Thursday, January 11, 2007

More on Sea Grant, Coastlines and Their Hypoxia Conclusion

Hundreds of millions of dollars are being spent on nitrogen reduction programs in New York City, New York State and Connecticut, in an effort to reduce the severity of hypoxia – that is, low levels of dissolved oxygen that can be damaging if not lethal to marine life – in Long Island Sound.

Is that money being well-spent? I think it is but I readily acknowledge that it’s hard to tell for sure right now. One thing I’m confident of however is that New York Sea Grant was wrong when it asserted in its Coastlines magazine that there’s already significant evidence that spending money on nitrogen reduction won’t solve the hypoxia problem.

The details of the Coastlines assertion are in a post from Monday, and in another post in which Jack Mattice, Sea Grant’s executive director, responded to my critique. The gist of it is that research (funded by Sea Grant) by two scientists from SUNY Stony Brook (Larry Swanson and Bob Wilson) indicates that because nitrogen entering the Sound has already been reduced by 31 percent, and because hypoxia hasn’t eased by a similar amount, the nitrogen reduction program is not going to work.

It’s a flawed conclusion, but it’s an important one because Sea Grant has been a participant in the Long Island Sound Study and cleanup for years, and because Mattice and Swanson are both members of the LISS management committee, which oversees the day to day work of the Long Island Sound program. There’s a presumption therefore that they know what they’re talking about and that people will listen to them

(Before I continue, I should add that I’m not sure how the Sea Grant researchers came up with 31 percent figure for nitrogen reduction. An EPA report called Sound Health, released last spring, said that nitrogen has been reduced by 24 percent. In an email to me, Mattice cited a letter to the editor of the Times that Swanson and Wilson published a year ago, but as far as I know their work hasn’t been published yet in a peer-reviewed journal, although I was told that it has been submitted.)

I asked two people involved in the Long Island Sound program what they thought of the Sea Grant/Swanson-Watson conclusion. Clearly these two people (Mark Tedesco, the director of EPA’s Long Island Sound office, and another person who asked me to keep his name out of it) are vested in the program, and it would be astounding if they said it wasn’t likely to succeed.

But they went further than that. They said that the people overseeing the cleanup have long expected that water quality improvements would lag behind nitrogen reductions, and that it is unreasonable to expect otherwise. Tedesco drew an analogy to global warming and carbon dioxide. Global warming is upon us now, and even if we stopped all carbon dioxide emissions tomorrow, global warming would continue for a long time because of the buildup of carbon in the atmosphere. The Long Island Sound nitrogen problem is similar: if we reduce nitrogen now, there still will be a lag time before we see the results.

The Long Island Sound program and cleanup is based on a target nitrogen reduction of 58.5 percent by 2014. So whether the nitrogen reduction is 31 percent or 24 percent, the program is barely halfway toward its goal. And that’s not enough to result in a corresponding increase in water quality.

Here’s what one of the Sound program managers told me: “I wouldn't really expect the Sound to respond as Jack and Larry suggest, i.e., a short-term load reduction observed in a rebound of oxygen loads. There's a lot of natural variability and natural effects on hypoxia severity that can't easily be sorted out in a three-year period. Plus there is a ‘memory’ in the Sound's sediments that affects recovery.”

Tedesco said the same thing: “No one expected that you’d turn off the flow and the next summer you’d see an immediate improvement in dissolved oxygen levels.”

He recalled a workshop in 1990 at which computer modelers and scientists estimated that once the nitrogen reduction goal was reached, it would still take five or six years at least to see the concomitant response in dissolved oxygen concentrations.

In his email to me, Jack Mattice went even further than saying that the 58.5 percent goal is inadequate. He said Swanson and Wilson conclude “that even stopping all sewage inputs to the sound will not eliminate the hypoxia problem.”

This brings me back to one of my original questions: If Swanson and Mattice believe that eliminating all sewage inputs to the Sound (which is never going to happen) will not end hypoxia, and therefore that ending some sewage inputs to the Sound (which is going to happen) will not end hypoxia either, have they communicated that to the people who are making the decisions about the Long Island Sound cleanup?

If reducing sewage will not eliminate hypoxia, do they believe that reducing sewage will ease the affects of hypoxia enough to make it worthwhile? Should we be doing more? Or should we give up? If we give up, how bad will conditions be on the Sound compared to what they will be if we continue? Mattice and Swanson, after all, are on the management committee. Swanson conducted the research and Mattice paid for it and published a summary of it in his magazine. You would think the management committee would be interested in knowing their conclusions.



Anonymous Robert Funicello said...

Tom asks important questions and the many friends of the Sound who have worked for years to implement the Long Island Sound Study's Comprehensive Conservation Management Plan and the resulting TMDL deserve better answers than Sea Grant has published to date.

9:30 AM  
Anonymous Bryan said...

Remembering your post on the apparent historical nature of hypoxia in the western LIS, I ask as a layman whether nitrogen reductions alone are going to solve the hypoxia problem. It sounds like other steps will be necessary, such as oyster and eel-grass plantings. Do we need to reduce the nitrogen levels first, in order for these other measures (i.e., oyster seeding) to have a chance at surviving?


10:22 AM  
Blogger Tom Andersen said...

You're right. Habitat restoration is a significant part of the cleanup plan and my recollection is that Audubon New York insisted on it to make sure that the ecosystem didn't get forget amid all the engineering fixes. The Long Island Sound Stewardship Program is part of this, and my recollection is that the Comprehensive Conservation and Management Plan specifies the restoration of 1,000 acres of coastal habitat and 100 river miles of habitat (although I can't find a link at the moment and might have the numbers wrong).

12:29 PM  
Blogger Sam said...

I was wondering about the chemistry so I checked out

Sure enough, it is very easy to measure nitrogen in water (remember I'm an air guy here). Waterborne nitrogen is the sum of:

* ammonia (NH4)
* nitrite (NO2)
* nitrate (NO3)

Using a simple reagent, all nitrogen species here is converted to NO3, and a color chart is used to record the correct concentration. If you have some good outfall flow rate data, you can figure tons of nitrate equivalent nitrogen you have added to the receivng water.

The only problem is you don't know if it is ammonia, nitrite, or nitrate. In the past, most wastewater treatment plants converted everything to nitrate, which didn't reduce "nitrogen" a single bit.

Removing nitrate (denitrification) involves some special bacteria and/or some advanced chemistry but it good to remove not only because it can cause eutrophication but also "brown blood fish disease."

In other words, even with relatively high DO concenrations, the environment may become impaired. As we know, it is usually the case the the nutrients cause blooms that suck all the oxygen out of the water, especially if phosphorus is available.

Nitrate is also common in areas with particulate emissions such as near New York. The most common pathways are conversion of nitrogen oxide to ammonium nitrate and ammonium sulfate (ionic state), being very good fertilizers in the water (dissolved state).

But can anybody tell me is you have a bunch of phosphate in the water? Look on the geology maps, since the stuff comes from rocks and run-off, definitely not the air. You can't make DNA without it. /Sam

9:11 PM  
Anonymous Anonymous said...

Something that has often been overlooked is that the phosphorus concentrations in rivers in Connecticut have declined through the 1970's, 80's and 90's as sewage treatment practices have improved, and phosphate detergents have been removed from use. The effect of this change has been beneficial for inland waters, reducing foams and algal blooms in rivers and impoundments. What is unclear is the effect of this change on the on hypoxia situation in the Sound. For instance, the N/P ratios have increased in many rivers in Connecticut with point sources, because of the phosphorus reductions. During the 1980's, the dominant form of nitrogen discharged from many sewage treatment plants in Connecticut changed from ammonia to nitrate nitrogen at many streams in Connecticut, due to improved sewage treatment. The effects of these changes in ratios N-species and relation to phosphorus on the algal communities in Long Island Sound are unknown. For examples see:
changes in N species
and changes in phosphorus,%20Mullaney.pdf


9:05 PM  

Post a Comment

<< Home

eXTReMe Tracker