PATTERNS OF POLYCHAETE WORM INFESTATION OF STONY CORALS IN THE NORTHERN RED SEA AND RELATIONSHIPS TO WATER CHEMISTRY

摘要

Coral reefs of the northern Red Sea are biodiverse and rich in endemisms, but also fragile and susceptible to stress by natural and anthropogenic disturbances. Colonies of several genera of reef-building stony corals at Eilat (Israeli Red Sea) recently have become infested with boring spionid polychaete worms, the presence of which has induced skeletal aberrations on corals. Of 656 corals examined, 218 (33.2%) were infested with boring spionid worms. The percent of infested coral colonies in the coral genera Leptastrea and Porites was significantly correlated with the concentration of total oxidized nitrogen (TON, NO_2 + NO_3) in the water column. TON levels also significantly predicted the likelihood of colony infestation in the corals Leptastrea, Pavona, and Porites, and the likelihood of skeletal aberration in Porites. High abundances of coral-boring polychaetes have been reported in other reef areas close to organic waste discharges. We conclude that anthropogenic nitrogen enrichment of waters surrounding coral reefs at Eilat may have caused corals to become vulnerable to infestation by boring spionid polychaetes, resulting in coral skeleton aberrations and increased susceptibility to damage by storms.