| Autor: |
Tuyisenge, Janvière, van Dam, Anne, Gettel, Gretchen, Irvine, Ken |
| Předmět: |
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| Zdroj: |
Annual Conference on Great Lakes Research Abstract Book; 2023, Vol. 66, p212-212, 1/3p |
| Abstrakt: |
Capture fisheries have been overexploited, leading to the development of cage aquaculture as an alternative for fish production. Such developments are rapidly spreading across Rwandan lakes: Kivu and Muhazi, colonizing understudied shallow and isolated zones. Uneaten fish feed, fish feces, and excretion products have adverse impacts on water and sediment quality and benthic processes, and the accumulation of sediment organic matter may lead to increased production of greenhouse gases. So far, possible environmental effects of the cage farms on Lakes Kivu and Muhazi have not been studied much. To formulate evidence-based regulations for sustainable cage fish farming in these lakes, it is essential to comprehend the environmental conditions at cage farms. This study compared nutrient concentrations and greenhouse gas fluxes between sites with and without cage aquaculture. According to the first results of the study show that average NH4 concentration was 5.1 µg/L at sites without cages and 56.4 µg/L at sites with cages in Lake Muhazi. In lake Kivu, the concentration of NH4 was also higher at cage sites (13.1 µg/L) than in cage-free sites (9.2 µg/L). Furthermore, results from Lake Kivu, show that methane gas concentration and fluxes were elevated inside cage farms. The pCH4 varied from 82 to 526 µatm, and 80 to 200 µatm inside and outside cage farms, respectively. FCH4 ranged between 0.6 and 191.9 mg/m²/h in cage farms and 0.5 to 20 mg/m²/h in sites without cages. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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