-shaped bacteria bloom, and though DNR analyzed the site, scientists could not determine if it was harmful. Because it was unknown, DNR recommended no swimming in the area. 

The bloom resulted in a strong smell, likely due to hydrogen sulfur since bacteria blooms are associated with anaerobic, or no oxygen, conditions. The bloom naturally dissipated within a few days.

Your awswer: Harmful

Correct answer: Harmful

Harmful to humans and benthic communities.

These are filamentous cyanobacteria that have floated to the surface and are decomposing during a 2010 bloom of Oscillatoria and Planktothrix on the Potomac River near Brunswick, Maryland. Oscillatoria can produce the liver toxin microcystin and Plantothrix can produce both liver and anatoxin, a neurotoxin responsible for cattle and dog deaths in other states.

A 2021 study that DNR collaborated on showed these mats have impacts on the benthic communities that are important food sources for fish.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Macroalgae.aspx

Your awswer: Not Harmful

Correct answer: Harmful

Harmful to humans and benthic communities.

These are filamentous cyanobacteria that have floated to the surface and are decomposing during a 2010 bloom of Oscillatoria and Planktothrix on the Potomac River near Brunswick, Maryland. Oscillatoria can produce the liver toxin microcystin and Plantothrix can produce both liver and anatoxin, a neurotoxin responsible for cattle and dog deaths in other states.

A 2021 study that DNR collaborated on showed these mats have impacts on the benthic communities that are important food sources for fish.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Macroalgae.aspx

Your answer: Harmful

Correct answer: Harmful

Harmful to humans.

This was a 2010 bloom of the cyanobacteria Anabaena, a potentially toxic cyanobacteria, in Trinity Lake, a private lake with swimming, in Charles County. This cyanobacteria can produce a potent neurotoxin, anatoxin, and liver toxin, microcystin. While no anatoxin was detected, samples were positive for microcystin at three sites but levels were all below threshold levels.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Anabaena-and-Aphanizomenon.aspx

Your answer: Not harmful

Correct answer: Harmful

Harmful to humans.

This was a 2010 bloom of the cyanobacteria Anabaena, a potentially toxic cyanobacteria, in Trinity Lake, a private lake with swimming, in Charles County. This cyanobacteria can produce a potent neurotoxin, anatoxin, and liver toxin, microcystin. While no anatoxin was detected, samples were positive for microcystin at three sites but levels were all below threshold levels.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Anabaena-and-Aphanizomenon.aspx

Your answer: Harmful

Correct answer: Harmful

Harmful to humans.

This is a 2014 cyanobacteria bloom in the South Pond at Ocean Pines. The cyanobacteria Oscillatoria tenuis was dominant. Additional cyanobacteria, Aphanocapsa and Microcystis, were observed at low concentrations. All species are potential producers of the liver toxin microcystin, which has harmful effects if ingested. The pond isn’t used for swimming or drinking, but DNR worked with the Worcester County Health Department to put up signs warning people about the bloom.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Microcystis.aspx

Your answer: Not harmful

Correct answer: Harmful

Harmful to humans.

This is a 2014 cyanobacteria bloom in the South Pond at Ocean Pines. The cyanobacteria Oscillatoria tenuis was dominant. Additional cyanobacteria, Aphanocapsa and Microcystis, were observed at low concentrations. All species are potential producers of the liver toxin microcystin, which has harmful effects if ingested. The pond isn’t used for swimming or drinking, but DNR worked with the Worcester County Health Department to put up signs warning people about the bloom.

For more information:

https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Microcystis.aspx

Because it is difficult to tell when blooms are harmful, DNR asks residents to report algal blooms on the department’s Eyes on the Bay website and to look out for foamy, scummy water of unusual color that may smell like rotting plants. People and pets should take caution and stay away from potential blooms, and people can take steps to reduce nutrient pol​lution​ to help prevent harmful algal blooms.

When in doubt, STAY OUT!

For more information on algal blooms, see https://eyesonthebay.dnr.maryland.gov/eyesonthebay/habs.cfm