Would raising your own fish for food be healthy? Practical?

Factual Questions
1

I was just wondering how they say fish is good for you, most of us don’t eat enough, but we shouldn’t eat too much because of mercury.

If I built my own pond & stocked it with tasty types of fish would those fish be good for me? How large a pond would I need? Would it be economical figuring I’d probably need extra filtration, etc?

How much fish do you think I could harvest, and what would be some good choices for fish? I’m thinking freshwater. Are freshwater fish as good for you as the deep, cold water ocean fish?

And what about saltwater? I’ve heard the price of shrimp has come down because so many people have created shrimp farms. How hard is that to do? I’m pretty sure raising saltwater fish would be too complicated & expensive.

2

A lot of questions here, I will try to weigh in on the ones that I can answer.

Farm raised fish have the potential to be healthier than ocean or estuarine commercially harvested fish because the farmer can control the water they live in.

I will warn you that many commercial fish feed pellets are made with fish protein harvested from pelagic schooling fish such as menhaden. It’s all well and good to raise fish in clean filtered water, but if the food you’re raising them on is high in PCBs or heavy metals, guess what? Your farm raised fish can have levels of these toxins as high or higher than those of ocean-caught fish.

A subsistence fish farm is a great idea as a hobby, but I highly doubt that you can start from scratch and grow your own fish economically, i.e., compete with commercially available frozen fish fillets.

Several people have tried combining aquaculture with hydroponic farming (a nice arrangement because fish waste serves the role of fertilizer) with limited success.

The best choice of a fish for farm raising depends on your climate and pond setup, as well as your personal taste for the finished product, but Tilapia are a good-tasting and fast-growing fish that are successfully farmed in warm climates all over the world. Unfortunately, they cannot survive water temperatures below about 50 degrees F and their rate of growth is much slower at low temps. This is why U.S. fish farmers in temperate climates typically grow catfish or specialty cold water species such as salmon or trout.

Costs to heat, cool, treat, or filter water year round are probably prohibitive in a small subsistence setup. Of course, if you have too many fish in a small pond with no natural source of food, you’ll also have to add supplemental food, which can be expensive as well.

On the other hand, if you have access to or can build a small impoundment 1/4 to 1/3 acre or more, it is definitely possible to grow and harvest your own freshwater fish with little to no work at all - just stock the pond with an appropriate mix of species and let nature take it’s course. I work on the east coast, so I do not know which native CA species would be appropriate for aquaculture, whether your climate is suited to Tilapia culture or whether you’d need any permits to carry out this plan.

Lastly, any fish, whether farm raised, recreationally caught or store bought may contain potentially harmful levels of PCBs or heavy metals. Your best bet is to avoid eating fatty species of fish and remove the skin and fat of any fish you eat before cooking. IMHO Women of reproductive age and children should probably limit their consumption of fish as a general precaution.

3

I am a fisheries biologist with experience in both fish culture and toxicology.

Stan’s info is good, but I would argue with him about his last paragraph, especially the last sentence. While some fish should not be eaten by children or women of reproductive age, there are plenty of sources of fish that are fine for anyone. You should know which sources are likely to be bad for you. I feed my family fish all the time.

As Stan says, you probably won’t come out ahead feeding fish, but you can put in a pond and the fish will be essentially free once the initial cost is cleared. Most of those fish should be very good for you unless you have some unusual situation. However, largemouth bass have a bit of a mercury accumulation problem (see below).

The most common contaminants that cause fish advisories are PCBs, Mercury, and in some cases chlordane. The EPA has set new and much lower, very conservative, limits on mercury consumption for women and children. Mercury is ubiquitous in the environment, due primarily to the burning of coal. Due to atmospheric deposition, some piscivores (fish-eating fish) can be high in mercury even if there appears to be no obvious source. Largemouth bass are notorious for concentrating mercury after they become old enough to go on an all-fish diet. You probably should not feed largemouth bass larger than 12" to your kids, regardless of where it is from. But again that is being very conservative. Bluegills and all but very large trout and catfish, for example, are usually very free of contaminants unless they come an especially contaminated environment or from a fish farm feeding them contaminated food. The Great Lakes all have a good supply of PCB, and Lake Michigan especially so, so if you are from Chicago I would leave those Lake Michigan fish alone.

4

For another professional opinion,

Yes the fish you’d raise would be good for you (as would most any kind of food you grow yourself - depending on what you add to it). How large a pond you need depends on how much work you want to put into the project, and how much fish you need. The work I’m talking about is both physical and research. If you want to throw in baby fish and let nature take it’s course, you need big water. You want to watch them grow every day, read up on chemistry, fish biology, and aquaculture, you need small water - even just a large tank or three.

Growing fish is sorta like growing your own, um, cash crop ;). You can throw some “babies” out in a back field on a farm, not really know what you’re doing, and maybe get a scraggly little harvest, OR you can do a ton of research and spend the big bucks for equipment, and get a good harvest in a basement. Climate, predators, and legality factor into both. The only difference is there’s (almost) no profit in fish, which is why substinence aquaculture - growing your own fish to eat - is usually only practiced large-scale in poorer countries/regions out of neccesity.

If you live in a city and want the fish to raise themselves, you won’t have enough space. If you want to raise enough for your family and have some extra, you’ll either need lots of water or lots of time to research how you’ll do it. Plus be ready for a few flops; something will go wrong sooner rather than later, so don’t use the rent money to get started. There is however a lot of literature and publications on growing fish in ponds - we’ve been doing it for thousands of years.

5

I grow tilapia in the back yard in a wading pool. They don’t get big, but there is little exspense involved and they are good.

6

Just to reiterate: You backyard pond is not going to be much different from a random stream in your area, as far as mercury goes.
Which doesn’t mean you shouldn’t eat any fish at all from it. Just limit how much if you’re pregnant, nursing, or likely to be or a small child.

You can find fish advisories on how much you should eat: http://www.epa.gov/waterscience/fish/
(as a note, some groups have said that the limits for Tuna in particular should be stricter-- but these aren’t going to be too far off).

7

There are some books available on backyard aquaculture at echonet.org.

8

A friend of mine lives on a lake that occupies several tens of acres. Every spring as soon as the ice melts he buys 250 6" long salmon trout and releases them. Although there are dozen or so properties abutting the lake, he is the only one who fishes assiduously and he gets enough fish out of there to feed him and his wife (as well as occasional visitors). When I visited in June, the fish were not biting and he explained that was because they were sated on the little flies that were everywhere. Later the fly population diminished and the fish were willing to try worms. I once caught a 16" fish there, which he estimated was likely a third year fish. It is cheap and essentially carefree. What would happen if he seriously stocked, I don’t know. I once caught a small (6") bass there, which he hadn’'t stocked.