Toward ecological intensification through the co-production of the floating macrophyte Azolla filiculoides and the giant gourami Osphronemus goramy Lacepède (1801) in Indonesian ponds

Several ecological services and functions are attributed to macrophytes, which may represent valuable resource for the ecological intensification of tropical fish farming. However, considering the multiple potential eco-services provided by macrophytes, the choice of the most appropriate species requires multiple criteria to assess these eco-services. Five floating macrophytes (Eichhornia crassipes, Lemna minor, Azolla filiculoides, Salvinia molesta and Salvinia spp.) were selected for this study. The six eco-services parameters compared among these macrophytes were: productivity (in % of seeded macrophytes), risk of non-productive cycles, nutritional value, impact on water quality, palatability (expressed as the percentage of plant ingested in 4 h) and ease of use. Experiments to determine these indicators were carried out in simple devices (net cages and plastic tanks) partially immerged in earthen ponds. The palatability of fresh macrophytes (whole or chopped) was studied in ponds using Osphronemus goramy juveniles. All indicators were scored from 1 to 5, and the highest score was assigned to the highest performer. These scores corresponded either to the evaluation of a single parameter (e.g. productivity) or to the average from scores of several parameters (e.g. nutritional score). Multiplier coefficients were applied for nutritional value and palatability. Azolla filiculoides showed the best scores for productivity; L. minor for nutritional value and palatability, and E. crassipes for the lowest risk of non-productive cycles and a positive impact on water quality. After integrating the scores in a multi-parameter matrix, A. filiculoides had the best overall score. The results of this approach to select macrophytes are discussed in light of the eco-services provided by macrophytes which may, in turn, promote the ecological intensification of tropical small-scale aquaculture.

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Climatic Niche Shift during Azolla filiculoides Invasion and Its Potential Distribution under Future Scenarios

Plants ◽

10.3390/plants8100424 ◽

2019 ◽

Vol 8 (10) ◽

pp. 424 ◽

Cited By ~ 1

Author(s):

Argantonio Rodríguez-Merino ◽

Rocío Fernández-Zamudio ◽

Pablo García-Murillo ◽

Jesús Muñoz

Keyword(s):

Native Species ◽

Potential Distribution ◽

Niche Overlap ◽

Niche Shift ◽

Distribution Models ◽

Azolla Filiculoides ◽

Global Circulation ◽

Global Circulation Models ◽

Distribution Ranges ◽

Floating Macrophyte

In order to prevent future biological invasions, it is crucial to know non-native species distributions. We evaluated the potential global distribution of Azolla filiculoides, a free-floating macrophyte native to the Americas by using species distribution models and niche equivalency tests to analyze the degree of niche overlap between the native and invaded ranges of the species. The models were projected under two future emission scenarios, three global circulation models and two time periods. Our results indicate a possible niche shift between the distribution ranges of the species, indicating that A. filiculoides can adapt to novel environmental conditions derived from climatic differences during the invasion process. Our models also show that the future potential distribution of A. filiculoides will decrease globally, although the species could colonize new vulnerable regions where it is currently absent. We highlight that species occurrence records in the invaded area are necessary to generate accurate models, which will, in turn, improve our ability to predict potential invasion risk areas.

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Potential Use of Aquatic Macrophytes to Enhance the Treatment of Septic Tank Liquids

Water Science & Technology ◽

10.2166/wst.1999.0166 ◽

1999 ◽

Vol 40 (3) ◽

pp. 225-232 ◽

Cited By ~ 2

Author(s):

S. Perdomo ◽

C. Bangueses ◽

J. Fuentes

Keyword(s):

Aquatic Macrophytes ◽

Typha Latifolia ◽

Correlation Coefficients ◽

Statistical Characteristics ◽

Septic Tank ◽

Conventional System ◽

Normal Probability ◽

Complete Treatment ◽

Floating Macrophyte ◽

Potential Use

In several urban and suburban areas, the problem of the disposal and treatment of septic tank liquids has not been solved yet. This paper deals with the primary operational evaluation of a conventional system of ponds used at Tarariras, in the Department of Colonia, Uruguay, as well as the potential use of aquatic macrophytes to enhance such treatment. The conventional system was sampled over a period of approximately one month at the end of the summer in order to determine the main parameters. Groups of up to 20 samples were studied to determine the normal distributions. Correlation coefficients were obtained for the normal probability plot between 0.84 and 0.99. The most relevant statistical characteristics were calculated for each parameter. The removal efficiency was 80.0% of BOD5, 58.5% of COD, 75.8% of NH4+-N, 9.5% of PO4−3-P and 38.5% of TSS. At the same time, batch and semi-continuous trials were carried out at bench scale with Eichhornia crassipes (floating macrophyte) and Typha latifolia (emergent macrophyte). The best efficiencies were obtained for the latter, with values of 96.6% of BOD5, 93.0% of COD, 99.6% of NH4+-N, 95.2% of PO4−3-P and 95.5% of TSS. It was concluded that constructed wetlands could be the answer to a more complete treatment process.

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