In Latin Maria translates to seas. Maria are flat areas on the surface of the moon. There are dark plains which are filled with lava erupted from the volcanic eruptions millions of years ago. Initially, these plains were thought to be seas filled with water but samples brought from the Lunar's surface showed that these were formed from the volcanic eruptions.
Hence, the given statement is true. Maria are flat areas on the moon's surface.
The secondary consumers population will increase due to the lack of predators, and because the secondary consumers population increases, the primary consumers population will decrease because there are more predators.