Portal de Periódicos da CAPES

Khảo sát sinh lượng và tác động của rong xanh (Cladophoraceae) trong đầm nuôi tôm quảng canh cải tiến ở tỉnh Bạc Liêu và Cà Mau

2017; Volume: 51; Linguagem: Inglês

10.22144/ctu.jvn.2017.084

2815-5599

Nguyễn Thị Ngọc Ánh, Trần Ngọc Hải, Đinh Thanh Hồng,

Marine and Coastal Ecosystems

Fluctuation of abundance and effect of green seaweeds on shrimps cultured in the improved extensive farms were investigated monthly from May 2015 to April 2016 at Bac Lieu and Ca Mau provinces. Results indicated that coverage percentage of seaweeds varied from 20% to 90% of farm area, green seaweed abundances and their natural productivities were relatively high with average ranges of 0.6-3.1 kg/m2 and 1.7-16.8 ton wet weight/ha, respectively. These parameters were greatly changed during sampling period, of which green seaweed productivity positively correlated with salinity in the farm. It was also found that development of seaweeds as indicated by coverage percentage largely influenced on water quality and shrimp yields in these farms as well as income of farmers. At coverage of >50%, the dissolved oxygen (DO) levels, and pH showed large variation during the day (DO: 3.2-6.8 mg/L and pH: 7.1-9.2). When seaweeds collapsed and decomposed, this caused high contents of NO2- (4.87±1.70 mg/L) and H2S (0.03±0.02 mg/L) resulting in detrimental effects on shrimps. Moreover, at coverage of ≤50%, shrimp yields and farmer incomes (233.4±98.1 kg/ha/year and 41.6±15.5 million VND/ha/year) were significantly higher (p50% (48.1±39.9 kg/ha/year and 13.3±6.5 million VND/ha/year). Therefore, it is recommended that farmers should maintain suitable coverage of seaweed in their farms within 50% of farm area.