Which data would be best analyzed and communicated using a histogram?

The best thing to visualize using a diagram in this case would be the last answer - the average number of clams dredged up at different depth ranges.

The reason for this is because on the X-axis of our histogram, we can use different ranges (5-10, 10-15 ...) and the Y-axis would represent the frequency or average number of clams that are being dredged up.