Carbon Sequestration of Additives of Artificial Reefs and Its Effect on Carbon Fixation of Ostrea Plicatula Gmelin

Abstract:

In this study we investigated the potential alteration of carbon sequestration capability of artificial reef eco-system caused by the additives peanut straw and Argopecten irradias shell. After the intensity test four types of reefs with different proportions of additives were selected for experiments, and the effects of additives on carbon fixation by various fouling organisms adhering to the reefs were analyzed. It was found that Ostrea plicatula Gmelin was the dominant species of fouling organisms, and that additives did not apparently affect the fouling organisms. Peanut straw and A. irradias shell did not improve the carbon sequestration of O. plicatula Gmelin (P>0.05). The calculation of carbon sequestration in the reefs with addition of shell showed that the minimum carbon content per unit reef was 104.13 kg and 2.60 kg per hollow stere, and that the maximum content per unit reef was 260.32 kg and 6.51 kg per hollow stere. As for reefs with straw, the minimum content per unit reef was 296.28 kg and 7.41 kg per hollow stere; the maximum content per unit reef was 740.70 kg and 18.52 kg per hollow stere. The total carbon fixed by experimental reefs was up to 2802.87 kg. In this experiment each unit included 250 reefs. Assuming all the reefs within the marine area of about 66.67 hm2 contain additives, we calculated that reefs with 10% substitution of A. irradias shell could fix 52040.00 kg carbon, and that reefs with 25% substitution of peanut straw could fix 370350.00 kg carbon. Our results suggested that sequestration of reefs could be an effective method to improve carbon sinking. The effects of crop straws and shell as additives of artificial reefs need to be further investigated in the future.