Striped bass population changes with weather

Salt water striped bass supposedly rebounded from overfishing in the 1980s but anglers report catches are down again. New research suggests weather might be the cause behind both drops. Wildlife managers "laid down severe catch limits" for the fish in the 1980s, and "the population recovered and fishing resumed in what is considered one of conservation's great success stories," Christopher Joyce of National Public Radio reports. Bob Wood, a biologist at the National Oceanic and Atmospheric Administration, theorizes the drops in striped bass populations were actually the result of shifting Atlantic weather. (Photo by Jay Fleming)

Wood's research points to the Atlantic Multidecadal Oscillation, "a mashup of wind and ocean currents, a flip-flop that happens every 35 years or so in the North Atlantic," as the culprit in the population drop. "Circulation changes in a way that warms the entire basin," Wood told Joyce. "And you can imagine if you warm the entire North Atlantic basin, you're changing the weather because the air and circulation patterns above the ocean are affected." That warming in turn affects river flow or salinity, sending ripples up the food chain.

When the AMO is "in a warm phase, springtime along the East Coast actually tends to be wet and cool — more rain, more water, more food," Joyce writes. "In the years following that phase, striper numbers tend to go up. Then the AMO flips — drier springs, less rain, less food. After a lag, it looks like striper numbers start to decline." Wood says understanding the weather shift could help set catch limits. "If we know that there is this [down] cycle coming up," he told Joyce, "we can keep that in our heads as we set limits." (Read more)