save your tears
Reef Relief is probably the org you want. Meanwhile, some facts might help here.
What most people think of as "reefs", those pretty coral eco-systems, don't exist much around the DR which, like the Mediterranean, has steep sides with very little habitat. It mostly has "shoals", not "reefs" as most people mean them. ONGs make a lot of donation money promoting their supposed ability to "bring back" mudbanks. Real reefs are another kettle of fish entirely.
Often reefs are referred to as "bleached". The ONGs sell the line that fishermen use chloro to chase out their prey, and that this "bleaches" the reefs. In reality, coral has cycles in which it goes fallow: grey/white, as in "bleached". It was discovered in the Virgin Islands that some of these cycles at our latitute are caused (or, the way nature works, perhaps we should say "helped") by microbes attached to, of all things, the red/brown Sahara dust which falls on us seasonally. Bet you thought that was road dust, even though you're sitting on the eastern shore line, huh? This honey of a fact doesn't get much publicity because it would turn off donor money.
Another inconvenient fact, as Al Gore would say, is that fishermen in the DR do not easily dive to 100 feet, as suggested by a DR1 poster in this thread. That's PADI resort diving stuff. A DR diver uses a few feet of vinyl garden hose attached to a gasoline driven compressor with an old rusty gas station air tank in a yola where his assistant shells and scales the catch he sends up from the bottom. And the bottom is in the Silver Banks, Mouchoir Banks, Navidad and Bahamas Banks where he often goes to jail for poaching.
100 foot fishing in the DR is for spoiled ex-pats and tourists with their multi-coloured dive gear and tall tales, or it's plain old line fishing from a yola from midnight to 9 a.m. before the wind gets up. Again, not on coral reefs and not romantic.
You want coral reefs, go to Ras Mohammet, Belize/Honduras barrier reef and its offshore reefs, Bay Islands of Honduras (yes, Roatan), countless atolls in Micronesia, many in Polynesia, not so many in Macronesia, and of course, the Bahamas Far Out Islands. And save your tears and your donations for them, they're all doing very well, thank you.