Review of documentary Sharkwater: Extinction by Rob Stewart

Rob Steward
Rob Stewart, award-winning biologist, photographer, conservationist, author and filmmaker

I just watched Sharkwater: Extinction (2018) a documentary that stars shark and ocean conservationist Rob Stewart. It’s the sequel to Sharkwater, which came out in 2007. According to the Sharkwater.com biography on Rob, his documentaries along with his activism, has saved 1/3 of the world’s sharks.

But sadly, I learned that 150 million sharks are killed a year, double the 73 million sharks a year number I heard many years ago. Sharks are killed not just for the shark fin trade anymore—shark can be found in cosmetics as squalene or squalane, in pet food or livestock feed and in the “fish” sold in stores and restaurants. Much of the fish in sold in stores is mislabeled, or in the case of shark intentionally mislabeled (maybe by the distributor or fisherman) so consumers will buy the product. It’s dangerous to eat shark because they are full of toxins like mercury. It’s recommended that pregnant women and children don’t eat shark because of that.

Rob and his cameraman got great footage of two sharks still alive in a gill net, but about to meet certain death. They were not able to save the sharks, but their footage helped convince legislators in California to ban gill nets in 2018. Gill nets can be miles long and are made of a clear monofilament that practically disappears underwater. Large animals such as sea turtles, sharks, whales and seabirds swim into the net and get stuck. All the above animals, except most sharks that need to keep swimming to get oxygen, need air to breathe. These caught animals drown before the fishermen pull the nets up.

Gill nets are used in target fisheries, such as for swordfish. Anything not a swordfish is considered bycatch. According to Oceana, an ocean conservation non-profit, up to 63 billion pounds of bycatch is caught every year and thrown back into the ocean. When Rob made Sharkwater: Extinction in 2016, it was only estimated to be 54 billion pounds. Sadly bycatch numbers are up. As is the sobering possibility that by 2050, there will be more plastic and trash in the ocean than fish.

It’s a sad documentary to watch in general, because much of the documentary is footage of shark fins or dead sharks. But there is enough footage of Rob swimming with sharks to be inspiring. The end is sad because Rob passed away before the documentary was complete, and his death completed it. He had been using a rebreather, which is advanced diving, while scuba diving off of Florida. He was looking to film a sawfish in the wild. A rebreather is great for filming wildlife because it produces no bubbles. Instead the carbon dioxide you breathe out is scrubbed out and you breathe in clean oxygen.

The ending montage made me cry, and not just because Rob had died. It’s his moving words that are inspiring. Thanks to his documentaries, his legacy will live on in shark conservationists worldwide. Please visit Sharkwater.com and read, 10 Easy Ways to Save Sharks and watch on Amazon Prime for free (if you’re a subscriber).

Meet the Pink Manta Ray!

pink manta ray, manta ray Australia
Pink Manta Ray from Australia photo by Kristian Lane/Instagram

Yes, I’m really a pink manta ray

My belly is pink, whereas in “normal” manta rays their belly is white with black spots and splotches on it. I’ve been nicknamed “Inspector Clouseau” from the movies and tv program called the Pink Panther. You clever humans!

Why am I a pink manta ray?

I don’t know, I think I was just born that way. You intelligent humans have ruled out stress. From a small skin sample (a biopsy) they have ruled out a diet full of red food, it’s not an infection or a genetic mutation.

My pink pigments

So now you humans guess that it’s a “unique expression of melanin” or that my skin pigments are just “off”. Duh, I could’ve told you that! After all there are “strawberry blonde leopards,” and “fuchsia grasshoppers,” due to something called erythrism. That causes animals to appear reddish or pinkish.

I’m a boy!

I was first seen in 2015 off of Australia’s Lady Elliot Island. I’m now 11 feet wide (wingtip to wingtip) and yes, I’m a boy. I was last seen as part of a courting train, which is when a line of males (in this case 8) chase a female to try and mate with. Her pheromones are quite irresistible! If she’s looking for unique, I’ve got all the other boys beat–I’m a pink manta ray after all!

My biggest predator…

Even though as a pink manta ray I stand out in a crowd of manta rays, I’m relatively safe from killer whales and great white sharks due to my size. In fact, my biggest potential predator is you humans!

Devil rays

Yes, all manta rays are at risk at being targeted and hunted by humans. Fishermen nicknamed us devil rays because our curled up head fins look like devil horns. We would often get tangled in their fishing nets and ruin them. They really didn’t like that or us because of that.

What are gill rakers?

Now us manta rays are targeted for our gill rakers. They are thin, comb-like strings on our gills that capture all the yummy plankton from the water I strain through my gills. In other words, my gill rakers are what keep me alive!

Even pink manta rays can’t outsmart humans though…

Unfortunately, a new not-so-traditional and controversial formula of Traditional Chinese Medicine utilizes gill rakers and humans now target us gentle and giant beings. We manta rays have the largest brain-to-body ratio of any fish, but alas, even our intelligence cannot keep us from being hunted, possibly someday to the point of extinction. Coupled with our lack of defense (we have no stingers) we have little hope of surviving unless humans stop targeting and killing us faster than we can reproduce. Its no wonder females have a train of males trying to court them—they only mate every two years and have pups every 2-5 years.

Also see Moby the Manta Ray: Happy Manta Ray Day!

For more on how you can help manta rays, visit these ocean conservation non-profits:

Manta Pacific Research Foundation

Manta Trust

Marine Megafauna Foundation

Wild Aid’s Manta Ray Program

Articles used in this blog post:

Rare pink manta ray spotted near Australia’s Lady Elliot Island

How manta rays gill rakers filter water without clogging

Manta ray reproduction

Duffy the Sea Turtle: Children’s Picture Book Review

Duffy's Lucky Escape children's book
Duffy’s Lucky Escape children’s picture book

“Duffy’s Lucky Escape,” by Ellie Jackson and Liz Oldmeadow, is a children’s picture book about a sea turtle. She lives on a colorful coral reef. Duffy was minding her own business when a storm came and washed her out to sea. There her adventure with trash in the ocean began…unknown to her she eats some plastic (sea turtles often mistake plastic bags for jellies). Fortunately she is rescued, rehabilitated, and eventually released back where she belongs.

“Duffy’s Lucky Escape” is based on real events. It is a charming children’s book that gently teaches kids about garbage in the oceans and the dangers that it poses to wildlife.

The illustrations are beautiful and colorful. They are realistic, but still cartoony as you’d expect from a children’s picture book. There are facts about sea turtles at the end as well as ways children can help ocean wildlife such as Duffy. For instance, everyone can use less plastic by using a reusable water bottle instead of single use water bottles and also not use plastic straws.

I highly recommend this book for any school-aged child—it would make a great addition to any library. It teaches in a gentle way, and it has actionable tips so children feel empowered to help ocean wildlife.

There are other Wild Tribe Heroes books. “Marli’s Tangled Tale” is about a puffin who gets tangled in a balloon from a balloon release. Another is “Nelson’s Dangerous Dive” about a whale who gets trapped in fishing nets. A newly released book is “Buddy’s Rainforest Rescue” about an orangutan and palm oil.

For more information, visit Wild Tribe Heroes

Manta Rays Have Social Lives!

manta ray, reef manta ray, Manta alfredi
Reef manta ray (manta alfredi) photo by: Shiyam ElkCloner, Wikimedia Commons

Hee, hee. Did you know manta rays have a social life? I know about manta rays social lives because I AM a manta ray. My name is Molly. Humans have only studied manta rays in depth (probably) for decades. Before we were admired for being a gentle giant, fishermen called us “devilfish.” Our curled up head fins look like devil horns, hence the name. Never mind most of the time we’re feeding and our cephalic fins are uncurled. We’d often get caught in fishermen’s nets by accident. The fishermen would get angry that not only did they have to untangle us, but they often had to repair their nets.

In any case, humans have come out with a research study showing that female reef manta rays (Manta alfredi) “show preference” to other female manta rays. I’d say we’re friends, or acquaintances at least for the short-term. We also remember our contact with each other.

We form bonds with other female manta rays over weeks and months but not necessarily longer. That’s okay as many times after a feeding frenzy, or a stop at a cleaning station, we go our separate ways. We don’t vocalize like whales, who keep in touch at long distances. When we get excited socially we can brighten the white splotches on our black backs. But we do have the largest brain-to-body ratio of any fish so it’s no wonder we can use some of our brainpower to recognize others.

The boys, well they’re on their own unless they group with other males, females and juveniles. The main times we all come together are for feeding (plankton for all!), at cleaning stations (ahh…), and for mating. A train of males will trail a female for a long time until she gives in and mates with one. It’s fun, up to a certain point. Who doesn’t like all that attention?

So although scientists study manta rays social lives, we are in trouble nowadays because of our gill rakers. The very body parts that keep us alive are now threatening our lives. Gill rakers are a covering on my gills, which not only help me breathe, but also feed. The gill rakers act like strainers. They filter ocean water as I swim. Plankton in the water stick to the gill rakers. Plankton are the tiny plants and animals that live in the ocean and are at the bottom of the food chain. The plankton builds up on my gill rakers and yum, time to swallow!

Unfortunately many humans covet our gill rakers for the Traditional Chinese Medicine market. There is no traditional formula that contains manta ray gill rakers, just a controversial new one.

I only have 1-2 pups every 2-5 years. That’s not very often, and we certainly can’t keep up with the fishermen killing us.

Other threats to manta rays, which are making us become endangered, are injuries from being entangled in discarded fishing nets, pollution (especially microplastics) and habitat destruction.

For more information on how you can help visit:

Marine Megafauna Foundation’s work with manta rays

Manta Trust and threats to manta rays

Wild Aid’s work in China to save manta rays

Paper published on 22 August 2019: Rob Perryman et al, “Social preferences and network structure in a population of reef manta rays” Behavioral Ecology and Sociobiology

Also see Meet the Pink Manta Ray

Interview with Shark Scientist Melissa Cristina Marquez

Melissa Cristina Marquez portrait
Shark Scientist Melissa Cristina Marquez

Melissa Cristina Marquez is a Marine Biologist, Wildlife Educator, TV Presenter, TEDx speaker, Podcast Host & Author from Sydney, Australia.

Tell me more about Fins United Initiative-how you got started, what you do, and how people can get involved-what are some ways people can help save sharks?

The organization was first established in 2013 in sunny Florida, and was dubbed as “Sarasota Fins.” Inspired by the lack of shark education and conservation integrated into school curriculum’s, I began creating the tools and products I believed will help inspire understanding of these beautiful creatures. As the program’s popularity grew, its educational outreach expanded and the need for a more encompassing name became clear: thus, The Fins United Initiative was born.

The Fins United Initiative is a shark, skate, ray and chimaera education and conservation program aiming to unite fin lovers worldwide. Our mission is to provide easy-to-access information on all sharks and their relatives worldwide through partnerships with educational institutions and other programs.

We are looking for representatives worldwide – and you don’t have to have a background in marine biology, just a passion for sharks and their relatives – to volunteer their time and go to classrooms, clubs, events, etc and give a #SharkTalk! Contact us here.

How do other cultures perceive sharks (other than as scary or dangerous)?

It really varies on the relationship a culture has with the ocean. Some cultures see sharks as these scary monsters will others perceive them as shapers of the land that are to be respected. I’m hoping to publish more information about this in the near future.

How has your cultural background affected your career?

It has made me a strong advocate for not just diversity in science and science communication but also inclusion. Many people think those terms are interchangeable but they are not the same thing. While science and science communication has become more diverse in the past decade, they still are not inclusive. Science, in general, is a very expensive industry to get into, leaving many at a disadvantage. My career has been shaped by my mission of giving my platform to others to speak their truth and their science.

Tell me more about your books and/or podcast-what are they about and how can we find them?

Joining forces with Speak Up for The Blue podcast, the ConCiencia Azul podcast is COMPLETELY IN SPANISH and interviews Spanish-speaking marine scientists, conservationists, grad students, photographers, and more from around the world. We discuss their studies and some of the unique challenges they face (such as racism, poverty, government corruption, etc).

There are people out there who are doing incredible work that doesn’t get highlighted, which is unfortunate. In many cases, they overcame obstacles, including racism and sexism, poverty, cultural and family expectations, and lack of mathematics background, in order to work and excel in the fields that they love. We Latinos y Latinas have the talent, and we often just lack the opportunity. This is my way of providing that opportunity to shine a light on them.

As for the books, I can’t talk too much about them other than it features an Afro-Latinx family that dedicate their lives to wildlife conservation and education. The series pulls from my life experiences, especially with what the main character (a young female) goes through. More information will be available in the next few months!

Interview with Shark Researcher Kristian Parton

Kristian Parton
Kristian Parton

This blog post is an interview with Kristian Parton, from the University of Exeter who is studying the effects of plastic pollution on sharks. He’s @KjParton on Twitter

What are some of the threats to sharks today?

KP- Blimey, where do I begin. It’s probably safe to say sharks (and rays) are some of the most threatened species in the worlds’ oceans. They have a variety of different threats, the most notable of which are without doubt overfishing and bycatch – these two practices are responsible for the removal of the greatest number of sharks from the seas. Then we move onto problems such as shark finning for traditional medicines, climate change, ocean acidification and plastic pollution!

Why should we save sharks?

KP- Well, not only are they absolutely awesome, they’re actually really important for the health and well-being of marine ecosystems. Sharks are top predators in the marine food web and consequently if you remove them this can have knock on impacts all the way down. I think it’s also vitally important to save threatened species for future generations. I remember the first time I saw a shark in the wild, it’s an experience I’ll never forget and I want the people who come after us to be able to experience that too.

How did you get started researching the impact of plastic pollution on sharks?

KP-Initially I was an undergraduate at the University of Exeter in the UK studying zoology, but took all the marine modules I possibly could. I knew I wanted to move straight into research after I graduated and have loved sharks since I was a young boy – so it was a no-brainer for me. It’s difficult to avoid the topic of plastic pollution at the moment, particularly in regards to turtles, seals and dolphins, but I read into a little bit more about how it might be impacting sharks and rays. It turns out the scientific literature is fairly scarce on the issue, so I dived in head first looking to expand our knowledge on how sharks and rays are really impacted by plastics – most notably via entanglement and ingestion.

Why did you found the Shark and Ray Entanglement Network?

KP-We founded ShaREN after our first publication a few weeks ago because we realised the issue of shark and ray entanglement in marine debris was severely underreported. In our research paper, we used Twitter reports to help document entanglement cases for sharks and rays and realised that it was occurring at higher levels on Twitter than it was in the scientific literature. We realised that the best way to try and collect more data on the topic was to create a citizen science platform where people around the world could submit their sightings of entangled sharks and rays. ShaREN is growing quickly and we’ve already had over 30 reports of entanglement since its creation a few weeks ago, but are always on the look out for more reports! If you do spot any entanglement incidents for sharks and rays, you can find the report form here: Shark and Ray Entanglement Network

Who’s your favorite Star Wars character(s)? (Both the interviewer and interviewee are big Star Wars Fans! Are you too? My favorites are the droids, R2D2 and BB-8)

KP-Hahah – that’s a tough question! I grew up around the prequels so I have a soft spot for them. I’d probably initially say Anakin, but he ends up going a bit mad (obviously) so I’d lean towards Ewan McGregor as Obi-Wan – what a legend! I can’t wait for the new TV series based around him.

Deep Blue is the Largest Great White Shark Ever Filmed

great white shark
Great White Shark Image by skeeze from Pixabay

The following is about Deep Blue, a Great White Shark most recently filmed in the Hawaiian Islands in January of 2019. She is estimated to be 20 feet long, weigh 2.5 tons, and to be 50 years old. She’ll keep growing throughout her long life. She was last filmed 2,400 miles away off of Guadalupe Island, which is off of Baja California, Mexico in 2013. She also was photographed in 1999.

Aha! I smell it—rotting whale flesh. There’s no smell quite like it. It gets my stomach rumbling, as I haven’t eaten in a month since the last whale carcass I feasted upon.

I can smell blood from miles away. This is necessary in the open ocean. Some dead whales sink and become food for the deep sea life. Thankfully others float, which is where I eat them.

There it is! I’ve found the dead whale. There is a feeding hierarchy, which means the biggest sharks eat first. That means the puny tiger sharks, who had been previously feeding on the whale, sensed me coming and are now gone. They have left me with my own personal banquet!

Great white sharks don’t travel in packs, but occasionally we’ll meet one another at opportunistic feedings such as this. I’ve swum past 2 other large female great white sharks in the area. I’m sure they’ll show up later if they haven’t already eaten.

Mmm, yummy. I open my mouth full of triangular, serrated and sharp teeth and close down on the squishy fat and meat of the dead whale. Blood fills the water around me. Wow, it feels good to have some food in my belly.

I take several more bites, closing my eyes right before I strike. Fortunately this whale can’t bite back and hurt my eyes!

Then some strange creatures show up. They jump off a boat and swim down alongside me. Humans are not on my menu. Not enough fat to even bother with!

Lights flash all around me from the humans. They stay out of my way as I continue to feed. Soon, I’ve gotten my fill of whale flesh. I’ll come back tomorrow when I’ve had time to digest some of the meat.

My belly is so big that I feel like I’m going to burst! I may look pregnant, but I’m not right now. My dozen pups were born while I was off the coastal waters. Now I swim off into the deep blue ocean to digest my huge meal.

Also see 10 Tiger Shark Not-so-Scary Facts

Wisdom the Albatross Has Hatched a New Chick!

Wisdom the Albatross
Wisdom the Laysan Albatross and her chick in 2018 photo by: USFWS

Hello, I’m Wisdom, a Laysan Albatross. I have exciting news! My chick has just hatched after about 2 months of incubation. My life partner, Akeakamai, and I have alternated sitting on the egg and feeding out at sea.

The average Laysan Albatross lives 50 years-I’m an exception as I’m at least 68 years old. I’m the oldest known wild bird! I was banded back in 1956 and estimated to be 5-6 years old since that’s when albatross start to lay eggs.

We, all 1 million albatross (of many species) lay our eggs and raise our chicks on Midway Atoll, just Northwest of Hawaii in the Papahanaumokuakea Marine National Monument. It is a beautiful place that consists of two flat sandy islands of 2.5 square miles, turquoise water and a stunning coral reef. Up to 3 million seabirds lay eggs and raise their chicks there.

The biologist, Chandler Robbins, that originally banded me in 1956 later me found me in 2002, 46 years later! I have been returning to my birthplace to make a nest ever since. The biologists first noticed me making a nest with Akeakamai in 2006.

Most albatross don’t lay eggs every year– I guess that also makes me an exception as I have laid an egg every year! I may have raised up to 36 chicks in my 68 years of life, but who’s counting?

We can travel up to 10,000 miles just in search of food like squid and fish eggs, fish and crustaceans that are found on the top of the ocean.

We spend 90% of our lives at sea, only stopping to rest on the ocean waves.
I’ve clocked at least 6 million miles of flying.

Biologists found a chick I raised in 2001 nesting just feet from me in 2017. I wish I could recognize my former chicks, but they grow up so fast that I can’t recognize them as adults.

After about 5-6 months, my new chick will fledge and head out to sea to find food, living as I have for the past 68 years.

Note: Plastics and microplastics have become a huge problem in the world’s oceans. Birds like Wisdom ingest plastic and pass it on to their chicks when they feed them, but don’t know that they are doing so. Albatross like Wisdom have been found with bellies full of plastic, many dying from that. See previous post, “Alby the Albatross and Plastic, Plastic Everywhere in the Ocean”

Mirror Self Recognition Test and Ocean Animals

dolphin mirror test, mirror self recognition test, self aware animals
Dolphin reacts to own image in mirror

With recent news that the cleaner wrasse might have mirror self-recognition (MSR), I thought I’d write about the ocean animals that have MSR. Bottlenose dolphins and killer whales have MSR for certain. Possible mirror self-recognition ocean animals include manta rays and cleaner wrasses. An ocean animal that failed the mirror self-recognition test is the octopus.

So what is self-recognition? With a mirror, self-aware animals such as chimpanzees and bottlenose dolphins recognize themselves and don’t react as if the image is another animal of the same species. Some animals that don’t have self-recognition react to their image in a mirror with aggression or other more positive social behaviors.

The mirror self-recognition test is when a human researcher places a mark somewhere conspicuous on a captive animal. With human babies, they place a paint mark on their foreheads. Starting at 18 months, human babies investigate the mark when they see themselves in a mirror.

Then the researchers place the test animal in front of a mirror and judge from their actions (usually curiosity) if they recognize themselves or not. Here are some examples from the ocean:

Bottlenose dolphins in captivity react to a mirror image by “opening their mouths, sticking out their tongues and showing novel behaviors.” When marked, they investigate the mark on their bodies by moving the marked area towards the mirror.

Killer whales in captivity were shown themselves unmarked in a mirror. Then they were marked. The whales behaved like they expected their appearance to be altered. This showed that they have self-recognition.

Manta rays possibly show mirror self-recognition. When captive manta rays had a mirror placed in their tank, they blew bubbles, which they normally don’t do. They also appeared to investigate their image in the mirror by turning their belly towards the mirror and swimming by the mirror repeatedly.

Cleaner wrasses were injected with a mark, which is how scientists mark fish in their studies. When their throats were marked and a mirror placed in their tank, the cleaner wrasses would rub their throats against the tank. Throat rubbing is not behavior seen in wild cleaner wrasses. When the mirror wasn’t in the tank, the wrasses didn’t rub. So seeing the mark in the mirror caused the throat rubbing and hence cleaner wrasses possibly have self-recognition.

As a side note, the inventor of the mirror self-recognition test, Gordon Gallup of the State University of New York, doesn’t think cleaner wrasses have self-recognition and that the study was flawed. What do you think?

Octopuses haven’t passed the mirror test, but in studies they do orient themselves towards the mirror. Octopuses rely on their sense of touch and don’t rely on vision as much as mammals do, so it makes sense they don’t show mirror self-recognition.

On a personal note, I have gone on scuba dives with manta rays off the coast of Hawaii. I looked them in the eye and saw straight into their soul. It was no different than looking into a dog or cat’s eyes. I knew something was going on behind them. I don’t doubt that manta rays are thinking beings and that they may be self-aware.

Websites consulted:
List of Animals That Have Passed the Mirror Test
Article, “Is this Fish Self-Aware?”

10 Fabulous Sea Cucumber Facts

sea cucumber facts, sea cucumber species, sea cucumber
Chocolate Chip Sea Cucumber photo by: NOAA National Ocean Service

10 Sea Cucumber Facts

1. Sea cucumbers are not a vegetable, but an invertebrate (animal without a backbone). They are like a squishy leather-like terrestrial cucumber with a mouth on one end and an anus on the other. They breathe through their anus(!)

2. There are 1,200 known species of sea cucumbers. Sea cucumbers come in many colors, including orange, red, and brown.

3. Sea cucumbers are echinoderms and are related to sea urchins and sea stars.

4. They are abundant on coral reefs, one per square meter on un-fished reefs. Below 15,000 feet (the deep sea), they make up 90 percent of life on the seafloor.

5. Small animals sometimes take refuge in the sea cucumber’s rectum!

6. They average 3-12 inches long, but can be as small as 0.75 inches and as long as 6.5 feet.

7. Sea cucumbers are nocturnal and play an important role on a coral reef. *see more below

8. Sea cucumbers have 2 lines of defense. They can shoot out white sticky threads that tangle up any predator. They also can expel their internal organs, which are then regenerated.

9. The larvae (“baby” sea cucumbers) of sea cucumbers are planktonic and float in the ocean currents. The adults are benthic, which means they live on the seafloor.

And our last sea cucumber fact:
10. A sea cucumber can live 5-10 years (if it doesn’t get eaten or fished out as an Asian delicacy).

*Sea cucumbers are scavengers and ingest sand to eat whatever’s “stuck” to it, much like an earthworm ingesting dirt for food. The sand moves through the sea cucumber’s acidic digestive tract. The acid dissolves calcium carbonate from the sand and it is pooped out into the surrounding seawater. Corals use that calcium carbonate to build their skeletons. Calcium carbonate is alkaline (like an antacid) and can buffer acidic seawater. Scientists are studying if sea cucumbers can help mitigate the negative effects of ocean acidification due to climate change. For more on ocean acidification, see Ollie the Octopus and Ocean Acidification Definition
Facts from:
7 Facts You Didn’t Know About Sea Cucumbers
National Geographic page on Sea Cucumbers
National Wildlife Federation’s Page on Sea Cucumbers