Coastal bioluminescent marine snow: fine structure of bioluminescence distribution

To determine if bioluminescent organisms were differentially concentrated within marine snow relative to ambient water, individual aggregates were photographed in situ and collected by hand using SCUBA, and mechanically stimulable bioluminescence (BL) was measured with an integrating sphere photomultiplier system. These are among the first measurements of BL on marine snow, and are the first quantitative estimates of BL marine snow over the water column in a coastal environment (East Sound, WA). BL in marine snow and ambient water varied significantly over short time scales (1–11 days) and vertical spatial scales (1–5 m resolution). BL was enriched up to 180 times within aggregates as compared to an equal volume of surrounding seawater. However, the contribution of BL associated with marine snow to total BL in the water column varied between