The die offs may be perfectly natural but they are adding up world wide. Fish kills are especially alarming for the survivalist. Your plans for harvesting fish after a collapse might go from hard work to impossible dream. From The Brownsville Herald:

A Texas Parks and Wildlife Department official said there were reports of floating fish as a cold snap hit South Texas Thursday.

A day earlier, the department had announced the temporary closure of saltwater fishing spots along the coast, including Brazos Santiago Pass near Brownsville.

On Thursday, Mark Lingo, the Lower Laguna Madre Ecosystem leader, said floating fish were reported near the pass.

“We’re on standby right now,” Lingo said. “We’re watching the weather and water temperatures. … We’re probably looking at a fish kill, but we don’t know how substantial it will be at this point.”

On Thursday morning water temperatures were below the “lethal threshold for a lot of fish” — 4 degrees to 10 degrees Celsius, or about 39.2 degrees to 50 degrees Fahrenheit, he said. A 3.9-degree Celsius reading, or 39 degrees Fahrenheit, came from the Coast Guard Thursday morning, he said.

A major freeze in 1989 dropped the temperature in Brownsville to 16 degrees, killing an estimated 11 million coastal fish, according to a TPWD press release. Texas has about two million acres of bays and estuaries that are susceptible to freeze, the same release said.

The magnitude of a possible fish kill likely won’t be known until this weekend or as late as Monday, Lingo said, because dead fish won’t float until temperatures warm up.

At least there’s some good news in this instance:

Despite the alarming nature of fish kills brought on by extreme weather, Lingo said it won’t necessarily affect the ecosystem negatively and other wildlife like shrimp and crabs will be unaffected.

“In the short term there will be less fish in the bay,” Lingo said. “In the long term, the fish will decompose and add nutrients. … It’s kind of like putting fertilizer on a field.”

The added nutrients, he said, will help algae grow, thereby increasing the number of shrimp because of a larger food source. This sort of ecosystem change has been seen in the past after cold snaps, he added.

Of course fishermen and charter boats will probably have a hard couple of years.