©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 1 Lesson #9 Commercial fishing: Aquaculture Vernon Asper USM

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 2

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 3 Aquaculture Aquaculture is growing organisms in the water under controlled conditions Also called “fish farming” Mariculture is aquaculture in salt water Aquaculture requires raising the organisms under favorable conditions until they are large enough to be harvested for food.

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 4 Aquaculture For aquaculture to be economically viable the species must be: –Marketable. –Inexpensive to grow. –Trophically efficient. –At marketable size within 1 to 2 years. –Disease resistant.

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 5 Aquaculture Challenges –Disease –Pollution regulations –Storm damage –Introduction of non-indigenous species –Vandalism –Fouling –Corrosion These are all inherent in any farming activity More acute in the ocean

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 6 Aquaculture Theoretically, anything living in the ocean can be “farmed” Either on land or in the ocean This can be: –Algae –Fish –Oysters –Shrimp –Others?

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 7 Aquaculture Alga-culture Algae are normally a contaminant in an aquarium (Finding Nemo!) But some organizations grow them for profit –Food (some cultures eat seaweed) –Algae are fed to other aquaculture species –Biofuels Also effective in pollution and sewage remediation

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 8 Finfish Traditionally, fish were grown in enclosures near shore These have become larger Many have moved onshore Catfish are grown in ponds like this

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 9 Finfish Fish can be grown in large “net pens” Generally near shore Fish are fed regularly Harvested when ready

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 10 Aquaculture The Norwegians have this down to a science Vast netpens produce salmon year- round Automated processing guts and filets Filets are sorted, packaged or post- processed

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 11 Aquaculture Other species are farmed too: –Tilapia –Trout –Redfish –Striped bass –Trout Some species are attractive but difficult: –Tuna –Dolphin fish –Red snapper

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 12 Aquaculture Concerns: 1) pollution –Fish pens release lots of organic material into the ocean Concentrated, not disperse like natural system Overwhelms local decomposers May even result in anoxia –Drugs: Antibiotics Vitamins hormones

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 13 Aquaculture Concerns: 2) non-indigenous species or genetic impact of escapees –Lots of fish escape –If they aren’t indigenous (local), they can displace the indigenous species –Even if they’re the same species, their genetic makeup can damage local populations

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 14 Aquaculture Concerns: 3) Disease –Putting so many organisms in a small space results in rapid spread of disease –This includes infections as well as parasites

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 15 Aquaculture Oysters Require brackish water –Too fresh and they die –Too salty and parasites get them Grow remarkably quickly –Pull carbonate from the water –Eat suspended particles

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 16 Aquaculture Oysters require hard substrate –If you have a muddy bottom, you have to add “culch” material “spat” (juveniles) are released in breeding –Settle on the hard substances –Grow to market size in one season

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 17 Aquaculture Oysters are typically grown in racks Hard substrate on suspended strings Good circulation Avoid bottom-dwelling predators Easy to manipulate

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 18 Aquaculture Oysters are farmed all over the world –US –New Zealand –Southeast Asia –England Sometimes for pearls Generally for meat

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 19 Aquaculture In Mississippi, some oyster aquaculture has been tried: 1) seabed leases: for a nominal fee, “farmers” can lease an area, plant “cultch” and have the exclusive right to harvest 2) oyster relaying: take oysters from contaminated waters to racks offshore where they can depurate 3) rack-mounted aquaculture from a barge near Cat Island

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 20

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 21

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 22

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 23 Aquaculture: Shrimp No viable, commercial shrimp aquaculture program exists (yet) in the US Difficult to raise due to: –Disease –Environmental regs –Labor intensive White Shrimp Brown Shrimp Pink Shrimp This is a ghost shrimp, like we catch on Horn Island. Not edible? This is the mantis shrimp we caught on our field trip

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 24 Aquaculture But overseas, it is huge. –Environmental rules don’t apply –Labor laws don’t exist

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 25 In the US, roughly 90% of the shrimp consumed are imported, pond-raised shrimp Biloxi processing plants process mostly imported shrimp They thaw, process and refreeze Good economics

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 26 Aquaculture: other Fish stocking programs –Striped Bass is all “put and take” in Mississippi –Fish raised at the GCRL (USM) and stocked in local waters Stock enhancement –Introduce juvenile fish to build populations –Red snapper is currently under culture at GCRL (USM) –Seatrout are next

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 27 Aquaculture Aquaculture is growing worldwide As wild stocks dwindle and recreational fishing pressure increases, this trend will continue

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 28 Aquaculture Currently, about one out of every four fish consumed spent part of its life in aquaculture For some organisms the percentage supplied by aquaculture is even larger.

©1996, West Publishing Company (Modified by Asper, 1997; revised by Lohrenz, 2000) Slide 29 Summary Aquaculture (fish farming) is a growing global industry Pollution, disease, storm damage, genetic implications and other challenges make aquaculture difficult Fishing pressure, contention between recreational and commercial fishermen, and environmental changes make aquaculture more viable.