How can an algal bloom disrupt an ecosystem?

An algal bloom can significantly disrupt an ecosystem primarily by overwhelming the environment with excess algae and producers. During an algal bloom, there is a rapid increase in the population of algae, often due to nutrient runoff from land, such as fertilizers containing nitrogen and phosphorus. This excessive growth can lead to several detrimental effects on the aquatic ecosystem.

As algae proliferate, they can block sunlight from reaching other aquatic plants and photosynthetic organisms, thereby inhibiting their growth. This reduction in light availability can alter the habitat and negatively affect the entire food web, which relies on these plants as primary producers. Furthermore, when the algae die off, their decomposition consumes a large amount of oxygen in the water, leading to hypoxic or anoxic conditions — a significant concern for fish and other aerobic organisms.

The sheer biomass of the algae can also create physical barriers, affecting water flow and the movement of other organisms. Additionally, some algal blooms can produce toxins that are harmful to wildlife and humans, further complicating the health and stability of the ecosystem. Thus, the overwhelming presence of algae disrupts not only the balance of producers and consumers but also the overall quality and functionality of the ecosystem.