Sometimes you can know a lot about a thing, except where it is. Your misplaced keys or wallet, for example

Or blue whales, for a more pertinent example. They're the largest mammals on Earth - reaching up to 100 feet long and weighing more than 150 tons - and science knows a lot about them, gleaned from many years of study. But predicting where the gentle giants are likely to be isn't always easy in areas where comprehensive data about them is lacking, a problem addressed in a recent study published in the journal Diversity and Distributions by researchers from the National Oceanic and Atmospheric Administration (NOAA).

The NOAA scientists collected 12 years worth of data on blue whale sightings off the U.S. west coast and the eastern tropical Pacific (an area running west from San Diego to Hawaii and south to Peru), including underwater topography and the presence of krill, a favorite food of blue whales.

Data in hand, the researchers created computer models from the information, to see if they could predict the presence of blue whale populations elsewhere. Their chosen search area? The northern Indian Ocean, which the researchers call a "data-poor" ecosystem where not enough is known about the enormous cetaceans.

The researchers found that the combined data from west coast and eastern tropical waters could be used to predict blue whale populations in the northern Indian Ocean, and their results dovetailed with what little historical data was available on the creatures in that part of the world. Existing data from well known habitats, then, could be used to make predictions about blue whale distributions in data-poor ecosystems.

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Predictions made by the habitat modeling tool can help protect blue whales in busy shipping lanes, where maritime officials, armed with predictive data, can adjust ship pathways to try to keep the vessels and whales from colliding.

In fact, the tool already has been used in that way. When the International Whaling Commission (IWC) needed to assess hectic shipping lane traffic off the coast of Sri Lanka, it used the results found in the NOAA study.

"Small changes in shipping routes can be a very effective way to address a serious conservation issue with minimal inconvenience to the shipping industry, but [they] rely on a good understanding of the relationship between whale distribution and habitat," said Russell Leaper, an IWC scientific committee member. "This study makes an important contribution towards that understanding."

"Marine mammals face threats from human activities in most of the world's oceans," said study lead Jessica Redfern in a statement, "but we lack the data needed to address these threats in many areas. The data collected aboard our surveys allow us to predict species habitat in other parts of the world. Understanding species habitat allows us to address conservation problems that are often unexpected and critical to maintaining healthy populations."

The conservation tool isn't the first to arise out of the use of predictive data. December 2016 brought news of WhaleWatch, another NOAA-derived system, this one built around 10 years of blue whale satellite tracking data that attempts to predict hotspots where the whales will be at given times of year.

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