Cons of Aquaculture
By:
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
Mangrove Tree Grove
Mission Bay, California
Fish Farm in place of Mangroves
Effects on the Benthic Environment
Area underneath a fish farm.
The sediment here has
become anoxic due to the
excess addition of biological
waste.
Pristine Benthic Community
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
fish
• 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
salmon
Farmed fish receive large doses
of antibiotics and are exposed a
variety of pesticides
Human health
risks
• antibiotics
• fungicides
•
dyes
• PCB
• 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
antibiotics
 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
Fungicides:
 Malachite green is a fungicide
used to keep fungus off the fish
eggs.
 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
risks
Dyes:
• artificial dye is added to the
meat to make it resemble the
red color of wild caught
salmon.
• The dyes are not well known
on whether there are health
risks
• 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
compounds.
• 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.
Mercury:
• 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
development.
 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
fish
• 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
time.
• Genetically modified fish can lead
to new allergens and reactions.
Socio-Economics
1) Threaten livelihood of
fishermen, lobstermen,
etc.
2) Expensive to start new
farm
3) Take a long time to see
profit
4) Banks skeptical about
loans
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
Philippines
Work Cited
http://www.pbs.org/emptyoceans/fts/fishmeal/viewpoints.html
http://truefoodnow.org/campaigns/fish/
http://www.peta.org/issues/animals-used-for-food/aquafarming.aspx
http://www.time.com/time/health/article/0,8599,1663604,00.html
http://www.centerforfoodsafety.org/pubs/human%20health%20and%20aquacul
ture%20fact%20sheet.pdf
http://www.montereybayaquarium.org/cr/cr_seafoodwatch/content/media/M
BA_SeafoodWatch_WestCoastGuide.pdf
http://apps.edf.org/page.cfm?tagID=15904
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.
Rebuttal
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
due to high mercury levels
 Other sources of Omega-3
fatty acids: walnuts, flaxseed,
and hemp
 Other protein sources should
be encourage
 Only fish the amount we
actually need
 Replant lost habitat (questions
arise with corals)
Aquaculture IS an
Environmental
Issue, still.
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 &
restaurants
• Fisheries respond to consumer
pressures – results in healthier
ocean
Inhumane treatment of
farmed fish
Farmed fish are confined to
cramped and filthy
enclosures being exposed
to parasitic infections,
diseases, and debilitating
injuries
Effects on Marine Birds and
Mammals