Early warning system for harmful algal blooms by determination of cholophyll-a concentration changes.
WHAT ARE ALGAL BLOOMS AND WHY MONITOR THEM?
Algal blooms tend to form in presence of ideal condition of temperature, nutrients and light. Algal blooms become harmful when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while producing toxic or negative effects on people, fish, shellfish, marine mammals, and birds.
The human illnesses caused by harmful algal blooms, though rare, can be debilitating or even fatal.
Harmful algal blooms’ occurence are on the rise and are becoming a major environmental concern in many states, not only because they affect the health of people and marine ecosystems, but also the prosperity of local economies.
In consequence, governments and environmental authorities request effective algal bloom monitoring tools.
WHY CHLOROPHYLL-A DETECTION?
Chlorophyll-a concentration is the most commonly used parameter for measuring algal concentration or biomass, and assessing the occurence of algal blooms.
All photosynthetic organisms contain chlorophyll. Among all forms of chlorophyll, only chlorophyll-a is common to all algae.
A few micrograms of chlorophyll-a per litre are considered to be normal. Concentrations beyond 10 or 20 μg/L are evaluated as algal bloom.
Only a small amount of the algal biomass is eaten by zooplankton, the remains sink to the bottom where they are decomposed by bacteria.
Oxygen at the bottom can fall to stress levels for most organisms or even to near zero - causing death of the ecosystem in the area.