Data from: Biological modification of coastal pH depends on community composition and time

Biological processes play important roles in determining how global changes manifest at local scales. Primary producers can absorb increased CO₂ via daytime photosynthesis, modifying pH in aquatic ecosystems. Yet producers and consumers also increase CO₂ via respiration. It is unclear whether biological modification of pH differs across the year, and, if so, what biotic and abiotic drivers underlie temporal differences. We addressed these questions using intensive study of tide pool ecosystems in Alaska, USA, including quarterly surveys of 34 pools over one year and monthly surveys of 5 pools from spring to fall in a second year. Here, we report values for physical conditions and changes in pH and dissolved oxygen during day and night as part of our effort to link physical and biological processes - and particularly the importance of time of year in determining the relationship between community composition and pH conditions - in coastal ecosystems.