 Climate change has caused significant changes in the physical and chemical properties of the ocean, which have had consequences for marine ecosystems. These changes include decreased calcification rates, population decline, advance in spring phenology, decrease in calcification, increase in warm water species abundance, and variation in evidence depending on region and taxonomy. Evidence of these changes is most common in the North Atlantic Ocean, but there is limited evidence of changes in other ocean regions and taxonomies. This article was authored by Elvira S. Polixanska, Elvira S. Polixanska, Michael T. Burroughs, and others.