Which of the following factors is NOT a reason for the importance of the tidal cycle in coastal ecosystems?

The tidal cycle plays a vital role in coastal ecosystems for several reasons, one of which is not related to the regulation of atmospheric pressure. The correct choice highlights that atmospheric pressure affects weather patterns and sea level but does not directly influence the tidal cycle's significance in marine environments.

The tidal cycle greatly impacts nutrient availability in shallow waters, enabling the movement of water that brings in nutrients vital for marine life, especially during high tides. In addition, tides create diverse habitats where intertidal organisms can thrive, as some species are specially adapted to live in areas that are only submerged during high tide. Furthermore, the timing of reproductive cycles in marine species, particularly for many fish and invertebrates, often aligns with tidal patterns, influencing spawning and the development of larval stages. These biological cycles are closely tied to the regular ebb and flow of tides, reflecting the tidal cycle's ecological importance.

Thus, the regulation of atmospheric pressure is not a relevant factor when discussing the significance of the tidal cycle in coastal ecosystems.