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Topic: Red Drift Algae, ... another serious, human-based change< Next Oldest | Next Newest >
Capn Jimbo Offline
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Posted: Feb. 06 2007,11:14

Sue Sea and I just returned from our getaway Paradise in Paradise, namely Sanibel Island.  For those who may not know, Sanibel is a lovely larger island, connected to Captiva and accessible by bridge.  The environment is well preserved, gross commercial development almost completely excluded.  Little meandering two lane road, miles of beaches, santuaries, Ding Darling Park, great fishing, kayaking, bike paths everywhere, art studios and the like.  An upscale retreat that ordinary people can access.

This may have changed!



A few years ago runoff from the sugar and agricultural interests, hurricane-related releases and a bit of sewage caused a number of outbreaks of red drift algae.

What is it and why does it happen?

Red drift algae is a form of reddish seaweed that, like sea grass, grows in beds and is found not far from shore.  The weed is easily dislodged and carried to nearby shores, ie Sanibel.

From the Stokes Birding Blog:

Quote

In the last few years, the hurricanes (more numerous because of global warming?) have dumped excessive water on FL. That water goes into Lake Okeechobee and, in order not to have the lake flood, much of that is released by the South Florida Water Management District and U.S. Army Corps of Engineers down the Caloosahatchee River to Sanibel Island’s surrounding waters. Trouble is, the polluted fresh water from the lake contains heavy nutrients, like nitrogen and phosporous, that contribute to excessive algae blooms and also dense sediments that hurt sea grass growth. The releases of this polluted water can kill oyster and clam beds, severely impact the marine environment and its wildlife, and hurt the toursim industry.


It was thought the algae was a temporary event, related to Big Sugar and the hurricanes of that time.  But it now appears the algae has taken a foothold and crowded out the normal, more typical species.

This is not good.

What effects will Red Drift Algae have?

As noted it will crowd out native and normal sea grasses and weeds.

Quote

Quoting Ding Darling:

"During the growing season, it grows incredibly fast," refuge manager Rob Jess said. "It has established itself, so it takes less nutrients. We've seen our seagrass beds decline by half in the past two years. The fishing is down. The mullet aren't here. The wilderness area has been tremendously devastated."


This affects both local birds and fish as well:

Quote

Ralph Woodring, 70, who was born on Sanibel, said it's bad.

"Nobody's catching any fish at all," Woodring said. "We had a little bait: Some glass minnows came in and stayed a couple of days and then left. We had a run of mullet a few weeks ago, but they left. There ain't any birds because there's nothing for them to eat. "We have a lot of shrimp and crabs, because there's nothing to eat them. Everything else is in #### short supply."

Woodring said the bay is crawling with an unusually large number of sea hares — shell-less mollusks that eat drift algae. Water in the bay should be murky, Woodring said, but it's been surface-to-bottom clear for months, which is a problem: Drift algae need sunlight, and they get plenty of it in clear water.


Sanibel is a MAJOR tourist destination and it goes without saying that mounds of rotting and VERY smelly vegetation have been widely reported and has led to a crisis in managing this problem.

So what can/is being done about it?

Not much.

The tourist interest just want it removed, with heavy equipment if necessary.  But a one-time clean up of Sanibel beaches is estimated to cost the small community around $1.5 million!  Clean it up, and two days later - yup - more piles.

And there is a real conflict with environmental interests.  So far the city will only allow tedious hand raking, drying and careful disposal during specific times only - as this is the only way to prevent significant damage to the beaches, birds and other reproducing wildlife (for which Sanibel is famous)

Quote

Today, Sanibel City Council authorized the cleanup of algae by property owners along their beaches, with an approved Beach Cleanup Permit. Raking of algae must be done exclusively by the use of hand tools such as rakes, shovels, or similar tools, and wheelbarrows. Algae must be air-dried and bagged separately for final disposal. Algae may not be co-mingled with other vegetation or household trash. Bagged, dried, algae should be placed roadside for pickup by Waste Pro


This creates an obvious conflict between two very powerful Sanibel interests - the tourist industry and the extensive environmental interests.  A real problem as the two are VERY connected as Sanibel is largely and environmental destination.  Natural, authentic, small, unspoiled and teeming with wildlife (and not the kind you see in Key West).

Even Sanibel's world famous shelling seemed affected.  Sue Sea has been visiting Sanibel for over 30 years and is a major sheller (and victim to the named "Sanibel Stoop").  Since the algae hit the beaches, shells have been hard to come by as they are displaced by the mounds.

My Personal Observations:



1.  This conflict may be unresolveable as machine clearing of the beaches may well destroy the environment that most visitors expect.  Hand-raking is impractical.  The cost is excessive either way, and two days after a clean-up, and...

It's back.

2.  Sanibel, though wealthy, is small sweet potatoes compared to Big Sugar and our prositutes, er, politicians.  When (push) comes to SUGAR SHOVE, well...

3.  The red algae now has a foothold.  It may well be that the environment's alteration is approaching permanent.  It's kinda like global warming - we act now, or else!

:capn:


Edited by Capn Jimbo on Feb. 06 2007,11:17

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PALADIN Offline
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Posted: Feb. 06 2007,19:28

This reminds me of the green algae outbreak they have in Europe...yikes!!

:cool:


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Capn Jimbo Offline
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Posted: April 09 2007,07:36

Red Tide Toxin vs Red Drift Algae (Runoff)

Because of a recent news release regarding the deaths of 26 manatee in Lee County - over just two weeks - I felt obligated to add to this thread.  And I do hope either Scupper Frank and/or Serge will chime in with their considerable expertise.  

In life I have learned to always note the changes that may contribute to problems.  It's hard for me not to correlate the red drift algae phenomena of recent years with manatee deaths.  Here's a brief history:

1.  The red drift algae made its first significant appearances in December of 2003 and January of 2004, concurrent with major releases of water from Lake Okeechobee.

2.  The U.S. Army Corps of Engineers and the South Florida Water Management District send water from the lake to the Caloosahatchee River on the west coast, and the St. Lucie on the east coast (Indian River Lagoon) - primarily to prevent flooding around the lake.  

3.  These releases contain huge amounts of primarily agricultural (Big Sugar) but also some urban run-off containing fertilizer, pesticides, et al.  Hurricanes were believed to have exacerabated things by stirring up the bottom accumulation.

4.  It is worthy of note that red algae blooms occurred simultaneously on both the east and west coast - exactly where these releases flow.  

5.  A Dr. LaPointe was hired by Lee County to study these releases and has completed a preliminary report - and which is not being released for some reason.

6.  Recent west coast media releases are blaming the recent 26 deaths on toxic red tide (not red drift algae, which is considered relatively harmless), correlating these with 151 deaths also blamed on red tide, in 1996.  Necropsies of eight of the 26 test positive for the red tide toxin.

7.  Seventy-one of those 151 occurred in just a 3 month period (March through May, 1996) and concentrated in Lee, Collier, Sarasota and Charlotte counties.

8.  This year so far there have been 72 deaths, of which roughly two-thirds have occured in Lee County.

9.  Despite newpaper claims of suspected toxic red tide involvement, state studies show no presence of Karenia brevis (the toxin) on the Southwest coast (Link to State Toxin Reports).

10. OTOH there are plenty of reports of runoff and red drift algae in Lee County.

More Questions than Answers:

It is hard ignore the correlation of the recent 26 deaths in just two weeks in Lee County with runoff, especially noting absence of red tide toxin.

Is it possible that the toxins found in the necropsies - though possibly fatal - might also be coincidental to causation by red drift algae effects?  How long do the toxins persist in their bodies?  

The red algae tends to take over areas, crowding out usual (and beneficial) seaweeds, fish and sea life and also depleting the water of normal oxygen levels.  Are the manatees forced to eat the red drift algae?   How does it affect their normal needs and activities?  Are the necropsies also checking for the elements of runoff?

Now correlation is certainly not cause - but it sure does raise questions.  Frank?  Serge?


:capn:


Edited by Capn Jimbo on April 09 2007,07:47

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The French Guy Offline
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Posted: April 12 2007,15:16

Jimbo:
There aren't many ways to release water after hurricanes... and to prevent Lake Okeechobee from overflowing, there is only one solution: evacuate the water through the canals... which, as you know lead to the ocean.
The Ocean has normally much more phosphorus than the pristine Everglades but is N limited (though there are some exceptions and some parts of Florida Bay is a good example).

Anyway, to really have a bloom, you need to have all the ingredients to make algae grow: Sufficient amount of light, nutrients in good balance (normally N:P is 16:1) as well as (at times) traces nutrients and vitamins (iron is a big deal in the ocean) and adequate temperature.

The increase in nutrients in the water leads to a proliferation of algae... called algal bloom, which, in theory is monospecific (one species dominates all the others).

Now you have to tease apart the floating red drift algae, which are macroalgae and generally non toxic, from the red algae blooms which are microalgae (dinoflagellate).

I wrote a post on that board (I think) about red algae blooms and, as such, I will not develop any further here. These blooms are generally toxic (dino toxin) and pretty bad for fish, but also for any animal inhabiting the water (manatee indeed)... which means also people bathing and at proximity of the polluted zones as the toxin travels airborn.

The red macroalgae are not toxic (generally) and some are edible. For example, Red macroalgae such as Nori (Porphyra spp) and a buch of others (Chondrus spp., Mastocarpus stellatus, Porphyridium etc.). I am not sure if manatee eats them, but they probably do and that should not cause them any harm. Actually, maybe some contractors could be hired to harvest these red algae since they contain Carrageenans, a very valuable ingredient found in any products requiring gelatin (Yogurts, ice cream, Jello etc.). That might be a good way to clear the sea and still make money.

This said, an over proliferation of algae (macro or micro), even non toxic has serious side effects. They generally out compete the other algae through nutrient competition but mainly through light competition. The bloom is indeed so dense that the light penetration is considerably reduced. Though the water column might remain clear (case of floating macro algae), the bottom and the underneath water (= under the macroalgal canopy) does not receive enough light, and, as such, the bottom community as well as the floating algae die. The bottom then becomes muddy (since everything, including the precious rooted seagrasses die) and unconsolidated. The bloom also limits itself through auto shading and augments the flux of dead material to the bottom.

Here is the dilemma.
If that material is not flushed out, the system remains enriched at all times because the dead material is degraded by the bacteria which release: 1- CO2 (so the water becomes anoxic = no oxygen nearby the sediment and completely anoxic at night because the bloom only respire at night = no photosynthesis at night); 2- nutrients become available in the water column and can maintain the bloom for a long time!

If no flushing occurs, the bloom is thus likely to maintain itself for a long time... especially if the sediment (which again is unconsolidated) is resuspended following a strong wind event.

To summarize: if no flushing occurs, the pool of nutrients remains in the system for a LONG time and this system is as stable (in the negative way) as the pristine one when the rooted seagrasses and the clear waters once existed.


SO: I am not very familiar with the water circulation on the west coast of Florida. To my understanding, it is pretty well established (= low residence time of the water). As such, as long as no new nutrient loading occurs, the system should be fine and the frequency of blooms should remain steady (after all, blooms always existed and are natural).
In Florida bay, especially Central bay and Barn Sound and the area around the construction on US-1, this might be different since the residence time of the water there is long.

Huh, was I clear enough?
Serge


PS. I will be interviewing at the SFWMD for the chief scientist, Lake Okeechobee division... So, wish me good luck on that one! Bonefish will be happy if I get that job! :-)


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