Pearcy and Fisher: Ocean distribution of A/osa sapidissima along the Pacific coast of North America. 
445 
Figure 3 
Catch of American shad (Alosa sapidissima ) in round haul purse seine sets conducted by Oregon State Univer- 
sity by month, for the combined years 1981-85. Catches are log 10 -transformed. Isobaths are 100 m and 200 m. 
California and Baja Mexico during January-June, fol- 
lowed by migrations far to the north during July-Octo- 
ber. Because ocean temperatures along the coast are 
often cooled by coastal upwelling during July, Leggett 
and Whitney thought that northward movements were 
diverted offshore to avoid these cool coastal waters. 
Data from our research surveys were collected mainly 
during the spring and summer; however, other data lend 
little support for shad migrations in the Pacific Ocean 
far to the south during the winter months. Data from 
commercial and sport landings of American shad along 
the Pacific coast indicate limited seasonal migrations 
along the West Coast. 
In British Columbia, over 100 t of shad have been 
landed in some years in bottom and midwater trawls 
from 1997 to 2009 (Davidson andFargo 5 ). This figure 
includes large catches from “unknown management” 
ocean areas in British Columbia (not shown in Table 2). 
From known ocean management areas, about 85% of 
the weight landed occurred between April and October 
(“summer” in Table 2) and most of these landings (95%) 
occurred during the months of August and October (see 
Figs. 1 and 2A). Shad were 260-580 mm fork length, 
most 400 mm or larger (about 0. 8-3.0 kg; Davidson 
and Fargo 5 ), mature, and over three years of age ac- 
cording to Petersen et al. (2003) and Hamman (1981). 
Large numbers of shad would not be expected in Brit- 
ish Columbia waters during the fall when cool water 
temperatures below 13°C prevail if their migration 
patterns were similar to those predicted or shown for 
the Atlantic coast by Leggett and Whitney (1972). These 
large catches often found off the northern Washington 
and British Columbia coasts (Figs. 1 and 2) indicate 
that many shad from the Columbia River region move 
to the north after spawning. Surface currents to the 
north along the coast during winter months, or the deep 
