Updated, 8:12 a.m.

Good morning on this iffy Tuesday.

Don’t judge a river by its color.

It’s a little something we learned from the River Project, a group studying and restoring the Hudson River Estuary.

“A lot of people look at the river and talk about it looking dirty, and obviously it’s not like pictures of the Caribbean,” said Nina Hitchings, who oversees the project’s wetlab on Pier 40.

But, she said, that murkiness is a good thing.

“There is a lot of algae and phytoplankton and zooplankton in the water column, making this a super productive ecosystem and making this a nursery for fish,” Ms. Hitchings told us. “Hundreds of years ago, before many people came, it would’ve been the same color.”

(June, in particular, is prime time for spawning in our aquatic backyard: The water is hot and salty, so oceanic fish and marine species use our gentler, shallower estuary as a nursery until the young fish mature enough to head out to sea.)