The Angelshark (Squatina squatina) typifies the fish most at risk of extinction: it grows to a large size and is cartilaginous, so it has characteristics which make it less resilient. Once common throughout Europe, it is now only found in the Canary Islands.
President Trump’s frequent trips during the winter to his Florida property, Mar-a-Lago, sparked protests from nearby residents, ethics watchdogs and some elected officials.
But here’s something that’s mostly escaped public attention: The trips are also bad for sharks.
Blacktip sharks are seen migrating along the southeast Florida coast. (Stephen M. Kajiura)
Granted, Trump has expressed his distaste for sharks more than once, so he probably wouldn’t lose sleep over disrupting research on the ocean’s top predator. On July 4, 2013, he fired off multiple tweets denigrating the ancient species, writing, “Sharks are last on my list — other than perhaps the losers and haters of the World!”
Stephen M. Kajiura, a professor of biological sciences at Florida Atlantic University, has conducted an aerial survey for the past seven years to record the abundance and migration patterns of blacktip sharks.
The aerial surveys involve a low flying plane that takes off from an airport included in the no-fly zone activated when President Trump is in Mar-a-Lago.
“He has no idea that he’s doing it, but it does mean a significant reduction,” Kajiura said, hastening to add that he’s “not complaining” but does believe it represents the first time there has been “a direct imposition on data collection by a visiting president.”
Because the president traveled to the property seven times over the course of his first 11 weeks in office, it reduced the number of surveys that the marine biologist could take during that period by one-third.
I spoke with Dr. Kajiura about these migrations after his presentation at Shark-Con, and this is definitely some interesting data. If you are interested in reading the most recently published results, you can access the paper here: Kajiura & Tellman, 2016.
Many species of catshark (family: Scyliorhinidae) lay eggs in tough egg cases known as mermaid’s purses. These cases have curly tendrils that tangle around objects to prevent them from floating away.
The gestation period of the egg can range from a few months to over a year, depending on the species and water temperature. If held against a light source, the developing embryo can easily be seem.
