Cons of Aquaculture

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					Cons of Aquaculture

                Megan Stransky
                 Nancy Joyce
                 Dano Ferons
                Janell Johnson
                        Aquaculture Net Pens and Cages

                                                         Net Pens are free flowing and nets are
                                                             able to move with the current
Cages are rigid structures where the nets do not move

                                                                 Fish runs are used so
                                                                  that fish are able to
                                                                   swim in circles to
                                                                   exercise muscles
                       Destruction of Natural Habitat

 Pristine Salt Marsh                                    Mission Bay, California

                                                        Fish Farm in place of Mangroves
Mangrove Tree Grove
                                Effects on the Benthic Environment

Area underneath a fish farm.                                            Pristine Benthic Community
The sediment here has
become anoxic due to the
excess addition of biological

                                                                     The chart on the left shows how waste
                                                                     from the fish farm enters the
                                                                     environment and benthic sediment.
                                                Aquaculture Defenses for Net
                                                      Pens and cages

                                                   Netting is used to prevent predatory
                                                   birds from eating fish from the top of
                                                                the Net Pen

 Underwater Anti-Predator nets are used to
deter mammalian predators and diving birds.
 Diver is at the bottom of one of these nets.
  Fish are held in a separate net pen above
Marine Birds and Mammals who have become
           victims of Aquaculture
Fish Meal and Fish Oil

• Fish Meal and Oil are
  manufactured from sardines,
  anchovies, sand eels, and other fin
• To create 2.2 lbs. of fish meal, it
  takes 10 lbs of smaller pelagic or
  open water fish
• Reverse protein factories
• The ocean can not sustain the
  amounts of fish used by the
  aquaculture industry
Food Safety
Farmed fish contain higher levels
of PCB’s and dioxins than wild
caught fish
Farmed salmon has 10 times the
level of contaminants as wild
Farmed fish receive large doses
of antibiotics and are exposed a
variety of pesticides
Human health
• antibiotics
• fungicides
•   dyes
• Mercury
• Genetically modified

Human Health risks
• Antibiotics:
• Used in aquaculture pens to control
  disease .
 antibiotics enter the water column from
  nets and are ingested by wild marine life
 In one study by the FDA, drug residues
  exceeded safe levels in wild fish around
  aquaculture nets.
 By using antibiotics, this raises the risk of
  bacteria becoming resistance to

           The FDA states, “Unregulated/unapproved drugs
            administered to aquacultured fish pose a potential human
            health hazard. These substances may be carcinogenic,
            allergenic, and/or may cause antibiotic resistance in man.”
Human Health risks

 Malachite green is a fungicide
  used to keep fungus off the fish
 Malachite green is a toxin,
  mutagenic, and carcinogenic
  Malachite green is prohibited in
  the USA
 the FDA does not inspect for
  malachite green in imported fish.
 Imported fish could be
  contaminated and you would not
  know until its to late.
Human health
• artificial dye is added to the
  meat to make it resemble the
  red color of wild caught
• The dyes are not well known
  on whether there are health
• a study has compared
  artificial dyes to hyperactivity
  in children and possible
  retinal damage.
Human health risks
Environmental toxins:
• PCBs, or polychlorinated biphenyls,
   are highly toxic industrial
• Farmed salmon contain such high
   levels of PCB that its not
   recommended to eat more than one
   meal a month based on the EPA’s
   recommended exposure level.
• Predatory fish such as tuna and
   salmon can have mercury
   concentrations in their bodies that
   exceed safely levels.
• It’s a huge hazard to pregnant
   women and small children.
• Mercury poisoning can cause blood
   pressure regulation, memory loss,
   tremors, vision loss and numbness
   of the fingers and toes.
          Case studies on PCB’s

 Based on the EPA
 Children of mothers who ate
  fish with large amounts of
  PCBs from the Great Lakes
  had smaller head size,
  reduced visual recognition
  and delayed muscle
 Older adults (49 to 86 years
  old) who ate fish containing
  PCBs and other
  contaminants had lower
  scores on several measures
  of memory and learning.
Genetically modified
• Genetically modified fish are being
  produced to enhance efficiency of
  fish production.
• Genetically modified fish grow
  quickly, resist disease, and can live
  in a large range of temperatures.
• These frankenfish increase
  economic value of producing
  more fish in a shorter amount of
• Genetically modified fish can lead
  to new allergens and reactions.
1) Threaten livelihood of
   fishermen, lobstermen,
2) Expensive to start new
3) Take a long time to see
4) Banks skeptical about
5) Resource Expenses
6) Lack of Appropriate areas
   to create farms combined
   with public opposition
800 Tons of fish died & rotted in fish farms in lake in
                         Work Cited,8599,1663604,00.html
Tomasso, J. R (editor). 2002. Aquaculture and the Environment in the United
States. U.S. Aquaculture Society, A chapter of the World Aquaculture Society,
Baton Rouge, Louisiana, USA.

Aquaculture is not the best
alternative to overfishing
Overfishing in
the Wild
 We are only supposed to have
  2-3 servings of fish per week       Aquaculture IS an
  due to high mercury levels
   Other sources of Omega-3          Environmental
    fatty acids: walnuts, flaxseed,
    and hemp                          Issue, still.
   Other protein sources should
    be encourage
 Only fish the amount we
  actually need
 Replant lost habitat (questions
  arise with corals)
Innovative ways to avoid bycatch

                 • Turtle Escape Doors
                 • Pingers place on nets emit
                    beeping noise keeping
                    porpoises, dolphins, other
                    sea mammals away
              • Protecting endangered fish –
                use seafood guide when
                purchasing fish in store &
              • Fisheries respond to consumer
                pressures – results in healthier
Inhumane treatment of
farmed fish

Farmed fish are confined to
cramped and filthy
enclosures being exposed
to parasitic infections,
diseases, and debilitating
Effects on Marine Birds and

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