The effects of different solids and biological filters in intensive pacific white shrimp (Litopenaeus vannamei) production systems
| Autor: | Andrew J. Ray, Leo J. Fleckenstein, Thomas W. Tierney, Jill C. Fisk |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Suspended solids biology Fouling 010604 marine biology & hydrobiology Litopenaeus 04 agricultural and veterinary sciences Aquatic Science Pulp and paper industry biology.organism_classification 01 natural sciences Shrimp law.invention Settling law Biofilter 040102 fisheries 0401 agriculture forestry and fisheries Environmental science Water quality Filtration |
| Zdroj: | Aquacultural Engineering. 91:102120 |
| ISSN: | 0144-8609 |
| DOI: | 10.1016/j.aquaeng.2020.102120 |
| Popis: | Biofloc systems rely on suspended solids in the water to house microbes that can remove or cycle nitrogenous wastes; however, nitrogen cycling can be inconsistent. In contrast, external biofilters are used in many recirculating systems to provide a more consistent environment for microbes to process nitrogen. Regardless of the biofiltration approach, solids levels must be controlled to prevent issues in shrimp such as gill fouling, low dissolved oxygen levels, and other negative impacts. The purpose of this study was to examine the effects of settling chambers versus foam fractionators for solids filtration and to compare external biofilters to the biofloc approach as biofiltration strategies. Sixteen 1-m3 round, polyethylene tanks were randomly assigned to four treatments, each of which had four replicate tanks. Eight biofloc systems were established: four using settling chambers for solids control (BF-S) and four using foam fractionators (BF-F). The other eight tanks used external biofilters; four had settling chambers (EB-S) and the other four had foam fractionators (EB-F). All 16 systems were stocked with 250 shrimp at an average size of 4.3 g which were grown for 85 days. There were no significant differences in shrimp production between treatments; however, variability was high in biofloc systems. Nitrite levels were significantly lower in systems with fractionators compared to systems with settling chambers. The concentrations of dissolved Na, Mg, Ca, Sr and Ba in the water were significantly reduced in treatments with settling chambers. The results of this study show that filtration choices significantly impact short- and long-term water quality and reusability but may not have much effect on shrimp production in the short-term. |
| Databáze: | OpenAIRE |
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