View Full Version : Fertilizer export and conservation project in the chesapeake bay area

11/04/2014, 11:47 AM
Hi everyone. I have a hypothetical question for the chemists and pragmatists out there.. If you arent familiar with the delmarva area or the chesapeake bay Ill fill you in. We have been dealing with disastrous red algae and water that is opaque after a few feet. The main reason for this, in my eyes, is the use of fertilizers that cause high phosphate levels in run off water.

would it THEORETICALLY be possible to set up a semi permeable membrane to separate the bay's water from the atlantic? and then after that, could we set up a large scale protein skimmer to pull out DOC? after pulling the DOC out we could recycle it and use it as fertilizer again, instead of pumping more and more new fertilizer into the system, limiting the growth of crabs, oysters, and other cold water inverts. the fertilizer that we did not use(i would assume there would be a surplus) we could store as extra.

PLEASE criticize this idea and let me know how I could make this a more reasonable idea. I understand that I would need a huge grant from the government and tons of permits but I'm not even close to that point haha.

Could we talk logistics for my life goal?? I am only 21 and still in college as an Environmental science major so I am no where close to having the experience some of you guys have. Let me know what you think!!!!

11/04/2014, 12:37 PM
How big is your skimmer?

11/04/2014, 01:45 PM
it would have to be huge considering the bay is a little more than 18 trillion gallons... i can only imagine the amount of energy this thing would have to use.. but you know what they say.. you should get a skimmer thats rated for twice the body of water lol.... anyone know where i can get a 36trillion gph pump??

11/04/2014, 07:18 PM
You'd be far better off tackling those nutrient inputs at the source. Both point source and non point source...i.e. things like sewage plants and run off. Trying to put up a semi permeable barrier (not sure what this will accomplish) will cost incredible amounts of money, block necessary water flow along with migrations of fish such as Striped Bass. Basically, it's going to cause more problems then it might solve.

11/04/2014, 07:27 PM
A better idea would be to drive up here to Lancaster and drop-kick (or something less violent, preferably) the farmers that pour nitrogenous compounds onto their fields like they're some sort of magic elixir for curing unsustainable farming practices.

Or convince private companies to improve storm run-off plans. Or work to improve the menhaden population in the bay. Or any number of things that are more feasible than building a massive, ugly, power hungry, probably ineffective protein skimmer.

Think about it: By the time the nitrogenous compounds reach the bay, they've already been processed into nitrate. Skimmers don't remove nitrate, they remove organics that break down into nitrate. It's already a problem before it reaches the bay so a skimmer won't be very effective.

Not to mention that any skimmate would probably include substances that we don't want to ingest. Antifreeze, oil, sewage, etc.

11/05/2014, 12:40 AM
Thank you! This is exactly what I was looking for. It didn't even occur to me that I would be affecting migrating animals. Also that was in order to somewhat "isolate" the filtration area to put a number on the amount of water being processed. Not sure how smart that was lol.

I never said this plan was rational and god knows it isn't happening with our govmnt. Just wanted to hear if it was worth talking about and have people poke holes. This idea was just means to an end that I'm working toward

Now I just did a small amount of research on menhaden and these fish sound promising. They process 5gallons of algae a minute! Are we talking free floating algae that cause opacity? Besides that, they are high in omega 3 and can be used for crop fertilization(or so I read).

Are there any initiatives out there to get these little guys back into the bay?

Also if anyone has heard other ideas or websites about cleaning the bay area I'd love to hear more

11/05/2014, 05:53 AM
Floating ideas is good, it's the only way to get feedback and maybe come up with a better idea ;)

You need to look at the whole ecosystem, including the ecosystems the one your interested in is attached to. Also look at the red tide organism itself, Cochlodinium polykrikoides. It kills fish, retards growth in shellfish, shades out sea grass and benthic algaes...just plain trouble. That means getting something to eat it is going to problematic. The real trick IMO is to look at the causes and what you can do to mitigate them. The easiest (but by no means easy) is to control runoff and clean up the runoff. This also brings in socioeconomic factors that are often competing. For instance, the baymen are all for making the golf courses stop fertilizing the greens while the golf courses want to keep fertilizing and having those nice greens. Also creating catchment basins and vegetative "swamp" filters for runoff, while working quite well, requires space that might not be publicly owned in the location it really needs to be situated...making for land use conflicts. That last method happens to work quite well when properly employed, and is low tech and relatively low cost...land cost aside.
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11/05/2014, 06:20 AM
According to the PA DEP:

Nitrogen and phosphorous are the major nonpoint source nutrient pollutants threatening the health of the Bay. Excessive amounts of chemical and organic nutrients being applied to crops may pollute water. In the upper portion of the Bay, it is estimated that 77% of the nitrogen and 53% of the phosphorous entering the Bay stems from Pennsylvania.

So there's a great place to start.

The CBF estimates that of total pollution, 41% comes from agriculture. If you're not familiar with the CBF (Chesapeake Bay Foundation), I'd go to their site and do some reading.

11/05/2014, 06:22 AM
Are there any initiatives out there to get these little guys back into the bay?

The problem has more to do with keeping them in the bay and not pulling them out to grind up/process for their omega-3's.

Here's what the CBF says:
Atlantic Menhaden (http://www.cbf.org/about-the-bay/more-than-just-the-bay/creatures-of-the-chesapeake/atlantic-menhaden)

We do not want to fish them to use for fertilizer. They play an extremely important role both as a consumer of algae and as a food source for larger fish (just about everything from flounder to blues to stripers). Recently, fishing quotas have been adjusted to limit menhaden harvests.

11/05/2014, 06:46 AM
@billsreef - the main reason I started thinking about the deportation of the nitrogen and phosphorus was because of that God awful red algae. Sounds like I should start lobbying in PA haha. In MD I believe there was a law passed or some kind of tax write off to encourage farmers to plant trees lines around their farms to prevent a lot of dirty run off. The vegetative basin is probably much more effective but it's the same concept correct? Run off passes through plants and the plants absorb the nitrogen and phosphorus before it reaches the bay. Sorry if that's redundant haha I like to be very clear.

@gbru316 - as billsreef mentioned earlier the red algae we've been experiencing in recent years kills off fish and bottom feeders. I thought this was the main contributor to the lack of menhaden. Now that I know the population is being destroyed from the harvesting I retract my statement about using them as fert and I'm happy to hear the quota is being lowered! PA has a crazy amount of farm land so seeing the stats on where the majority of the problem stems from isn't shocking. Again... It seems as though I should think twice about that internship at the national aquarium and move into politics haha

11/05/2014, 06:58 AM
Again... It seems as though I should think twice about that internship at the national aquarium and move into politics haha

Scientists don't make policy decisions that affect our environment. Politicians do.

Another species that does a great deal of good for the bay is the oyster. Populations have plummeted over the past few decades but some gains are being observed. If we can restore the menhaden and oyster populations, the bay will be in much better shape.

11/05/2014, 11:43 AM
The vegetative basin is probably much more effective but it's the same concept correct? Run off passes through plants and the plants absorb the nitrogen and phosphorus before it reaches the bay. Sorry if that's redundant haha I like to be very clear.

You've got the idea. Fast growing plants like native grasses will remove more N and P faster than slower growing trees.

11/05/2014, 12:43 PM
Look up phytoremediation.

Also with plants esp. trees they have an impact on water temperatures.

11/05/2014, 01:57 PM
I have been hearing a good amount of talk about the oyster population recently. my question about the oysters is- we know inverts in our aquarium require very low levels of nitrates and phosphates to thrive. Would this affect the growth of the oysters? I understand they're filter feeders but some of the heavy metals in the bay are concerning to me as well. Is this a valid concern?

it is incredible how much we know about specific plants and what elements they absorb. after some research on phytoremediation and hypoaccumulators, it seems as though there are about 15 plants that could consume the majority of heavy metals and other toxic elements caused from industrialized areas and farmland. Will be doing more research later today on the effectiveness of these plants in relation to placement and amount planted per acre of farmland.

This thread is really helpful and I appreciate you all taking the time to talk with a conservationist noobie.

11/05/2014, 02:16 PM
This thread is really helpful and I appreciate you all taking the time to talk with a conservationist noobie.

No problem. I have a vested interest in the bay. We're moving south from Lancaster because of the excellent job market in my industry between DC and Baltimore and I'd really like to find somewhere close enough to the water so I can spend my weekends fishing, kayaking, and generally enjoying it.

There's also always been something that's lured me to the bay, from a rather young age. I've never been able to put my finger on it.

11/05/2014, 02:18 PM
Here's something that I find really interesting:

Chesapeake Bay Interpretive Buoy System (http://buoybay.noaa.gov/news/nitrate-sensor-installed-cbibs-susquehanna-buoy)

Real time dissolved oxygen at a number of buoys strategically placed around the bay. The Susquehanna buoy also has real time nitrate monitoring. The Susqy is currently discharging about 1 mg/L of NO3 into the bay.

While no formal definitions of “how much is too much” for nitrate in the Bay have been set, the Chesapeake Bay Program’s Phytoplankton Index of Biotic Integrity (PIBI) notes that Chesapeake water with more than 0.07 mg/L of dissolved inorganic nitrogen is considered degraded. Remember, this measurement is for total nitrogen—not only nitrate. But if nitrate levels are greater than 0.07 mg/L, because DIN is the sum those three forms of nitrogen including nitrate, DIN levels must also be greater than 0.07 mg/L.

11/05/2014, 04:52 PM
Eusturine critters like oysters tolerate much higher nutrient levels than the reef critters we keep in our tanks. Other than the effects on algae and subsequent HAB's (Harmful Algae Blooms), the oysters really don't care what the N and P levels of the water are. Heavy metals are another matter, they can effect larval development, not to mention bioaccumulation up the food chain...with us at the top. Add in fishing pressures, salinity changes, and MSX (an oyster disease), and it is certainly a tough road for oyster restoration.