I am an open water swimmer. Why are sharks curious to approach?

Swimming in clear water is the best way when going for open water swims and staying away from any structures (natural or human built) is good. Sharks are not attracted by Vaseline or any other such products and the appearance of one would be primarily based on sound pattern picked up by a shark, and your position (at the surface)... for a (large) shark anything floating at the surface is unhealthy (except for birds of course) thus two sensory organs suggest some form of idea that here is something to be checked out: sound and vision. Although we do not look like anything known - I attached you the paper on the non-existence of the 'mistaken identity theory' - they still like to explore. Should you see a shark getting curious, stop swimming, go vertical, start sculling with your hands while keeping your legs still, and pivot to keep the shark in sight. Should it still come closer then apply face-guide-push-move... 


Last update on 2017-04-03 by Dr. Erich Ritter.

Are sharks attracted to bright colored suits?

There is no research done that would support this. My experience is that it is not the bright colors that attract a shark but small bright batches on a dark suit... the emphasis here is on "small"... from a distance any dark suit will eventually blend in with the environment (easily noticed when it gets dark, or low visibility), however, the bright batch remains bright and is the only thing seen from distance. Should such a batch have the shape and size of a typical wound of a fish (which is normally white due the connective tissue, or white muscles) a shark seems to be attracted to that very spot... and may further investigate.

Last update on 2016-09-24 by Dr. Erich Ritter.

Are sharks (of same type) similar in their agressiveness level if the sharks come from very different geographic locations or can a location somehow impact shark behavior?

Each shark is perfectly adapted to its preferred prey. However, different areas may have a different food base and specimen of the same species may have to feed on different items in the respective area, due to seasonality etc. With that in mind, it may happen that when a food source gets scarce, the shark might be more vigilant towards other prey which could then also affect the way they approach humans in that area.

Last update on 2016-08-24 by Dr. Erich Ritter.

It is said that human blood attracts sharks?

Human blood does not seem to be an attractant, for any of the species that have been involved with humans. That people who hurt themselves for whatever reason (and were bleeding) have been attractive to sharks likely stems from the effect that they move more agitated in the water, creating non-rhythmical sound patterns and it is these frequencies that are likely the main attractor.

Last update on 2016-08-16 by Dr. Erich Ritter.

I am spending some time at a beach in Florida this summer. Is there anything I should know about sharks?

First of all, the likelihood of being approached by one is very slim. Nevertheless, should you see a shark, stop with all activities and stand up or go vertical (should you be in deeper water) and let your legs dangle. The only motion is to pivot (turn with the shark) to keep an eye on its swim pattern. Should you be in deeper water use your hands and scull to keep turning. Once the shark moves away from you (even just temporarily) you can slowly move (backwards if necessary) but keep the shark (shadow) in sight. Should the shark turn and come closer again, stop moving. And then repeat.

Last update on 2016-08-16 by Dr. Erich Ritter.

Are white sharks really close to extinction?

Yes, they are. Some of us (including me) believe that they are already biologically extinct, meaning that there are not enough males and females out there anymore to maintain the respective populations. A recent paper that calculated the number of white sharks for California mentioned that there about 250 specimen left, give or take another 100.


Last update on 2016-08-16 by Dr. Erich Ritter.

Why does Florida have the most shark attacks worldwide?

Good question. On one side Florida’s east coast is pretty much the longest beach in the world with the most people in the water at any given time. In addition too, some of the biters (blacktips, silkies and spinners) are quite abundant during summer months. One reason for that is due to feeding, but also mating… However, there is an area (close to Ponce de Leon, Volusia County) that has more bites than anywhere else. Some environmental circumstances are likely the reason. Nevertheless, if ratio (number of bites/number of people in a given area) is the marker, then an area in South Carolina would be the prime spot. The rate to get bitten there is 8 times higher than the highest one in Florida.

Last update on 2016-08-29 by Dr. Erich Ritter.

I use a strobe when taking pictures, does it attract sharks?

Yes and now. I just came back from Fiji and some of the bull sharks there acted on the use of strobes by swimming away from the diver. But most of the time I do not see a reaction at all. The only thing that can be said with some certainty is that a shark will not react “toward the diver,” meaning biting or bumping the strobe, camera or person.

Last update on 2016-08-29 by Dr. Erich Ritter.