[Insecurity]

a discussion recently came up in my house hold that perplexed me. i was wondering if anyone knows anything about these dead zones in the bay.

[Volunteer]

On any given day, anywhere I fish seems to be a dead zone!

[tcannonsr]

It is red algae, it blossoms when there is little wind, high temps., and the right nutrients. It absorbs all of the oxygen and the fish suffocate.

[Getaway]

The northern part of the bay, Maryland, has trouble with this every year recently. In that area, it has been the result of oxygen depletion of the water. Polution of all types are causing this to occur more and more each year. In some areas, all life disappears for a time.

[woodyhf]

Makes you want to think twice before dumping all that fertilizer on your lawn!

http://www.cbf.org/s...ications_sotb06

[Insecurity]

i knew about the red algea but i was wondering if there was something else causing this too.

[morsere]

i knew about the red algea but i was wondering if there was something else causing this too.

<{POST_SNAPBACK}>

The dead zone is actually a result of a number of environmental factors and generally occurs in the upper bay (in the deeper channels). It is highly correlated with strong runoff years (i.e. lots of rainfall in the Ches Bay watershed means a greater dead zone). Increased rainfall brings excess nutrients to the bay which stimulates a large spring phytoplankton bloom. This bloom is generally composed of diatoms (which are generally good things to have as they become food for clams/oysters/scallops and zooplankton and eventually the fish we catch).

Every year we get a spring bloom in the bay, and this is usually a good thing since this bloom supports most of the life in the bay. But because we have altered the ecosystem, it has become eutrophied and the blooms have become larger and more prolific.

Too much of a good thing is bad, and the excess algae settles to the bottom where they are consumed by bacteria. The bacteria use up the oxygen in the water as they break down the algae. Because this occurs in the deep channels, mixing of the water column is minimal so there is no atmospheric exchange and no way to get oxygen back into the water. The lack of oxygen is what causes a dead zone. These dead zones can last most of the summer, depending on the weather.

Red tides are a different beast alltogether. These are blooms of dinoflagellates that may produce toxins or cause other harmful effects, such as shellfish mortality. They can occur at any time of the year, though they are most prominent in the spring and summer months.

[STEEL REEL]

Great Reply, morsere! I hear it has alot to do with the Nitrogen being flushed into the bay from the run off. I live on a reservoir and encorage my neighbors not to fertilize the lawn. I figure, mow long green fertilized lawn or spend the time FISHING. Seems like a no-brainer to me!!