It’s easy to see the destructive forces of high winds and heavy rains on land. What’s less obvious are the effects of these massive storms underwater. They can wreak short-term havoc on some recreational fisheries. And although nature has a way of healing itself, the widespread fish kills documented in the Carolinas are a stark reminder of what hurricanes do beneath the surface.
According North Carolina Wildlife Resources Commission biologists, plummeting dissolved oxygen levels caused fish kills that went on for weeks in more than 15 rivers across the state. Fish kills were reported in many coastal rivers, but they also stretched far inland as flood waters caused significant drops in dissolved oxygen levels. Fish essentially suffocated, as they were unable to absorb enough oxygen through their gills.
Shallow mud flats and estuaries, like the excellent inshore fisheries of the Florida Panhandle, experience a massive influx of cold, fresh rainwater. This reduces salinity and temperature and kills fish. It can also impact the food web. Larger fish might be able to flee from unsuitable conditions, but crabs and other smaller, slower moving marine life are trapped.
In the surf and farther offshore, strong currents and large waves that extend well below the surface are destructive to bottom structure like reefs. They also mix the ocean’s layers, which are normally arranged top to bottom by salinity and temperature. Larger marine animals, such as sharks, are known to just swim away on the approach of a large storm. However, with rapid salinity and dissolved oxygen changes, marine life can suffer for months following a large hurricane.