By Adam Weaver, TWP Intern
Experienced San Francisco Bay area fishermen will almost certainly be familiar with the striped bass (Morone saxatilis). The fish is caught year round, but summer and fall are the best times to reel in one of these Bay residents. Striped bass were introduced to the Bay from the East Coast beginning in 1879. That year, 132 small bass were released in Martinez after arriving by rail from New Jersey. A second introduction of around 300 bass took place in 1882. Within a couple of decades, the commercial net catch was over a million pounds a year! Today, the striped bass is one of the most commonly fished species in the Bay.
Why were the striped bass so successful? One reason is that a 15-pound female can produce over a million eggs! Females usually spawn for the first time in their 4th or 5th year when they are 21 to 25 inches long. Striped bass begin spawning in the spring in warmer water temperatures in open fresh water areas such as the San Joaquin, Middle and Sacramento rivers. Striped bass are an anadromous fish, which means they are born and spawn in freshwater, but spend much of their life in seawater. Because of this, by mid-June each year, most adult bass have left freshwater areas and have returned to the Bay or ocean. Other anadromous fish include white sturgeon and salmon. The fall migration back to the Delta starts in October.
Another reason for the striped bass’ proliferation in the Bay may be because they are voracious eaters. After hatching, small bass feed on zooplankton, but then move on to mysid shrimp and amphipods. As bass increase in size, they switch to larger food sources, such as anchovies or herring. In the Delta, larger bass eat threadfin shad, younger striped bass, and other small fish. Striped bass do not actively feed when the water is cold. Striped bass are thought to live up to 30 years! It is possible to estimate the age of a striped bass if you know the length or the weight of the fish. For example, a fish that is 36 inches long is probably about 12 years old.
I hope this offers some new found insight for anyone fishing or observing fishing around the Bay this summer and fall. You need only to drop a line to learn more about these fish up close and personal. And remember, good things come to those who wade.