Cons of Aquaculture By: Megan Stransky Nancy Joyce Dano Ferons Janell Johnson.
Transcript of Cons of Aquaculture By: Megan Stransky Nancy Joyce Dano Ferons Janell Johnson.
Cons of Aquaculture
By:
Megan StranskyNancy JoyceDano Ferons
Janell Johnson
Aquaculture Net Pens and Cages
Cages are rigid structures where the nets do not move
Net Pens are free flowing and nets are able to move with the current
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
Mangrove Tree Grove Fish Farm in place of Mangroves
Effects on the Benthic Environment
Pristine Benthic CommunityArea underneath a fish farm. The sediment here has become anoxic due to the excess addition of biological waste.
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
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
Food Safety
• antibiotics
• fungicides
• dyes
• PCB
• Mercury
• Genetically modified
Human health risks
•
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.
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
Human health risksEnvironmental 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-Economics1) 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 Expenses6) Lack of Appropriate
areas to create farms combined with public opposition
800 Tons of fish died & rotted in fish farms in lake in Philippines
http://www.pbs.org/emptyoceans/fts/fishmeal/viewpoints.htmlhttp://truefoodnow.org/campaigns/fish/http://www.peta.org/issues/animals-used-for-food/aquafarming.aspxhttp://www.time.com/time/health/article/0,8599,1663604,00.htmlhttp://www.centerforfoodsafety.org/pubs/human%20health%20and%20aquaculture%20fact%20sheet.pdfhttp://www.montereybayaquarium.org/cr/cr_seafoodwatch/content/media/MBA_SeafoodWatch_WestCoastGuide.pdfhttp://apps.edf.org/page.cfm?tagID=15904Tomasso, 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.
Work Cited
Aquaculture is not the best alternative to overfishing
Rebuttal
Overfishing in the Wild
Aquaculture IS an Environmental Issue, still.
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)
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