Virtual project

Platform -> Virtual project -> Solving problems in… -> Adapting of fisheries management to…

Adapting of fisheries management to the changing Irtysh water basin hydrological regime

Fresh water deficit in recent years become a worldwide problem.In addition to measures to conserve water in the reservoirs of the Irtysh cascade in anticipation of the low water period, certain measures are necessary with regard to fisheries management.
Added to favourite:
0
23.08.2013
281
0

Adapting of fisheries management to the changing

Irtysh water basin hydrological regime

Y.V. Kulikov – Director of Altay Department of Kazakh Fishery Research Institute

Fresh water deficit in recent years become a worldwide problem. The most sharply he stands in the arid zone, which applies to the territory of Kazakhstan. It would seem, east of where the flowing deep river Irtysh, created three large reservoirs, free from water shortages. Especially, after the collapse of the irrigation system of the Irtysh stopped to pick up for this purpose and a half cubic kilometers of water, and feed them. Satpaev canal (Irtysh-Karaganda) is now working only half of its capacity. But a number of years hanging over the Irtysh new threat - increasing water intake in China.

The People's Republic of China in 1999 regulated flow of the river is 250 km from the Republic of Razakhstan border, built a canal to supply water to the city of Karamay enterprises. Diversion of water from the river is gradually increasing. The capacity of the Irtysh-Karamay - 2.1 km3 per year. If you add 1 cubic kilometers, which the Chinese take away from the Irtysh River for domestic use since feudal times, you get an impressive figure - 3 km3 at an average annual runoff of the river near the settlement of Buran about 9 km3. In practice, one-third of the river is taken.

The most productive and important for fisheries is the lake Zaysan. In a dry year weaning 1 km3 of water leads to a decrease in the water level of 32 cm, the water area of 170 km2 (total area of 3000 km2 or less), in such boundaries spawning already almost there. Weaning 3 km3 - Reservoir ceases to exist, is divided into two reservoirs - Zaysan and part of the river. Weaning 1 km3 lead to substantial losses for fisheries, weaning 3 km3 would have disastrous consequences for ecological communities, Bukhtarma reservoir is divided into two separate body of water, breeding grounds for fish almost left.

But when considering a question we often forget about the other important component - the natural cycle of water content of the Irtysh. And it plays an essential role. Figure 1 shows the water level in the reservoir Buhtarma (hydrologically Reservoir and Lake Zaysan are integrated) in the high water, the average water and low water years. Range of fluctuations of the water level is 5 meters.

Figure 1 – Seasonal water level in the Buhtarma reservoir at middle-water (annual averige),

low-water (2009) and high-water (2002) years

In recent years, due to the abstraction of water in China, the drain of the Black Irtysh declining, the average annual flow at 9 km3 actually reaches 6,4 km3 of water. Water storage in Upper Irtysh reservoirs such that it can partially compensate for the loss of water in China. But it is necessary to take certain measures in each sector of the economy, including fisheries. Figure 2 shows the dynamics of the water content of 2002-2012. Noticeable low water periods – 2008-2009, 2012. And repeatability low water years increases. Such low water periods were observed in 1983-84, 1992, 1999-2000, 2008-09, 2012.

Figure 2 – Dynamics of average annual water level of the Bukhtarma
reservoir (and the lake Zaysan) for a number of years

The natural cycle of water availability is always played an important role in the region's water provision. Especially since it has become a significant role in the last decade. Table 1 shows the evolution of average levels, and the volume of annual catches of fish in the Buhtarma reservoir (including Lake Zaysan) in the 1990s.

Table 1 – Comparison of water availability and fish catches in Buhtarma reservoir in the 1990s

Year

The average annual water level, m

The average annual water volume, km3

annualfish catch, tn

1990

398,40

31,94

7926

1991

397,77

29,21

8519

1992

397,54

28,25

7429

1993

399,47

36,86

7016

1994

400,72

43,04

5484

1995

400,35

41,16

5537

1996

399,52

37,10

6762

1997

399,26

35,84

7041

In low water years, water shortages have suffered not only the energy and agriculture, but also fisheries. Dramatically, 2-3 times, decreased efficiency of natural reproduction of fish stocks, the yield of juvenile fishes. At the same time, against the background of inefficient management of fish stocks and protect them in dry years there was a sharp increase in the uncontrolled fish catch. This was due to the decreased concentration of fish in the area and increase the catch per unit effort. Table 1 also shows the catches of fish in different water availability years. In the context of stable water level in 1990-92, annual catch of fish, the average for the three years, was 7.96 thousand of tons. In 1994-95, the high-water years, because dispersal of fish on the increased area and some overfishing, it fell to 5.5 thousand of tons in year, and in 1996-97 it stabilized at 6.9 thousand of tons per year. Thus, the natural cycles of water availability play an important role not only as to whether the spawning grounds for fish, but also in the development of fish stocks. The fishing industry in a sharp drop in the parameters of the reservoir and increase efficiency by reducing the area of fishing, will inevitably catch more fish than it should, despite the limits and prohibitions.

Table 2shows the evolutionof average water levelsandthe volumeof annualcatchesof fish in theshallow part ofthe mostproductiveBuhtarma reservoir – LakeZaysan – in 2006-2011. The volume of waterin the lakevariesin 2 times (in 2007-11.7km3,in2009-5.7km3,in2011-11.9km3). At the same time, the annual catch of fishvariesby 1.4times (high-water 2010 – 5.0 thousandtons,in dry2009 – 7.0 thousand tons).In2009, with the1.5-times thereduction of the area, and 2-times thedecrease in the volumeof waterin the lakeZaysanlakefish stockshave been underminedas a result ofoverfishing.Despite the sharpincrease inthe parametersof the reservoirin 2010-11, fish catches havenotreached the averagelevel(6.2 thousand tons).

Table 2 – The ratioof water availability andcatchesfishin the lakeZaysaninthe 2000s

Year

The average annual water level, m

The average annual water volume, km3

annualfish catch, tn

2007

399,05

11,68

5535

2008

397,91

8,25

5838

2009

396,98

5,66

7034

2010

398,63

10,38

5001

2011

399,13

11,93

4976

Thus, in addition to measures to conserve water in the reservoirs of the Irtysh cascade in anticipation of the low water period, certain measures are necessary with regard to fisheries management.

Upon the occurrence oflow-waterperiod, we must:

– In the field of economics to introduce restrictions on the consumption of water by all users.
– In the field of fisheries to reduce sharply limits (quotas) on fishing in the next calendar year.
– Enter the individual specifications of the catch per unit effort for each water body for small-, medium-and high-water years.

This will reduce some of the press of fishing on fish stocks in low water years and maintain them at a certain level which is sufficient for self-replication and the subsequent increase in the more affluent periods.

Comments

+ Add a comment