For anyone curious about this who didn't want to watch the video, the trap consists of:
1. A large woven cone
2. A smaller woven cone without a tip
The smaller cone is placed in the larger one; shrimp swim into the small cone to explore, but then get caught in the space between the two cones when they try to get out (presumably because it's difficult to find the single entrance).
He mentions that the only skill necessary is basketweaving -- I wonder if it would be possible to carve something similar (two interlocking geometric shapes) or if the trap being woven is essential to its function, for example, for allowing flowing water in to entice shrimp.
One of the parts that stood out for me was
> In practice, a long stretch of creek might have several traps collecting food each day without any effort on the part of the fisherman.
If he were to go whole hog long-term, shrimp traps would free up his time for doing other crafts in ways that spear fishing or actively hunting wouldn't, though I suppose the local yield of shrimp would factor into that (whether he could collect enough calories consistently to fund his other efforts).
100 grams of shrimp are roughly 100 calories. Let's generously assume that one shrimp from the video yields 200 grams of meat. So he would need to continuously catch 10 shrimp a day to satisfy a 2000 calorie diet. Seems to me that the shrimp population of this stream in the video would be exhausted pretty quickly and he would need to move elsewhere to continue hitting his calorie goals.
Given that we are surrounded by an incredible amount of high-calorie food (100g of a Snicker's bar provide 488 calories), it is easy to forget how difficult it is to source calories in the wild.
You're off by a factor of over 20. A reasonable ballpark estimate for the total mass of a shrimp is 10g. The amount of usable meat is less (though in a survival scenario you would eat the whole thing, head included). Hell, the average meat yield from a standard size blue crab is only around 60g.
You would need to eat netfulls of shrimp per day to meet caloric requirements, not just ten! Anecdotally, I can toss back dozens of appetizer shrimp and still be hungry for a main course.
River shrimps are very common. It wouldn't surprise me if that creek held a thousand of those shrimps. Taking out 1% every day may actually be sustainable, as it takes out grown shrimps that otherwise would eat smaller shrimps.
And that's to survive on shrimp alone. It would be foolish to try that, not only because it wouldn't be a good diet, but also because putting all your eggs in one basket definitely isn't a good idea if your live depends on it.
And of, course, he may catch other edible animals, too, such as eels (this kind of trap is still commonly used in commercial eel fishing in Western Europe; if I had such a trap, I would consider putting a dead shrimp or other meat in such a trap to attract eels)
He had some yams with it, as well! But yes, I think the big gain here is protein, two shrimp a day in the diet of a family with five members would be a huge boost vs. hit and miss hunting / gathering.
> I wonder if it would be possible to carve something similar (two interlocking geometric shapes) or if the trap being woven is essential to its function, for example, for allowing flowing water in to entice shrimp.
Yes.
Some traps work by allowing water to flow through, e.g. you can dam a stream and have water flow only through your trap. Or you can make solid bottle traps that fish explore and get trapped in.
1. A large woven cone
2. A smaller woven cone without a tip
The smaller cone is placed in the larger one; shrimp swim into the small cone to explore, but then get caught in the space between the two cones when they try to get out (presumably because it's difficult to find the single entrance).
He mentions that the only skill necessary is basketweaving -- I wonder if it would be possible to carve something similar (two interlocking geometric shapes) or if the trap being woven is essential to its function, for example, for allowing flowing water in to entice shrimp.
One of the parts that stood out for me was
> In practice, a long stretch of creek might have several traps collecting food each day without any effort on the part of the fisherman.
If he were to go whole hog long-term, shrimp traps would free up his time for doing other crafts in ways that spear fishing or actively hunting wouldn't, though I suppose the local yield of shrimp would factor into that (whether he could collect enough calories consistently to fund his other efforts).