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Interview with Shark Researcher Kristian Parton

Elasmobranchs, Interviews, Sharks

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

Elasmobranchs, Sharks, sharks
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!

Seabirds

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”

Ocean Animals and the Mirror Self Recognition Test

Elasmobranchs, Moby the Manta Ray
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. 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.

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

10 Fabulous Sea Cucumber Facts

10 facts, Other Marine Animals
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