Glass sponge reefs concentrate large amounts of biological silicon (Si) over relatively small areas of the seafloor. We examined the role of glass sponges in biological silicon (Si) cycling by calculating a Si budget for 3 glass sponge reefs (Howe, Fraser, and Galiano) in the Strait of Georgia (SOG), British Columbia, Canada. The main reef-forming glass sponge Aphrocallistes vastus is heavily silicified, with 80% of its dry weight composed of biogenic silica (bSi). We used...

Corals and their photosymbionts experience inherent changes in light along depth gradients, leading them to have evolved several well-investigated photoacclimation strategies. As coral calcification is influenced by light (a process described as LEC-“light enhanced calcification”), studies have sought to determine the link between photosynthesis and calcification, but many puzzling aspects still persist. Here we examine the physiology of Euphyllia paradivisa, a coral species found at a wide range of depths but that is strictly mesophotic...