What's Killing the Chesapeake?

[jazz lady (Premo)]

There is a great one page article in the Sunday, September 4, 2005 edition of The Washington Post on page C13 about the forces that are slowly choking the life out of the Chesapeake Bay. Unfortunately, the article is not online but it is definitely worth looking at.

Years of pollution from farms, sewage plants and suburban lawns have thrown the Chesapeake Bay out of balance, producing large blooms of algae that rob the bay of oxygen that oysters, rockfish, blue crabs and others need to live. In August, 41 percent of the bay's mainstem - beginning at the Patapsco River, near Baltimore, and extending more than 100 miles south to the mouth of the York River, near Hampton Roads - had low levels of oxygen, which stress aquatic life. About 11 percent of the mainstem was a dead zone, where life cannot be supported.

Over a TENTH of the bay can no longer support life. This is absolutely scary and incredible.

The Problem: Most of the bay's primary pollutants - nitrogen and phosphorus - come from man-made sources that enter rivers and streams and make their way into the bay. Nitrogen is essential to the production of plant and animal tissue; phosphorus is needed in the process of converting sunlight into useable engery forms. Both have always existed in the bay, but not at the current concentrations.

Pollution caused by agricultural runoff, sewage plants and industrial wastewater, and fertilizer washed off suburban lawns and golf courses spark algae blooms, an explosive growth of algae that decreases the level of dissolved oxygen in the water and blocks out light needed by the underwater grasses. As the oxygen levels drop, it stresses wildlife. When the algae blooms die, the decomposition process removes even MORE oxygen from the water, leading to fish and crab kills or driving them from their preferred habitat and/or stressing or killing species that are not mobile like oysters, clams, worms, and other organisms on which crabs and fish feed. This is very apparent in the graph of the declining oyster harvest, where is has gone from almost 39 MILLION of pounds in 1955 to only 315 THOUSAND pounds in 2004.

So what action is being taken?

In 2000, a group of state and federal leaders agreed to a set of goals for cleaning up the Chesapeake. Halfway to the deadline of 2010, many important areas of the cleanup are far off the pace.

The bay states and DC agreed to reduce nitrogen and phosphorus pollutants entering the bay. Some of the techniques to do this include upgrading sewage treatment plants, decreasing lawn fertilizer applications to lawns, new farming practices to curb runoff, and energy conservation to lessen the demand on power plants that emit nitrogen.

www.washingtonpost.com

The graphics are striking in the article and hope you can check them out.

I just wonder if it's too little, too late for the Chesapeake. I sure hope not.

[Ken King (Premo)]

Is it pollution, algae growth, over fishing or a combination of the three that is the problem?

For me over fishing gets my vote.

Usually with pollution both fish and plant life both are severely impacted. In this case we have algae growth being a claimed contributor, yet isn't that one of the main items fish eat? And as a plant doesn't it, through photosynthesis, give off oxygen?

If we stop raping the bay of fish like the Virginians do (aircraft spotting and then massive nettings for processing them into fertilizers and oils) wouldn't there be more fish to eat any overgrowth of algae?

[jazz lady (Premo)]

Pollution is causing the algae growth, which in turn is killing the wildlife and bay grasses. Fish and other critters cannot survive in the low levels of oxygen in the water TO eat the algae.

The article was focusing on pollution that is choking the bay, but I totally agree that overfishing is also a deep problem, especially in combination with the other factors. Oysters have had a triple whammy - pollution, over-harvesting and a pair of introduced diseases - which has almost decimated the entire population.

[Ken King (Premo)]

Originally Posted by jazz lady

Pollution is causing the algae growth, which in turn is killing the wildlife and bay grasses. Fish and other critters cannot survive in the low levels of oxygen in the water TO eat the algae.

The article was focusing on pollution that is choking the bay, but I totally agree that overfishing is also a deep problem, especially in combination with the other factors. Oysters have had a triple whammy - pollution, over-harvesting and a pair of introduced diseases - which has almost decimated the entire population.

And that is a contradiction to this that I don't understand, the killing of the bay grasses. 25 to 30 years ago the grasses, in the waters that I live near, had all but disappeared, but now they are returning in abundance. Of course we do have more central sewage facilities and less septic type systems so that might explain it for this area, but are we doing a better job then the other areas of the bay?

And I guess I still don't understand algae, does it or does it not give off oxygen during the course of its existance like other plant life?

[jazz lady (Premo)]

Originally Posted by Ken King

And that is a contradiction to this that I don't understand, the killing of the bay grasses. 25 to 30 years ago the grasses, in the waters that I live near, had all but disappeared, but now they are returning in abundance. Of course we do have more central sewage facilities and less septic type systems so that might explain it for this area, but are we doing a better job then the other areas of the bay?

There may be pockets where it is getting better, but overall the health of the bay is declining:

Low levels of dissolve oxygen have become more common and widespread since the 1950s. They are lasting longer, dropping lower and spreading farther throughout the sytem. Much of what happens in the bay in any given year, however, is contingent on weather. About 75 percent of nutrient pollution comes from runoff. Heavy snowfalls in winter or rains in spring determine how far the pollution will spread.
...
This year, bay specialists predicted that the levels of dissoved oxygen would plummet. This spring was unusually cool, which slowed the decomposition of algae blooms in the deeper waters. When temperatures suddenly soared in June, scientists began to see anoxic levels rising. By early August, 41 percent of the bay had low levels of dissolved oxygen.

Pollution coupled with weather conditions was a potent one-two punch. The graph in the paper shows most of this area of low levels of dissolved oxygen in the deeper channel areas, so that would jive with your observation of recovery of grasses in the relatively shallower waters near your home.

And I guess I still don't understand algae, does it or does it not give off oxygen during the course of its existance like other plant life?

The problem lies in when the algae bloom dies (more from the article):

As pollutants are washed downstream, excess nutrients fuel the explosive growth of algae that decreases the level of dissolved oxygen in the water and blocks out light need by the underwater grasses.

(What is dissolved oxygen? Oxygen gets into water by diffusion from the surrounding air, when wind mixes it into surface waters, and as a waste product of phtosynthesis. Water temperature is a key factor: Warm water contains less oxygen than cold water. Dissolved oxygen is consume in the water by respiration and decomposition.)

When the algae blooms die, then decomposition process removes more oxygen from the water.

My take is that any good from the algae is negated and then some when it dies. The bloom also blocks the sunlight from reaching the grasses and caused THEM to die and decompose, further depleting the dissolved oxygen in the water.

[Ken King (Premo)]

Originally Posted by jazz lady

There may be pockets where it is getting better, but overall the health of the bay is declining:


Pollution coupled with weather conditions was a potent one-two punch. The graph in the paper shows most of this area of low levels of dissolved oxygen in the deeper channel areas, so that would jive with your observation of recovery of grasses in the relatively shallower waters near your home.

The problem lies in when the algae bloom dies (more from the article):

My take is that any good from the algae is negated and then some when it dies. The bloom also blocks the sunlight from reaching the grasses and caused THEM to die and decompose, further depleting the dissolved oxygen in the water.

So we need something to EAT the algae before it dies or gets too large to block the sun, right? More fish might just be the ticket. And this fish

[jazz lady (Premo)]

Originally Posted by Ken King

So we need something to EAT the algae before it dies or gets too large to block the sun, right? More fish might just be the ticket.

That may be true. But I thought they needed the bay grasses to spawn and raise their young and they are on the decline. I need to research this more.

Ironically, the rockfish population rebounded big time after the fishing moratoriums but it doesn't look like they like algae. The article mentioned rockfish might be in trouble again shortly because menhaden, one of their main food sources, may be overharvested now.

[Ken King (Premo)]

Originally Posted by jazz lady

That may be true. But I thought they needed the bay grasses to spawn and raise their young and they are on the decline. I need to research this more.

Ironically, the rockfish population rebounded big time after the fishing moratoriums but it doesn't look like they like algae. The article mentioned rockfish might be in trouble again shortly because menhaden, one of their main food sources, may be overharvested now.

I think the "Rock" is predatory in nature. Oh, yeah, I added a link in the post above for the fish I see as being raped and impacting the bay the most, the Atlantic Menhaden.

[jazz lady (Premo)]

Chesapeake Bay watershed boundary

A watershed is an area of land that is crisscrossed by smaller waterways that drain into a large body of water. The bay's 64,000 square mile watershed includes parts of six states (NY, PA, MD, DE, VA, WV) and the District.

So it's not just Maryland and Virginia that need to be involved in the fight to save the Chesapeake. The range is from just north of Cooperstown, NY in the north to Norfolk in the south. All of the tributaries in this area feed into the bay at some point.

[jazz lady (Premo)]

Originally Posted by Ken King

I think the "Rock" is predatory in nature. Oh, yeah, I added a link in the post above for the fish I see as being raped and impacting the bay the most, the Atlantic Menhaden.

Good link. Mankind seems to be set upon trying to save one species like the rockfish and destroying another one, the menhaden, at the same time.