The ports of Los Angeles and Long Beach are aggressively advertising and giving customers discounts at a time when they and most other U.S. ports are wrapping up their worst ever year-over-year decline in shipping business. In 2009, the two ports moved about 2.5 million fewer containers than the year before. … The decline has been felt by veteran longshoremen who are unable to find more than two or three days of work a week and by part-timers who find none. Coming back from a year like that isn’t the biggest concern of Southern California port officials. Their larger worry comes from new competitors in Canada and Mexico, not to mention U.S. ports on the Gulf of Mexico and the East Coast that have elbowed their way past smaller West Coast ports in the last decade.