Which variable is commonly controlled in experiments involving marine ecosystems?

In experiments involving marine ecosystems, controlling temperature is essential because it significantly influences various biological and chemical processes within the ecosystem. Marine organisms are often ectothermic (cold-blooded) and rely on environmental temperatures to regulate their metabolic rates. Variations in temperature can affect growth rates, reproduction, respiration, and the overall health of marine organisms. By controlling temperature in experiments, researchers can isolate its effects and better understand its impact on marine species and their interactions within the ecosystem. This allows for more accurate conclusions regarding the responses of marine organisms to environmental changes, which is crucial for understanding how ecosystems might react to global climate change and other anthropogenic influences.

In contrast, while aspects like wind speed, precipitation levels, and duration of sunlight can affect marine ecosystems, they are often not as directly controlled in experimental settings compared to temperature, which is typically seen as a key factor in maintaining the stability of the laboratory conditions required for these studies.