ACCLIMATIZATION OF FISH IN THE PACIFIC STATES. 
413 
River, or San Joaquin River, or Suisun Bay during a whole year, but the fact is 
established that in every month and on every day it is possible to find shad in 
quantities in those waters. 
It seems probable that the constant supply of shad in the northern tributaries of 
San Francisco Bay is kept up by the arrival of new bodies of fish from the salt water, 
which take the place of those that have spawned and gone to sea. The movement of 
schools in and out of the Golden Gate is well recognized. 
Monterey Bay seems to be a loitering and feeding ground for shad bound to or 
from the Sacramento. According to the statement of the California fish commis- 
sioners in their report for 1878-79, the shad which leave the Sacramento River follow 
the coast to that bay, where they are supposed to find an abundance of food, for a 
few are taken in the fishermen’s nets every week throughout the year. 
As it is only during the salmon season that shad are caught in the Columbia 
River, very little is known of their movements and the times of their arrival and 
departure. They are caught from April to July, inclusive, but after the latter part 
of July few are taken. It is generally supposed that most of them enter the sea 
about that time. Mr. Alexander says that, as no person lias been interested enough 
to study the migratory habits of the shad in the Columbia basin, nearly all the ideas 
advanced concerning them are speculation, but what is now known of their habits 
would indicate that a much larger proportion of the shad of this river enter the sea 
in a general body than do those inhabiting the Sacramento. 
THE SPAWNING SEASON AND GROUNDS. 
The change in the spawning season of the shad incident to their introduction to 
the waters of the Pacific Coast is one of the most interesting features connected with 
the results of acclimatization. On the Atlantic Coast the spawning season of the 
shad rarely lasts longer than five or six weeks in a given river basin, and in places is 
shorter during some seasons. 
In California, according to the testimony of reputable dealers, shad are found 
with ripe spawn from December to August. Inasmuch as the ripe roe is often taken 
from the fish by the San Francisco dealers and sold separate, the dealers are in posi- 
tion to make accurate observations on this point. May, however, is the month when 
most of the shad in the Sacramento region are thought to undergo the spawning 
process. Many shad examined by the writer in May and June, 1894, contained ripe 
spawn, and the roe was often seen exposed for sale in the San Francisco market 
during those months. 
The principal spawning-grounds for shad in California are in the lower parts of 
the Sacramento and San Joaquin rivers, in the numerous sloughs in the delta of those 
streams, and in the lakes of the so-called tule lands — alluvial islands in the beds 
of the rivers. These tule lands were at one time under splendid cultivation, but, 
becoming neglected, the river broke through the embankments and formed lakes of 
various sizes on the sites of former plantations. Some of the tule ponds are from 10 
to 15 feet deep, but the average is only 5 or 0 feet. At some places near the point of 
communication with the sloughs or river the tule waters are vei’y deep; one cut on 
Sherman Island, which was recently surveyed, was 65 feet deep within the levee. In 
these tule waters the shad and striped bass are found at all seasons, and are generally 
believed to spawn there. They are certainly well suited for spawning-grounds, the 
