structural:summarization, linguistic:voice_change
Flora and fauna

The shores of the lake contain individual willow trees and riparian forests, mostly composed of various species of Populus. Plants include common reed (Phragmites australis), lesser Indian reed mace (Typha angustata) and several species of cane – Schoenoplectus littoralis, S. lacustris and endemic S. kasachstanicus. Under water grow two types of Myriophyllum – spiked (M. spicatum) and whorled (M. verticillatum); several kinds of Potamogeton – shining (P. lucens), perfoliate (P. perfoliatus), kinky (P. crispus), fennel (P. pectinatus) and P. macrocarpus; as well as common bladderwort (Utricularia vulgaris), rigid hornwort (Ceratophyllum demersum) and two species of Najas. Phytoplankton, the concentration of which was 1.127 g/L in 1985, is represented by numerous species of algae.

The lake used to have a rich fauna, but since 1970, biodiversity began to decline due to deterioration of water quality. Before then, there were abundant shellfish, crustaceans, chironomidae and oligochaeta, as well as zooplankton (concentration 1.87 g/L in 1985), especially in the western part. The lake hosted about 20 species of fish, 6 of which were native: Ili marinka (Schizothorax pseudoaksaiensis), Balkhash marinka (S. argentatus), Balkhash perch (Perca schrenkii), Triplophysa strauchii, T. labiata and Balkhash minnow (Rhynchocypris poljakowii). Other fish species were alien: common carp (Cyprinus carpio), spine, Oriental bream (Abramis brama orientalis), Aral barbel (Luciobarbus brachycephalus), Siberian dace (Leuciscus baicalensis), tench (Tinca tinca), European perch (Perca fluviatilis), wels catfish (Silurus glanis), osman (Diptychus), Prussian carp (Carassius gibelio) and others. The fishery was focused on carp, perch, asp (Leuciscus aspius) and bream.

Abundant and dense reeds in the southern part of the lake, especially in the delta of the Ili River, served as a haven for birds and animals. Changes in the water level led to the degradation of the delta – since 1970, its area decreased from 3,046 to 1,876 km, reducing wetlands and riparian forests which were inhabited by birds and animals. Land development, application of pesticides, overgrazing and deforestation also contributed to the decrease in biodiversity. Of the 342 species of vertebrates, 22 are endangered and are listed in the Red Book of Kazakhstan. Forests of the Ili delta were inhabited by the rare (now probably extinct) Caspian tiger and its prey, wild boar. Around the 1940s, Canadian muskrat was brought to the Ili delta; it quickly acclimatized, feeding on Typha, and was trapped for fur, up to 1 million animals per year. However, recent changes in the water level destroyed its habitat, bringing the fur industry to a halt.

Balkhash is also the habitat of 120 types of bird, including cormorants, marbled teal, pheasants, golden eagle and great egret; 12 of those are endangered, including great white pelican, Dalmatian pelican, Eurasian spoonbill, whooper swan and white-tailed eagle.