I love the American measurement units. How many bald eagles of explosives are needed to destroy three football fields worth of reef?

The quote you're referring to came from the study's lead author, a Brit. Presumably he was referring to soccer (which everyone else calls "football"). Furthermore, a soccer field and an American football field are reasonably close in area, so it gets the point across in any case.

However, I will now refer to explosives exclusively in units of Bald Eagles when referring to their mass, and "star spangles" when referring to their energy output.

This isn't a uniquely American thing to be fair, in the UK it's not unusual to discuss area in terms of football pitches or for very large areas, Wales.

What a low value comment. In this case, a European football (soccer) field/pitch is reasonably close in size to an American football field. If the article had used square feet or acres, your comment might be more relevant. Google tells me that FIFA football pitch size is 105 meters long by 68 meters wide (7140 sq m). American football field size is 110 meters long by 53 meters wide (5830 sq m).

four to five Big Mac's worth.

advanced question for the college types: how many if you supersize it?