One of the benefits of an aquaponics system, of course, is raising edible fish. Ideally, the fish should grow quickly and be efficient at converting the food they eat into body mass. It also helps if the fish are hardy and can adapt to changes in their environment. Having a mild taste that many people find appealing doesn't hurt either. Tilapia meet this description, so it is no surprise that they are a favored species of aquaponists. The only downside to raising tilapia that I can see is they are tropical and cannot survive in water temperatures below about 50 degrees Fahrenheit. This can and does present a problem for anyone attempting to raise them in a temperate climate.
Where I live in the central United States, the first frost usually comes around October 15th. But as you might guess, nighttime temperatures begin dipping into the 40's by mid-September. This change in seasons pretty much dictates the ideal harvest time for any tilapia that are being raised outdoors. Even though we've already had several overnight lows in the 30's. the lowest the water temperature ever got in the tilapia pool was 54. That's primarily because a large volume of water acts as a heat reservoir. This enabled me to delay harvest day until the first weekend in October.
The method I chose to dispatch the fish prior to gutting them was to immerse them in ice water. This kills them within a few minutes, and seems pretty humane to me.
as easy as netting fish in a barrel :)
I have read that, in most parts of the world, fish are traditionally cooked whole. That is, head intact. Evidently the exception to this practice is my own culture, presumably because we Americans prefer our meat having as little resemblance to a previously-alive animal as possible. I suppose on some level I can understand how folks might find staring into the eye of a fish they are about to consume somewhat creepy. But neither I nor my wife have any such reservations, and since not having to filet all these fish meant the cleaning process would be much quicker, I opted to go with the rest of the world on this. I should also mention that, in addition to there being edible meat in and around the head that would otherwise be wasted, some people believe leaving it on improves the taste of the whole fish. Not sure if I'm buying that one, but as they say, the proof is in the pudding.
My dad passed away when I was a young boy, so I never had the opportunity to learn many things that fathers teach their sons. One of those things was how to clean a fish. Fortunately for me, today we have the internet and you-tube. I am constantly amazed at all the regular folks who take the time to record and post helpful "how-to" videos online. What an incredible resource for do-it-yourselfers! So... after watching a couple of people demonstrate their technique for gutting and de-scaling a fish, I was ready to tackle the job.
I was surprised how easy it is, really. After a short learning curve, I was down to five minutes per fish. That was at a slow, careful pace. I'm sure I could do it in two or three minutes if I rushed, but I was in no hurry. And yes, I'm sure there are those who can do it in 10 or 15 seconds, but I had nothing to prove. One thing is for certain, it beats hand-plucking poultry feathers!
a small 2-3" incision
the chickens enjoyed the entrails
lots of scales... hoping the chickens eat these too - a good source of calcium for eggshell production
In total, I processed 41 fish. I fileted the last one just for comparison. I read somewhere that if you filet a fish, you end up with about 30% of the whole. Add in a lack of experience and, well, my result was probably closer to 20%. Yet another reason to go the "cooked-whole" route.
these were vacuum packed in pairs after freezing solid
My wife used THIS recipe to prepare two of the fish for dinner that night. I don't know if it was the fact that they were so fresh, or the seasonings they were cooked with, or that they were raised from babies right here on the farm, but we both agreed that they were the best tilapia either of us had ever eaten. Seriously, you should try this recipe.
One fish apiece was more than enough to fill us. It was a little work picking out the bones, but no big deal; certainly worth the time saved in cleaning them. The skin was delicious, and at the end of the meal we had just a small pile of bones left which will eventually be used to make fish broth.
One note of interest: I thought I had about fifty fish, total, before processing. As it turns out, my estimate was low. After harvesting 41 of them, I still have about 30 adults left. The remaining fish are all indoors in the IBC tank, so there are no worries they will be killed by the imminent colder weather. I will probably do one more harvest in November, and that should be it until next summer.
Our freezer is now well-stocked with tilapia. As my aquaponics operation expands in the coming months, my plan is to raise about 500 mature fish per year for our own consumption, to be harvested quarterly. I've got close to that many fry swimming around in aquariums out in the garage right now, so barring any catastrophe, that plan has already been "hatched". :) Stay tuned for further developments. Don't forget you can click on the pictures to enlarge them.
from this:
to this:
(in approximately 12 months)
That top picture was taken on June 1st 2013. Two of those tiny guys ended up in the lower picture about a year later. You can read the story of how those fish were raised to maturity HERE.
