Prickly Shark Nimbly Maneuvers Above Seafloor
Nimbly hovering above the seabed, this 1-meter-long prickly shark (Echinorhinus cookie) was spotted by our team at a depth of 660 meters (2,185 feet) near Howland Island in the Pacific Remote Islands Marine National Monument (PRIMNM).
These sluggish bottom-dwellers are named for thorny projections, known as denticles, that run along their body, each measuring up to .4 centimeters (.15 inch) in length! Even though they have 40 knife-like teeth, prickly sharks pose no harm to humans.
Prickly sharks are mostly found in the depths below 100 meters (330 feet), though some may occur as deep as 1,500 meters (4,900 feet). These bottom-dwelling sharks are tolerant of lower levels of oxygen which allows them to live in places that other sharks cannot, such as the continental slopes and submarine canyons of the Pacific Ocean.
Grayish brown in color with a short snout and stout body, prickly sharks can grow up to four meters (13 feet) in length. They are voracious eaters and consume a variety of fishes, squids, octopuses, and even other sharks! Prickly sharks exhibit diel migration patterns, which means that they rest during the day in deep offshore waters and move to shallower inshore waters to feed at dusk.
We are continuing to gather information about the topography, geology, and biology of this important and diverse marine ecosystem. In addition to helping wildlife populations be more resilient, the Monument protects an untold amount of marine biodiversity including the over 130 isolated seamounts and deep ocean that will be included in the expansion area.
The main objective of this expedition is to collect deepwater baseline information to support science and management decisions in and around U.S. marine protected areas in the central Pacific. We will conduct seafloor mapping and acquire video, biological, chemical, and geological samples in deep-sea portions of the Pacific Remote Islands Marine National Monument in order to better understand marine habitats, biogeographic patterns, seafloor mineral distribution, and the geologic history of these areas.