Toxic effects of traditional Ethiopian fish poisoning plant Milletia ferruginea (Hochst) seed extract on aquatic macroinvertebrates.

The present investigation was carried out to evaluate the toxic effects of traditional Ethiopian fish poisoning plant Birbira [vernacular name (local native language, Amharic); Milletia ferruginea] seed extract on aquatic macroinvertebrates, Baetidae (Mayflies) and Hydropsychidae (Caddisflies), under laboratory conditions. In Ethiopia, toxic plant; Milletia ferruginea pulverized seeds have been used for fish poisoning since time immemorial. Macroinvertebrates are important biological indicators of alteration in the natural water sources. Milletia ferruginea seed extract was applied at concentrations of 125, 250, 500 1000 and 2000 ppm on Hydropsychididae whereas Baetidae were exposed at various concentrations viz., 31.25, 62.5, 125, 250 & 500 ppm. Milletia ferruginea seeds crude extract of lethal doses (LCso and LC90) required for Baetidae 49.29 mg/l and 172.52 mg/l were respectively and the respective doses (LC50 and LC90) against Hydropsychidae were 679.64 mg/l and 2383.93 mg/l. The present investigation end result demonstrated that Milletia ferruginea seed extracts were extremely toxic to Baetidae than Hydropsychididae. As a result, application of Milletia ferruginea seed extracts into the rivers/streams for fish poisoning possibly leads to contamination and disruption of food chain in the aquatic ecosystem. Therefore, the concerned authorities should launch appropriate awareness campaign among the local inhabitants and fisherman about adverse effect of Birbira seed extracts. Furthermore, providing alternative ecofriendly techniques for fish harvesting may possibly bring constructive out come in the near future.

Laboratory evaluation of Ethiopian local plant Phytolacca dodecandra extract for its toxicity effectiveness against aquatic macroinvertebrates.

In this study, we evaluated the toxicity effectiveness of berries crude extract of Endod [vernacular name (local native language, Amharic); Phytolacca dodecandra] against aquatic macroinvertebrates Baetidae (Mayflies) and Hydropsychidae (Caddisflies), under laboratory conditions. In Ethiopia, toxic plant, berries of Phytolacca dodecandra are being commonly used for washing clothes and to control fresh water snails. Macroinvertebrates are useful biological indicators of change in the aquatic ecosystems. The present study clearly revealed that the LC50 and LC90 values for berries crude extract of Phytolacca dodecandra against Baetidae were 181.94 and 525.78 mg/l and lethal doses (LC50 and LC90) required for Hydropsychidae were 1060.69 and 4120.4 mg/l respectively. The present investigation demonstrated that Baetidae was more susceptible than Hydropsychidae, even at shorter exposure period of 2 h. From our preliminary investigation the toxicity effectiveness of crude extracts of Phytolacca dodecandra has been clearly shown. In addition, it requires further explorations which address both the toxicity activity and the active principles that are responsible for its toxicity effectiveness. Ultimately, the release/introduction of Phytolacca dodecandra plant berries extracts into the river/streams leads to disruption of food chain in the aquatic ecosystem. Therefore, at this moment preserving the aquatic ecosystem is extremely essential and inevitable.