SALTWATER / BRACKISH-WATER AQ [objectives] Chapter 14

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

HYDROMETER

REFRACTOMETER

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

SHORE AQUACULTURE

INTERTIDAL AQUACULTURE

SUBLITTORAL

SEABED AQUACULTURE

OPEN OCEAN

SHRIMP AQUACULTURE

• Ideal for intensive cultivation

• Grow rapidly in intensive facilities

• Great product demand

• Main species cultured:

*brown shrimp

*white shrimp

*pink shrimp

SHRIMP

brown white

pink tiger

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

sockeye coho

chum pink

FISH LADDERS

SALMON EGGS, ALEVINS, AND SMOLT

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

BIVALVE MOLLUSKSoyster clams

mussels

scallops

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

HARVESTING

• Oysters cultured on seafloor are typically harvested by tonging, dredging, or diving

OYSTER GARDENING

GASTROPODS

• Two gastropods are primarily cultured; abalone and snails (escargot)

OTHER CULTURED SPECIES

• Lobsters• Blue crabs• Mullet• Milkfish• Pompano• Redfish• Cobia• Flounder • Grouper• Dolphin

LOBSTERS

Maine lobster Florida spiney lobster

BLUE CRABS

MULLET

MILKFISH

POMPANO

REDFISH

COBIA (LING)

FLOUNDER

GROUPER

DOLPHIN (MAHI MAHI)