Degradation Experiment Algae Nutrition and Weight. A Canadian Healthy Oceans Network Ecosystem Function Project, EF-11

This experiment monitored the nutritional characteristics of two algal species, one invasive (Codium fragile) and one native (Saccharina latissima) during degradation on sediments offshore of a shallow kelp bed. Twenty four mesh bags, each containing ~500g of either C. fragile or S. latissima were contained in cages and placed on sediments at 19 m water depth (2 species x 12 replicates = 24 total bags). Three bags of each species were collected at roughly monthly intervals. Change in mass from time 0 was then measured and used to calculate degradation rate. Stable isotope ratios of d13C and d15N, %C, %N, C/N and concentration of Dimethylsulfoniopropionate were measured on each sample. At each sampling time (T0, T1, T2, T3 = 0, 28, 56, 85, and 112 days) the same measures were taken on three control samples of C. fragile and S. latissima collected from the shallow algal bed (~5 m depth) inshore of the experiment location. Sample ID is a unique sample number, Treatment ID is the treatment number, Group indicates weather the sample was from the degradation or control group, and initial weight and final weight indicate the weight of the sample at T0 and at the time it was collected. Measures of changes in mass were not applicable in the control treatments, as these represent live algae in the shallow