I've wondered for a while what causes algal blooms. These blooms are bad, because the algae overproduces and then dies, and the bacteria which feed on it are aerobic, and take all the oxygen out of the water, causing fish and animals to suffocate. But, we can take advantage of reported blooms to go collect specimens.

 In the past, algal blooms have been blamed on phosphorous from fertilizer run-off, or from overuse of phosphorous detergens. But this doesn't really explain why blooms will often appear so concentrated and far from those Phosphorous sources.

 Today I was reading the wikipedia article an phosphoric acid, and the article mentions that  rust removers, as gells, called 'Naval Jelly'. I suspect that this is being used on boats, and this is simply hosed off into the water, or perhaps a chunk of gell further up the hull is eventually washed into the ocean, where it dissolves. I recall that iron is also an important nutrient for certain species of algae. So, shipyards and marinas may be the source of a lot of the algal blooms.

 Not that this is really related to algae for biodiesel, at all. Just thought you might be interested in this idea. 

 I would say in the US the number one cause would be runoff from glof courses and the US obscession with the perfect green lawn.

bobk:

  I've wondered for a while what causes algal blooms.

There are many different algae and many reasons for 'blooms'. Some are natural and some are man made. Some have direct causes and some have indirect. I know of 2 personally;

Lake Michigan and Cladophora

Russ wonders why on earth anyone would consider actually purposefully growing algae when he is knee deep in it!?!?!?!  Anywho... why is it there? Cladophora started ~ 40 years ago but has really gotten worse over the past 25.

Turns out its a combo of human impacts. Yes farming in P rich soils and adding N doesnt help. Yes these nutrients get into the lake and offer dissolved nut's for the algae but that isnt the big real reason. Yes its the city dumping as much as the farmers are but in a concentrated area but that isnt the big reason. Yes its the expensive lake front housing ruining lakeshore plant buffer zones but that isnt the big reason. Yes its the loss of wetlands to development and storm water management failures but that isnt the big reason. Its something much more interesting... its because we have a new friend cleaning up the lake, Zebra mussels.

The mussels clean out the naturally turbid water and allow light to reach deeper into the water where the rocks are. Not only is the dissolved P and N by human land use adding to the issues but so are (tho my friend Harvey doesnt mention it in the link) the mussels also recycling P back into the form algae love. Its a 'perfect storm' of a invasive spp. causing a huge, ecosystem shifting cascade of events. Its likely that by removing the dominance the mussels have now will reduce the 'algal blooms' that poor Russ smells every year. What really sux is that it didnt start like that, yet he has to bear the cost (smell and disease) of it.

Lake Winnebago...

Its obvious that land use issue have impacted this lake greatly. ~160 yrs ago, they dam'ed the Fox and made Lake Winnebage bigger and also a few up-river rivers into shallow lakes.

Winnebago and Fond du Lac means stinky water to pre-white men and its quite clear that every July/August, the algae become so thick that you could almost walk across the lake. But lately... the blooms have really become quite toxic.  It has been building for many years as noted in this water quality report (yes, if you look close enough, on a few pix you can see where froggy lives). It is also quite clear to anyone paying attn that these recent algal blooms are not only different but much more frequent and its likely to get much much worse. Why?

Ground water moves very slowly. All the P and N loaded ground water will slowly perculate thru to the lake for the next 30-50 years. And its not like anyone has changed the land use issues. So its hard for me as an ecologist to see how this nasty algal bloom trend isnt going to continue.

Its not only costly to the environment but its becoming a huge liability to our infrastructure and it seems without a solution. This is what they said in 1999, 'Just pay us and we will take care of it'. The reality is actually this, 'Um, the water is too thick and our technology cant handle it'.

Moral of the story? Its never one reason and there is usually not 1 person to blame and make pay (If I find the bastard who brought zebra mussels to the lakes, he is in big trouble!@!@). I find this to be the proof that we need an 'ecology tax' and an army of ecologists doing this sorts of work. Buffer zones, better land use practices, eliminating nutrient and biomass loading into our water, reduce loading into groundwater, better city storm water management. Specifically... I have a small solution that the board might like... algae/wetland filters. Harvesting out the biomass gets biofuels and a recycling method of nutrients. Im thinking Phragmites as the main crop. Heck, maybe I'll even turn my roof into a thatch...

 

 Bob,

Many blooms are of natural causes.  Each case is likely different.   For the human triggered ones, you and Tuesday are correct.  The prime cause is probably agricultural runoff.  One of the biggest recurring one is the Dead Zone at the mouth of the Mississippi.  The increase in corn acreage in the Midwest is worrying people because the Dead Zone may grow. 

Naval Jelly is used in such low quantities it is probably not a suspect. 

Here in Louisiana, the dead zones are much larger away from the mouth of the Mississippi R., To the West going into Texas waters. Most of that is over fertilization by sugar cane and rice farmers. I'd like to blame it all on the farmers further up North, but thay are not the single largest culprit. We in Louisiana are. Some of the smaller towns along rivers emptying in the Gulf water treatment facilities are practiacally non existant. A few people I have known have had cuts while swiming in these rivers and, within eight hours, are near death from staff infections. WE, the local residents, are a very large part of the problem. People down here do not like to pay taxes and we get what we are willing to pay for.

Why don't we use 'algae trawlers' to respond to these events, pull in the algae and turn it into biodiesel? What am I missing?

 John,

Most species of algae contain only a small percentage of oil. 

 I'd like to know more about the nutrient content of these "red tides".

Tuesday:

 I'd like to know more about the nutrient content of these "red tides".

You mean the organism themselves or the water nutrient content?