Does Poop Attract Sharks? Aqua Dumpers Beware!

When you gotta go, you gotta go, and sometimes that means taking a dump in the ocean (also known as an aqua poo). Perhaps in fear of some kind of karmic retribution, some of the more cautious beachgoers have wondered: is it possible that pooping in the ocean attracts sharks?

shark threat

After all, sharks are able to detect a drop of blood from hundreds of meters away, so perhaps other bodily discharges may also attract them. In this article, we will delve into this icky topic and put to rest once and for all whether or not sharks are attracted to human poop or not.

Do sharks like to eat poop?

Sharks are not known to have a preference for eating poop. Their diets typically consist of various marine animals, depending on the species of shark. For example, great white sharks prefer seals and sea lions, while whale sharks feed mainly on plankton. 

Poop is not a primary or desired food source for any known species of shark. While they might incidentally consume fecal matter when feeding on other prey, there’s little evidence to suggest they actively seek out or prefer feces as a food source.

There is a theory that sharks may follow a pod of whales to eat their poop if they are desperate enough. The theory paints sharks as opportunistic creatures, willing to even eat poop until something better comes along.

Can sharks detect human waste in the water?

Sharks have an incredibly keen sense of smell, which they use to detect even trace amounts of substances in the water. Their olfactory senses are advanced enough to detect one drop of blood in a million drops of water. 

Given this acute sensitivity, it is possible for sharks to detect human waste in the water. However, this does not necessarily mean they are attracted to it or consider it a food source. The detection of a scent and the attraction or reaction to it are two separate matters.

How far away can a shark detect scents in the ocean?

Sharks’ olfactory abilities are among the most advanced in the animal kingdom. Some species, depending on the conditions of the water (e.g., currents, temperature), can detect scents from several hundred meters away. 

Factors like water currents play a significant role in scent distribution. For instance, if there’s a strong current carrying a scent, sharks might be able to detect it from even further away. 

However, pinpointing an exact distance for all shark species and all conditions is challenging, as it can vary widely.

Does human urine or feces attract sharks more?

There’s no definitive scientific evidence to suggest that sharks have a preference for human urine or feces or that either substance specifically attracts them. While sharks can likely detect both due to their acute olfactory senses, this doesn’t mean they are attracted to them as potential food sources. 

One theory that tangentially supports the idea that poop attracts sharks is that when humans poop in the ocean, the poop can result in an algae bloom. Coral reef fish feed on algae, and sharks are attracted to the coral reef fish that congregate around the algae, but the marine life are not interested in the poop itself.

Does human poop repel sharks?

There’s no concrete scientific evidence to suggest that human feces repel sharks. While sharks have a keen sense of smell, they primarily rely on this sense to locate prey. The presence of human waste in the water does not appear to play a significant role in attracting or repelling sharks.

For example, if you see a shark and then defecate in fear, it would not likely change the shark’s behavior around you for better or worse. Just because they can detect a substance doesn’t mean they have a behavioral response to it, whether positive or negative.

If human waste doesn’t attract sharks, why do some people believe it does?

The belief that human waste attracts sharks might stem from a few sources:

  1. Misinformation and Myths: Over the years, various myths about sharks have been perpetuated, sometimes even by well-known figures, often due to a lack of understanding about these creatures.
  2. Popular Media: Movies, TV shows, and sensationalized news can sometimes portray sharks as aggressive creatures drawn to the slightest scent in the water. This portrayal, although often exaggerated, can influence public perception.
  3. General Fear: Sharks are often misunderstood and feared. When people enter an environment where they feel vulnerable, they may grasp onto any information (or misinformation) that offers an explanation for potential dangers, regardless of its validity.
  4. Anecdotal Evidence: Personal stories or experiences, even if they are rare or misinterpreted, can spread and become accepted as general truths.

Does the composition of human waste in saltwater affect shark attraction?

The composition of human waste can change in saltwater. When introduced to saltwater:

  1. Dilution: Both urine and feces will dilute relatively quickly, dispersing their components.
  2. Chemical Reactions: Saltwater, due to its salinity and mineral content, can cause chemical reactions with the substances found in human waste. This can alter the pH or break down certain compounds.
  3. Bacterial Activity: Saltwater has its microbial ecosystem. When human waste is introduced, the native bacteria might act upon it, leading to further decomposition and potential changes in its composition.

However, even with these changes, there’s no solid evidence to suggest that the altered composition of human waste in saltwater has any significant effect on shark attraction.

Do other marine animals get attracted to or repelled by human waste?

Human waste can introduce nutrients into the marine ecosystem, potentially leading to localized blooms of algae or other microorganisms. 

Some marine animals that feed on these microorganisms, like certain small fish or filter feeders, might indirectly be drawn to areas with increased nutrient concentrations. However, this would be a secondary effect, not a direct attraction to the waste itself.

On the other hand, large concentrations of human waste can be detrimental to marine ecosystems, leading to oxygen depletion and negatively affecting marine life. In areas with significant pollution or untreated sewage discharge, many marine species can be harmed or repelled.