Effect of direct “seeding” binders and embryonic sporophyte sizes on the development of the sugar kelp, Saccharina latissima

The overall objective of this study is to present an assessment of embryonic sporophyte development directly “seeded” on growing substrates using the proprietary binder AtSea and three formulations of calcium alginate. We conducted two independent experiments under controlled conditions in a laboratory setup. First, we compared the effect of salinity (0 ppt, 29 ppt, and 35 ppt) on the performance of the calcium alginate formulations. Second, we assessed the effect of direct seeding with binders on the development of sporophytes of four different size classes (i.e., 83.7, 183.1, 345.2, and 522.0 μm in length). Our results show that salinity affects the performance of calcium alginate with 0 ppt media allowing the formation of a thicker hydrogel than that formulated with 29 and 35 ppt. Results also show that AtSea retained more sporophytes than any formulations of calcium alginate. Although effective when cultures were maintained in complete stillness (i.e., no water motion), we detected 70–80% detachment when aeration was added. We also observed what appeared to be delayed sporophyte development compared with sporophytes growing as free floaters.