Harmful Algal Blooms & Brown Tides

Taylor Aselin, Lindsay Amari, Sophie Mancini

1. Explanation of what causes an HAB or a Dead Zone?

Dead zones are areas where there is not a lot of dissolved oxygen in the water and marine life in the water die if they aren’t mobile but if they are mobile they can swim away and leave so they don’t die.

2. What type(s) of organisms are involved?

The types of organisms involved include algae who begin the process by growing out of control and producing harmful toxins such as phosphorous and nitrogen. This causes the algae to then spread along the water's surface and block light energy coming from the sun which prevents nutrients and oxygen to be absorbed by organisms living in the water. Oxygen is necessary for most marine mammals, so this process is very harmful and deadly to them. Humans can also become sick if they eat an animal such as shellfish that has absorbed these harmful toxins in the water. HAB's cause a decrease in population for species of marine life, but also for animals that prey on marine mammals, such as birds, because they have less food that they need in order to survive. Because of this, HAB's affect the entire food chain.

3. What are the ecological impacts?

Stated in question 2, The algae produce very dangerous toxins that can kill and or sicken any living things, and create dead zones. It also causes destruction of food chains, loss of species and populations, pollution of water and air surrounding dead zones, and impacts human food supply, human health, and animal health.

4. What are the economic impacts?

5. Geographic locations

6. What can be done to reduce eliminate or manage excess nutrients and solve this issue?

Dead zones are caused by too much nutrients, so If we manage nutrients and try to restore the dead zones and work together to help these areas. The dead zones are growing so by managing nutrients we can try to save the dead zones and not have it spread.
Pacific Ocean Dead Zones GREEN.tv