saltwater / brackish- water aq [objectives] chapter 14 discuss fundamentals of sw/bw aq identify and...
TRANSCRIPT
SALTWATER / BRACKISH-WATER AQ [objectives]
Chapter 14
• Discuss fundamentals of sw/bw AQ
• Identify and explain the kinds of facilities and sites
• ID and explain production considerations
• Discuss government regs
• Discuss culture of shrimp, salmon, mollusks, crustaceans and fish
FUNDAMENTALS
• 15 states have shorelines on the Atlantic Ocean, 5 on the GOM, and 5 on Pacific
• Saltwater and brackish-water aquaculture is called as mariculture
• Salinity is the amount of salt in water
• Salinity is measured either with a hydrometer, a refractometer, or a salinometer
SITES AND FACILITIES
• Shore – land next to the ocean
• Intertidal – area covered with water during high tide but not during low
• Sublittoral – shallow inshore areas
• Seabed – the ground always covered by the sea
• Open ocean – away from shore
SHRIMP AQUACULTURE
• Ideal for intensive cultivation
• Grow rapidly in intensive facilities
• Great product demand
• Main species cultured:
*brown shrimp
*white shrimp
*pink shrimp
PRODUCING SEED
• Gravid females must be captured or produced
• Capturing larval shrimp from the wild is difficult
• Baby shrimp are called nauplii and eat plankton
• Postlarval stage lasts about 50 days• Production ranges from 1000-5000
pounds per acre
SALMON AQUACULTURE
• Salmon are anadromous (live in saltwater; spawn in freshwater)
• Salmon farming – fish are raised from fry in tanks, ponds, or cages
• Salmon ranching – smolt are released in streams; they migrate to ocean; grow to adults and return to release stream to spawn
MOLLUSKS
• The oyster is the most important mollusk commonly cultured in the U.S.
• Other cultured bivalves include clams, mussels, and scallops
• Cultured gastropods include abalone and snails
OYSTER AQUACULTURE
• Oysters change from males to females as they get larger
• One female may release 50 to 100 million eggs per spawn
• Eggs hatch within a few hours after fertilization
• Turn into spat after 2 weeks and settle onto hard substrate (cultch)
OYSTER AQUACULTURE (cont’d.)
• Oysters are filter feeders (plankton)• Commonly grown on seabed, trays, cages,
rafts, and nets• Oysters require little management except
for diseases and predators• Diseases include oyster fungus, dermo,
and MSX• Predators include fish, seastars, and
gastropods
OYSTER PREDATORSOyster drill
Cownose ray
Sea star
OTHER CULTURED SPECIES
• Lobsters• Blue crabs• Mullet• Milkfish• Pompano• Redfish• Cobia• Flounder • Grouper• Dolphin