December 31, 2019 — The following was released by NOAA Fisheries:
Atlantic sturgeon were once a highly valued fishery along the U.S. East Coast. Their populations declined dramatically in the late 1800s when they were overfished for their eggs for high-quality caviar. Four of the five distinct population segments—those in the Chesapeake Bay, Delaware Bay, New York Bight, and South Atlantic—are now listed as an endangered species. These fish can be impressively large—up to 14 feet long and 800 pounds—but they are still vulnerable.
Habitat loss poses challenges for the recovery of the sturgeon population. Many places they need to live and reproduce are affected by degraded water quality or lack of the hard-bottom areas they need for spawning. Sturgeon can be injured or killed when hit by commercial and recreational boats. Virginia’s James River—occupied during the fall migration by a group of sturgeon—is frequently transited by shipping.
Scientists from the NOAA Chesapeake Bay Office use sonar technology to map areas that could include sturgeon habitat. This helps them better understand the habitat features those places may offer. Sonar data can describe what the bottom is like in great detail—not just how deep it is, but whether it is sandy, muddy, rocky, or some other bottom type. After scientists gather the data, they create maps to identify areas that have hard, rough bottoms where sturgeon could spawn.