|Coastal bioluminescent marine snow: fine structure of bioluminescence distribution|
Herren, C.M.; Alldredge, A.L.; Case, J.F. (2004). Coastal bioluminescent marine snow: fine structure of bioluminescence distribution. Cont. Shelf Res. 24(3): 413-429
In: Continental Shelf Research. Pergamon Press: Oxford; New York. ISSN 0278-4343, more
|Authors|| || Top |
- Herren, C.M.
- Alldredge, A.L.
- Case, J.F.
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 <1%, due to the relatively low total volume occupied by marine snow in the water column, and 78%, when the majority of total BL was associated with marine snow. Even though BL marine snow was relatively rare at times, these aggregates produced BL many times brighter than individual dinoflagellates. Although BL on aggregates was correlated with depth, the brightest aggregate BL was not consistently found at the thermocline, a region where marine snow concentrations are frequently high. Aggregate mass was found to be a significant predictor of aggregate BL for detritus-based marine snow. The heterotrophic dinoflagellate, Protoperidinium leonis, made the largest contribution to both BL in aggregates and to the overall water column. Concentrations of the bioluminescent dinoflagellates Protoperidinium spp. and Noctiluca scintillans were significantly correlated with BL per aggregate as a function of depth, date, and type of marine snow. Because BL has been shown to deter herbivore grazing on individual BL dinoflagellates, BL-enriched marine snow may likewise, avoid consumption and play an important role in coastal carbon cycling and food web structure.