The designation of three vast areas of the Pacific Ocean as national monuments -done with the stroke of President Bush's pen on Tuesday — has made environmental history. It creates the largest protected ocean area in the world, and a welcome defense of marine ecosystems.

And while it's a major advance, more can be done to provide better protection, including providing funds for enforcement.

The Mariana Trench, Pacific Remote Islands and Rose Atoll national monuments cover nearly 200,000 square miles. They include wildlife-rich reefs and atolls and vast, ecologically diverse coral covers.

Bush's action comes two years after he gave the same designation to 140,000 square miles of the Northwestern Hawaiian Islands.

The combined effect of these designations will not only help preserve these fragile ecosystems; it will also help scientists understand the degradation of marine systems close to populated areas and how they might be restored.

The newest monuments are protected from 3 to 50 miles out; that could have been extended to 200 miles.

And simply applying a designation will not protect the areas from poachers or debris. Enforcement and cleanup efforts must be part of the program.

Nonetheless, this represents a major win for environmental protection, one that future generations are sure to enjoy.