142
200, maximum 10,600/l). The snails Radix and
Hippeutis are common. Also, shells of Valvata
are quite abundant in swamps associated with
the infl owing rivers. Species of Chironomus and
Nais are also found. Further, the lake generally
depicts a potential piscian biomass of c
99 kg ha
−1 (Liu 1989 ). Concomitantly, 24 species of AM under 16 families cover 5–25 % of
the lake area, including stands of Phragmites
communis and Typha sp. near the mouth of the
infl owing Konqi River (Lu et al. 1979 ). Primary
production is 1.64 g m
−2 day
−1 .
Fishery
The Bosten Lake portrayed a catch of about
100 t year
−1 before 1965, which was dominated
by A. laticeps and S. biddulphi . Later, fi ngerlings
of bighead carp, black carp, silver carp, grass
carp, common carp and crucian carp were introduced in 1962–1965. Subsequently, in 1966, a
fi sh farm was established to promote artifi cial
spawning and culture of fi ngerlings for stocking.
Artifi cial spawning of grass carp and silver carp
has been particularly successful, and about 5.5
million fi ngerlings have been introduced to the
lake since 1973. Since 1978, perch has dominated the catch (55–78 %), and the total annual
catch now is about 500 t. Later, the annual catch
is said to have been boosted to about 2,000 t.
Management changes have been imposed to protect spawning populations, and, also, to protect
cyprinids against predation by perch.
In addition , Bosten Lake in combination with
Ulungur Lake is often considered as the principal
lake fi sheries in Xinjiang Province (Liu 1989 ),
with a combined production that peaked at
7,100 t in 1971 and later about 4,000 t. The
average yield in the province has increased from
15 kg ha
−1 in 1981 to 139.5 kg ha
−1 in 1987. In
1987 68,600 ha were stocked with fi sh, including
reservoirs (63.5 % of total area), natural lakes
(11 %), ponds (6.4 %) and swamps (17.9 %), and
total production was 14,050 t. Seventy percent of
this fi gure came from aquaculture, including production from reservoirs (33 %) and ponds and
swamps (>60 %).
Notwithstanding the above, Bosten Lake is
said to have good water quality and abundant
plankton from a fi shery point of view, but benthos
is sparse. In addition, the proportion of carnivorous fi sh (perch) is considered to be too high.
In addition to above, some of the other lakes in
the region are as follows.
Gyaring Lake and Ngoring Lake
Lakes Gyaring and Ngoring , each lying at an altitude of 4,155 and 4,138 m MSL, respectively,
between 97° 54′ E–34° 55′ N and 97° 41′ E–34°
53′ N, respectively, are oligotrophic lakes situated on the upper Yellow River in Qinghai
Province. They are 20 km apart but linked by the
river and so have similar fi sh assemblages including Chuanchia labiosa , Diptychus pachycheilus ,
Gymnocypris eckloni , Platypharodon extremus
and Schizopygopsis pylzovi (Schizothoracinae)
and Triplophysa microps (syn. T. dorsonatus ),
T. scleropterus and T. siluroides (Noemacheilinae).
The fi shery was opened in the 1960s and has
persisted despite diffi culties in transport and marketing. G. eckloni and P. extremus are dominant
in Ngoring and Gyaring lakes, respectively (Zhu
et al. 1984 ). The two lakes have surface area
(km
2 ), volume (10
8 m
3 ), maximum depth (m) and
average depth (m) of 526, 46.82, 31, 8.917.6 and
610, 107.5, 18, 7.6, respectively. Annual rainfall
and evaporation are c 322 mm year
−1 and
1,315 mm year
−1 , respectively, in both Gyaring
and Ngoring lakes. Further, lakes Gyaring and
Ngoring, respectively, have the following
physico-chemical characteristics of water: average temperature −4 and −4 °C, transparency 1.0
and 3.0 m, pH 8.6 and 8.5, DO 6.4 and 7.7 mg l
−1 ,
TA 3.5 and 3.4 mg l
−1
, TH 10.6 and 9.5 mg l
−1 ,
PO 4 7.0 and 0.039 mg l
−1 and NO 3 <0.001 and
<0.001 mg l
−1 . AM biomass usually reveals 400
and 61.5 g m
−2 in lakes Gyaring and Ngoring,
respectively. On the other hand, phytoplanktonic
biomass generally show 1.37, 0.16 and 0.73,
0.50 g/m
3 , respectively, and zooplanktonic biomass usually shows 400 and 61.5 g m
−2 and 0.16
and 0.50 g/m
3
, respectively, in lakes Gyaring and
Ngoring, respectively.
Yamdrok Lake
Yamdrok Lake is said to be one of the largest
lakes in Xizang Province situated on the northern
6 Lakes of the World
200, maximum 10,600/l). The snails Radix and
Hippeutis are common. Also, shells of Valvata
are quite abundant in swamps associated with
the infl owing rivers. Species of Chironomus and
Nais are also found. Further, the lake generally
depicts a potential piscian biomass of c
99 kg ha
−1 (Liu 1989 ). Concomitantly, 24 species of AM under 16 families cover 5–25 % of
the lake area, including stands of Phragmites
communis and Typha sp. near the mouth of the
infl owing Konqi River (Lu et al. 1979 ). Primary
production is 1.64 g m
−2 day
−1 .
Fishery
The Bosten Lake portrayed a catch of about
100 t year
−1 before 1965, which was dominated
by A. laticeps and S. biddulphi . Later, fi ngerlings
of bighead carp, black carp, silver carp, grass
carp, common carp and crucian carp were introduced in 1962–1965. Subsequently, in 1966, a
fi sh farm was established to promote artifi cial
spawning and culture of fi ngerlings for stocking.
Artifi cial spawning of grass carp and silver carp
has been particularly successful, and about 5.5
million fi ngerlings have been introduced to the
lake since 1973. Since 1978, perch has dominated the catch (55–78 %), and the total annual
catch now is about 500 t. Later, the annual catch
is said to have been boosted to about 2,000 t.
Management changes have been imposed to protect spawning populations, and, also, to protect
cyprinids against predation by perch.
In addition , Bosten Lake in combination with
Ulungur Lake is often considered as the principal
lake fi sheries in Xinjiang Province (Liu 1989 ),
with a combined production that peaked at
7,100 t in 1971 and later about 4,000 t. The
average yield in the province has increased from
15 kg ha
−1 in 1981 to 139.5 kg ha
−1 in 1987. In
1987 68,600 ha were stocked with fi sh, including
reservoirs (63.5 % of total area), natural lakes
(11 %), ponds (6.4 %) and swamps (17.9 %), and
total production was 14,050 t. Seventy percent of
this fi gure came from aquaculture, including production from reservoirs (33 %) and ponds and
swamps (>60 %).
Notwithstanding the above, Bosten Lake is
said to have good water quality and abundant
plankton from a fi shery point of view, but benthos
is sparse. In addition, the proportion of carnivorous fi sh (perch) is considered to be too high.
In addition to above, some of the other lakes in
the region are as follows.
Gyaring Lake and Ngoring Lake
Lakes Gyaring and Ngoring , each lying at an altitude of 4,155 and 4,138 m MSL, respectively,
between 97° 54′ E–34° 55′ N and 97° 41′ E–34°
53′ N, respectively, are oligotrophic lakes situated on the upper Yellow River in Qinghai
Province. They are 20 km apart but linked by the
river and so have similar fi sh assemblages including Chuanchia labiosa , Diptychus pachycheilus ,
Gymnocypris eckloni , Platypharodon extremus
and Schizopygopsis pylzovi (Schizothoracinae)
and Triplophysa microps (syn. T. dorsonatus ),
T. scleropterus and T. siluroides (Noemacheilinae).
The fi shery was opened in the 1960s and has
persisted despite diffi culties in transport and marketing. G. eckloni and P. extremus are dominant
in Ngoring and Gyaring lakes, respectively (Zhu
et al. 1984 ). The two lakes have surface area
(km
2 ), volume (10
8 m
3 ), maximum depth (m) and
average depth (m) of 526, 46.82, 31, 8.917.6 and
610, 107.5, 18, 7.6, respectively. Annual rainfall
and evaporation are c 322 mm year
−1 and
1,315 mm year
−1 , respectively, in both Gyaring
and Ngoring lakes. Further, lakes Gyaring and
Ngoring, respectively, have the following
physico-chemical characteristics of water: average temperature −4 and −4 °C, transparency 1.0
and 3.0 m, pH 8.6 and 8.5, DO 6.4 and 7.7 mg l
−1 ,
TA 3.5 and 3.4 mg l
−1
, TH 10.6 and 9.5 mg l
−1 ,
PO 4 7.0 and 0.039 mg l
−1 and NO 3 <0.001 and
<0.001 mg l
−1 . AM biomass usually reveals 400
and 61.5 g m
−2 in lakes Gyaring and Ngoring,
respectively. On the other hand, phytoplanktonic
biomass generally show 1.37, 0.16 and 0.73,
0.50 g/m
3 , respectively, and zooplanktonic biomass usually shows 400 and 61.5 g m
−2 and 0.16
and 0.50 g/m
3
, respectively, in lakes Gyaring and
Ngoring, respectively.
Yamdrok Lake
Yamdrok Lake is said to be one of the largest
lakes in Xizang Province situated on the northern
6 Lakes of the World