Open AccessImprovement of Water Quality by the Macroalga, Gracilaria lemaneiformis (Rhodophyta), near Aquaculture Effluent Outlets
Author(s) -
Xu Yongjian,
Fang Jianguang,
Tang Qisheng,
Lin Junda,
Le Guanzong,
Liao Lv
Publication year - 2008
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.2008.00180.x
Subject(s) - biology , effluent , biofilter , aquaculture , gracilaria , nutrient , mariculture , algae , biomass (ecology) , hatchery , chemical oxygen demand , water quality , zoology , aquatic plant , fishery , botany , agronomy , macrophyte , wastewater , ecology , environmental science , fish <actinopterygii> , environmental engineering
Raft culture of the seaweed, Gracilaria lemaneiformis (Bory) Dawson, was used as biofilter for purifying effluent and removing nutrients from the nearby animal aquaculture. The results showed that the cultivated seaweed grew well outside effluent discharge outlets for growout ponds and a hatchery plant. The biomass (fresh weight) of Gracilaria from the 0.5‐ha area outside the growout ponds increased about 60 times, from 80 to 4750 g/m during the 65 d of experiment (with the daily special growth rate [SGR] of 3.87%/d); the yield was 30.4 tons and 93.97 kg N and 12.81 kg P were removed; the seaweed biomass from the 0.2‐ha area outside the hatchery outlet increased 37.5 times, from <100 to 3600 g/m (with SGR of 3.4%/d); the yield was 10.4 tons and 31.7 kg N and 4.33 kg P were removed. Several water quality parameters such as dissolved oxygen, secchi disk depth, and pH value in the algal cultivation area were substantially higher than those in the noncultivation zone, whereas chemical oxygen demand, dissolved inorganic nitrogen, and dissolved inorganic phosphorous at both areas were similar.