Algpopulationer

Algpopulationer are populations of algae, a diverse group of photosynthetic organisms that inhabit aquatic environments. They include microalgae such as diatoms, dinoflagellates, green algae, and cyanobacteria, as well as macroalgae like seaweeds in coastal systems. Algal populations form the base of many aquatic food webs and contribute substantially to primary production and biogeochemical cycling, including carbon fixation and oxygen generation.

Growth and regulation: Algal population size is governed by light, nutrients (notably nitrogen and phosphorus), temperature, and water mixing or stratification. Nutrient availability often limits growth; nutrient pulses can trigger rapid increases, while light limitation, grazing by herbivores, and viral infections can suppress it. Population dynamics range from steady growth to episodic blooms, sometimes occurring as harmful algal blooms (HABs) that release toxins, affect water quality, or cause hypoxia when biomass decays.

Measurement and monitoring: Population assessments use cell counting (microscopy, flow cytometry), chlorophyll a measurements, pigment analysis, molecular methods, and remote sensing. Satellite imagery tracks large-scale blooms, while in situ sampling provides species-level information and toxin testing where relevant.

Ecological and management context: Algal populations respond to climate change, nutrient inputs, and hydrology. Management aims include reducing nutrient loads, monitoring for HABs, and protecting water resources. Understanding algal population dynamics is essential for predicting ecosystem responses and safeguarding fisheries, tourism, and drinking-water safety.