Think about how much there must be in that sample to override fish DNA!
April 9, 2019 2:25 PM Subscribe
I just got the results back from my class' foray in sequencing fish samples. ARE YOU READY? They're a mind-bender. (twitter thread) (threadreader)
That's interesting but if you were to do this at a coastal city Japanese restaurant would you get different results? A-sit down restaurant that charges $25 minimum for a small plate of fancy edo style sushi, or are we talking cheap fast sushi places by often by non-Japan trained chefs? Sushi has social cachet so the reason fraud happens is because the real ingredients are in such small supply, there's a mass consumer demand that's unfortunately met like how olive oil is fake or mis-sourced as well.
posted by polymodus at 2:35 PM on April 9, 2019 [1 favorite]
posted by polymodus at 2:35 PM on April 9, 2019 [1 favorite]
That's interesting but if you were to do this at a coastal city Japanese restaurant would you get different results?
For sushi made by chefs who buy individual fish daily, I'd expect 100% accurate matches, unless there are false results in the mix (like body louse?). The vast majority of U.S. chefs, and especially grocery stores, must rely upon the supply chain to deliver fresh fish from all over the world, and for those fish to retain their proper labels as they are turned into slabs of fish-looking meat we see in stores.
posted by filthy light thief at 2:39 PM on April 9, 2019 [7 favorites]
For sushi made by chefs who buy individual fish daily, I'd expect 100% accurate matches, unless there are false results in the mix (like body louse?). The vast majority of U.S. chefs, and especially grocery stores, must rely upon the supply chain to deliver fresh fish from all over the world, and for those fish to retain their proper labels as they are turned into slabs of fish-looking meat we see in stores.
posted by filthy light thief at 2:39 PM on April 9, 2019 [7 favorites]
Also I wonder if you would have the same results in Japan?
posted by polymodus at 2:40 PM on April 9, 2019
posted by polymodus at 2:40 PM on April 9, 2019
I'm sceptical that tilapia can be passed off as red tuna. That's not like passing trout off as salmon; they have absolutely different colours and textures.
posted by Joe in Australia at 2:41 PM on April 9, 2019 [11 favorites]
posted by Joe in Australia at 2:41 PM on April 9, 2019 [11 favorites]
I have no better place than this to report that I had fun yesterday calling fish "fish meat".
posted by stinkfoot at 2:42 PM on April 9, 2019 [8 favorites]
posted by stinkfoot at 2:42 PM on April 9, 2019 [8 favorites]
Ah. Escolar.
I guess they really can't bill it as "diarrhea fish" on the menu now, can they?
posted by mandolin conspiracy at 2:43 PM on April 9, 2019 [5 favorites]
I guess they really can't bill it as "diarrhea fish" on the menu now, can they?
posted by mandolin conspiracy at 2:43 PM on April 9, 2019 [5 favorites]
Yeah, I too had the "Tilapia as red tuna? Salmon as body louse? This speaks more to potential process problems..." reaction.
Which also got me wondering, given that the previous thread was about electrophoresis, how many DNA tests in criminal proceedings are similarly flawed but taken as gospel because science!?
posted by straw at 2:45 PM on April 9, 2019 [16 favorites]
Which also got me wondering, given that the previous thread was about electrophoresis, how many DNA tests in criminal proceedings are similarly flawed but taken as gospel because science!?
posted by straw at 2:45 PM on April 9, 2019 [16 favorites]
Someone in there asks about the color, how can there be such a range for "salmon"?
My brother operates both a trout farm, and a salmon boat. Trout-food manufacturers have a range of products, with a color chart, for what color you want the trout flesh to come out as, from pink to red.
posted by StickyCarpet at 2:46 PM on April 9, 2019 [29 favorites]
My brother operates both a trout farm, and a salmon boat. Trout-food manufacturers have a range of products, with a color chart, for what color you want the trout flesh to come out as, from pink to red.
posted by StickyCarpet at 2:46 PM on April 9, 2019 [29 favorites]
Escolar is super tasty.
Only time I've had it to my knowledge the chef was super clear about what it was. So we knew what to look up the next day when we had urgent questions.
posted by feckless at 2:58 PM on April 9, 2019 [8 favorites]
Only time I've had it to my knowledge the chef was super clear about what it was. So we knew what to look up the next day when we had urgent questions.
posted by feckless at 2:58 PM on April 9, 2019 [8 favorites]
I'm sceptical that tilapia can be passed off as red tuna.
There is no such fish as "red tuna".
posted by beagle at 2:59 PM on April 9, 2019 [4 favorites]
There is no such fish as "red tuna".
posted by beagle at 2:59 PM on April 9, 2019 [4 favorites]
One of the comments on the Twitter thread is about how fish is dyed red to pass as other fish.
posted by tofu_crouton at 3:10 PM on April 9, 2019
posted by tofu_crouton at 3:10 PM on April 9, 2019
“No prob, but this isn’t Maine lobster.” “I assure you it is.” “With this concave uropod? I think not!”
Pedantry, perhaps, but hilarious.
posted by GenjiandProust at 3:12 PM on April 9, 2019 [16 favorites]
Pedantry, perhaps, but hilarious.
posted by GenjiandProust at 3:12 PM on April 9, 2019 [16 favorites]
Yeah round the parts where I have roamed, I am well aware that white tuna is escolar and will be offended if I recieve anything other than escolar for the white tuna. I love that shit. If you think that's living dangerously, well, congrats i guess.
posted by some loser at 3:14 PM on April 9, 2019 [1 favorite]
posted by some loser at 3:14 PM on April 9, 2019 [1 favorite]
My mother in law has a lot of opinions that I disagree with. They start at innocuous ("we absolutely must steep this tea for the amount of time it says on the tin!") to annoying ("I couldn't possibly eat this yogurt since you've given me a dinner spoon, rather than a dessert spoon!" actual quote) to straight-up Islamophobia (example redacted because nobody needs more of that in life).
But the one that makes me see red the most often is her insistence that we eat more fish. It's probably because with time, she has learned not to say the most bigoted things?
But once in a while, she does the fishing thing, trotting it out on a purely, "But it's HEALTHY!" basis. And then I talk to her about how commercial fish stocks are all overfished. And then points to her Monterey Bay Sustainable Fishery pamphlet that says certain fishes are FINE to eat, and I'm about to start yelling about accountability in seafood supply chains, but at this point, my husband gives me a sad, patient look because this is the eighteenth time I've had this argument with his mom about over the last ten years, at which point, I shut my gob and start thinking about Gwendoline Christie's red carpet looks.
But like, lady, they aren't even fucking honest with you about whether it's tilapia or tuna. The fuck you think it's accurately labeled about whether it's line-caught or spear-caught???????
posted by joyceanmachine at 3:20 PM on April 9, 2019 [15 favorites]
But the one that makes me see red the most often is her insistence that we eat more fish. It's probably because with time, she has learned not to say the most bigoted things?
But once in a while, she does the fishing thing, trotting it out on a purely, "But it's HEALTHY!" basis. And then I talk to her about how commercial fish stocks are all overfished. And then points to her Monterey Bay Sustainable Fishery pamphlet that says certain fishes are FINE to eat, and I'm about to start yelling about accountability in seafood supply chains, but at this point, my husband gives me a sad, patient look because this is the eighteenth time I've had this argument with his mom about over the last ten years, at which point, I shut my gob and start thinking about Gwendoline Christie's red carpet looks.
But like, lady, they aren't even fucking honest with you about whether it's tilapia or tuna. The fuck you think it's accurately labeled about whether it's line-caught or spear-caught???????
posted by joyceanmachine at 3:20 PM on April 9, 2019 [15 favorites]
Which also got me wondering, given that the previous thread was about electrophoresis, how many DNA tests in criminal proceedings are similarly flawed but taken as gospel because science!?
Probably none because they are not being done by students on poorly collected samples in a contaminated lab area as an exercise and because they use replicates and are not using meta barcoding against loads of species without proper controls to make sure youre not getting random hits to other species.
But switching fish is a real problem that lots of real, actual, professionally done studies have already identified.
posted by fshgrl at 3:20 PM on April 9, 2019 [21 favorites]
Probably none because they are not being done by students on poorly collected samples in a contaminated lab area as an exercise and because they use replicates and are not using meta barcoding against loads of species without proper controls to make sure youre not getting random hits to other species.
But switching fish is a real problem that lots of real, actual, professionally done studies have already identified.
posted by fshgrl at 3:20 PM on April 9, 2019 [21 favorites]
I would bet money the body louse sequence is actually the salmon louse, which is a notorious salmon farm pest and can be present in huge disgusting numbers in a badly run farm.
posted by benzenedream at 3:26 PM on April 9, 2019 [36 favorites]
posted by benzenedream at 3:26 PM on April 9, 2019 [36 favorites]
There was something else going around awhile back that was like they shined a black light on some tamago and it lit up with all this like bioluminescent stuff that had no business being there?? I think about that every time I eat tamago. And how we're killing the ocean.
posted by bleep at 3:38 PM on April 9, 2019
posted by bleep at 3:38 PM on April 9, 2019
I would bet money the body louse sequence is actually the salmon louse, which is a notorious salmon farm pest and can be present in huge disgusting numbers in a badly run farm.
Oh, that's the first explanation I've seen to make any sense on the louse.
I mentioned on Twitter this week that we do a similar lab, but we provide all the fish samples for testing and provide students with a subset. My instructor turns up at a local fish counter--she's been asking the class to vote where they want her to go--and asks the fishmongers for a bunch of small slices of fish for science purposes, and they cut her a bunch of little slivers, and then my students extract DNA, run PCRs to amplify a barcoding gene, and then if they have any sequence we send them off to be sequenced. (We actually are running gels to confirm the PCRs work this week, and I'm loading the successful amplifications into wells on a plate for sequencing. Week after this, we'll look at the data!) I've been teaching this lab since we started sequencing fish, which is I think about two years now, and we must have run at least twenty samples in that time.
We've never had a sample come back as anything remotely interesting, unless you count our repeated verification that imitation crab isn't made of crab. (Admittedly, that bit can be fun.) We do occasionally get bacterial amplification, probably from bacteria hanging out on the fish as it sits out. That might have been why DNA extracted from a fish returned a louse sequence--sometimes the degenerate primers really, really make friends with a contaminant.
I'm lobbying to allow students to bring in frozen chunks of their own fish for their own use next semester, if they want to. (Both my instructor and I have qualms about requiring students to go out for a sushi dinner--what if they can't afford it or don't want to?--so we will probably also continue to offer fish samples for extraction, no matter what.) We also test for the presence or absence of a popular GMO primer in foods they get to bring in (as long as they are plant-based, anyway; our control requires a plant-based sample), and I've also never been surprised by that one.
Incidentally, at least in Austin's supply chain, Chipotle's tortilla chips are indeed GMO-free.
posted by sciatrix at 3:38 PM on April 9, 2019 [45 favorites]
Oh, that's the first explanation I've seen to make any sense on the louse.
I mentioned on Twitter this week that we do a similar lab, but we provide all the fish samples for testing and provide students with a subset. My instructor turns up at a local fish counter--she's been asking the class to vote where they want her to go--and asks the fishmongers for a bunch of small slices of fish for science purposes, and they cut her a bunch of little slivers, and then my students extract DNA, run PCRs to amplify a barcoding gene, and then if they have any sequence we send them off to be sequenced. (We actually are running gels to confirm the PCRs work this week, and I'm loading the successful amplifications into wells on a plate for sequencing. Week after this, we'll look at the data!) I've been teaching this lab since we started sequencing fish, which is I think about two years now, and we must have run at least twenty samples in that time.
We've never had a sample come back as anything remotely interesting, unless you count our repeated verification that imitation crab isn't made of crab. (Admittedly, that bit can be fun.) We do occasionally get bacterial amplification, probably from bacteria hanging out on the fish as it sits out. That might have been why DNA extracted from a fish returned a louse sequence--sometimes the degenerate primers really, really make friends with a contaminant.
I'm lobbying to allow students to bring in frozen chunks of their own fish for their own use next semester, if they want to. (Both my instructor and I have qualms about requiring students to go out for a sushi dinner--what if they can't afford it or don't want to?--so we will probably also continue to offer fish samples for extraction, no matter what.) We also test for the presence or absence of a popular GMO primer in foods they get to bring in (as long as they are plant-based, anyway; our control requires a plant-based sample), and I've also never been surprised by that one.
Incidentally, at least in Austin's supply chain, Chipotle's tortilla chips are indeed GMO-free.
posted by sciatrix at 3:38 PM on April 9, 2019 [45 favorites]
I'm not sure if i like some of the endpoints of going really hard on this. There's a sushi place here that flies in all their fish, every 24 hours, so that they can know the exact origin etc of them and people pay for it.
Like, to a certain degree, is expecting to regularly(or even occasionally) eat a type of fish that isn't common locally, which leads to this fraud, even sustainable?
This fraud is silly, but honestly i just respect places that use simple easily available/local fish or just say "fish" more because the alternative is like, verified supply chains of stuff coming from really far away and that's off-putting to me.
posted by emptythought at 3:43 PM on April 9, 2019 [2 favorites]
Like, to a certain degree, is expecting to regularly(or even occasionally) eat a type of fish that isn't common locally, which leads to this fraud, even sustainable?
This fraud is silly, but honestly i just respect places that use simple easily available/local fish or just say "fish" more because the alternative is like, verified supply chains of stuff coming from really far away and that's off-putting to me.
posted by emptythought at 3:43 PM on April 9, 2019 [2 favorites]
From the comments: DNA sequencing of mushrooms in a shop-bought packet of porcini results in the description of three species new to science. Wow!
posted by asperity at 3:45 PM on April 9, 2019 [9 favorites]
posted by asperity at 3:45 PM on April 9, 2019 [9 favorites]
Well, actually it was the rainbow trout mousse.
posted by peeedro at 3:46 PM on April 9, 2019 [9 favorites]
posted by peeedro at 3:46 PM on April 9, 2019 [9 favorites]
"But once in a while, she does the fishing thing, trotting it out on a purely, "But it's HEALTHY!" basis."
I'm confused at where your frustrations are from here, I have been told I should have more fish/omegatrons in ym diet but the nearest ocean is full of oil and even worse oil-removers? Are you saying the argument with her is that she wants to eat fish sometimes but you think it's never okay to eat fish? Your post didn't specify a diet that excludes fish, and I'm guessing it's a matter of supply chain ethics for you, which would make me think you'd be excluding any animals' meats or byproducts? I don't eat much fish, when I do it's almost always Sushi of some sort, and I rarely know exactly what it's made of and now I see that it doesn't matter what I think or am told it is. Pardon my ignorance on these issues, I though your anecdote was amusing but I'm afraid I might be as oblivious or naive to some of what you're frustrated about so I'm just curious and want to understand!
posted by GoblinHoney at 3:47 PM on April 9, 2019 [3 favorites]
I'm confused at where your frustrations are from here, I have been told I should have more fish/omegatrons in ym diet but the nearest ocean is full of oil and even worse oil-removers? Are you saying the argument with her is that she wants to eat fish sometimes but you think it's never okay to eat fish? Your post didn't specify a diet that excludes fish, and I'm guessing it's a matter of supply chain ethics for you, which would make me think you'd be excluding any animals' meats or byproducts? I don't eat much fish, when I do it's almost always Sushi of some sort, and I rarely know exactly what it's made of and now I see that it doesn't matter what I think or am told it is. Pardon my ignorance on these issues, I though your anecdote was amusing but I'm afraid I might be as oblivious or naive to some of what you're frustrated about so I'm just curious and want to understand!
posted by GoblinHoney at 3:47 PM on April 9, 2019 [3 favorites]
*GMO promoter, not primer. That's going to bother me all night....
posted by sciatrix at 3:48 PM on April 9, 2019 [1 favorite]
posted by sciatrix at 3:48 PM on April 9, 2019 [1 favorite]
verified supply chains of stuff coming from really far away and that's off-putting to me.
That level of supply-chain management might be what we need to keep people from profiting off worker abuse. It'd be nice for it to be more difficult to, uh, launder? sweatshop-produced clothing or other goods manufactured by enslaved people. Exploiters rely on what they do being out of sight (of the people with purchasing power), and distance is the easiest way to keep abuse invisible.
It's not and shouldn't be the only thing in that toolbox. But it is kinda cool that things like cotton are starting to have commercial DNA sequencing to verify point of origin. When there are negative externalities, tracking where they come from might help us capture them and see that they're paid for by the responsible parties.
"Might" is carrying a lot of weight with this argument, though, and I'm pretty sure nobody's managed to get apartment complex dog shit DNA registries to work for their intended purpose yet. So, uh. *shrug*
posted by asperity at 3:55 PM on April 9, 2019 [3 favorites]
That level of supply-chain management might be what we need to keep people from profiting off worker abuse. It'd be nice for it to be more difficult to, uh, launder? sweatshop-produced clothing or other goods manufactured by enslaved people. Exploiters rely on what they do being out of sight (of the people with purchasing power), and distance is the easiest way to keep abuse invisible.
It's not and shouldn't be the only thing in that toolbox. But it is kinda cool that things like cotton are starting to have commercial DNA sequencing to verify point of origin. When there are negative externalities, tracking where they come from might help us capture them and see that they're paid for by the responsible parties.
"Might" is carrying a lot of weight with this argument, though, and I'm pretty sure nobody's managed to get apartment complex dog shit DNA registries to work for their intended purpose yet. So, uh. *shrug*
posted by asperity at 3:55 PM on April 9, 2019 [3 favorites]
GMO promoter, not primer.
One's a lobbyist, the other's an educator. It's like the difference between sophists and philosophers.
posted by biogeo at 3:57 PM on April 9, 2019 [3 favorites]
One's a lobbyist, the other's an educator. It's like the difference between sophists and philosophers.
posted by biogeo at 3:57 PM on April 9, 2019 [3 favorites]
"But it is kinda cool that things like cotton are starting to have commercial DNA sequencing to verify point of origin."
I wonder how long it will be before "DNA sequence verified genuine" becomes just another thing to slap on food to charge an extra buck or two. All Natural! GMO free! Organic! Genuine DNA! Actual Matter! Valence Electron Purity! Exotic-matter-free!
posted by GoblinHoney at 4:03 PM on April 9, 2019 [11 favorites]
I wonder how long it will be before "DNA sequence verified genuine" becomes just another thing to slap on food to charge an extra buck or two. All Natural! GMO free! Organic! Genuine DNA! Actual Matter! Valence Electron Purity! Exotic-matter-free!
posted by GoblinHoney at 4:03 PM on April 9, 2019 [11 favorites]
There is no such fish as "red tuna".
Well that's like saying dark meat is not chicken thighs, etc., for culinary concept purposes, as opposed to scientific classification. It's just semantics.
posted by polymodus at 4:12 PM on April 9, 2019 [1 favorite]
Well that's like saying dark meat is not chicken thighs, etc., for culinary concept purposes, as opposed to scientific classification. It's just semantics.
posted by polymodus at 4:12 PM on April 9, 2019 [1 favorite]
Hence why buying locally, fraught though that may be in some ways sure, is the choice we make when it comes to seafood, especially shrimp (bonus points for no slave labor shrimp since we're near the ocean/historic shrimping ports).
posted by RolandOfEld at 4:21 PM on April 9, 2019 [1 favorite]
posted by RolandOfEld at 4:21 PM on April 9, 2019 [1 favorite]
I would bet money the body louse sequence is actually the salmon louse, which is a notorious salmon farm pest and can be present in huge disgusting numbers in a badly run farm.
...
Oh, that's the first explanation I've seen to make any sense on the louse.
I don't know how much sense it makes, because Wiki says the salmon louse is a copepod, and a body louse is an insect. I don't know jack about how this DNA test actually works, but DNA of a copepod ought to be no more similar to a body louse than it is to a honeybee or monarch butterfly.
posted by polecat at 4:33 PM on April 9, 2019 [10 favorites]
...
Oh, that's the first explanation I've seen to make any sense on the louse.
I don't know how much sense it makes, because Wiki says the salmon louse is a copepod, and a body louse is an insect. I don't know jack about how this DNA test actually works, but DNA of a copepod ought to be no more similar to a body louse than it is to a honeybee or monarch butterfly.
posted by polecat at 4:33 PM on April 9, 2019 [10 favorites]
To be fair, body lice really give your average pescatarian something a little more special than they are used to...
posted by Nanukthedog at 4:39 PM on April 9, 2019
posted by Nanukthedog at 4:39 PM on April 9, 2019
I was hoping for "We tested the Atlantic cod, until one student looked at the results and gasped, "So _that's_ where my dad disappeared to!"
posted by delfin at 4:55 PM on April 9, 2019 [14 favorites]
posted by delfin at 4:55 PM on April 9, 2019 [14 favorites]
I was about to chime in here and say that human body louse is pretty uncommon these days, but then I checked and realised that the human head and body louse are just two subspecies of Pediculus humanus, so while the actual body louse isn't at all common, the head louse is very common indeed. So in summary, ICK!
posted by Fuchsoid at 4:58 PM on April 9, 2019 [1 favorite]
posted by Fuchsoid at 4:58 PM on April 9, 2019 [1 favorite]
Metafilter: sometimes the degenerate primers really, really make friends with a contaminant.
posted by Pastor of Muppets at 5:06 PM on April 9, 2019 [7 favorites]
posted by Pastor of Muppets at 5:06 PM on April 9, 2019 [7 favorites]
I don't know how much sense it makes, because Wiki says the salmon louse is a copepod, and a body louse is an insect. I don't know jack about how this DNA test actually works, but DNA of a copepod ought to be no more similar to a body louse than it is to a honeybee or monarch butterfly.
Agreed. I was also assuming that the sequences were getting BLASTed against something like the NCBI nt database which has a lot of legacy stuff in it, and that something was annotated poorly as louse. It would be interesting to see the actual alignment and taxid of the hit to confirm. If it was a 50bp contiguous perfect body louse sequence it might be real, but if it was heavily gapped and low complexity it may have just been a louse repeat element that happens to look like a primer-dimer no-template expansion product.
posted by benzenedream at 5:27 PM on April 9, 2019 [11 favorites]
Agreed. I was also assuming that the sequences were getting BLASTed against something like the NCBI nt database which has a lot of legacy stuff in it, and that something was annotated poorly as louse. It would be interesting to see the actual alignment and taxid of the hit to confirm. If it was a 50bp contiguous perfect body louse sequence it might be real, but if it was heavily gapped and low complexity it may have just been a louse repeat element that happens to look like a primer-dimer no-template expansion product.
posted by benzenedream at 5:27 PM on April 9, 2019 [11 favorites]
But switching fish is a real problem that lots of real, actual, professionally done studies have already identified.
So is sloppy forensic science, though - a direct comparison probably isn't fair but straw isn't exactly crazy to suggest it might be an ssue.
posted by atoxyl at 5:52 PM on April 9, 2019 [2 favorites]
So is sloppy forensic science, though - a direct comparison probably isn't fair but straw isn't exactly crazy to suggest it might be an ssue.
posted by atoxyl at 5:52 PM on April 9, 2019 [2 favorites]
I suspect the students all went to the same cheap sushi restaurant chain, that does no diligence on the source of what they buy.
I live in Atlantic salmon farming territory. You can't buy wild Atlantic salmon. The salmon they raise in the various bays around here would have white flesh like any cod or haddock, except for the dye they feed them. They are a virulent bright peachy-pink colour because when they are dyed much more pink than is natural they sell better. They are mushy. The salmon have no room to swim so their muscles have never been exercised and they are really soft. And because of the overcrowding every other thing that lives in the small bays where they put the fish farms dies. There is just so much mulm produced. And they frequently lose the whole enclosure to infestations of fish lice. Other people who were using the bay are generally not very happy about the fish farm being installed but it's the ocean not private water frontage, so anyone is allowed to moor there, even if what they are mooring kills everything for hundreds of yards around. If they were releasing gasoline or something and killing everything they could get an injunction and make them stop, but not when it's fish poop.
I only buy Pacific salmon. Pacific salmon is tough and dry. I find that reassuring.
posted by Jane the Brown at 6:13 PM on April 9, 2019 [8 favorites]
I live in Atlantic salmon farming territory. You can't buy wild Atlantic salmon. The salmon they raise in the various bays around here would have white flesh like any cod or haddock, except for the dye they feed them. They are a virulent bright peachy-pink colour because when they are dyed much more pink than is natural they sell better. They are mushy. The salmon have no room to swim so their muscles have never been exercised and they are really soft. And because of the overcrowding every other thing that lives in the small bays where they put the fish farms dies. There is just so much mulm produced. And they frequently lose the whole enclosure to infestations of fish lice. Other people who were using the bay are generally not very happy about the fish farm being installed but it's the ocean not private water frontage, so anyone is allowed to moor there, even if what they are mooring kills everything for hundreds of yards around. If they were releasing gasoline or something and killing everything they could get an injunction and make them stop, but not when it's fish poop.
I only buy Pacific salmon. Pacific salmon is tough and dry. I find that reassuring.
posted by Jane the Brown at 6:13 PM on April 9, 2019 [8 favorites]
This is a Bio Prof at a college teaching students to sequence DNA. It's pretty much their job to make errors, screw up the samples, whatever. I've been aware that a lot of fish isn't what is claims to be, but this is pretty bad. I'm in Maine and many fisheries are closed or limited, causing hardship among the fishing trade, and it will take a long time for fisheries to recover. Lobster has been well-managed in Maine, but climate change is having an effect.
posted by theora55 at 6:29 PM on April 9, 2019 [2 favorites]
posted by theora55 at 6:29 PM on April 9, 2019 [2 favorites]
Escolar is very tasty and in sushi doses, quite benign.
Escolar masquerading as other fish in larger portions is a BAD BAD thing.
posted by sjswitzer at 6:56 PM on April 9, 2019 [1 favorite]
Escolar masquerading as other fish in larger portions is a BAD BAD thing.
posted by sjswitzer at 6:56 PM on April 9, 2019 [1 favorite]
Having worked for years at wholesale and retail seafood places I have so many thoughts on this. I would love to be able to do this at home every once in a while and briefly thought about doing a DIY secret-shopper type seafood audit but it never went anywhere.
I too am surprised about the tilapia/tuna mixup, as others have stated above they are totally different in texture etc. I strongly suspect the chef would have been complicit in this as I have only ever seen tilapia arrive in fillet form and it is unmistakably Not Tuna.
Some suppliers of cut tuna (loins) would use CO (aka "colorless smoke") to make the flesh appear redder. I don't think it's illegal but it's definitely misleading.
Naming conventions in seafood still drive me nuts, mainly because there are a bunch of species that you are 100% legally allowed to call names that are not related to what they actually are. I am certain that this inertia/laziness is partly why seafood vendors are frequently viewed as unethical or untrustworthy.
"Rock cod"? "Pacific red snapper"? -> rockfish
"Black cod"? -> sablefish
"Lemon snapper"? -> monchong/pomfret
etc etc. I could go on at length (and often do) but maybe I should stop here
posted by pagrus at 8:07 PM on April 9, 2019 [7 favorites]
I too am surprised about the tilapia/tuna mixup, as others have stated above they are totally different in texture etc. I strongly suspect the chef would have been complicit in this as I have only ever seen tilapia arrive in fillet form and it is unmistakably Not Tuna.
Some suppliers of cut tuna (loins) would use CO (aka "colorless smoke") to make the flesh appear redder. I don't think it's illegal but it's definitely misleading.
Naming conventions in seafood still drive me nuts, mainly because there are a bunch of species that you are 100% legally allowed to call names that are not related to what they actually are. I am certain that this inertia/laziness is partly why seafood vendors are frequently viewed as unethical or untrustworthy.
"Rock cod"? "Pacific red snapper"? -> rockfish
"Black cod"? -> sablefish
"Lemon snapper"? -> monchong/pomfret
etc etc. I could go on at length (and often do) but maybe I should stop here
posted by pagrus at 8:07 PM on April 9, 2019 [7 favorites]
Naming conventions in seafood still drive me nuts, mainly because there are a bunch of species that you are 100% legally allowed to call names that are not related to what they actually are.
One of the fish we always do in this lab is Chilean sea bass--it's always extremely entertaining when the students get the pingback for Dissostichus eleginoides, go hunting to find out what it is, and then get the name Patagonian toothfish on their first pass for a common name. I usually have about three or four conversations with each table about marketing and names for fish species over the course of each section, one for each table of students. It's one of the more entertaining aspects of a lab in which I'm otherwise acting as glorified IT support for the course of the afternoon.
posted by sciatrix at 8:12 PM on April 9, 2019 [16 favorites]
One of the fish we always do in this lab is Chilean sea bass--it's always extremely entertaining when the students get the pingback for Dissostichus eleginoides, go hunting to find out what it is, and then get the name Patagonian toothfish on their first pass for a common name. I usually have about three or four conversations with each table about marketing and names for fish species over the course of each section, one for each table of students. It's one of the more entertaining aspects of a lab in which I'm otherwise acting as glorified IT support for the course of the afternoon.
posted by sciatrix at 8:12 PM on April 9, 2019 [16 favorites]
I should also add that it's possible even for wild salmon to have dramatic color changes over the course of a season or between species. Coho tends to be paler, sockeye is redder, king/chinook can be anywhere from pale grey ("ivory king salmon") to blotchy grey/orange, to orange, to super dark red-orange. These are all pacific species and not all are "tough and dry" as stated above.
My understanding is that steelhead is in fact a kind of trout that gets to salmon size, so that could be confusing for sure. I'm no fish biologist though, so that could just be a misunderstanding on my part.
I don't even really like to eat salmon all that much-- I'm more of a sablefish/sole/rockfish kind of guy-- but as you can imagine it's a pretty big deal in Northern California
posted by pagrus at 8:15 PM on April 9, 2019 [3 favorites]
My understanding is that steelhead is in fact a kind of trout that gets to salmon size, so that could be confusing for sure. I'm no fish biologist though, so that could just be a misunderstanding on my part.
I don't even really like to eat salmon all that much-- I'm more of a sablefish/sole/rockfish kind of guy-- but as you can imagine it's a pretty big deal in Northern California
posted by pagrus at 8:15 PM on April 9, 2019 [3 favorites]
Chile bass was sort of what kicked off my interest in all this stuff for me, I was working as a filleter in like 1998 or something and saw a box labelled "patagonian toothfish".
I told the sales guys they should start calling it that because it sounded cooler, they thought I was out of my mind.
posted by pagrus at 8:21 PM on April 9, 2019
I told the sales guys they should start calling it that because it sounded cooler, they thought I was out of my mind.
posted by pagrus at 8:21 PM on April 9, 2019
Steelhead is a sea-run (anadromous) rainbow trout. Most trout have fairly plastic lifestyles and some proportion of them will be sea-run if they're connected to the ocean and able to make it at all. Like Idaho, for example- there are sea-run trout in Idaho!
verified supply chains of stuff coming from really far away and that's off-putting to me.
You're allowed to go an catch your own fish you know. I highly recommend it.
posted by fshgrl at 9:12 PM on April 9, 2019 [8 favorites]
verified supply chains of stuff coming from really far away and that's off-putting to me.
You're allowed to go an catch your own fish you know. I highly recommend it.
posted by fshgrl at 9:12 PM on April 9, 2019 [8 favorites]
My understanding is that steelhead is in fact a kind of trout that gets to salmon size, so that could be confusing for sure. I'm no fish biologist though, so that could just be a misunderstanding on my part.
As a non-biologist who is a fisherperson, I do know that steelhead are rainbow trout that migrate from salt water to fresh water to spawn.
posted by mandolin conspiracy at 9:13 PM on April 9, 2019 [2 favorites]
As a non-biologist who is a fisherperson, I do know that steelhead are rainbow trout that migrate from salt water to fresh water to spawn.
posted by mandolin conspiracy at 9:13 PM on April 9, 2019 [2 favorites]
On preview, what fshgrl said.
"Anadromous" is now my word of the day.
posted by mandolin conspiracy at 9:14 PM on April 9, 2019
"Anadromous" is now my word of the day.
posted by mandolin conspiracy at 9:14 PM on April 9, 2019
Tomorrow you can enjoy "catadromous:" fish, such as eels, that swim from fresh to salt water to spawn.
posted by Rumple at 9:42 PM on April 9, 2019 [3 favorites]
posted by Rumple at 9:42 PM on April 9, 2019 [3 favorites]
you can have my gas-station sushi when you pry it from my numb, spasming hands
posted by um at 10:49 PM on April 9, 2019 [2 favorites]
posted by um at 10:49 PM on April 9, 2019 [2 favorites]
What we need in this is more blockchain. Yep.
posted by Katemonkey at 1:16 AM on April 10, 2019 [2 favorites]
posted by Katemonkey at 1:16 AM on April 10, 2019 [2 favorites]
I used to buy sockeye from the Tseshaht folks along the Somass river. They'd catch them by net then sell them out of the trunks of their cars along the road within sight of the water. It was good times and man, was that shit tasty. And cheap! I fear that that sort of local production will soon be a thing of the past.
posted by klanawa at 2:50 AM on April 10, 2019 [2 favorites]
posted by klanawa at 2:50 AM on April 10, 2019 [2 favorites]
Hence why buying locally, fraught though that may be in some ways sure, is the choice we make when it comes to seafood....
....
You're allowed to go an catch your own fish you know. I highly recommend it.
Yes to both of these. I grew up in New England, but eat very little seafood these days - and the biggest reason why is because nothing in the world compares to the seafood the way I know it, which is "fish that we caught with our own rods and reels on Grandpa's boat this afternoon" or "clams we dug up on the beach off Sippican Point yesterday and which have been soaking in the big sink in Grandma's basement ever since" or "the two lobsters that we found when we checked Grandpa's traps this morning".
Sustainable - because four adults and two kids working with three fishing rods and a couple shovels can't help but take only what they need and leave the rest (we lost a lot of fish trying to reel them in). We also knew exactly where our fish came from. But even that's not the reason that's better - it's because no fish in the world tastes as good as fish that fresh and I'm now spoiled for it.
I actually favor bluefish, something which a lot of people say they find oily and overly strong; but I've never felt that way, and I think it's because I was eating it only a couple hours after it was caught and most other people probably eat it later than that. A friend of mine likes fishing off his kayak in New York Harbor, and a few months back had some especially good luck and stumbled onto a school of bluefish; he called me from his boat as he was paddling back in to offer me some, and when I enthusiastically said yes, he turned up at my house 90 minutes later with 4 8-ounce filets - one of which I immediately slapped onto a pan and slung under the broiler (which I'd had heated up and waiting) and the rest I immediately froze. My friend, my roommate and I dined on a big filet of bluefish a few minutes later and I'm waiting for the right time to dip into the other 3 filets.
My fish eating habits tend towards sustainability, and I know where my fish comes from, but those are fringe benefits to the main reward which is that the fish I eat actually tastes good.
posted by EmpressCallipygos at 4:18 AM on April 10, 2019 [5 favorites]
....
You're allowed to go an catch your own fish you know. I highly recommend it.
Yes to both of these. I grew up in New England, but eat very little seafood these days - and the biggest reason why is because nothing in the world compares to the seafood the way I know it, which is "fish that we caught with our own rods and reels on Grandpa's boat this afternoon" or "clams we dug up on the beach off Sippican Point yesterday and which have been soaking in the big sink in Grandma's basement ever since" or "the two lobsters that we found when we checked Grandpa's traps this morning".
Sustainable - because four adults and two kids working with three fishing rods and a couple shovels can't help but take only what they need and leave the rest (we lost a lot of fish trying to reel them in). We also knew exactly where our fish came from. But even that's not the reason that's better - it's because no fish in the world tastes as good as fish that fresh and I'm now spoiled for it.
I actually favor bluefish, something which a lot of people say they find oily and overly strong; but I've never felt that way, and I think it's because I was eating it only a couple hours after it was caught and most other people probably eat it later than that. A friend of mine likes fishing off his kayak in New York Harbor, and a few months back had some especially good luck and stumbled onto a school of bluefish; he called me from his boat as he was paddling back in to offer me some, and when I enthusiastically said yes, he turned up at my house 90 minutes later with 4 8-ounce filets - one of which I immediately slapped onto a pan and slung under the broiler (which I'd had heated up and waiting) and the rest I immediately froze. My friend, my roommate and I dined on a big filet of bluefish a few minutes later and I'm waiting for the right time to dip into the other 3 filets.
My fish eating habits tend towards sustainability, and I know where my fish comes from, but those are fringe benefits to the main reward which is that the fish I eat actually tastes good.
posted by EmpressCallipygos at 4:18 AM on April 10, 2019 [5 favorites]
Hah, I just had salmon for lunch that I lightly cured. If it had body louse in, apparently they taste pretty good.
posted by lucidium at 4:50 AM on April 10, 2019
posted by lucidium at 4:50 AM on April 10, 2019
I suspect the students all went to the same cheap sushi restaurant chain, that does no diligence on the source of what they buy.
It's more likely that all the sushi places in London, Ontario (where Fanshawe College is) buy from the same distribution source. It's not a huge city (400K roughly) and all the fish is going to be flown in.
posted by srboisvert at 5:25 AM on April 10, 2019 [3 favorites]
It's more likely that all the sushi places in London, Ontario (where Fanshawe College is) buy from the same distribution source. It's not a huge city (400K roughly) and all the fish is going to be flown in.
posted by srboisvert at 5:25 AM on April 10, 2019 [3 favorites]
This is exactly the “Buckle up, bitches, we’re going to cancel Beau motherfucking Brummell” thread style that Rosa Lyster skewered in The Outline this week, and it is just as irritating when applied to biology as to history.
posted by strangely stunted trees at 5:27 AM on April 10, 2019 [5 favorites]
posted by strangely stunted trees at 5:27 AM on April 10, 2019 [5 favorites]
"how many DNA tests in criminal proceedings are similarly flawed but taken as gospel because science!?"
MANY MANY MANY MANY. There's a whole chunk of problematic issues collectively called "the CSI effect" where juries who are used to TV forensic shows expect forensic evidence, assign massive weight to it and consider it 100% reliable even when experts caution in their testimony that it's only 80% reliable or whatever, and will discard eyewitness testimony because it's not forensics. (In fact that Atlantic article has a good example of a kid who HAD AN ALIBI and it was just ignored in favor of appallingly shitty DNA "evidence" that was obviously mishandled.)
Plus there are many shitty forensic "experts" selling flat nonsense and making a lot of money doing it.
posted by Eyebrows McGee at 5:33 AM on April 10, 2019 [11 favorites]
MANY MANY MANY MANY. There's a whole chunk of problematic issues collectively called "the CSI effect" where juries who are used to TV forensic shows expect forensic evidence, assign massive weight to it and consider it 100% reliable even when experts caution in their testimony that it's only 80% reliable or whatever, and will discard eyewitness testimony because it's not forensics. (In fact that Atlantic article has a good example of a kid who HAD AN ALIBI and it was just ignored in favor of appallingly shitty DNA "evidence" that was obviously mishandled.)
Plus there are many shitty forensic "experts" selling flat nonsense and making a lot of money doing it.
posted by Eyebrows McGee at 5:33 AM on April 10, 2019 [11 favorites]
I took a day off last week to go to the beach. The timing was not optimal and I did not give advance notice. Thank you for giving me the perfect answer for the HR system:
Duration: 1 full day.
Reason: Acute catadromia.
I can't wait to go camping in the mountains soon so I can use anadromia as a reason.
posted by Dr. Curare at 7:42 AM on April 10, 2019 [2 favorites]
Duration: 1 full day.
Reason: Acute catadromia.
I can't wait to go camping in the mountains soon so I can use anadromia as a reason.
posted by Dr. Curare at 7:42 AM on April 10, 2019 [2 favorites]
Anadromous, Catadromous, Amphidromous, Oceanodromous, or Potamodromous
By the looks of it you could plan days off work on a river rafting trip and getting lost as sea as well.
posted by Rumple at 8:37 AM on April 10, 2019 [1 favorite]
By the looks of it you could plan days off work on a river rafting trip and getting lost as sea as well.
posted by Rumple at 8:37 AM on April 10, 2019 [1 favorite]
What I want to know is which is the most common cheap fish that is masquerading as the more expensive fish? Because I'll just save myself time and money and start purchasing the cheap impostor instead of the fakes. Tilapia?
posted by SonInLawOfSam at 8:44 AM on April 10, 2019 [1 favorite]
posted by SonInLawOfSam at 8:44 AM on April 10, 2019 [1 favorite]
I’ve been working in the fish-distribution business for a while now. My employers are honest people, but there is a lot (A LOT) of fraud goes on up and down the chain - not just substitution but dodgy stuff around import restrictions, shocking biosecurity breaches, you name it.
When it comes to what you are going to get pretending to be something else, here at the take-out level it’s basa (if they are super cheap), or hake/hokie (if they are a bit classier). Amazing how many fish-and-chip places I know get one type of fish delivered, yet have a dozen species at varying prices on the menu. How anyone can pass basa (which is basically vaguely fishy snot even when cooked perfectly) as pink snapper I have no idea, but I guess it’s the same way their customers think they’re getting said snapper for $6 with chips.
Further up the cost pyramid, there’s a lot of give-and-take around white fish species - the common names mean very little in taxonomic terms, so you can get away with a lot by just calling something ‘snapper’ or ‘cod’. The chefs know that the customers mostly can’t tell the difference (see ‘basa’, above) - even the ones who like to be honest will substitute if something isn’t available and you can bet they don’t reprint the menu when they do. There is also quite a bit of flexibility with the truth about origins - you know, when the menu was printed you really were buying locally sourced baramundi, but the next week you realised that you could buy ‘literally the same fish’ from Indonesia for 75% the price, and the customers like the bigger portions...
posted by memetoclast at 9:14 AM on April 10, 2019 [4 favorites]
When it comes to what you are going to get pretending to be something else, here at the take-out level it’s basa (if they are super cheap), or hake/hokie (if they are a bit classier). Amazing how many fish-and-chip places I know get one type of fish delivered, yet have a dozen species at varying prices on the menu. How anyone can pass basa (which is basically vaguely fishy snot even when cooked perfectly) as pink snapper I have no idea, but I guess it’s the same way their customers think they’re getting said snapper for $6 with chips.
Further up the cost pyramid, there’s a lot of give-and-take around white fish species - the common names mean very little in taxonomic terms, so you can get away with a lot by just calling something ‘snapper’ or ‘cod’. The chefs know that the customers mostly can’t tell the difference (see ‘basa’, above) - even the ones who like to be honest will substitute if something isn’t available and you can bet they don’t reprint the menu when they do. There is also quite a bit of flexibility with the truth about origins - you know, when the menu was printed you really were buying locally sourced baramundi, but the next week you realised that you could buy ‘literally the same fish’ from Indonesia for 75% the price, and the customers like the bigger portions...
posted by memetoclast at 9:14 AM on April 10, 2019 [4 favorites]
My parents both had a bizarre insistence that scallops weren't "real", and were in fact just cookie-cutter chunks of shark fin. It took several minutes of baffled conversation to clarify that they weren't just talking about misidentified seafood, but that there actually wasn't such a thing as an animal called a "scallop", it was just a tricky industry term for 'round cut of whatever'. Nevermind the fact that 'shark fin' would be vastly more expensive than 'any other bivalve', or the difference between cartilage and muscle tissue... Apparently some badly remembered Fox news report was at the root of it all.
posted by FatherDagon at 12:45 PM on April 10, 2019 [5 favorites]
posted by FatherDagon at 12:45 PM on April 10, 2019 [5 favorites]
Weird, my parents said they were punched out circles of skate wings.
Probably because they were expensive they needed us not to want them.
posted by Rumple at 8:07 PM on April 10, 2019 [2 favorites]
Probably because they were expensive they needed us not to want them.
posted by Rumple at 8:07 PM on April 10, 2019 [2 favorites]
My parents both had a bizarre insistence that scallops weren't "real", and were in fact just cookie-cutter chunks of shark fin. It took several minutes of baffled conversation to clarify that they weren't just talking about misidentified seafood, but that there actually wasn't such a thing as an animal called a "scallop", it was just a tricky industry term for 'round cut of whatever'.
That would be an incredibly elaborate hoax to perpetrate.
posted by juv3nal at 11:21 PM on April 10, 2019
That would be an incredibly elaborate hoax to perpetrate.
posted by juv3nal at 11:21 PM on April 10, 2019
My parents both had a bizarre insistence that scallops weren't "real", and were in fact just cookie-cutter chunks of shark fin.
I caught a stingray once. For whatever reason, the guy who was de facto lead of the trip threw it back. Easily, the first half-dozen people I showed pictures to said, "Oh, that's good eating. Tastes just like scallops!" (including the guy's wife!). So, I don't think there would be a market for fake scallops,but apparently some things do taste like them?
We also knew exactly where our fish came from. But even that's not the reason that's better - it's because no fish in the world tastes as good as fish that fresh and I'm now spoiled for it.
100% agree. (I have also had pronghorn that we hunted, goats and pigs that we raised and we will have chicken eventually too. All amazing.) If you ever get a chance, I also recommend fresh shrimp.
True story: I was sitting in one of my favorite "dive" bars and one of the local's cell phone rings. Conversation was "Alright. See you in 30 minutes." He hangs up and says, to no one in particular, "Shrimp boat is here." The whole bar just starts handing him money.
I say to the bartender something along the lines of WTF? She says, "Do you like shrimp?" Yeah. "Are you okay with them being head on?" I guess? "Just give him $10 then."
30 minutes later everyone there is sitting with (I think) two pounds of shrimp caught right out of the bay or the port. We tabbed out, went straight home, cleaned and cooked them. They tasted like shrimp but melted like butter on your tongue. I couldn't eat shrimp for six months after that, I was so spoiled.
posted by a non mouse, a cow herd at 2:33 PM on April 14, 2019 [6 favorites]
I caught a stingray once. For whatever reason, the guy who was de facto lead of the trip threw it back. Easily, the first half-dozen people I showed pictures to said, "Oh, that's good eating. Tastes just like scallops!" (including the guy's wife!). So, I don't think there would be a market for fake scallops,but apparently some things do taste like them?
We also knew exactly where our fish came from. But even that's not the reason that's better - it's because no fish in the world tastes as good as fish that fresh and I'm now spoiled for it.
100% agree. (I have also had pronghorn that we hunted, goats and pigs that we raised and we will have chicken eventually too. All amazing.) If you ever get a chance, I also recommend fresh shrimp.
True story: I was sitting in one of my favorite "dive" bars and one of the local's cell phone rings. Conversation was "Alright. See you in 30 minutes." He hangs up and says, to no one in particular, "Shrimp boat is here." The whole bar just starts handing him money.
I say to the bartender something along the lines of WTF? She says, "Do you like shrimp?" Yeah. "Are you okay with them being head on?" I guess? "Just give him $10 then."
30 minutes later everyone there is sitting with (I think) two pounds of shrimp caught right out of the bay or the port. We tabbed out, went straight home, cleaned and cooked them. They tasted like shrimp but melted like butter on your tongue. I couldn't eat shrimp for six months after that, I was so spoiled.
posted by a non mouse, a cow herd at 2:33 PM on April 14, 2019 [6 favorites]
Edit window is past, and I promise not to derail after this, but this is what the underside of a stingray looks like. (Kinda reminds me of Lady Cassandra from Dr. Who)
posted by a non mouse, a cow herd at 2:44 PM on April 14, 2019
posted by a non mouse, a cow herd at 2:44 PM on April 14, 2019
My parents both had a bizarre insistence that scallops weren't "real", and were in fact just cookie-cutter chunks of shark fin. It took several minutes of baffled conversation to clarify that they weren't just talking about misidentified seafood, but that there actually wasn't such a thing as an animal called a "scallop", it was just a tricky industry term for 'round cut of whatever'.
That would be an incredibly elaborate hoax to perpetrate.
No, it happens all the time with skates, which are a type of ray. Very common fraud. I've had them served to me in Seattle more than once.
Scallops are not served in the shell but cooked.
posted by fshgrl at 8:10 PM on April 19, 2019 [1 favorite]
That would be an incredibly elaborate hoax to perpetrate.
No, it happens all the time with skates, which are a type of ray. Very common fraud. I've had them served to me in Seattle more than once.
Scallops are not served in the shell but cooked.
posted by fshgrl at 8:10 PM on April 19, 2019 [1 favorite]
They’re served cooked on the half shell though. And the point wasn’t that fraud couldn’t happen, it’s that it can’t be happening enough to fool 99.9% of the people 99.9% of the time which would need to be the case if real scallops didn’t exist.
posted by juv3nal at 5:27 PM on April 20, 2019
posted by juv3nal at 5:27 PM on April 20, 2019
I have almost never had scallops served in the shell, and I've had scallops at a lot of restaurants. Clams and mussels are usually in shell, oysters most of the time, scallops seldom. So easy to fake.
posted by tavella at 9:54 PM on April 20, 2019 [1 favorite]
posted by tavella at 9:54 PM on April 20, 2019 [1 favorite]
« Older Was Socialism Sexy? | Science and Futurism with Isaac Arthur Newer »
This thread has been archived and is closed to new comments
posted by Construction Concern at 2:34 PM on April 9, 2019 [15 favorites]