Revegetating the Talakhaya watershed

Within the Talakhaya watershed lie some of CNMI’s very rare fresh water streams which discharge onto the adjacent reef flats. These coral reefs, like many others around the world, are adapted to clean, freshwater discharge (runoff).

Unfortunately, polluted runoff originates from illegal burning by poachers that hunt deer in the Talakhaya watershed. Burning results in the exposure of barren soils, which are easily eroded during a rain event, and wash down to the ocean. The brown runoff has several negative effects upon coral reef communities, three important ones are listed below.

1. Direct burial of corals and other sessile (non-moving) organisms by sediment particles.

2. Blocking of sunlight penetration. Corals and many other reef organisms need sunlight to photosynthesize. Murky water decreases the amount of energy that the sun can deliver to these organisms.

3. Sediment particles have nutrients attached to them which “fertilize” nearby waters.

Oceanic waters where coral reefs exists are usually oligotrophic (nutrient poor) which is why we can see the beautiful reef structures when we look from high above. Increased nutrients allow millions of phytoplankton (tiny single cell algae) to bloom. This bloom creates murky water and blocks the sunlight from reaching the corals (similar to #2 above). When these millions of tiny phytoplankton die and settle on the coral reef, their decaying bodies provide excess nutrients (fertilizer) to help macroalgae grow. This is not good because it allows the macroalgae to outcompete the corals for space on the reef.

Revegetation and community awareness efforts have already benefited Talakhaya watershed. This summer, 25 Luta Livelihoods volunteers successfully planted 25,000 seedlings in the As Onan and Alesna areas of the Talakhaya watershed. In 2007, 35 community volunteers planted over 22,000 grass and tree seedlings in the As Onan area. In 2006, student and adult volunteers from the Public School System planted 2,500 seedlings. The vegetation will hopefully stabilize the barren soils.

For more information contact the DEQ’s Marine Biologist, Peter Houk, or the Talakhaya Watershed Coordinator, Kathleen Herrmann at 664-8500. [B][I](Author: Peter Houk, DEQ Marine Biologist)[/I][/B]