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The Mysterious Megamouth Shark

April 10 2018

The Megamouth is one of our ocean's most enigmatic shark species. We know almost nothing about this iconic and mysterious deep-sea giant. Recently, Taiwan has had a spike in Megamouth encounters. When fishers catch a Megamouth, the crew cannot afford to release the shark, and they are sold in the fish markets. The captains on this very small fishing fleet have agreed to allow us to study, tag, and RELEASE these peaceful giants, if we compensate them for the price the animal would bring at the market.

April 10 2018


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Mission Underway

After talking to locals we have been directed to a fish auction on on the Northeastern coast of Taiwan. This auction receives catches from around Taiwan and we were eager to checked out some of the weird sharks that they get.

Sharks are these markets are often taken as bycatch (caught by accident while fishings for other species) but are still consumed. We were interested to learn that there is a value on rare sharks and consumers like to eat unusual animals.

Among the species we saw were Blue Sharks, Bronze Whalers, and hammerheads. They also had a few Gulper Sharks which are rare, deep-sea sharks known for their slow reproduction. Finally we spotted one large (8.6 ft) False Catshark, a very rare species that is poorly known. This relatively large species has tiny teeth the size of grains of sand, and the pups (baby sharks) eat each other in the womb.

We talked to the auctioneer, and he said Megamouths, while rare in the market were seen a few times every year during this season. We were optimistic and excited to know that we were in the right place at the right time.


Paul and I are on the ground and well underway in Taiwan. The captain of our fishing vessel promises that we will indeed find a Megamouth.

Fisherman here primarily target sunfish. These gentle giants can weigh over a ton and typically make their way around slowly and awkwardly in search of jellyfish. Their size, and the fact that they can lay up to 300 million eggs at a time, make them a very sustainable food option here and in Japan. In the recent past, these boats have also been landing megamouths as well - and there is indeed a market for them.

In the coming weeks, we hope to not only tag these sharks, but we also want to explore the culture and commerce surrounding them. Science, conservation, and fishing are uneasy bedfellows. We are lucky enough to have connected with a captain who is interested in our work. We hope to find out a little more about the demand for Megamouths in the fish markets along the coast.

Tagging these giants will hopefully provide a wellspring of data to get a preliminary picture of their numbers and movement.

Science knows almost nothing about these animals. The only way we can begin to formulate a conservation plan is with the data from Paul's tags....

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Hey guys! What's the latest? Eager to hear how things are going...

+1 did you find one???

Preparation Stage

Spending some time designing a tagging method. We are using 18 month tags we have to make sure the dart stays in place and nothing wears out or corrodes before the tag pop-off date.

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Very cool Paul! Will this be the first time a megamouth is tagged for this long?

We made a quick stop in Berkeley, CA yesterday before jetting off to Taiwan to pick up the latest and greatest offering by OpenROV - the hot off the presses Trident underwater drone.

Zach and the team at OpenROV are passionate about making exploration something that is available to everyone. We hope to use the Trident to track tagged Megamouth sharks as they descend back into the depths.

We outfitted this guy with some add ons: three standard GoPro clips for side dive lights and an added GoPro 6 up top to give us a slightly different camera angle to use in conjunction with the onboard camera.

Using it is super easy! We were flying it around the test tank in minutes. Once we get to Taiwan, we'll be doing some buoyancy tests then putting it to use as we track the elusive Megamouth shark.

Thank you to everyone at OpenROV for hosting us! We'll report back from the field once we've road(?) tested the Trident!

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Great to meet you guys. Can't wait to see what you find with the Trident!

Thanks, David!

Thanks, David! We can't wait to post what we see with our souped up Trident!

Expedition Background

Although the Megamouth is a large species of shark reaching ~20 ft in length, it remained undetected by humans until about 40 years ago. Since its recent discovery very few Megamouths have been encountered with just over 100 individuals recorded in human history. However, a small fishing village in Taiwan is experiencing a large number of Megamouths a few weeks out of the year. These landings mostly go unreported and undetected by science. The fishers have contacted us with photographic evidence of these encounters.

For this expedition a small team will go to the rural fishing village and work with local fishers to catch and tag one of the most elusive and mysterious species of sharks on the planet. Working within the small window that Megamouths are accessible, we aim to collect data to study for years to come. Along with other information we will collect life history data, tissue for isotope analysis, and we will release Megamouths with 12 month satellite tags.

Almost nothing is known about Megamouth Sharks. We hope that the wealth of data we aim to collect will supply policy makers with the information they need to management this majestic species.

This looks like an incredible expedition Paul. Can't wait to follow along here. When are you heading out?

Paul, this is so exciting. Can't wait to hear more. How many Megamouths are you hoping to tag?

Thanks you guys! I am really excited. Things are happening pretty fast. The fisheries in Taiwan are starting to catch Megamouths and I am trying to get out there in two weeks. I am trying to tag 4 Megamouths during this trip. The tags will track their movement as well as depth, temp, conductivity, etc. for 18 months.