108 
REPORT OF BOARD OF FISH AND GAME COMMISSIONERS. 
made very large and so placed that the fish can be trapped and guided 
into the pen without handling. 
There were several theories advanced to account for the poor run of 
bass in the San Joaquin River. For a year the dredgers had been active 
building up the levees and the silt and dirt thus stirred up might cause 
the bass to shun the river. Another theory was that the bass turned 
into and continued on through the flooded Sherman Island, whose 
levees had broken the year before, and continued up the Sacramento. 
The number of bass taken in the Sacramento was larger than the 
spring before, which seems to bear out this theory. 
Another theory is that the bass are becoming scarce, due to the large 
catches and to the destruction of bass in the reclaimed islands when they 
were pumped dry. The scarcity of the bass in the San Joaquin may 
be due to all of these causes. Certainly immense numbers of bass have 
been destroyed in the islands. When the levees break the small river 
fish and carp enter the flooded lands and the bass also seem to prefer 
these islands for feeding grounds; and when the levees are built up 
again and the water pumped out, many tons of bass of all sizes are left. 
The fishermen say that the sand bars and flats in the San Joaquin, 
which used to be of clean sand, are now covered with silt and trash 
stirred up by the dredgers, and they catch no bass now on these bars, 
where formerly they were often taken. 
Most of the bass taken at Bouldin Island this season were taken in 
Georgiana Slough on their way through to the Sacramento. The 
catch on the Sacramento was larger than the year before, the largest 
number being taken in Steamboat Slough. The run was quite good in 
.1 
Cache Slough and Prospect Slough. 
•V 
Season of 1910. —During this season two fishermen and boat were 
employed to fish for striped bass in the neighborhood of Bouldin 
Island, and another boat and two fishermen were employed to fish in 
Cache Slough and tributaries on the Sacramento side. 
The run of spawn bass on the San Joaquin was better than the 
previous season, but all females taken were green and immature. Ripe 
males were taken in plenty. The river above Bouldin and all sloughs 
within ten miles were fished, the fishing being done mostly by night. 
The Mokelumne River was also explored. Bass were taken only near 
Bouldin Island mostly in the main river. 
The Cache Slough country on the Sacramento was thoroughly 
explored. The striped bass are found in increasing numbers each year 
in this region. The greater number of bass are taken in Steamboat 
Slough, just above the mouth of Cache Slough, during the early part 
of the runs. Later they are found more plentiful in Cache Slough, 
where they are taken in nets in the main slough. Most of the bass 
running up Cache Slough turn off and ascend the clear water of Pros- 
