Final answer:
The primary limiting factors for pelagic algae growth in freshwater biomes are nitrogen and phosphorus, which are essential minerals. An excess of these nutrients can lead to algal blooms, negatively impacting aquatic ecosystems by reducing visibility, depleting oxygen, and causing dead zones. Factors such as sunlight, oxygen, and physical space also influence algal productivity, but nitrogen and phosphorus are often the critical elements.
Step-by-step explanation:
When considering the ecological requirements of pelagic algae, several factors influence their survival and growth. However, in freshwater biomes such as lakes and ponds, nitrogen and phosphorus are primarily the most important limiting minerals or nutrients. These nutrients are vital for phytoplankton growth, and their scarcity can limit algal productivity. When there is an overabundance, typically from sources like sewage and fertilized land runoff, it can lead to excessive algal growth or algal blooms, which can then cause other problems like reduced light penetration, oxygen depletion, and harm to aquatic life due to the creation of aphotic conditions and subsequent dead zones.
In marine habitats like Lake Erie and the Gulf of Mexico, phosphorus control and storm water runoff are significant challenges, affecting not only algae but the entire ecosystem. It is important to recognize that environmental conditions are dynamic, and a range of factors can become limiting under different circumstances. These include availability of sunlight, dissolved oxygen, other nutrients, and physical space, among others.