bioturbáció

Bioturbation is the churning and mixing of sediment by living organisms. This process is a fundamental aspect of benthic ecology and plays a crucial role in shaping the physical and chemical characteristics of aquatic and terrestrial environments. Organisms that contribute to bioturbation are known as bioturbators and include a wide range of fauna, such as burrowing invertebrates like worms, clams, and crustaceans, as well as larger animals like fish and mammals.

The impact of bioturbation is multifaceted. Physically, it can disrupt sedimentary layering, homogenize sediment properties, and create or destroy pore spaces. This mixing affects sediment stability, water flow through sediments, and the distribution of organic matter. Chemically, bioturbation facilitates the exchange of dissolved substances between the sediment and overlying water. It can oxygenate deeper sediment layers, influence nutrient cycling by redistributing reactive elements, and alter the chemical gradients that control biogeochemical processes.

The intensity and type of bioturbation vary greatly depending on the abundance and behavior of the local fauna, as well as the sediment type. In areas with high bioturbator activity, sediments can be extensively mixed, leading to a more uniform structure and chemistry. Conversely, in less disturbed environments, distinct sedimentary layers may be preserved. Bioturbation is thus a key indicator of ecological activity and influences the habitat suitability for other organisms, the fate of contaminants, and the geological record of past environments.