61 replies to this topic

[zendiver]

When I had my encounter with the Tiger Shark, I did quite amount of research on several of the sharks, two of which were the Tiger (go figure) and the Bull.

Tiger Sharks
The Tiger Shark hunts alone and gets its name from the dark stripes across its back, which fade as the shark grows older. It is a deadly predator who will eat anything it can catch and get down its throat. It has an extraordinary sense of smell, and almost two-thirds of its brain is dedicated to processing information about scents.

The tiger shark is one of the most feared sharks in the world because it is known to be a man-eater. It has a very large mouth, with powerful jaws. Its teeth are flat, triangular, notched and serrated and can slice right through many things. It really doesn't care what it eats, and all kinds of things have been found in its stomach, including metal objects like car license plates.

When a tiger shark loses one of its teeth, it will grow another one to replace the lost or broken tooth. Its head is kind of wedge shaped which makes it really easy for the shark to turn quickly to one side. It can weigh up to 2,200 pounds, on average, and is usually 10 to 16 feet long, but can grow up to 23 feet long. It has a long upper tail lobe that helps to provide its sudden bursts of speed.

The tiger shark has good eyesight, but probably uses its other senses to find and catch its prey. With its awesome sense of smell it can pick up the faintest trace of blood in the water and follow it to the source. The tiger shark has electrorecptors that allow it to sense even the tiniest of movements in its prey. The electrorecptors are so sensitive that even the smallest muscle twitch will be picked up. This helps the shark locate prey in dark, murky water as well.

The sharks can have between 10 and 80 (yes 80) young in each brood. The mother will carry her young in her body for nine months, they do not lay eggs in the water like other fish. When the sharks are born they begin to hunt for themselves right away. They are able to swim as soon as they are born, and have a full set of teeth.

Tiger sharks are found in coastal, tropical water throughout the world. They will spread south and north in the summer following the warm water currents. They have traveled as far south as New Zealand, and as far north as Japan and the northern United States. During the winter months it will stay closer to the equator. They are solitary creatures, as well as nomadic, who can travel up to 50 miles in one day. They are thought to live for 30 to 40 years, but no-one really knows for sure.

The tiger shark is second only to the white shark in number of reported attacks on humans. Its large size and voraciousness make it a formidable predator in the ocean. Tiger sharks can be curious and aggressive towards humans in the water and must be considered with a great deal of respect.

Bull Sharks
According to the International Shark Attack File (ISAF) bull sharks are historically responsible for at least 69 unprovoked attacks on humans around the world, 17 of which resulted in fatality. In reality this species is likely responsible for many more, and has been considered by many experts to be the most dangerous shark in the world. It's large size, occurrence in freshwater bodies, and greater abundance in close proximity to numerous human populations in the tropics makes it more of a potential threat than either the white shark or tiger shark. Since the bull shark occurs in numerous Third World regions including Central America, Mexico, India, east and west Africa, the Middle East, Southeast Asia, and South Pacific Islands, attacks are often not reported. The bull shark is also not as easily identifiable as the white or tiger shark, so is likely responsible for a large percentage of attacks with unidentified culprits.

The bull shark has been considered to be a potential culprit in the infamous series of five attacks in New Jersey in 1916 which resulted in four tragic fatalities over a 12 day period. Three of these attacks occurred in Matawan Creek, a shallow tidal river, only 40 feet (12 m) across, 1.5 miles (2.4 km) from bay waters, and over 15 miles (24 km) from the open ocean; not a location where any other large shark species would likely occur. A 7.5 foot (2.25 m) white shark was captured two days after the last attack, however, just 4 miles (6.4 km) from the mouth of Matawan Creek, and allegedly contained human remains in its stomach. A 9 foot (2.7 m) bull shark was also captured a day later only 10 miles (16 km) from Matawan. This has been a topic of controversy for many years, and there is evidence that points at both the bull shark and the white shark as culprits.

These are some things that can be done to avoid the chance of an unwanted encounter with a bull shark:

Avoid swimming near river mouths or other estuaries with turbid waters where bull sharks are known to occur.
Do not swim near schools of fish in inshore areas. These schools are often pursued by large predators.
Be cautious if spearfishing. Bull sharks are known to approach spearfishermen carrying their catch.
Do not duplicate the practices of some television "adventurers" who flagrantly disregard common sense for showboating around sharks while underwater.

[wreck_maniac]

drbill...the latter in jextracts post would mean a bull shark

[jextract]

Yes, that is what I meant. Love seeing sharks in the wild, however I generally stay out of the water here when whites are sighted. No need to tempt fate. When I was in Kosrae, Micronesia, we could dive anywhere on the island EXCEPT the mouth of the harbor for exactly the reason that ZD identified in his posting - bulls and tigers are known to patrol the area. I do recall seeing a special on Discovery Channel or National Geographic Channel on that New Jersey shark attack.

ZD, you see tigers at the Flower Gardens somewhat regularly, don't you? I think I might be packin' an extra pair of Depends after that!

[cmt489]

PS- cmt489: if you ever dive with Jextract just remember what a dive knife is really for- to slow down your buddy so you can make the escape!

Duly noted!

[Walter]

Back in the day, BC's used to have CO2 inflators. If you needed quick buoyancy on the surface, you could pull a cord which would cause a CO2 cartridge to inflate your BC.

We used to say, "If you see a shark, pull your knife, stab your buddy and pull his CO2 inflator."

We always worried about the ones who didn't laugh.

Jamie,

While Tigers and Bulls are more likely to attack than most, it's still unlikely. If I saw a Tiger, I'd get out of the water. I'd swim slowly, while keeping an eye on the shark, with no erratic movements to the boat and exit the water, skipping my safety stop. If I saw a Bull, unless he was acting aggressive, I'd continue my dive, keeping an eye on the shark.

I'm not generally afraid of sharks, but I do have respect for them. I would be afraid of an Oceanic Whitetip and would not stay in the water if they were spotted. I believe they are the shark most likely to attack. The good news is they don't generally frequent shallow water where we normally dive.

[drbill]

I don't know if I posted to this board on the tiger shark encounter I had in the Sea of Cortez back about 1972. I was near Bahia de Kino on the mainland Mexican coast. My TA and I were paddling a Klepper folboat kayak (rubberized canvas over a wooden frame) out to Pelican Island about 5 miles from our campsite.

About 3 miles out I caught something out of the corner of my eye and looked. There was a large dorsal fin heading straight for the kayak's bow (where I paddled). I raised my paddle and kept staring at the approaching shark. It rolled and focused its eye on me. I nearly needed Depends at that point. It rolled back and went directly under my body, lifting the kayak partially out of the water.

We both went silent. A few minutes later my TA asked "Did you see that?" I said, "yes... and I felt it." Now my TA had been special forces in 'Nam and was one of the most fearless people I've ever known. We were both scared to death. Based on the length of our kayak, we estimated the shark to be about 22' long.

For some stupid reason we paddled to the island (it was closer). We were too scared to head back, but realized at nightfall it was going to be cold and we had no food, water or shelter. We paddled back in a wind that caused waves and made us very uneasy. Fortunately people at the base camp realized we were out and placed a Coleman lantern on the beach to guide us in. Unfortunately they did not save any dinner for us.

The two of us walked into the small fishing village and went into an old corrugated tin restaurant there. As we entered, the room hushed and people started pointing at us. The other expedition leader, who spoke Spanish and was already in the shanty, went over to talk to the fishermen. He came over and said "you were out at Pelican Island in a kayak today weren't you?" We said yes. He said the fishermen saw us out there in that tiny boat with El Grande Tiburon. They thought we were the bravest men in the Sea of Cortez that day. The shark apparently swam off the stern of their shrimp fleet and occasionally ate a crewman who slipped off the deck.

We were given all the beer we could eat and a grouper soup complete with scales, skull and eyeballs!

Don't think I want to see one underwater after that.

I also have had great whites follow my kayak as I paddled near the island's West End and backside.


Doc

PS- Walter, what do you mean "back in the days?" My BCD as recently as two years ago had a CO-2 cartridge inflator! Hmm... maybe I truly am stuck in the 60's (or more accurately the late 70's).

Edited by drbill, 26 July 2004 - 08:29 PM.

[WreckWench]

My experience with sharks centers around 3 species...nurse sharks which are jokingly referred to as underwater puppy dogs...I am not concerned about them however I would not attempt to 'ride' one as I've seen may a diver attempt to do; Atlantic Sand Tiger Sharks....related to Mako's and not considered aggressive. We dive with hundreds of them and actually seek them out. The final species I typically dive with is a bull shark. The bulls we see during the day are usually lone preditors and we will move away from this shark upon sight expecially if swimming in an agressive behavarior with shoulders slumped or dropped. We do not dive at night as that is when the bulls feed and therefore we str avoiding the bulk of the risk associated with seeing sharks in NC. And finally we now restrict hunting on some of our NC trips for the same reason!

Basically sharks are beautiful creatures and get a bum rap in our society. I for one love them and hope to see more of them in the wild. -ww

[Walter]

Bill,

I mean if I hadn't explained the CO2 inflator, it's likely not more than 10 or 15 members would have understood the reference. I have a horse collar with a CO2 inflator. I even use it from time to time, but when I dive vintage, I usually dive with pre BC gear.

[canuckdiver]

Bill,

I mean if I hadn't explained the CO2 inflator, it's likely not more than 10 or 15 members would have understood the reference. I have a horse collar with a CO2 inflator. I even use it from time to time, but when I dive vintage, I usually dive with pre BC gear.

LOL, Walter, I guess I would be among that 10-15


And yes, I still LOVE my Aqualung rocket fins ! :fatboyscuba:

[Walter]

I still LOVE my Aqualung rocket fins !

Adam,

How?

[canuckdiver]

I still LOVE my Aqualung rocket fins !

Adam,

How?

Still have a couple of sets of them Walter

(as well as my horse collar, and Healthways reg )

[Walter]

I like my Duck Feet, but I hate Rockets.

[canuckdiver]

I like my Duck Feet, but I hate Rockets.

LOL, the duck feet were cool too.

and I still enjoy using my tri-window mask (really freaks out the boat captains around here..)

[zendiver]

ZD, you see tigers at the Flower Gardens somewhat regularly, don't you? I think I might be packin' an extra pair of Depends after that!

Jamie,

During the migration and mating months of the hammerheads (Feb to Apr), yes we do see them on a regular basis. During the day, I don't worry much about them and actually try and seek them out to get video, BUT "Dusk to Dawn", is a whole nother story.

[vereli]

Wow, great replies. Thank you for sharing your stories.

wreck_maniac: does the repellent you use look like the one on page 2 of this thread?

Jextract's & drbill: you guys are too much!

Note to myself: buy an oversized diving knife before the next dive.

Walter: Did Mischievous see you wearing your Duck Feet when she thought you were one sexiest man alive? Yes I’ve read that tread too and had to ask. :anna:

Edited by vereli, 27 July 2004 - 01:09 PM.