The young fish get sucked into the ships’ filter systems that suck in seawater to cool off the engines, causing a shutdown on the engines. Without being able to run their engines, the big ships hauling heavy loads can’t steer. No collisions were reported, but the issue has led ships to run aground in the past.
The menhaden problem was encountered from early July to early September. Dry winters followed by wet springs, plus high salinity, contributed to the menhaden population boom. Menhaden tend to stay in water depths of one to eight feet.
Source: Houston Chronicle