Appendix V
SUMMARIES OF TRAWLER LOGBOOK DATA, 1980–92

Annual catch records by months and designated fishing areas (see Fig. 5.2). These data are derived from the trawler captains' estimates, and may not correspond closely with the Bureau's statistical records. Note that records for several years are incomplete.

Figure 1.1

Qinghai Lake, showing locations from the text.

Fig. 3.1

Bathymetric map of Qinghai Lake, surveyed in 1961–63. From Academia Sinica (1979).

Fig. 3.2

Depth profiles of area and volume. Note lake surface elevations in 1961–63 and 1990.

Fig. 3.3

Annual average water-level elevations (on above sea level) in Qinghai Lake, 1956–90.

Fig. 3.4

Average annual evaporation and precipitation in the Qinghai Lake region, 1970–90.

Fig. 3.5

Comparative annual discharges of the Buha and Shaliu rivers, 1970–90.

Fig. 3.6

Average monthly flows in the Buha (upper) and Shaliu rivers (lower), 1970–90.

Fig. 3.7

Responses of the lake level to changes in the water balance, 1970–90. The broken line indicates a water deficit of-800 mm (see text).

Fig. 3.8

Average monthly air temperatures in the Qinghai Lake region and near-shore lake water temperatures, 1970–90.

Fig. 3.9

Temperature-depth profiles at station 2 in South Bay, Qinghai Lake, 1990.

Fig. 3.10

Vertical profiles of light penetration, oxygen saturation and temperature at station 2 in South Bay, Qinghai Lake, 12 September 1990.

Fig. 4.1

The beginning of the spawning run in the Buha River in 1989–90, In relation to average monthly discharge.

Fig.4.2

Regressions of weight on standard length for naked carp sampled in 1990–92.

Fig. 4.3

Relationship of age and standard length for naked carp sampled in 1990–92.

Fig. 4.4

Relationship of age and total weight for naked carp sampled in 1990–92.

Figure 4.5

Plot of length versus age for naked carp sampled in 1990–92. The solid line indicates a Von Bertalanffy model fitted by the least-squares method, whereas the broken line represents a model fitted by Zhang &Chen (1980) using earlier data.

Figure 4.6

Frequency distributions of the lengths of fish in monofilament fleet-net samples from various locations in 1991.

Figure 5.1

Annual fishery production for Qinghai Province and the Qinghai Lake Fish Factory, 1959–92, compiled from records of the Bureau of Aquatic Products. See Table 5.1 for further details.

Figure 5.2

Fishing areas in Qinghai Lake, used for monitoring the movements of trawlers from the Fish Factory.

Figure 5.3

Catch per unit effort (CPUE) in the principal trawl areas, 1980–91. Area H, near the Buna mouth, and area M, near the Fish Factory, together contributed roughly half the average annual catch over this period. Area H was not fished significantly in 1990.

Figure 5.4

Trends in catch per unit effort, calculated on a lakewide basis, since 1980. Annual Fish Factory production also is shown, although this may not accurately reflect changes in the total catch. Note that the new trawler fleet was introduced in 1989–90.