FROM FOOD TO FUEL: KELP MARICULTURE RESEARCH IN ALASKA

Commercial mariculture of seaweeds in Alaska is in its infancy.  Currently there are only a handful of farmers producing commercial amounts of seaweeds and  almost all are kelp species.  In the late 1980s work on the giant kelp, Macrocystis , was undertaken to augment the herring spawn on kelp industry.   This work was carried out in Juneau and Sitka with help from Japanese mariculture experts.  Outplants grew well in the winter, but began to degrade over the summer .  Fertilization appeared to reverse this degradation.    

Recently we have been researching optimal ways to grow kelps such as Saccharina latissima  (sugar kelp), Alaria marginata (ribbon kelp) and Nereocystis luetkeana (bull kelp) for commercial potential.   Saccharina latissima growing near Juneau, Alaska behaves as an annual with growth of the juvenile sporophyte beginning in late winter. Beds of S. latissima near Juneau have been found mostly in low energy, shallow subtidal areas of mixed mud, shell hash, sand and small rocks. O utplants on seeded string wrapped around longlines show optimal growth when set out in October/November and harvested in April, corresponding to the start of the spring phytoplankton bloom.  

We are currently working on a DOE/ARPA-E MARI NER project to determine the best way to grow Saccharina latissima in very large, offshore arrays for the eventual purpose of biofuel production .  There are three major aspects of the research: determining how to seed longlines with S. latissima, designing an economical outplanting structure and developing methods to efficiently harvest the product.   Aside from the standard method of releasing spores from fertile fronds on cremona-like string, we have attempted to accomplish "direct seeding" on string and on longlines.