Biomass and nutrient flux measurements on Holothuria atra populations on windward reef flats at Enewetak, Marshall Islands

A population survey of the holothurian, Holothuria atra, on the interisland coral reefs of Enewetak revealed average animal densities of about 3 animals m-2 in the zone of small coral heads, Median fresh weighy was 60 g, The size distribution of these animals was negatively correlated with water velocity along the reef. Ammonia release rates for three species of holothurians, H. atra, H. difficilus and Actinopyga mauritina were weight specific, The release of annnonia by H. atra on Transect II was equivalent to 9% of the total amnnonia exported from the reef proper. The release of phosphorus followed the general rules set for size - metabolism relationships. Nitrogen/phosphorus release ratios are 25:1 for 1 gram fresh weight animals and 42:1 for 60 gram animals, Urea is also releasedhttps://scholarworks.wm.edu/vimsbooks/1138/thumbnail.jp