The growth of cargo flows through South China's Shenzhen port has registered a notable slowdown and industry analysts believe this might reflect the contraction of the country's manufacturing sector.

Close to the country's light industry hub, South China's Shenzhen port has seen rapid growth in container flows during the past decade. The growth has declined since 2009 as the world economy is clawing back from the financial recession. In recent months the port's cargo volume was growing at a pace much slower than other Chinese ports.

In 2011, Shenzhen port handled 22.57 million containers, up 0.27 percent from the previous year, according to data from Shenzhen Ports Association. This is one of the lowest cargo volume increases among Chinese ports.

By contrast, container flows through Guangzhou port surged 13.4 percent year-on-year to 14.23 million boxes during this period.

In the meantime, growth in throughput in Chinese ports declined by 12 percent in July compared with the same period last year, the latest official data showed.

China's official PMI, one of the earliest indicators of China's economy, fell more than expected to 49.2 in August from 50.1 in July, the lowest in nine months. Anything below 50 indicates overall activity is contracting. Meanwhile, HSBC's China's manufacturing activity fell to 47.6 in August.