This week, scientists and coastal residents across the United States are drawing attention to the importance of local waterways, called estuaries.
Those are the bays, lagoons, harbors and wetlands that provide vital nurseries for marine life and play a big part in the local economy.
"They're a very intricate system; they're a very dynamic system," said Karina Johnston, director of Watershed Programs for the Bay Foundation on a recent visit to the Pacific coast near L.A. "They have life that is supported both by the salty ocean water that comes in with the tides and the freshwater that comes down, in this case, from the Ballona Creek watershed."
That forms an important habitat for some marine species, such as the large halibut that is an important fish both for consumers and fishermen. Nationwide, estuaries and coastal waters provide habitat for 75 percent of the U.S. commercial fish catch and 80 to 90 percent of the recreational fish catch, according to Restore America's Estuaries, a nonprofit.
But estuaries across the nation are facing threats to their health, including urbanization, pollution from runoff and sea level rise due to climate change.
In Southern California, the ongoing drought poses another concern.
"Even in the dry season, like today, when we haven't seen rain in months and months, we are still getting dry weather water running off of our streets, from our sprinklers, washing our cars, into the Ballona Creek Channel," said Johnston. "This changes up what the proportion of fresh water and salt water is in this area."
Correction: A previous version of this post misspelled the name of Karina Johnston, director of Watershed Programs for the Bay Foundation. KPCC regrets the error.