We received this photo Monday of a dead sturgeon floating in the Hudson off the Upper West Side of Manhattan. About 5 feet long, it’s surrounded by debris, a dead eel, countless plastic bottle caps, a Dunkin’ cup, plastic jug, and other bits of plastic trash.

A man and his son spotted the sturgeon Monday morning and said it looked it like it had a head injury, perhaps from a boat propeller.

This scene brings our eyes back to the challenges we still face. So many days, we can look out at the wide expanse of the river, with all its beauty, and imagine that the river is healed. In these areas where debris accumulates, we sometimes see a harsher story.

The Hudson River is a rough place for endangered sturgeon to try to recover. Let’s not forget that the Hudson is a vital path and a nursery for migratory fish – like Atlantic sturgeon, as this one appears to be – whose existence as a species depends on their ability to enter the Hudson and return again to the ocean.

Since the last Ice Age, Atlantic sturgeon have been coming into New York Harbor and up into the Hudson to spawn. Now, they run a gauntlet of high-speed and deep-draft vessels with propellers. Vessel strikes are a significant cause of death – even without the spike in numbers we saw during construction activity for the Tappan Zee Bridge replacement.

Meanwhile we have an ongoing deluge of plastic pollution, shooting out through storm drains and sewers when it rains. Researchers are finding microplastic particles in all the creatures that inhabit coastal waters. And they are just now trying to understand what these particles, and the contaminants that adhere to them, are doing to marine life, to the food web, and to us.

We’re a long way from coexisting with a living river, a wilderness river, so essential to so many species. We need to keep trying.