When my house celebrated its 100th birthday this year, an architect friend asked if I had a copy of its Sanborn map. If you live in Mexico City or a U.S. city that was around in the mid-1800s to mid 1900s there may be a Sanborn map of your neighborhood, annotated and colored so that insurance companies could assess fire risks. You can trace back to the first property lines and follow what was built over decades, from stables to factories to apartment buildings. And by trace, I mean scroll through digitized scans at the Library of Congress or visit a local library or historical society that holds physical copies. A set of the first maps, of the city of Boston, would have cost you $100 at a time when average daily wages were $1.50 and a dozen eggs cost 20¢. These maps were data works-for-hire for insurance companies, not originally intended for public use but now freely available everywhere and (at least according to that architect friend) still used in modern permit and boundary reviews. 

Why in this quantum computing year of 2025 am I thinking about huge, hand-colored, paper atlases? Because I am thinking about how data survives. Insurance companies valued these maps enough to pay for them and presumably made money using them. The detailed documentation helped the information retain its usefulness 150 years into the future, even as the ways people used the maps changed. Digital versions are saved not only at a major government repository but also via distributed networks across academic, state, and local libraries. The descriptive digital metadata includes persistent identifiers and standardized fields to make it easy to discover and combine with other data. We owe our present day access to the Sanborn maps to the work of the invisible data stewards who created that metadata, as well as to those who held on to the books for decades, negotiated their release from the insurance companies, and painstakingly scanned each page.

Today, U.S. ocean and climate data is disappearing, as both CODE and EDGI have documented. Websites are offline, cloud storage contracts have been cancelled, and funding has been cut for the physical tools of monitoring - satellites, ships, tags, underwater sensors, buoys, and cameras. Data stewards are being fired or forced out of public service.  Even when data can be backed up, it can be difficult to revive it without the people who know the data best, who wrote the code to manage the data and run the models, and who have spent years building relationships with the companies and communities that rely on it. There’s a global network actively preserving ocean and climate data, but we know we can’t save everything.

What can we do now to ensure that data is as valuable as possible for our future selves? If you’re an ocean data steward, use a common data standard to organize and document your data. Publish it on a public repository. Put your code on GitHub or GitLab. Make an audio memo of yourself working through a dataset to capture the little details a new data user might miss. Like a go bag, package up your data before you think you might need to. Then take a break - data stewardship is hard, essential work. 

If you’re a data user, get ready for gaps. Reach out to your data steward contacts and learn all you can. Keep an eye on notices of data product changes at dataindex.us and the NESDIS change tracker. Learn to use the Internet Archive’s Wayback Machine. Many private sector innovations, like AI weather forecasting, were trained on public data and depend on large-scale NOAA and NASA data programs. If that’s your company, get loud about what you need and why it matters. Start new data collaborations that can support your business needs and make data public, like Climate Central is doing with the Billion Dollar Disaster tool.

Looking at the Sanborn maps today, they are clearly not the territory. They leave out poor neighborhoods and other places companies weren’t interested in insuring. A patchwork of data presents challenges of omissions and biases, but it is better than no data at all. The future of the ocean is the future of all of us and we can’t look away. We are living at a time when innovations in sensors, computing, data science, and communications make it possible for us to know the ocean like never before. We have the capacity and the resources to collect new data and create new information tools that help us protect our homes, our neighbors, our food systems, our economy, and the ocean places we love. Here’s to the next generation of data stewards who will make that happen.

- Kate & Rachael