Journal of Tropical Oceanography ›› 2025, Vol. 44 ›› Issue (2): 147-156.doi: 10.11978/2024086CSTR: 32234.14.2024086

• Marine Biology • Previous Articles     Next Articles

Algae-fish interactions and wastewater quality control in recirculating aquaculture systems

GUO Youyou1(), XIE Enyi1, XIN Rong1, LIN Kun1, LIAO Jiawei1, CHEN Chunli1, WANG Huihui1, YANG Wencheng1, CUI Jianjun1(), MO Feng2, WEN Qijiao2   

  1. 1. Fisheries College of Guangdong Ocean University, Zhanjiang 524088, China
    2. Lianjiang Shrimp Farming Group Limited, Zhanjiang 524499, China
  • Received:2024-04-15 Revised:2024-06-10 Online:2025-03-10 Published:2025-04-11
  • Contact: CUI Jianjun
  • Supported by:
    National Key Research and Development Program of China(2022YFD2401303); Technical Service(B23315)

Abstract:

This study investigated the impacts of algae-fish interactions on wastewater purification in a recirculating aquaculture system, with and without the high-temperature resistant Gracilaria spp. as the experimental alga. The effects of Gracilaria spp. on the quality of the system wastewater and the growth performance of the hybrid pearl gentian groupers (Epinephelus fuscoguttatus × E. lanceolatus) were examined. The results showed that the presence of Gracilaria spp.. 1) improved wastewater quality and reduced the concentrations of ammonia nitrogen, nitrite, and phosphate in the wastewater in the grouper culture bucket by 5.05%, 98.81%, and 69.26%, respectively, compared with the control group without Gracilaria spp., and 2) promoted the growth performance of the groupers, with their weight gain rate and survival rate in the experimental group increasing by 2.10- and 1.69-fold (to 67.37% and 96.43%), respectively, compared with the control group. In addition, the Gracilaria spp. grew rapidly in the experimental treatment. Their specific growth rate was more than 3%·d-1 and their wet weight was more than 1.5 times as much during the culture experiments. We also conducted a Granger causality test. Our results confirmed that the addition of Gracilaria spp. to a recirculating aquaculture system should reduce the ammonia nitrogen concentration and increase the biomass and survival rate of the groupers. The study showed that a recirculating aquaculture system not only enhanced the mutualistic relationship between algae and fish but also efficiently improved water quality, potentially leading to further development and application of multi-level integrated aquaculture models.

Key words: Gracilaria spp., pearl gentian grouper, recirculating aquaculture system, interdependence effect, wastewater quality control

CLC Number: 

  • P735.124