Ridership is down on South Jersey rail lines, and local officials attribute much of the decline to the recession and gasoline prices that are off sharply from their 2008 highs.

The passenger drop-off is especially steep on the Atlantic City Rail Line, which has been hit hard as fewer gamblers and employees travel to the economically troubled casinos.

The Atlantic City line, operated by NJ Transit to and from Philadelphia, saw ridership drop by 21 percent in the three months that ended Sept. 30, compared with the same period in 2008. Ridership for the quarter was 315,400 trips, compared with 399,200 a year earlier. Average weekday trips in the period were down from 4,550 last year to 3,450 this year.

Another indication of Atlantic City's woes was the announcement last week of cutbacks in the 10-month-old New York-Atlantic City rail service. The weekend Atlantic City Express Service (ACES), subsidized by three casinos, will be reduced to 11 trips, from the current 18, beginning next Friday.

The River Line light-rail trains that operate between Camden and Trenton saw ridership decline 6.5 percent in the three-month period, from 779,700 trips to 728,700. The average number of weekday trips was 9,200, down from 9,850, NJ Transit spokesman Dan Stessel said.

Stessel noted that both the River Line and Atlantic City Line had set ridership records in the three-month period in 2008, as gas prices peaked midyear. Since then, he said, more affordable gas and declining employment have hurt traffic.

At PATCO, the commuter rail line between Philadelphia and South Jersey, ridership dropped slightly this year, to 10.03 million riders from 10.1 million riders. PATCO officials said they expected a further slight decline next year, to about 10 million riders.

Mass transit ridership has declined in Philadelphia, as well. SEPTA reported Regional Rail ridership for the quarter ended Sept. 30 was down 7 percent compared with a year earlier, while city bus and subway ridership was down 4 percent. Rail ridership soared briefly during last month's six-day strike by SEPTA bus and subway operators, when average weekday ridership increased by 42,000, or about 36 percent.

Contact staff writer Paul Nussbaum at 215-854-4587 or pnussbaum@phillynews.com.