Black Water

Romancer writes "The Naples Daily News has an article about an environmental anomaly discovered by local fisherman: "They've dubbed it black water, and they're demanding that local, state and national government agencies find out what's causing it." With the Ice shelf falling and now this, solutions are helping but might be a bit late."

Comments

'Black Water'

[Cy Guy]

FYI, this is a common plumbing term for raw sewage.

My vote for responsible parties would have to include the FL sugar industry. They have been one the worst polluters in US history, and wouldn't even be there if the US government didn't impose the harshest import restrictions & tariffs for any agricultural product on foreign sugar.

Because of the sugar subsidies, the industry polutes, practices penury (the labor practice of keeping workers permanently in debt, so that they effectively have to live/work as slaves), and export other food industry jobs which pay good union wages out of the country where companies can buy sugar at world prices.

According to an old salt...

[Zarf]

I asked my coworker here that used to do Marine studies in Biscayne and Florida Bay, his answer was so thoroughly educational and authoritative sounding I thought I'd post it here:

Zarf:
> You guys ever hear of this stuff?

I've seen it.

As you are well aware, every drop of seawater is loaded with micro-organisms. Try to cheat and jump start your aquarium by getting a few buckets of seawater straight from the source, but screw it up and don't aerate it or give it enough light. Leave it in the car trunk too long. Or just leave seawater standing in the bowl in your sailboat's head. The water dies. It doesn't even have the good manners to stay clear. It turns black and anaerobic, and fits the description in the Naples' article. An absentee captain who kept his motorboat in the slip next to me used to complain that someone was breaking onto his boat and using his head without flushing it when he wasn't around. He just left water sitting in it for weeks on end. Same stuff.

BTW, "blackwater" means sewage to us sailors. Even the phrase "deadwater" is already used. ("Deadwater" is where there is a sharp boundary very near the surface between fresh melted glacier water and seawater. This boundary supports internal waves. Displacement boats at the surface create a second wake at the boundary which slows them to a crawl, hence the name. This is usually found in fjords.... but I digress.)

I've got two ideas about where this stuff came from. The first is that something was released into the water that killed everything. Some sort of toxic dumping. I'm sure that's what some people are thinking. But I think that's overstating what happened.

More likely, the cause wasn't so deliberately evil. My guess is that someone ballasted a very large ship with a lot of seawater. The water sat in her tanks for a long time, and died just as though it were sitting in my sailboat's head too long. Then, as they approached port, they realized they'd forgotten to dump it overboard offshore. So they dumped on the coastal shelf on the way in. The fish know something is wrong, which is why they're avoiding it and acting funny. But it's nothing as actively toxic as a red tide bloom. Just ballast water.

It's important to realize that the waters there are relatively still. I should know, this was the very stuff I studied at RSMAS. The Straits of Florida act as a bandpass filter and so only a weak diurnal tide is left (the strong lunar driven semi-diurnal tides are restricted to the East coast of the state). If the Loop Current is even in the area right now (it meanders wildly and unpredictably) it probably isn't riding up onto the shelf where this ballastwater is or it would have swept this stuff away. I haven't looked at Florida weather lately, but maybe they haven't had a good strong cold front for a while either. Wind driven circulation is important; cold fronts are the biggest feature around Florida during this season. Heck, maybe it would have stayed together through weather events like that. Given those conditions and assuming the salinity of the ballast water is close to the surrounding water, diffusion will be painfully slow and patches will remain identifiable for a long time. (I used to use freshwater releases from the mainland as a tracer; I'd zip around in a speedboat and map the salinity across Biscayne and Florida Bay from one week to the next. You could follow the blobs of water even though their integrity was being attacked by density driven circulation from its low salinity.) What is left is a weak flow, a combination of wind and tidally driven pumping, that slowly brings water from that area into Florida Bay and then pumps it south through passes between the Keys into Hawk Channel. On the other side, the boundary between chalky/murky green runoff from Florida Bay and the cleaner Florida Straits water is so clear it can be seen from a boat as a sharp line. Perhaps the residents in the Keys will get a close view of it as it passes by?

Slainte'
John

John doesn't read slashdot anyhow so this information might never have made a post here. But, I do find his explination remarkable in that it gives a relatively simple cause that seems very plausable. I like answers like that so I could be a little biased especially since it takes a lot of steam out of the hype surrounding the story.

I know this won't get modded up now but perhaps a few people will read this and be enlightened.