Valerica Macovei


THE HYDRO AND BIOLOGICAL CHARACTERISTIC OF WATER FROM AN ORNAMENTAL LAKE

Valerica Macovei, I. GÓlca

Abstract
The researchers was done at The Research Station for Aquaculture and Aquatic Ecology Iasi in the vegetation period of 2008 and had as an objective the identification of phyto and zooplanctonic formations from the ornamental lake populated with two species of fish, Cyprinus carpio si Ctenopharyngodon idella, and the abundance of systematic groups.
The collecting of material realized in the period July-September 2008. The planctonic samples obtained throw filtration of 10 litters of water with the planctonic net. The material which was filtered was remake, quantitative and qualitative, in laboratory.
The remaking in laboratory consists in the sedimentation of the samples in time of 21 days, centrifugalization in time of 5 minutes. The numerical evaluation and the identification of species were done in laboratory with the microscope HC 1 using the counted camera. We established the qualitative components of every sample and, at the end, the frequency of phyto and zooplanktonic organisms.
The hydro biological analyze of water from the ornamental lake indicated an equilibrium between the main phyto and zooplanktonic groups developed in the sweet stagnant waters. Thus, the systemic phyto planktonic groups were represented of 18 taxons, the chlorophyll groups with 6 taxons and the cyanophiceae groups with 3 taxons.
The systemic zoo planktonic groups were represented by 8 taxons from witch 4 taxons for rotifers, 3 for crustaceans and 1 for insects. We observed that the best represented is the group of rotifers, especially in July and the purest represented is the group of crustaceans.

Key words: ornamental lake, fish, aquaculture