Setting Up an Adjustable Long-Line System (ALS) Oyster Farm
When setting up an adjustable long-line system (ALS), you must carefully plan how you will space the poles and lines to give your oysters the best water flow and give yourself room to maneuver a boat to tend to the baskets. Lines should be arranged perpendicular to the prevailing winds to maximize basket movement and oyster tumbling. Watch this video from SEAPA for more information about setting up your ALS farm.
Checking Oyster Seed Size
As with floating systems, it is essential that you pick the right basket for the size of your oysters or seed. If the pores (holes) in the basket mesh are too big, seed may spill out. If they’re too small, they’re more likely to clog. ALS baskets come in different mesh (pore) sizes – 3 mm, 6 mm, and 12 mm – and as your oysters grow, you can move them into baskets with larger pores. To check that you are using the correct basket, place a sample of seed or oysters in the basket and tumble it to make sure that none fall out. Once you have found the right size basket, you can proceed with stocking your farm.
ALS Basket Stocking Density
Scientists and industry experts have extensively studied stocking densities to maximize oyster growth and minimize biofouling. As a rule, you should stock your baskets no more than one third full. This will allow your oysters to get enough nutrients, water, and oxygen while still having room to tumble slightly to develop the shell shape and cup that is preferred in cultured oysters. Leaving room for tumbling will also help clean biofouling (such as algae and barnacles) off the oysters, improving their appearance for market. As your oysters grow, you will have to split them into multiple baskets to keep them at one-third density.
Splitting ALS Baskets
Oysters grow fast – they can go from filling one third of a basket to as much as three quarters full in a matter of weeks. As oysters grow and take up more room in their basket, they will need to be removed and split to maintain proper density. If you don’t split the baskets, they can get too heavy, putting stress on your gear and lines. Also, an overcrowded basket doesn’t leave enough room for tumbling, which may cause your oysters to grow into undesirable shapes such as long and skinny. They must have room to tumble to develop the full, deep cup that buyers prefer.
Just like people, younger oysters grow faster than older ones. Thus, it is important to have plenty of extra baskets available early on to frequently split seed as they develop into larger oysters. Once the oysters reach 2 inches, their growth will slow, so you won’t have to split baskets as often.
Always be sure to keep extra oyster baskets on hand. You never know when one might be damaged or need to be split.
