Estuaries are affected by rising sea levels in different ways, depending on their size and shape. A study using computer models showed that in most estuaries, higher sea levels make tides stronger. However, in short estuaries with low tides at the mouth, rising sea levels actually weaken the tides. The study also found that the location of the points with the weakest tides in an estuary can change with rising sea levels. Estuaries that are more shallow or have strong river inflows show bigger changes in tidal range. These findings can help managers and decision makers understand how different types of estuaries might respond to rising sea levels.