Martius also speculated that the fish were attracted by the "odor" of urine. Later experimental evidence has shown this to be false, as the fish actually hunt by sight and have no attraction to urine at all.
Human urine contains something called nitrates, which can cause increased algae in the water, making it toxic to the fish and other wildlife. "Urine, although sterile, is considered a biohazard and should be discarded appropriately.
Although extreme amounts of nitrogen aren't good for the ecosystem, the small amounts of urea we produce feed into the ocean's nitrogen cycle. You could go so far as to say that your pee is one of many factors contributing to the circle of life in the ocean — meaning it's not hurting the fish.
But are they attracted to blood or urine? Sharks are attracted to blood in the water. While they can smell human urine, they aren't particularly interested in it. Any tasty, smelly odorant is likely to get a shark excited but their sense of smell is no better than that of a tuna, and tiny amounts will go unnoticed.
A lot of fish get rid of the pee through an tiny opening, called a pore, that's near their rear ends—and in some fish, waste also goes out through the skin or the gills.
The differences in acidity and dissolved oxygen, not to mention all of the fat, proteins, carbohydrates, and other minerals in the milk that might clog the creature's gills, would quickly spell trouble. The animal would likely die within minutes, if not sooner.
A surprising number of creatures—from reindeer to locusts—have a known affinity for human urine. And for some species, this craving for our minerals has dramatically shaped their behavior.
There are some folks, however, who disagree with urine-as-attraction and believe that human urine deters nosey bears. But the majority of experts oppose this view. Two other no-no's that you should be aware of: You don't have to bury urine; and you shouldn't pee on vegetation.
Menstrual blood in the water could be detected by a shark, just like any urine or other bodily fluids. However, there is no positive evidence that menstruation is a factor in shark bites.
Urine nutrients become pollution when they enter the watershed. In the US, the nutrients in urine often pass through wastewater treatment plants and into rivers, lakes, and bays. Once in the aquatic environment, excess nutrients (particularly nitrogen and phosphorus) can cause harmful algal blooms (HABs).
Why do freshwater fish excrete a large amount of very dilute urine? Because they live in a hypoosmotic solution, their cells tend to accumulate a lot of solute that must be excreted. Because they live in a hyperosmotic solution, their cells take up an excess of water that must be excreted.
Upstream bacterial migrations often occur where liquids flow in one direction, such as the human urinary tract and intravenous and urinary catheters. How far and how fast bacteria can swim upstream has long been poorly understood.
While this may seem merely unappealing, a 2014 study suggested that urine can actually combine with the chlorine disinfectant in swimming pool water to make potentially harmful chemicals. The researchers recommend that all swimmers avoid urinating in swimming pools to prevent these chemicals from forming.
In trimethylaminuria, the body is unable to turn a strong-smelling chemical called trimethylamine – produced in the gut when bacteria break down certain foods – into a different chemical that doesn't smell. This means trimethylamine builds up in the body and gets into bodily fluids like sweat.
Cat, dog, or human hair or urine sprinkled in a garden also appears to have no impact on rats. Beware of anyone claiming they have a secret weapon or chemical that will get rid of rats. There is none.
If foxes are indigenous to your area, fox urine is a very good natural repellent for snakes when spread around your property. Snakes have an elevated sense of smell and are ultra-sensitive to odors and fumes.
As chemical fertilizer shortages persist, peecycling – the process of recycling human urine – could increase the yield of nutrient-rich crops.
Human beings tend to avoid places that smell of urine. But to mice, there is something positively addictive about the scent; they like to go back to a spot where they found the excretions again and again.
Not only are dogs able to smell human pee, but they can detect specific scent notes within the urine. Thus, they can pick up the smell of hormones, sugar, and things like if the person has an infection or not. This amazing ability is down to the super-sensitive nature of the canine sense of smell.
In conclusion, approximately 1.6% of all urinary sediment samples examined in daily clinical practice contain at least one sperm. There is considerable overlap between the factors associated with the presence of at least one sperm in urinary sediment and those that are strongly associated with ejaculatory disorders.
Fish have gills that allow them to “breathe” oxygen dissolved in the water. Water enters the mouth, passes over the gills, and exits the body through a special opening. This keeps an adequate amount of water in their bodies and they don't feel thirsty.
In general, grieving is unlikely in fish - unless you have individually bonded fish which might be possible in some species.
As soon as a fish dies, the other fish in the tank will begin feasting on their former friend. It's not personal; it's nature. Don't assume they murdered their former tank mate. They are just taking the opportunity to have a fresh meal.