The Seaweed Aquaculture Project

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A new type of aquaculture is coming to the Peconic Bays, joining the growing shellfish aquaculture industry. Globally, seaweed aquaculture is a $6 billion dollar industry,  dominated by Asian and Indo-Pacific countries for the last century, but in recent years, western countries are joining the movement. Seaweeds are not only a nutritious food (think sushi, salads) but are also used as additives in foods and products we use everyday.  Carrageenan, agar and alginate produced from seaweeds are used as binding, thickening and gelling agents in ice cream, baby food and formula, yogurt, salad dressings, basically most creamy foods we eat, as well as non-edible products we use everyday such as toothpaste and shaving cream.  Other important industries that rely on seaweed additives are the pharmaceutical industry (petri dish medium, capsules, tablets), the cosmetic industry (lipstick, lotion) the textile industry, and most recently for the production of biofuel and fertilizer.

This growing demand has tremendous economic potential that officials in our region are ready to tap into, but the bonus is that it can also benefit the environment. This emerging “green industry” can improve water quality by extracting nitrogen and carbon from the water, all while producing a high-demand, renewable product. The first step is to test the feasibility of growing seaweeds in local waters in a sustainable and profitable way without interfering with other marine industries. This is where we come in.

The “Peconic Estuary Seaweed Aquaculture Feasibility Study” (aka The Seaweed Project) aims to evaluate the potential of this new industry in Suffolk County waters within the Peconic Estuary.  Under the guidance of Dr. Charles Yarish at the University of Connecticut, the region’s leading expert on seaweed culture, Cornell Cooperative Extension (CCE) scientists will grow sugar kelp (Saccharina latissima) at several sites throughout the Peconic Estuary. Sugar kelp is a brown macroalgae that is a cold water species; it thrives in our region during the cooler months of the year (November – May) where it can grow to several meters long typically at depths of 3-5 meters, and like most macroalgae it requires a hard substrate to attach to. Kelp is typically farmed using a series of long lines running parallel to each other and set to a specific depth below the surface, but in order to identify ideal depths for grow out in our region, single, vertical “dropper lines” were designed. CCE is already familiar with  long line aquaculture systems; we designed and currently maintain the “Bay Scallop Spawner Sanctuary” in Orient Harbor that has helped rebound the bay scallop industry in the Peconics.

Just this week, Dr. Yarish’s lab provided CCE the “seed strings”,  which is basically “baby kelp” that has set on monofilament line. The lab at UCONN produced these seed strings extracting gametes from reproductive kelp collected by CCE divers this fall. The seed strings were spooled on PVC pipe which were encased in a tube filled with seawater until deployment. Deployment day was on December 13th, 2016; upon arriving at each site,  the strings were carefully wrapped around thick pot line that was previously attached to a typical mooring set-up (mushroom anchor, chain, line and mooring buoy). As the kelp grows, it’s holdfasts will wrap around the thicker line. The sites will be monitored throughout the winter as necessary, and come spring, each line will be harvested, kelp biomass at each interval will be measured and tissues will be sampled for C, P and N content. This will help generate an estimate of nutrient bioextraction that occurred throughout the winter at each site. The results as well as techniques and methodology for the Seaweed Project will be refined, adapted and implemented by CCE. Check back for updates on this exciting project!

This project is fully or partially funded by the County of Suffolk