EXPECTED VS ACTUAL DIVERSITY OF THE KELP Alaria marginata ZOOSPORES IN MARICULTURE SEEDING

Alaria marginata is a kelp species in the mid to low intertidal and is of commercial importance in the growing Alaskan mariculture industry. Understanding how sporophyte parent origin affects microscopic kelp survival, growth, and reproduction is important for informing regulators to understand how seeding string in a hatchery may affect wild gene flow. Do gametophytes from one sporophyte parent collected directly next to another outperform its neighbor? 

In this study we investigated differences in the characteristics of gametophytes of A. marginata from sporophytes collected from a microscale (1-10 m) and on larger scales (>10 km) within the Juneau, AK area. Fertile sporophytes were collected from two sites (AUK and SUN). Spore release was conducted and zoospore densities were adjusted to the same concentration. Nine petri dishes were seeded from each sporophyte parent and placed in a lit incubator at 12° C.

Dishes were monitored daily, with weekly media changes over a 20-day period. Dishes were monitored for gametophyte length and settlement density.

Our preliminary results suggest that site as well as sporophyte parent nested within site were significant factors in growth and density of gametophytes measured. Results from an upcoming second round of sporophyte parent effects on growth is underway.