Discovery of a Great Hammerhead Nursery

Happy Shark Week (if you celebrate), and I’m so excited to share our newly published open access paper about our research on juvenile great hammerheads (Sphyrna mokarran) with you! (It’s been hard to keep this one to ourselves).

Great hammerheads are an iconic shark species which have undergone significant population declines globally. In 2019, they were assessed as Critically Endangered by the IUCN Red List, which reported overfishing as the greatest threat to their survival. Great hammerheads are known to make incredible long-range migrations and cross state and international boundaries, making them challenging to protect as adults. Little is known about where they are born or where they spend their early years of their life, although there have been scattered reports of juveniles from the Gulf of Mexico, the Florida Keys, and one report from Georgia.

Identifying habitats that are important to juvenile sharks matters because young sharks are often the most vulnerable individuals in a population, and their survival is vital to the future of their species. Many juvenile sharks spend time in “nursery areas”—places where they are less likely to be eaten by predators, or where food resources are abundant. They then expand their ranges as they age, covering more distance as they grow larger. Identifying nurseries has long been a conservation priority for managers and scientists. After several years of research, our team has collected the first scientific evidence of a nursery area for great hammerhead sharks on the Atlantic coast of the United States—within sight of the skyline of Miami, Florida.

There’s a three-part established test for an area to be identified as a shark nursery: 1) Juvenile sharks are more commonly encountered in that habitat than elsewhere; 2) they remain in the area for extended periods; and 3) The area is used repeatedly over years. Our results demonstrate that this area definitely meets two of these criteria, with preliminary evidence that it also meets the third. We’ve found the same habitat may be a nursery area for several other shark species too, including scalloped hammerheads, another Critically Endangered species!

Although great and scalloped hammerheads are protected in Florida waters and must be released if caught, hammerhead sharks often die or suffer serious harm from capture stress. Some of these juvenile individuals were caught with hooks from prior encounters with recreational anglers still embedded in their jaws. We hope learning more about this nursery can help us reduce threats to and better protect these small sharks. We can’t wait to share further updates as new results come in from the project’s telemetry expansion, supported by the Nature Trust of the Americas and a National Geographic Explorer Grant.

Our short scientific paper documenting this work is available open access through the journal Conservation Science and Practice, you can visit the project website here, or I hope you will watch the incredible video (also embedded at the top of the post).

Fun Science FRIEDay – A fish without blood

Amidst all the hysteria surrounding the seemingly unstoppable COVID-19, we bring you a story of a fish without blood. In 1928 a biologist sampling off the coast of Antarctica pulled up an unusual fish. It was extremely pale (translucent in some parts), had large eyes and a long toothed snout, and somewhat resembled a crocodile (it was later named the “white crocodile fish). Unbeknownst at the time, but the biologist had just stumbled on a fish containing no red blood pigments (hemoglobin) and no red blood cells – he iron-rich protein such cells use to bind and ferry oxygen through the circulatory system from heart to lungs to tissues and back again. The fish was one of  sixteen species of what is now commonly referred to as icefishes that comprise the family Channichthyidae, endemic around the Antarctic continent.

The Antarctic ice fish on the seafloor surrounded by brittle stars. (Photo credit:  E Jorgensen/Alfred Wegener Institute)
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Fun Science FRIEDay – Suspended Animation

Scientists (and sci-fi fans) have to varying degrees been discussing the concept of suspended animation for years; the idea that the biological functions of the human body can somehow be put on “pause” for a prescribed period of time while preserving the physiological capabilities. If you’ve ever watched any sci-fi movie depicting interstellar travel you have probably seen some iteration of this concept as a way to get around the plot conundrum of the vastness of space and space travel times, relative to natural human aging and human life span. The basic principle of suspended animation already exists within the natural world, associated with the lethargic state of animals or plants that appear, over a period, to be dead but can then “wake-up” or prevail without suffering any apparent harm. This concept is often termed in different contexts: hibernation, dormancy, or anabiosis (this last terms refers to some aquatic invertebrates and plants in scarcity conditions). It is these real-world examples that likely inspire the human imagination of the possibilities for suspended human animation. The concept of suspended human animation is more commonly viewed through the lens of science fiction (and interstellar travel), however, the shift of this concept from scientific fiction to science reality has a more practical human application.

Computer artwork of futuristic humans in suspended animation (Photo credit: Science Photo Library).
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Fun Science FRIEDay – The Emperor of all Maladies

The Emperor of all Maladies is how Siddhartha Mukherjee, an Indian-born American physician and oncologist, aptly described cancer. Cancer, this scourge of mankind going back as far as 4,600 years ago when it was identified by the Egyptian physician Imhotep (the first in recorded history). Cancer takes one of the most successful traits of complex eukaryotes, cell division, and weaponizes it in unchecked cellular growth; some even consider cancer to be a more evolved form of cell division. This ailment has plagued humanity, and baffled physicians for centuries as they attempt to tackle the seemingly impossible, discover a cure for cancer.

Scanning electron micrograph of a human T cell. (NIAID/Flickr/CC BY 2.0)
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Fun Science FRIEDay – Inception

Inception, a clever movie starring Leonardo DiCaprio where the premise of the story is to sneak into a person’s subconscious and implant an idea or a memory whilst they sleep. When the person awakes from their slumber they cannot distinguish the implanted memory from their own. It makes for blockbuster cinematography, but the practical concept is quite frightening to think about: the ability to artificially implant memories inches closer to the prospect of reality distortion.

Zebra Finch – Birds (Credit: Paul Dinning)
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Fun Science FRIEDay – Gut Enzyme Turns Blood Into Type O

The process of blood transfusions, started in the late 19th century and perfected in the early 20th century, were a big advancement in modern medicine and the treatment of human health. Part of the improvements in this procedure was the discovery of the various blood types in humans, and how that affects how the immune system responds to and “accepts” blood transfusions. Recently, researchers from the University of British Columbia may have found a reliable way to use a bacterial enzyme from the human gut to convert any type of blood into type O – which is compatible with nearly everyone.

Animation of red blood cells (Photo credit: meghanmecrazy)

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Fun Science FRIEDay – Resurrection

Life has unbelievably complex and diverse strategies to ensure survival. Organisms are able to go dormant during unfavorable conditions, and resuscitate once the environment becomes ideal again. This can play out over relatively short time periods such as when animals hibernate, or over longer periods where organisms can go into stasis, e.g. reviving bacteria from 250 million year old salt crystals.

Researchers in Russia recently thawed out permafrost sediment frozen for the past 42,000 years, and revealed once frozen and now living nematodes. Yes you heard that correctly, worms birthed and subsequently frozen during the Pleistocene (42,000 years earlier) were just resurrected in the 21st century. Frankenstein, eat your heart out.

Eophasma jurasicum, a fossilized nematode. (Photo credit: Ghedoghedo)

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Fun Science FRIEDay – The Break-up

Our lives are a blip in the space time continuum. As a result, it can seem that the Earth is relatively static, with many of the large scale dynamic changes that shape our sphere largely unnoticeable to us occurring on geological time-scales. One such change is the movement of landmasses on earth, better known as plate tectonics.

Earth’s landmasses are not static but in constant flux. The Earth’s lithosphere (formed by the crust and the upper part of the mantle) is broken up into a number of tectonic plates that move relative to each other at varying speeds, “gliding” over a viscous asthenosphere. There is still ongoing debate about what force or forces causes this movement, but whatever the forces are they can also cause the plates to rupture, forming rifts, and potential leading to the development of new plate boundaries. When this happens landmasses break-up and new continents forms; this is currently happening in the East African Rift in southwestern Kenya.

View of East African Rift in Kenya from space (Photo credit: Google Earth. Data SIO, NOAA, US Navy, NGA, GEBCO).

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Fun Science FRIEDay – A blood test for cancer

Cancer is a tricky disease. It comes in many varieties and can pop-up anywhere in the body seemingly at random. The somewhat cryptic nature of this disease can make diagnosis difficult; this can be frustrating because most cancers are treatable if diagnosed early. Thats what makes this most recent breakthrough all the more exciting; a method to detect cancer through a single blood test!

The blood test is called CancerSEEK and its speculated that it would cost less than 500 USD, which is comparable to or lower than other screening tests. CancerSEEK, is a single blood test that was shown to detect 8 types of common cancer (ovary, liver, stomach, pancreas, esophagus, colorectum, lung, and breast) and helps identify the location of the cancer.

Photo credit: fotoquique – Getty Images

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Fun Science FRIEDay – Think water comes in just liquid, ice and gas? Think again!

One of the most basic things that we learn when growing up is that water can exist in 3 different states of matter: as a gas (water vapor), as a liquid (water… water), and as a solid (ice). This basic and fundamental concept has recently been turned upside down as scientist have discovered that water might also exists in a fourth state; liquid water it appears might actually come in two different states. A collaborative team of researchers led by Dr. Laura Maestro at Oxford University, found that the  physical properties of water changed their behavior between 50 and 60℃ potentially changing to a second physical state of water.

(Photo credit: Pixabay/Public Domain Pictures via CC0 Public Domain)

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