BIOCHEMICAL-COMPOSITION OF ORGANIC AGGREGATES PRODUCED FROM MARINE MACROPHYTE-DERIVED DISSOLVED ORGANIC-MATTER

Organic aggregates produced by bubbling dissolved organic material released from five different coastal macrophytes were analyzed for biochemical composition (carbohydrate, protein, carbon, and nitrogen content). The composition of aggregates did not reflect that of either the macrophyte or the soluble material from which they were derived and did not vary with species. These results, coupled with the fact that aggregate composition was similar to that reported for bacteria, support the hypothesis that the process of aggregation was largely driven by microbial processes. The composition of morphous detritus (recognizable fragments of decomposing macrophytes) did vary with species and was related to that of the initial macrophyte. Morphous detritus had higher C: N ratios and was lower in protein than aggregates. The composition of aggregates was also different than that reported for marine snow.