I'm just copy/pasting this from my Facebook account, but it still belongs in here. I added in the bit about the Snapper just for this post so it's a little different than Facebook.
First, to get the ball rolling is a moral concern about Tilapia.
1. Fact: Tilapia has very little fat, calories, carbs, or sodium, and is an excellent source of Phosphorus, Niacin, Selenium, B12 and Potassium.
2. Fact: Tilapia sells like hotcakes in gourmet stores and high-end fish markets.
3. Fact: Tilapia consume over 6 times their own mass in other fish's fecal matter.
4. Fact: Tilapia are #99 on the IUCN's 100 of the World's Worst Alien Invasive Species list.
It is a healthy fish to eat, but at what cost?
They are widely used as biological control for aquatic plant problems.
The fish is known as a "shitmouth" in most aquatic circles, and is also a problematic invasive species that will take over most new territories.
"'Arizona stocks tilapia in the canals that serve as the drinking water sources for the cities of Phoenix, Mesa and others. The fish help purify the water by consuming vegetation and detritus, greatly reducing purification costs."
Arizona also dumps their sewage into canals that then feed into water-treatment plants to be purified into drinking water. The tilapia feed on the sewage and act as a biological shit-filter. They'll also eat the algae that grows rampant in the canals from high-levels of waste-nutrients.
On the other hand, they also purify the water from such things, which causes other species of fish to grow in population, size and health. However, since the fish are flourishing on account of an "outside" source and not from their own accord, this could lead to problems later when the pond/aquatic area is over-stocked on the natural fish. But by that time, the tilapia would have reproduced beyond controllable numbers and would need to expand their "zone" to accommodate their numbers. Pushing themselves upstream, they'll be interfering and disrupting the aquatic life-cycle in that area as well. But on the sewage treatment issue, the tilapia are a much more viable way of cleaning than using various chemicals and is a much cheaper solution. The treatment plants can also be cheaper to build and maintain, as there's less waste to be pushed through and processed by human methods.
Then again, if we're talking about farmed fish, this is a whole different story. Sort of.
Salmon fisheries use tilapia to clean the holding pens. What does this mean? Fisheries usually have 1/3 of their holding pens empty for moving fish around. When a pen gets too dirty to keep salmon in, they'll migrate them to a different holding pen, then push tilapia into the previously occupied area to clean. Since the tilapia love eating other fish's waste, they're in heaven while in the dirty, shit-filled pen. They can also hold about 4x more tilapia per volume in a pen than salmon, so there's usually as much tilapia in a fishery as there are salmon, even though there may only be one or two pens for the tilapia.
So my question to you is this: do you feel comfortable eating fish that thrive off other fish's fecal matter, is on the World's Worst Invasive Species List, and acts as a living scrub-brush to clean dirty water?
Moving on from the Toilet Scrubber of the sea to the Head Scratchers of confusion.
What exactly is Basa fish?
This is a question that's been bothering me for a while now.
About 8 months ago, we started getting frozen Basa fillets at work. The box they are shipped in says "Pangasius hypophthalmus." However, we price them as Frozen Basa Fillets (at $1.29/100grams... pretty damn cheap for fish). I decided to Google-Search "Basa Fish" then and saw that it was a type of catfish. I then questioned my boss about it, saying "So basa is catfish, right? I thought catfish was too cheap of a fish to sell here?" (Since I work at a very high-end store) and he was puzzled. "Basa isn't catfish... it's closer to sole than catfish, but quite a bit oilier, like a cod almost. Actually, I don't * know, I just sell the * stuff." and he laughed. Those weren't his exact words, as I left the profanity out where the asterisks are.
But now that I finally brought a couple fillets home to try, I'm doing some research before I start cooking it. I remembered that the box had "hypophthalmus" on it, so I Google-Searched "Basa + hypophthalmus" and found a Wikipedia Article on Iridescent Shark.
WTF?
The second sentence explains it all:
This fish is also known as ... striped catfish in the food fish market, and occasionally incorrectly as basa...
Basically it's a catfish, but known as a shark and sold as a totally different fish called basa.
So if you're ever in the market to buy Basa, make sure it's the real Basa, which is VERY hard to find in North America, as 90% of basa sold is actually this "Pangasius hypophthalmus" catfish, when you should be finding the "Pangasius bocourti" catfish.
Then again, you could swing it the other way and say you're having shark for dinner.
Another fish that confused me was Lingcod.
Being a fish unique to the west coast of North America only (Basically from Anchorage, Alaska down to La Paz, Mexico), it's a very common fish in seafood markets along there. However, the majority of people buying it falsely believe that it is a type of cod-fish.
Not many people buying it know that there's also a fish called Ling (Common Ling) that's fished and eaten in Northeastern Atlantic waters and is common in Iceland, British Isles and the Norse coast. It's flesh is similar to cod and is usually interchangeable in most recipes.
Cod, on the other hand, is a very common place fish found along the coastlines of northeastern US, around the Maritimes in Canada, around Greenland, Iceland, British Isles, Spain, Portugal, the English Channel, Norway, Sweden, Denmark, Netherlands and Germany. Surrounding countries periodically get Cod imported. There's also Pacific cod, which is three times the size of Atlantic Cod and found around the northwestern parts of the US and along the BC/Alaska coastline.
Then we come to Lingcod. Not very close to Cod-fish or Ling, it received its name simply because it resembled them.
It's very high in Protein, but also very high in Cholesterol (30% and 12% daily intake/100grams respectively) and is considered a sub-par fish for healthy eating.
Basically what I'm trying to say here is that if you're buying Lingcod, it's not a cod-fish, nor is it ling. It's a totally separate family and should be treated as such.
Following the lines of Cod-fish, I want to touch on Sablefish.
When I first started working at Urban Fare, we were selling Sablefish faster than we were selling Ahi Tuna. However, it was expensive for us to get in, so we stopped carrying it around April of '09. During it's time being sold with us, I tried to find out what it was. My boss kept saying that Sablefish is Black Cod and that the names are interchangeable. The only reason it's called Sablefish is so restaurants can mark it as a higher fish than a cod and thus charge more for it (which is weird, because of where they're found). And that's basically what we were doing as well. Our pricing system had Black Cod at 3.99/100grams (on par with Halibut) while Sablefish was at 4.99/100grams (on par with Ahi Tuna), so we priced it as Sablefish.
When we stopped getting it in, people were going ecstatic trying to find Sablefish, and finally settling for the Black Cod on Granville Island.
However, Sablefish and Black Cod are different genus.
Sablefish are found in the sea beds of the North Pacific 1-2 miles deep, while the Black Cod are found at the opposite pole, around New Zealand and sub-Antarctic waters. This confuses me with the pricing scheme, as the fish coming from Antarctic waters is cheaper than the one fished up by Alaska.
They are commonly labeled as the same fish in markets, and are usually interchangeable in most recipes, but are a vastly different fish. I highly suggest making sure you are actually getting Sablefish when you ask for it at the market, as well as actually getting Black Cod.
Another one to look out for is Red Snapper.
I didn't realize this until just recently, but the Red Snapper we get in at work goes by the name of Red Snapper at Blundell Seafoods, while it goes by Rockfish over at Albion Fisheries.
Doing a bit of research shows me that Red Snapper's species are in the Lutjanus genus, while Rockfish are in the Sebastes genus. Totally different Order, totally different Family, totally different Genus. Nowhere near the same species. I'm assuming that since two competing seafood distributors in Vancouver refer to them by different names, they must be different fish, but mistakenly labeled as Red Snapper. I know that there is a large difference when we get the fillets in at work: Blundell's fillets are MUCH larger than Albion's (sometimes up to 350grams as opposed to 125grams), but the taste is pretty much identical between the two.
I'm not sure how other seafood distributors label their Red Snapper, as I've only ever dealt with those two, but I would just make sure you are actually getting Red Snapper an not Rockfish, or some other fish from the same family as the Red Snapper (Lutjanidae family would encompass all Snappers, and there's about 100 different species under the Snapper umbrella).
