An algal bloom is a rapid increase or accumulation of algae in a water body, often visible as green, red, or brown discolouration on the surface.
Algal blooms are primarily caused by excess nutrients (like nitrogen and phosphorus) entering water bodies, often from agricultural runoff, wastewater, or urban pollution. Warm temperatures, sunlight, and stagnant water also contribute.
No, most algal blooms are harmless. However, harmful algal blooms (HABs) can produce toxins, harm marine life, and disrupt ecosystems.
Some algal blooms release toxins that can cause skin irritation, respiratory issues, or gastrointestinal problems if ingested or inhaled. Always avoid direct contact with discoloured or slimy water.
Avoid eating fish or shellfish from affected areas, as they may contain toxins that can cause food poisoning, including paralytic shellfish poisoning (PSP) or ciguatera poisoning.
Blooms can block sunlight, disrupt photosynthesis, and deplete oxygen in the water when the algae decay, creating “dead zones” where aquatic life cannot survive.
Yes, harmful algal blooms can kill fish, seabirds, marine mammals, and other wildlife by depleting oxygen or releasing toxins.
Yes, climate change exacerbates algal blooms by warming water temperatures and increasing heavy rainfall, which washes nutrients into waterways.
Reduce nutrient pollution by controlling agricultural runoff, improving wastewater treatment, and minimizing fertilizer use. Planting vegetation along waterways can also help filter runoff.
Algal blooms are monitored through satellite imagery, water sampling, and toxin testing by environmental agencies and research organizations.
Red tides are a type of harmful algal bloom caused by dinoflagellates, microscopic algae that can produce toxins. Despite the name, not all red tides are red.
Some blooms support ecosystems by providing food for marine organisms. However, excessive blooms often do more harm than good.