| A | B |
|---|
| algal bloom | rapid growth of a population of algae |
| red tide | algal blooms in salt water |
| eutrophication | nutrients build up in a lake or pond over time causing an increase in the growth of algae |
| Why are saltwater algal blooms called red tides? | Because the algae that form them often contain red pigments that turn the water red. |
| What two conditions often cause red tides? | increase of nutrients in the water and increase in ocean temperature |
| How can red tides be dangerous to humans? | Algae that form red tides form toxins that build up in shellfish that people then eat. |
| What organisms are affected by red tides? | fish, other orgaisms, and people |
| What human sources increase eutrophication? | fertilizer runoff; sewage treatment wastewater |
| Why do pond organisms die with eutrophication? | plants and algae beneath the surface can't make food because there is not enough sunlight getting through |
| saltwater algal bloom | grows in oceans and bays |
| freshwater algal bloom | grows in lakes and ponds |
| How are saltwater and freshwater blooms similar? | Both occur when nutrients in the water increase. |
| decomposers | bacteria that cause organisms to die because they use up oxygen as a result of eutrophication |
| Would it be easier to control saltwater or freshwater blooms? | Freshwater blooms grow in smaller areas and it is easier to identify nutrient sources and measure effects. |
| dinoflagellates and diatoms | two kinds of algae that often cause red tides |
| What determines the color of saltwater blooms? | pigments contained by the species of algae that bloom |
