15 research outputs found
RESEARCH INTO THE EFFECT OF HEAVY METALS AND THEIR BINARY MIXTURE ON THE CARDIO-RESPIRATORY SYSTEM OF FISH LARVAE / SUNKIŲJŲ METALŲ IR JŲ BINARINIO MIÅ INIO POVEIKIO ŽUVŲ KARDIORESPIRACINEI SISTEMAI ANKSTYVOJOJE ONTOGENEZÄJE TYRIMAI
This article investigates toxic effects of heavy metals (Ni, Cu) and their binary mixture (Ni+Cu) on the cardio-respiratory system of rainbow trout (Oncorhynchus mykiss) larvae depending on the type of metal, metal concentration and the duration of their exposure. The one-day larvae of rainbow trout were exposed to Ni (0,1; 0,2 mg/l, respectively), Cu (0,25; 0;5 mg/l, respectively) and their binary mixture. During long-term exposure (30 days), the physiological parameters of larvae, e.g. heart rate (counts/min), gill ventilation frequency (counts/min) after 5, 10 and 20 days of exposure were recorded. During experimental studies, the effects of heavy metals and their binary mixture on the heart rate and gill ventilation frequency of rainbow trout larvae depending on the type of metal, their concentrations and exposure duration were determined. Consequently, comparative studies on toxic effects of heavy metals and their binary mixture on the cardio-respiratory system of rainbow trout larvae showed that the binary mixture was more toxic to larvae than to single metals.
Santrauka
Å iame straipsnyje nagrinÄjamas sunkiųjų metalų (Ni, Cu) ir jų binarinio miÅ”inio (Ni + Cu) toksinis poveikis vaivorykÅ”tinio upÄtakio (Oncorhynchus mykiss) lervų kardiorespiracinei sistemai, priklausomai nuo veikiamo metalo rÅ«Å”ies, metalų koncentracijos ir ekspozicijos trukmÄs. VaivorykÅ”tinio upÄtakio vienadienÄs lervos buvo veikiamos Ni (0,1; 0,2 mg/l), Cu (0,25; 0,5 mg/l) ir jų binariniu miÅ”iniu. Ilgalaikio tyrimo metu (30 parų) buvo registruojami lervų fiziologiniai rodikliaiĀ ā Å”irdies ir kvÄpavimo dažniai (krt./min.) po 5, 10 ir 20 parų ekspozicijos. Atlikus eksperimentinius tyrimus, nustatytas sunkiųjų metalų ir jų binarinio miÅ”inio poveikis vaivorykÅ”tinio upÄtakio lervų Å”irdies ir kvÄpavimo dažniams, priklausomai nuo veikiamo metalo rÅ«Å”ies, koncentracijos ir ekspozicijos trukmÄs. Tyrimo rezultatai rodo, kad atskirų sunkiųjų metalų (Ni, Cu) poveikis lervų kardiorespiracinei sistemai silpnesnis, nei veikiant metalų binariniu miÅ”iniu.
Raktiniai žodžiai:Ā varis; nikelis; binarinis miÅ”inys; kardiorespiracinÄ sistema; žuvys; lervo
Development and Sensitivity of a 12-h Laboratory Test with DaphniaĀ magna Straus Based on Avoidance of Pulp Mill Effluents
Abstract Studies on avoidance of contaminants by aquatic organisms verified that such behavior may have crucial ecological implications. Yet, avoidance tests have not been considered in ecological risk assessments. This study aimed at developing a short-term test with Daphnia magna Straus based on avoidance of pulp mill effluents and at comparing its sensitivity to the standard 21 d D. magna reproduction test. The avoidance effective dilution values (12 h EDil20 and EDil50) were as sensitive as the 21 d EDil20 and EDil50 values for reproduction. Therefore, this easily standardizable short-term test can be recommended as a valuable complementary tool in ecological risk assessments