Algae blooms in the Chesapeake River

[TedP]

I've read that one of the common ways to keep a reef tank's water clean is by using an algae filter. Several different variations are currently available from systems that incorporate live sand, live rock and macro algae in a refugium to the old algae turf scrubbers. If I understand correctly, the algae is supposed to remove some nutrients from the water as well as take up CO2 as part of photosynthesis. As a byproduct, O2 is released.

In an article in the Washington Post, the writer suggests that an algae bloom in Chesapeake River is causing oxygen poor conditions which in turn is suffocating the local fauna. Does someone know if 1) the algae blooms are in fact robbing the water of oxygen in the Chesapeake River and 2) What the differences are in that environment vs. the reef tank environment that would cause such drastic differences in the effect that the algae has to the environment?

The article can be accessed by going to:
http://www.washingtonpost.com/wp-dyn/ar ... 3Aug6.html

Thanks,

TedP

 

[Len]

Ted.

My thinking goes....

While photosynthesis produces O2 as a byproduct, the additional biomass plants foster also produces lots of organic decay that robs O2 from the water. Plants only photosynthesize when there is light, and during the night they actually consume some oxygen. Organic breakdown and animal respiration happens 24/7. The net effect would result in a loss of O2 in the long term.

In reef aquariums, I think this potential problem is alleviated by actively controlling the conditions in which our algae grow, most notably pruning back specimens before they die-off or go "sexual."

In addition, the chemistry of saltwater and freshwater are vastly dissimiliar, so that might play a role. Reef aquariums are also heavily circulated with lots of gas exchange compared to rivers. Plus, reef tank ecosystems are usually pretty young and don't suffer the long term effects. People have observed that old reef aquariums (say, 5+ years) have noticably depressed pH and O2 levels compared to newer tanks.

That's my rambling thoughts at least

 

[klingsa]

Yeah, what Len said! See how smart I am?? :wink: :wink:

The only other thing I was thinking about is the large amount of microorganisms that make their homes in algae mats. We can see that in our tanks. So, I'd imagine that large amounts of algae in the river could simply increase the food source and protective environment needed for the freshwater equivalents of major pod populations.

Sara

 

[TedP]

Minor correction.. the algae bloom is in the Chesapeake bay.

 

[klingsa]

Ok, then, what I said, but for saltwater! See, we're flexible.

Sara