Fish Farming

In the beginning of the year there, was an article I wrote about published in Biology News about the rapidly growing industry of fish farming. Aquaculture is now responsible for 50% of all the consumed fish in the world. In a study completed by Stanford University, growth trends and environmental impact were looked into. While this move into aquaculture seems promising and sustainable, there are still a few kinks to work out.

While the farms reduce strain of wild fisheries for certain species, many species are still farmed in pretty unsustainable ways. Many fish farms use large amounts of fish oil and fish meal to enhance the flavor of the fish they are eating. All of this fish oil and fish meal comes from wild caught anchovies and sardines. This is putting a strain on those fisheries. Small schooling fish like these are an important part of the ecosystems in which they thrive so reducing their numbers could cause a significant strain on other forms of wildlife. To produce one pound of salmon, it is estimated that approximately five pounds of wild caught fish are used. Salmon is still a popular choice for consumers around the world, so that is literally tons of wild fish caught. Makes the salmon you eat seem a bit more valuable, doesn't it?

Not all farm raised fish have this sort of impact, though. There are many species of fish that are very well farmed and incredibly sustainable. Many of these are vegetarian fish like carp and tilapia. Between 1997 and 2007, there was a decrease in the amount of fishmeal used to raise these fish by about half. However, there is such a high demand for these fish that many of the farms still use some fishmeal and 12 million metric tons of fishmeal were used for vegetarian fish in 2007! That is a lot of fishmeal! NOAA is working on a plan to regulate and better manage these farms to become more sustainable and really become less of a strain on the marine ecosystem and the environment. Remember, to really know where your fish is from, just ask. If you want more info, download a Seafood Watch guide for your area. You can even check during dinner from your cell phone by going to mobile.seafoodwatch.org. I carry a sushi guide and national guide with me everywhere I go!

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The New Environmentally-Friendly (?!?!) Plastic

This photo is from the USDA and is therefore public domain.

There is a new plastic (well not that new) on the market and it's gaining popularity. This plastic is made from corn and touts its biodegradability. The material is polylactic acid and it has been known about for over a century. It is only now gaining popularity due to another wave (similar to the early 90's) of eco-consciousness.

While this new plastic does have a few things going for it (a renewable resource and, in principle, compostable) there are a few things a lot of people haven't really studied or answered.

The pros:

• Regular plastics use an average of 200,000 barrels of oil a day to produce our demand
• Corn is a renewable resource and the plants help offset the amount of carbon produced in the plastic's manufacture
• Plastics take up 25% of dumps by volume
  
• PLA (polylactic acid) is compostable within 3 months at a controlled composting facility
• It costs less than $1.00 to make a pound of PLA (see here)
• Generates less air pollution to make
  

The cons:

• PLA takes much longer to compost in a bin or even in a landfill
• There are only 113 controlled compost facilities nationwide... only a quarter of these facilities accept residential scraps
• PLA must be kept separate from other plastics to keep it from tainting their recycling process
• Estimates for this breaking down in landfills are anywhere between 100 and 1,000 years (see here)
• Cannot survive temperatures of 114 degrees Fahrenheit
  

Possible cons (of the controversial type)

• Made of highly genetically modified food
• Is using a food product to make non-food stuffs while people are going hungry
• Still supports single use and disposables still adding to landfills

So it seems that the pros and cons are evenly matched and there are some controversial issues that are brought up... but I guess at least it is a start in the right direction. At least there is a push for biodegradable containers.

The biggest manufacturer of PLA in North America is NatureWorks. Go check out the website and tell me what you think!

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Seafood Watch

The Monterey Bay Aquarium has a unique program that I learned about by picking up a card at my university entitled "Seafood Watch." What I picked up was actually a pocket guide that allowed me to see which types of seafood were harvested in ways that can sustain each of their respective ecosystems. The website goes into more detail.

While protecting our oceans supply of fish may seem like an obvious thing to do for some, for others it is not so obvious. I am gonna try to give a short reasoning as to why fish are vital.

First off, there are about 27,000 species of fish, making up more than 1/2 of all documented vertebrates. Also, they live in water, which covers most of the earth. 70% of the earth is salt water and salt water makes up 97% of liquid water. Fresh water covers 1% of the earth but only .0093% of it is in liquid form. So fishes (yes that is a word) dominate a much larger region than terrestrial invertebrates. This makes them prime for various scientific studies as there are fish that can handle tons of pressure variations and various temperatures from boiling lakes to freezing icecaps. Yet because they all live in water, there are constraints to how they form so most fish are recognizable as fish.

If you are into science, more than likely some research on fish has been done in your area.
Areas of interests that fish can help with:
-Ecology
-fisheries
-habitat segregation
-marine natural products: venoms toxins and mucus
-Enzyme kinetics
-physiological adaptations
-food science
-how to freeze cells
-morphology
-hydrodynamics
-survival (lost at sea?)
-bioluminescence
-reproductive strategies

.... the list goes on and on so I will not bore you.

However(!), due to overfishing and unsound farming practices, we are either losing good land to bad farming or depleting fish supplies everywhere. Many people rely on fish as an important part of their diets. In some places it is THE MAIN source of vital protein. Overfishing can seriously impede the production of a species of fish the following year. You need fish to make more fish! There is a fine line between taking just enough to sustain it properly and overfishing. Unfortunately, greed usually wins.

Also, bad fish farming practices can lead to overfishing too, since most fish eat fish meal in these farms. Also, valuable, usually arable land is lost to create these farms. Net pen farming can be bad as well due to the amount of feces in an area polluting nearby coastlines. Again, there are safe farming practices that can be taken. There is more information on all of this at the above website. While you are there download a seafood guide for you wallet or order some to pass out to people you know who eat fish but want things to be a bit better for the oceans.

A view from Lerkenlund into Magens Bay

All photos Copyright me under Creative Commons. you can use it, but give me credit somewhere!

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