Ocean of Hope

10 Interesting Great White Shark Facts

Great White Shark Facts: Photo credit: Elias Levy via Visualhunt / CC BY
Great White Shark: Photo credit: Elias Levy via Visualhunt / CC BY

10 Interesting Great White Shark Facts

1. Great white sharks are the largest predatory fish in the oceans.

2. The great white shark’s scientific name Carcharodon carcharias means ragged tooth.

3. The largest great white sharks recorded were over 20 feet long (6.1 m) and weighed over 5,000 pounds (2,268 kg).

4. Like all sharks, great white sharks have a “sixth sense” that detects electrical impulses such as your heart beating.

5. Adult great white sharks eat sea lions, seals, small toothed whales, sea turtles and carrion (meat from already dead animals). Young great white sharks eat mainly fish and rays.

6. Great white shark pups are 50-60 pounds at birth (22.7-27 kg), and 47-59 inches (120-150 cm) long.

7. Great white sharks are considered warm-blooded (like mammals) or endothermic. Their body temperature is warmer than the water surrounding them.

8. The only enemies of great white sharks are killer whales, larger sharks, and humans (who kill up to 100 million sharks of all species per year).

9. Recent studies suggest great white sharks use their excellent eyesight to spot their prey.

And the last great white shark fact is:
10. The IUCN (International Union for the Conservation of Nature) considers great white sharks “vulnerable” to extinction (and not endangered-yet).

Also see: 10 Cool Shark Facts: Your Questions Answered!

Great White Shark’s Adventure at the Monterey Bay Aquarium

Children’s Book Review: If Sharks Disappeared by Lily Williams

Book: "If Sharks Disappeared" by Lily Williams
Book: “If Sharks Disappeared” by Lily Williams

If Sharks Disappeared, is written and illustrated by Lily Williams, and published by Roaring Brook Press. It is a much needed book about sharks. There are numerous children’s books about sharks, but not many show sharks in a positive light.

Instead of painting sharks as blood-thirsty human eaters, Williams shows how important sharks are to the ocean ecosystem. There is one “scary” picture of a great white shark, but it is cartoon-like enough not to be really scary. Otherwise Williams’ charming artwork depicts sharks as not scary and almost friendly (which most are!).

My favorite page shows a couple dozen sharks of different sizes and shapes. As a marine biologist it was a puzzle to try and figure them all out as they are not labeled. I also liked how there was dark-skinned girl as our guide throughout the book as showing diversity is becoming important in children’s books.

The “if sharks disappeared” portion of the book is not alarmist, but rational showing literally an ecosystem without sharks. The backmatter consists of a glossary and more information about how sharks are in trouble and what you can do to save them.

All in all, not just shark-loving kids will like this book. Most readers will be delighted with Williams’ shark artwork and will learn more about sharks at the same time. I highly recommend that you check out If Sharks Disappeared! (link to order)

Hammerhead Sharks at Cocos Island

Hammerhead Sharks, Cocos Island Photo by Edwar Herreno, Undersea Hunter
School of Hammerhead Sharks, Cocos Island Photo by Edwar Herreno, Undersea Hunter

Ah, it feels great to swim around in a school of Hammerhead Sharks. My name is Sam. Here at Cocos Island, off of the shore of Costa Rica, I can roam free with hundreds of other hammerhead sharks. I used to swim in schools of thousands of hammerhead sharks before the humans came. In other areas of the oceans, populations of all types of sharks have been decimated.

Unfortunately, fishermen target sharks for their fins. Ouch, I need my fins to steer and swim, thank you very much. The shark fins are used in a soup served in many Asian countries, mainly China.

Fortunately, there are shark fin bans around the globe. The United States for instance, has 11 states and 3 territories that ban the sale, trade and possession of shark fins. Recently, on June 23, 2016 a bill called the Shark Fin Elimination Act of 2016 (S.3095/H.R. 5584) began its call to action in the United States Congress. This bill would ban the selling of shark fins across the entire United States. Stay tuned for updates!

Another reason for hope is Marine Protected Areas or MPA’s. There are over 6,500 MPA’s around the globe that fully or partially protect the flora and fauna that live there. These MPA’s make up less than 2 percent of all the world’s oceans though. Humans can do better than that! In contrast, up to 15 percent of land is protected.

Animals such as giant manta rays and whale sharks sometimes come to Cocos Island. They are protected while here, but once they swim into international waters, they are fair game for fishermen. That’s why it’s so important that scientists tag these migrant animals and see where they go. For instance, it isn’t known where female whale sharks give birth. Once humans find out, it will be important to protect the whale sharks’ pupping grounds.

I hope you’ve enjoyed my lesson today-please come visit me and my friends someday! Cocos Island is one of the best SCUBA diving sites in the world!

My Manta Ray Encounter

manta ray
Close encounter with a manta ray (notice the plankton in the water) photo by: Cherilyn Jose

This blog post won second place in the 2016 San Mateo County Fair’s Literary Contest for best blog entry!

My Manta Ray Encounter

From the back of the boat, I made a giant stride into the black nighttime water. Underwater, the cumbersome SCUBA equipment strapped to my back was weightless. Warm water crept into my wetsuit. Exhaling, I descended into the pitch black. Pinching my nose and blowing out through it cleared my ears every few feet, and the pain in my ears felt like when ascending in an airplane. Exhaled bubbles surrounded and reassured me. My only lifeline underwater was working properly. I paused to marvel at breathing underwater.

My descent stopped near the bottom of the coral reef. Narrow beams of light danced around as other divers searched for life on the night coral reef. My highlighted view showed motionless fish sleeping. Multi-legged critters scampered out of my light. A hungry moray eel caught an unwary squirrelfish.

Ten minutes of swimming brought me to the “campfire.” Placed in the center of this underwater campfire was a bundle of dive lights so the insects of the sea, tiny plankton, swarmed together. Swarms of plankton attracted various hungry sea animals including fish, and the guests for the night. Divers pointed their lights towards the surface to attract more plankton. Settling down on my knees in the moderate current, plankton surrounded me. Little white dots darted to and fro in front of my dive mask. My dry mouth came from breathing the arid air from my tank and made me cough into my regulator. My eyes watered from the coughing, then cleared. Something emerged in the distance.

From the muted black darkness, and through the backdrop of the bright Hollywood lights of videographers, came an alien behemoth that glided over the all the divers. She was the star attraction for tonight, a manta ray. Her black back with white patches looked spray painted. Her flattened head and head fins swayed in her swim path. Her head fins unfurled to help funnel water into her cavernous mouth.

Her diamond-shaped body measured at least 6 feet across. She flapped her triangular pectoral fins in unison like a bird’s wings. Each powerful flap of her wings sent her flying within inches of divers’ heads.

The manta ray’s black back contrasted with her stark white underbelly. Her belly was full of black splotches. Splotch patterns are as unique as a human fingerprint and they allow scientists to identify and name individuals over time. The manta ray I saw was named Shirley. She gracefully flew inches over my head. I was reminded of the opening scene from the original Star Wars movie when an Imperial Star Destroyer appears to fly over the audience’s heads.

We divers are not supposed to hold their breath underwater, but in a briefing on the boat we were told not exhale bubbles directly onto a manta ray. I unconsciously held my breath as having Shirley so close to me took my breath away. I looked straight into one of Shirley’s eyes. They reflected such depth and soul that I couldn’t help but feel a deep connection with this alien being. It was like looking into a mammal’s eyes. Only manta rays are fish. They have the largest brain of any fish in the ocean, and a similar brain to body ratio as mammals. There is no doubt in my mind that manta rays are thinking beings. What they are thinking is a mystery to us humans though.

With her mouth agape, Shirley’s wide throat was visible. Her gills reverberated from the passage of water through them. A manta ray’s gills not only extract oxygen from the water around them, but also extract food like plankton. She closed her mouth periodically, presumably to swallow the plethora of plankton caught in her gill rakers.

I watched in awe as Shirley did loop de loops to gather plankton. The barrel rolls that manta rays perform are a magnificent underwater ballet. They are elegant and graceful. I could watch them for hours barrel rolling.

Later, another manta ray showed up. His name was Uhane Nui, which means “Great Spirit” in Hawaiian. Estimates placed his wingspan at eight feet across. Manta rays are the largest rays in the ocean. This one was huge. Shirley stayed in the lights, but Uhane Nui faded into the darkness and emerged from the bright videographer lights. Each appearance was a surprise and delight. The manta rays could come within inches of the divers and never bump into them. They could turn on a dime.

That magical night off of Kailua-Kona, Hawaii was my first encounter with manta rays. Upon arriving home, I devoured all the information I could find about them. I was dismayed to find out manta rays are killed when they get stuck in fishermen’s nets. Historically, fishermen would exact revenge on any manta rays that got stuck in their fishing nets and kill them.

I was later horrified to learn that today manta rays are now being targeted by fishermen. I got involved in the fight for California to ban the sale, trade and possession of shark fins. Now, much like sharks being targeted only for their fins, manta rays are now being hunted solely for their gill rakers. Gill rakers are used in controversial new formulas of Traditional Chinese Medicine. Often those hunting for shark fins will fin a shark alive and toss it back into the ocean to die a slow and agonizing death. Similarly, those hunting manta rays will kill them, cut out the gill rakers, and throw out the rest of the manta ray. Killing them that way is inhumane and wasteful.

A live manta ray is worth more alive than dead. Experts estimate a manta ray is worth one million USD over its lifetime due to ecotourism, but worth only five hundred USD when dead. Globally manta ray tourism is estimated to be 100 million USD annually. I’m hooked on SCUBA diving with manta rays-I will add to that total!

What it’s Like to SCUBA Dive: Part I

manta ray cleaning station
Me and a manta ray at a cleaning station

I have returned from a SCUBA diving trip to the Big Island of Hawaii, and I am inspired to share the joy of diving with those that may never learn to dive. PADI, a leading SCUBA diving organization that certifies divers, has certified over 23 million SCUBA divers. That means (assuming most of the certifications from PADI were in the USA) less than 1% of people in the USA have gone diving.

Here’s a description of what it’s like to suit up on a boat dive and actually enter the water:
(This assumes that the gear is already setup, which also takes time to do and will be a part of a different post)

Gearing up for me starts with a fleece-lined dive skin. This layer helps keep me warm, and it helps the wetsuit slide on more easily. Then it’s the farmer john wetsuit layer (think overalls). After sliding it on, I get help with the Velcro shoulder straps. The shortie part of the wetsuit (it covers the chest, arms, crouch and part of thighs) is next. I put on the booties on my feet under the leg portion of my farmer john wetsuit.

It’s time to defog my mask with defog drops (others use spit, dilute baby shampoo or defog gel). I rub them on the inner windows of my mask, and rinse in water. It’s then time to sit down on the bench in front of my gear. I check that my tank and dive computer are on. I put my flippers on. I strap on my BCD (Buoyancy Compensator Device) on like a backpack, and clip or Velcro several straps to me. I shimmy my way out of my seat and shuffle to the back of the boat. Take a giant stride off the dive platform, signal I’m okay to the boat, and get camera from crew member.

I let all the air out of my BCD and start to descend. I clear my ears frequently (it’s the same as when you pop your ears on an airplane). Near the bottom I add air to my BCD so I don’t hit the bottom, especially if it’s a coral reef. I always marvel at some point during my dive at how I’m breathing underwater. It’s a weird yet exhilarating feeling. I look around at all the fish and coral, and look around frequently for large visitors such as dolphins and tiger sharks that prove quite elusive.

I usually follow a dive guide so I don’t get lost. More experienced divers, especially photographers, go off on their own. I take lots of pictures even though I know they aren’t good. They serve as a reminder of the fish and coral I’ve seen. I check my dive computer frequently to monitor depth and air consumption. By 500 psi I signal to my buddy and dive guide that I need to surface (a thumbs up) and the guide points up to the boat above and waves goodbye. I do a safety stop for 3 minutes at 15 feet. Then I kick up to the boat’s ladder and take off my fins. I give them and my camera to a crew member on the boat. I haul myself out of the water and waddle over to my spot on the bench. Once the tank is in place, it’s time to unstrap myself and share what I saw with my fellow SCUBA divers!