Hello, and welcome to Five Things, I'm Dana Taylor, today is Sunday, August 20, 2023.

Ten days ago, the National Oceanic and Atmospheric Administration, or NOAA, revised its hurricane

forecast to above normal due to record warm temperatures at sea surfaces. Roughly 40%

of the world's oceans are experiencing marine heat waves, the most since satellite tracking

started in 1991. This temperature shift is especially notable in the Gulf States, Florida,

Louisiana, and Texas, hitting record highs this July. This is worrisome on multiple fronts,

the health of those ecosystems, the hurricane season, and the impact of El Nino.

What's causing these marine heat waves? And should we be worried? Here to help us dig into

this, I'm now joined by Dr. Capnic, Chief Scientist for the National Oceanic and Atmospheric

Administration. Dr. Capnic, thanks for joining me. Thank you for having me.

Okay, so I'll start with the last part of that question and ask you to give us NOAA's

definition of what a marine heat wave is. A marine heat wave is a heat wave that's

happening in the ocean or any aquatic environment. So it's when you get temperatures that

are above normal. And these events can last over a day or several days or even months.

By all accounts, waters end and around the Gulf States. I'm in Florida. Louisiana, Texas,

they've hit record highs this July. Temperatures we've seen have been in the 90s. So what

impact might this have on the health of things like coral reefs and the ecosystems they

support? You just like us, when it gets hot, we get stressed. And what we're seeing in

the ocean is that fisheries are being stressed by this heat, especially coral reefs, which

are really susceptible to heat. They have this symbad relationship in their tissues where

algae live in their tissues. And when they are hot for a prolonged period of time and what

we're seeing is over a week in many places, they expel that algae. And so the coral reefs

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