37 things I learned about shark ecology and conservation for my dissertation

The fam attending my dissertation defense

The fam attending my dissertation defense

After a little more than 5 years of hard work, I’ve officially completed my Ph.D.! You can read my dissertation (“An Integrative and Interdisciplinary Approach to Shark Conservation: Policy Solutions, Ecosystem Role, and Stakeholder Attitudes”) online here in its entirety.

In case there are some among you who don’t really want to read a 281 page dissertation but are curious about what I found, I’ve prepared this blog post to summarize my key conclusions. (Note: this does not include every conclusion. Some are aggregated together, and some more technical conclusions are omitted for this summary).

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Fun Science FRIEDay – Visualize the Seafloor

Happy FSF! As some of you may know (and for those who don’t), I study the bottom of the ocean, and I do so primarily using innovative technology to image the seafloor (e.g., Wormcam). The interesting work I’ve conducted has resulted in me having the opportunity to present my work to a larger lay audience, in the form of a TEDx presentation.

(Photo Credit: TEDx Newport)

(Photo Credit: TEDx Newport)

I am giving my TED talk with my good buddy and colleague Steve Sabo.  In our talk, “A Picture is Worth a Thousand Worms”, Steve & I will illustrate the significance of the ocean floor through advancements in underwater camera technology and data visualization, making complex science more accessible for everyone.

Our TED photo (Photo credit: Meg Heriot)

Our TED photo (Photo credit: Meg Heriot)

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Fun Science FRIEDay – Underwater World of Pollination

Pollination. I think most people understand why this is important (or maybe I should say, I hope). To put it simply, the process of pollination facilitates reproduction in plants by transferring pollen from one plant to another. In the terrestrial world, this can be mediated by physical forcing (e.g., wind) or by animals (e.g., insects) – and its why people are freaking out about the loss of bees due to pesticides (because they are a primary pollinator), but I digress. Until relatively recently, pollination by animals was not thought to occur in the ocean. Unlike on land, where most flowering plants rely on creatures to carry pollen, plant reproduction in an aquatic world was surmised to rely exclusively on currents and tides. However, a team of researchers led by marine biologist Brigitta van Tussenbroek revoked the long standing paradigm that pollen in the sea is transported only by water, discovering and documenting the process of zoobenthophilous pollination (a term they coined).

Gamarid amphipod feeding on pollen or mucilage of a male flower of the seagrass Thalassia testudinum at night. (Photo credit: Tussenbroek et al. 2012)

Gamarid amphipod feeding on pollen of a male
flower of the seagrass Thalassia testudinum at night. (Photo credit: Tussenbroek et al. 2012)

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Fun Science FRIEDay – Shark Daycare

A great white shark nursery in the North Atlantic that was discovered in 1985 south of Cape Cod in the waters off Montauk, New York  has received renewed attention due to the increased activity of white sharks off cape cod in recent years. The nursery was first documented in 1985 by Casey and Pratt who deduced the presence of a nursery based on the number of juvenile sightings and landings in the area. This work was followed up recently  by OCEARCH (an organization dedicated to generating scientific data related to tracking/telemetry and biological studies of keystone marine species such as great white sharks), which tagged and tracked nine infant great whites to the nursery, located a few miles off Montauk.

Great White Shark. Image courtesy animals.NationalGeographic.com

Great White Shark. Image courtesy animals.NationalGeographic.com

Photo of a great white shark in Mexico by Terry Goss, WikiMedia Commons. http://commons.wikimedia.org/wiki/File:White_shark.jpg

Photo of a great white shark in Mexico by Terry Goss, WikiMedia Commons. http://commons.wikimedia.org/wiki/File:White_shark.jpg

 

 

 

 

 

 

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Seagull swallowed by tuna

The tuna that ate a seagull, and other bird swallowing marine megafauna

Once again, the internet is in a fervour over a rarely documented, but pretty common, animal interaction.  The video below shows fishermen at a pier in L’Escala, Spain tossing small fish to a tuna.  A nearby seagull went for the same fish and was ingested by the tuna, much to everyone’s surprise.  Naturally, the tuna spat out the seagull, luckily uninjured, and it flew away to dive another day:

Seabirds are often ingested by marine megafauna since both groups forage in the same areas, often on the exact same prey.  This video was an artificial overlap of foraging animals created by the people tossing fish from the pier, but in natural settings where two animals feed on the same prey and one of those animals is considerably larger than the other, the smaller animal faces a pretty high risk of being swallowed.

This is especially true for lunge-feeding whales that take in large mouthfuls of fish, water, and anything else at the surface.  Haynes et al. identified three Glaucous-winged gulls in the fecal remains of foraging humpback whales in Glacier Bay, Alaska.  The birds were mostly intact, suggesting that humpback whales aren’t capable of digesting birds well (we’ve all been there).

All of the examples above are accidental ingestion, but some marine animals deliberately target birds for food, too.  Tiger sharks seasonally aggregate at the Hawaiian Islands of French Frigate Shoals to forage on albatross fledglings.  Fledglings are fat, slow, and naïve, making them easy and profitable prey.  This foraging strategy is common among sharks and is the same reason white sharks target seal colonies during South African winters.

The alien giant catfish of the river Tarn in southwestern France is an aquatic example.  They have also acquired a taste for feathered food and learned to ambush aloof pigeons, with a success rate of 28%:

Although not mega- megafauna, the Hilaire’s Side-necked turtles of Brazil have been documented consuming pigeons in a scene that honestly rivals Jaws.  Who’s slow now? (Edit: Thanks to @mattkeevil for the reference!)

Marine and aquatic animals do indeed eat birds, accidentally and deliberately.  Exactly how regularly this happens is unknown, but this antipodean pairing is essentially the chocolate shake and fries of the natural world.  The bottom line is, if you are in the same space where something bigger than you is foraging, you might get swallowed.  Birds, and humans, alike:

Fun Science FRIEDay – Osprey Version of the Truman Show #ospreycam

Do you ever get that feeling that you are being watched? I imagine that is what the ospreys at the nesting platform at the Virginia Institute of Marine Science (VIMS) must feel, if they notice at all. These birds have a camera that is trained on their nest 24/7 during the osprey breeding season (generally from mid-March to October).

Osprey in a nest on the campus of the Virginia Institute of Marine Science (Photo Credit: VIMS)

Osprey in a nest on the campus of the Virginia Institute of Marine Science (Photo Credit: VIMS)

Ospreys are unique among North American raptors for their diet of live fish and ability to dive into the water to catch them. As a result of their life history strategies, osprey nests occur around nearly any body of water: saltmarshes, rivers, ponds, reservoirs, estuaries, and even coral reefs. The placement of OspreyCam at VIMS provides us with an around-the-clock window into the world and “family” dynamics of these amazing birds. We are able to watch as a mating pair cohabit their nest and use it to rear their young. As you can imagine, once the chickies hatch, things get quite interesting in the osprey nest!

Checkout the addictive live feed below, and happy FSF!!

One of the world’s rarest birds is also the squee-est

Introducing the spoon-billed sandpiper:

(c) Roland Digby/WWT/PA Wire, originally published http://www.westerndailypress.co.uk/world-s-rarest-birds-hand-reared-experts-returned/story-27630995-detail/story.html#ixzz3jFOW6Q43

(c) Roland Digby/WWT/PA Wire, originally published here.

Spoon-billed sandpipers are migratory wader birds that breed in the sub-Arctic and winter in southeast Asia.  Best estimates point to less than 100 breeding pairs left in the wild due to a decrease of breeding habitat in the Arctic and increase of bird-hunters in Asia.  Don’t worry, this is a story about #OceanOptimism…

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Dusky Sharks: Whale Killers

It’s generally thought that baleen whales are too large to be successfully attacked by most marine predators.  Orcas are typically considered the only real predatory threat to large whales, and even they have to use teamwork to take down a young whale.  Large sharks, which also sit near the top of the marine food web, are known to scavenge on whale carcasses as a nutritious and blubbery supplement to their usual diet of fishes and smaller marine mammals.  However, evidence has been found that white sharks actually take a proactive approach to increasing the whale carcass supply by attacking live northern right whale calves.  Now researchers in South Africa directly observed dusky sharks actively teaming up to bring down a humpback whale calf.

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Fun Science FRIEDay – Ocean Acidification, More Than Just pH

You have probably heard that as the global climate changes due to human influence the sea surface is going to rise and the oceans will get warmer and more acidic. The bit about the oceans increasing in acidity is particularly troubling because it implies calcium carbonate based organisms (oysters, snails, corals, etc.) will simply dissolve in this future dystopian acid-ocean (that is a bit of an oversimplification, but you get the idea).

Ocean acidity is determined by measuring the pH, which relates acidity based on the number of hydrogen ions found in the water. So long story short, as more and more carbon dioxide (CO2) is emitted into the atmosphere, it in-turn fluxes into the oceans forming carbonic acid which results in the release of hydrogen ions lowering the pH. Simple logic would suggest that this spells bad news for calcifying organism (poor Mr. Snail).

Healthy Pretopod shell (left) and degraded Pteropod shell due to ocean acidification (right). (Photo credit: NOAA [climate.gov])

Healthy Pretopod shell (left) and degraded Pteropod shell due to ocean acidification (right). (Photo credit: NOAA [climate.gov])

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