This ionic movement causes a flagellum (a small propeller) on the outside of the alga to begin rotating, which propels the cell towards the light, allowing it to photosynthesise better.
According to an unpublished study† of the cost of blooms off America in 1987-92, totalotal bill averages only about $40m a year.One explanation for the recent flourishing of blooms is that new species of alga are being introduced in the ballast water of ships and in new species of farmed shellfish.
In Texas, in the Laguna Madre, a brown tide caused by an alga called Aureoumbra lugunensis lasted for seven years.
His chosen alga is unusual because when it is exposed to blue light, certain proteins within the algal cell respond by allowing sodium ions into the cell.
This is believed to be the remains of an alga and, like a mitochondrion or a chloroplast, it has a small genome of its own.
In the Mediterranean, where local sea plants have been weakened by pollution, an alga called Caulerpa taxifolia has taken root.
A few types of alga are clearly harmful.
One symptom is "harmful algal blooms"—sudden growths of a single type of alga which are usually unsightly, often foul-smelling and occasionally toxic.
The process occurs in almost all algae, and in fact much of what is known about photosynthesis was first discovered by studying the green alga Chlorella.
Since the amount of light absorbed depends upon the pigment composition and concentration found in the alga, some algae absorb more light at a given wavelength, and therefore, potentially, those algae can convert more light energy of that wavelength to chemical energy via photosynthesis.
In many red algae (e.g., Palmaria), numerous adjacent filaments joined laterally create the gross morphological form of the alga.
