Cawley Grace F, Décima Moira, Mast Andrea, Prairie Jennifer C
DEPARTMENT OF ENVIRONMENTAL AND OCEAN SCIENCES, UNIVERSITY OF SAN DIEGO, 5998 ALCALA PARK, SAN DIEGO, CA 92110-80091, USA.
SCRIPPS INSTITUTION OF OCEANOGRAPHY, UNIVERSITY OF CALIFORNIA, SAN DIEGO, 9500 GILMAN DR., LA JOLLA, CA 92093-0227, USA.
J Plankton Res. 2021 Nov 12;43(6):957-973. doi: 10.1093/plankt/fbab074. eCollection 2021 Nov-Dec.
Marine snow, formed through the aggregation of phytoplankton and other organic matter, can be consumed by various types of zooplankton, affecting both planktonic trophic dynamics and the export of carbon to depth. This study focuses on how two factors-phytoplankton growth phase and species-affect copepod feeding on marine snow. To do this, we conducted a series of grazing experiments using gut pigment and stable isotope methods to quantify the ingestion of the copepod, , on both marine snow aggregates and individual phytoplankton. Results demonstrate that marine snow can represent a substantial food source for copepods, comparable to rates on individual phytoplankton. Moreover, we found that both the overall ingestion and the relative ingestion of aggregates vs. individual phytoplankton depended on phytoplankton growth phase for experiments conducted with the diatom . Although copepods consumed aggregates composed of at similar rates as those composed of , no effect of growth phase was observed for . These findings suggest that marine snow can be an important source of nutrition for copepods, but that its role in planktonic food webs may differ depending on the phytoplankton community composition and the stage of phytoplankton blooms.
海雪是由浮游植物和其他有机物质聚集形成的，各种浮游动物都可以食用海雪，这既影响浮游生物的营养动态，也影响碳向深海的输出。本研究聚焦于浮游植物生长阶段和种类这两个因素如何影响桡足类动物对海雪的摄食。为此，我们进行了一系列摄食实验，运用肠道色素和稳定同位素方法来量化桡足类动物 对海雪聚集体和单个浮游植物的摄食量。结果表明，海雪可以成为桡足类动物的重要食物来源，其摄食率与单个浮游植物相当。此外，我们发现，对于用硅藻 进行的实验，聚集体与单个浮游植物的总体摄食量和相对摄食量均取决于浮游植物的生长阶段。尽管桡足类动物对由 组成的聚集体和由 组成的聚集体的摄食率相似，但对于 而言，未观察到生长阶段的影响。这些发现表明，海雪可能是桡足类动物重要的营养来源，但其在浮游食物网中的作用可能因浮游植物群落组成和浮游植物水华阶段的不同而有所差异。
