The following letter from WBUR CEO Margaret Low was sent to WBUR donors on Wednesday.

I’m writing to let you know about what’s unfolding at WBUR. As someone who has been there for us, I want you to hear the news from me first. Buckle up. This is a bit of a long read, but the story is pretty simple. WBUR has never been stronger and our business has never been harder.

Let me start with the good news. We’re ranked the #1 news station in Boston. Our listening audience is growing steadily and our digital numbers are on the rise, too — WBUR newsletters and podcasts have legions of loyal fans. CitySpace at the Lavine Broadcast Center, our state-of-the-art venue on Commonwealth Avenue, is buzzing with live events many nights a week.

In addition to our ambitious local reporting, WBUR produces Here & Now and On Point. Two national shows that reach millions of people across the country. We’re in the midst of a digital transformation — modernizing our technology to personalize our relationships with everyone who engages with WBUR.

We’re proud of our thoughtful, fair, trustworthy coverage that sheds light, deepens understanding, and enriches people’s lives. There is a pressing need for this kind of journalism, and yet the number of high-quality news sources is shrinking. Why? Because the old economics of our business can no longer sustain us.

At WBUR we’ve seen a dramatic loss of sponsorship support. In the digital age, almost all that money now goes to the big platforms — like Facebook, Google, Amazon and Spotify. This is bad news for the news business and has created big gaps that can’t easily be filled. In the last five years, our annual on-air sponsorship income (underwriting) has dropped by more than 40 percent — nearly $7 million.

Our story is not unique. There are daily reports of buyouts and layoffs at news organizations across the country — from The Washington Post to The Wall Street Journal, The Los Angeles Times, CNN, NPR, and many of our public radio peers. Last month, WAMU in Washington, DC announced layoffs. It’s clear we haven’t seen the last of it.

Sponsorship dollars won’t return to previous levels. These are not temporary ups and downs. They’re long-term shifts. It’s also worth noting that just 3 percent of WBUR’s annual budget comes from the Corporation for Public Broadcasting. It’s a common misperception that public radio is largely supported by government funding. That’s not the case.

Since I joined WBUR four years ago, we’ve kept our spending essentially flat and at the same time transformed the organization in significant ways. As I shared with my colleagues at a recent all-hands meeting, given our current economics, we’ll likely need to make some tough choices in the coming months. That could include everything from freezing open positions to eliminating jobs.

WBUR is brimming with talent and ambition and we’re building a path to the future. That takes time and resources — and can quickly be undermined by short-term cuts that diminish the journalism, as we’ve seen with the collapse of so many newspapers across the country.

This is a different story than we’ve told before. It’s unlike our usual on-air fundraising appeals. The stark reality is this — in order to survive, we need the people who count on us every day to dig deeper than they ever have before. We must rely more heavily on our members now. We also need our loyal fans who’ve never given to do so.

I’ve committed my life to journalism in the public interest out of a conviction that the work we do is of vital importance to our city and our country. We must find a way to sustain a public good that has been nurtured for more than half a century.

We’re in a race against time. But we see a path forward and know that philanthropic investment is key. My hope is for the kind of support that would help secure the future for WBUR. An organization that is beloved and trusted by millions of people in Boston and beyond.

Margaret Low is the chief executive officer of WBUR.