When hiking in the California High Sierras, my husband John and I always took along our fly fishing rods. We usually planned to include a few brown, golden, or rainbow trout in our menu.

Apologies to vegans, but truthfully, after five or ten days carrying heavy packs, hiking through difficult territory, and subsisting on gorp (raisins, M & Ms, and peanuts), freeze dried food, and boiled water, a dinner of fresh caught trout tasted like a bit of heaven.

I loved fly fishing in the Sierras. Doing so was tricky—flys with hooks easily snag trees, and trees lined the streams along our trails. We couldn’t let the line out as far as we might on a wide river. We usually had to swish the line from side to side over the stream rather than back and forth over our heads. But angling just right to make the fly land gently was part of what made fishing in the High Sierras an engrossing challenge.

The fish we hunted often hid beneath fallen logs. They lay concealed, watching for a fly or mosquito to land and float up close. The partially submerged trees gave the fish the chance to surprise a bug and snag its dinner.

Knowing their hiding places, those logs gave us an opportunity to catch our dinner, as well. We knew the trout were there, lying in wait beneath the sunken trunks.

In the Sierras, fallen trees provide hiding places fish need for survival. But trees play more than a single role in the survival of fish species. Trees also help make fish fat.

In 2014, the BBC reported on a study showing that deforestation is reducing freshwater fish populations. According to Andrew Tanentzap from the University of Cambridge’s Department of Plant Sciences, “Where you have more dissolved forest matter you have more bacteria, more bacteria equals more zooplankton. Areas with the most zooplankton had the largest, fattest fish.” And higher quantities.

Simply put, when we remove forest cover, the fish that depend upon it go hungry. Fewer young fish survive to adulthood. Those that do survive are too skinny to make a good dinner.

As the article noted, this problem effects more than the fish. “Freshwater fishes make up more than 6% of the world’s annual animal protein supplies for humans” and, alarmingly, “they are the major and often only source of animal protein for low income families across Bangladesh, Indonesia, and the Philippines.” These are places where millions of poor families—men, women, and children—are already hungry.

What we often forget, when people urge action on climate change; or call us to reforest rather than deforest; or say that we ought to retain policies that protect the air, land, and water; or that the Environmental Protection Agency needs to be substantially funded if it is to conduct research and enact regulations to save the environment, even if these actions are sometimes inconvenient; is that saving our environment not only helps the air, land, water, or species we are protecting, but our own species, as well.

Caring for the environment saves lives. It is fundamentally pro-life.

Abusing the environment takes lives. It kills.

There is no way around these facts.

Caring for this earth isn’t a simple obligation. It will take all the energy and creativity we have. I, for one, am struggling to find my way forward to make a difference.

The air, land, and water are worth preserving for themselves. And so are other species. But we ought to also realize that human lives are at stake if we don’t act, persistently, assertively, and proactively, to care for this still lovely fragile blue planet.

We share this ecosystem with millions of other people whose lives depend upon the world’s continuing resources.