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.
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
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. 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 dived 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.
List of Animals That Have Passed the Mirror Test
Article, “Is this Fish Self-Aware?”
The Shark Club is an adult fiction novel about a love triangle between a shark-obsessed woman, her childhood love, and the newfound love in her life. It is chock full of facts about the ocean’s inhabitants and is reverent to the ocean itself. It was nice to see written what it’s like to SCUBA dive-not just the mechanics, but the thoughts and emotions that one feels while immersed in the ocean.
As for the love triangle, it wasn’t obvious at the start or through the book whom she’d end up with, and the ending was a bit surprising at first, but was satisfying once I thought about it.
It would be one thing if it were a purely love triangle, but it’s more like a square or even pentagon if you count Maeve’s obsession with sharks despite being bitten by one as a child, and her meeting the daughter of her ex-fiancee, his infidelity the reason for her breakup with Daniel.
Maeve’s love of sharks hindered her first relationship with Daniel as she “chose” the sharks (on an expedition) over Daniel right before they were to be married. Many people are addicted to work and prize it above all else, and Maeve is one of them. I think it’s noble that she’s so committed to her job as a shark biologist and always jetting off to far flung research sites around the world, but it’s clear she has regrets leaving Daniel right before their wedding (and he cheats on her and has a child out of wedlock).
When Maeve meets Hazel, who is 6 years old, she “falls” for the scientist-in-the-making and nurtures her love of sharks and prehistoric sea monsters. They form the “Shark Club” with Maeve, Daniel, and Hazel as members. Maeve and Hazel search for shark teeth on the beach and later make a necklace from it. It’s a cute storyline, and critical to understanding the ending.
All the ocean facts Taylor mentions rang true too me as a marine biologist, but I did wonder why she had to round up the figure of how many sharks a year are killed to 80 million. Usually 73 or 100 million sharks killed a year is the figure given. It’s hard to be accurate with such a high number, and clearly it’s not sustainable to kill that many sharks a year.
The book pays respect to Dr. Sylvia Earle, “Her Deepness,” or as I like to say, the female Jacques Cousteau. She is the most prominent oceanographer alive today, having traveled to the deep ocean and spending 7,000 hours underwater in her life. The protagonist, Maeve, names a lemon shark she likes after her. The author also mentions the on-going lemon sharks studies at the Bimini Research Station in the Bahamas. The book also mentions Dr. Andrea Marshall, also known as “The Queen of the Mantas.” The author mentions her non-profit research facility (The Marine Megafauna Foundation) in Mozambique, Africa. Lastly she mentions Julia Whitty, the author of “The Fragile Edge,” about a woman’s relationship to the ocean.
The side story with her fraternal twin Robin is important, but the ending with him seemed out-of-character and less plausible than the rest of the book. But he, and her aunt Perri who raised them when their parents died, are important in Maeve’s life and that’s why their storylines are included.
I haven’t mentioned the rest of the love triangle, Maeve’s colleague from the Bahamas. Nicholas is technically still married and workplace romances are frowned upon. So Nicholas and Maeve were never officially together, though Nicholas comes to visit her at her Aunt Perri’s hotel where Maeve and Robin grew up and still live. They finally discuss a possible relationship, but put it on hold until Nicholas resolves his marriage in England.
The hotel is in sunny Florida and Maeve has a job there at the Conservancy (forgot full name). If only we all had jobs that would let us fly off to exotic locations for months at a time and still have a job when your return home. This is another reason for you to be jealous of Maeve, besides having two men pine for her.
If you happen to be scared of sharks, I hope you come away from this book with a healthy respect for them. If you love the ocean-especially being in or on it- then run, don’t walk to buy or check-out this book. I requested that my local library buy a few copies and they did! If you like romances, don’t worry as the Maeve biology stuff takes a back seat to the romance.
In short, those who love the ocean will love this book. Those looking for a different sort of love triangle (Daniel, Nicolas, Hazel and the sharks in general) will enjoy this book. There’s no graphic sex so this book could be read by young adults looking to read something beyond teen romances. If there hadn’t been sharks in this book I wouldn’t have picked it up, but fortunately the shark biologist premise sucked me in for 271 pages.
10 Tiger Shark Facts
1. A tiger shark’s stripes fade as he gets older.
2. Tiger sharks are the second most dangerous sharks to humans (after great white sharks)
3. Tiger sharks eat a variety of animals, including sea turtles (their teeth can crack their shells), seabirds, stingrays, sea snakes, fish, mollusks, crustaceans, small sharks and dead whales.
4. Tiger sharks will eat literally anything. They have been found with garbage, plastic bags, license plates and old tires in their stomachs.
5. Tiger sharks on average grow to 10-14 feet long(3-4.3m) (but can grow up to 20-25 feet long [6.1m-7.6m]) and weigh 850-1400 pounds (386-635 kg)(up to 1900 pounds [862kg]).
6. The only sharks larger than the tiger sharks are whale sharks, basking sharks and great white sharks.
7. Tiger sharks generally live alone, but when they do come together in groups they have a social hierarchy based on size. The larger sharks get first dibs on the food source, such as a dead whale.
8. Tiger sharks are killed for their fins, skin and meat. Their liver has high levels of vitamin A and are used in supplements. Their fins are used in the dish, shark fin soup.
9. Tiger sharks are considered “near threatened” (to extinction) on the IUCN Red List. They are just one spot above of “least concern.”
And the final tiger shark fact is:
10. A female tiger shark’s gestation period is 14-16 months, and she can give birth to 10-82 pups.
Meet Deep Blue-The Largest Great White Shark Ever Filmed
Great White Shark’s Adventure at the Monterey Bay Aquarium
For more information: National Geographic’s Tiger Sharks
Shark’s World Information on Tiger Sharks
Tiger Shark Facts