These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fridge Logic: The little girl who got killed by a Goliath Tigerfish as a result of her amulet belt has this, which just makes it more tragic. Yes, good and bad magic, spirits, all that is Serious Business out in Africa — however, surely people who have been surviving by fishing in the waters for centuries would have worked out that "shiny flashy thing in water" means "good bait for predatory fish and crocodiles"? Good fishers and hunters get to be good by studying, observing and understanding their quarry. So how could they not think "belt of shiny bottlecaps" is counter-intuitive to repel tigerfish, which are some of the most common predatory fish in that region?
Goddamned Bats: Kind of a Real Life example in "Silent Assassin". When trying to catch a short-tailed river stingray, Jeremy constantly catches piranha, or has his bait stolen by (he presumes) piranha. He caught a couple of catfish, too, but the piranha were the main problem.
It seems that whenever he goes to South America, he catches/gets his bait stolen by piranha before he actually catches the intended fish.
It's either this or Demonic Spiders when Jeremy keeps trying to catch a Sawfish, but no matter where he goes, all he seems to pull out of the water are bull sharks.
Iron Woobie | Stoic Woobie: The Sawfish. Not only is it really just a gentle giant, but it's been nearly fished to extinction (and almost always just for its badass titular Natural Weapon). As a result, it's had to resort to breeding far upstream in rivers. In fact, the one that he finally catches at the end of the sawfish episode has bull shark bite marks, and crocodile bitemarks on its body. And this was just a baby. It really says a lot about this animals plight when you remember that it's intentionally going into these areas as it's still safer than going out into its preferred areas where the humans are. Humans Are Bastards, indeed.
Tear Jerker: The Goliath Tigerfish episode. One of the attacks was a little girl, whose shiny belt attracted the Tigerfish which killed her. The belt was supposed to protect her from bad spirits in the river.
Although not as the little girl, try not to feel bad for Jeremy after the third time he tries to land the Tigerfish and doesn't. They way he voices his disappointment almost sounds like a Despair Event Horizon.
The last few minutes of the 'Russian Killer' episode are largely about how screwed the featured fish, the kaluga sturgeon, is, due to the caviar market.
In one episode, Jeremy travels to a Matis village in South America only to learn that the village is in the midst of a vigil for the chief's mother whom is near death from an unknown illness. The sight and sounds of the whole village mourning her imminent passing is incredibly sobering.