Container activity at Port Houston began slowing in late March as the coronavirus outbreak continued to threaten the global economy, port officials said this week.

The port handled 248,280 twenty-foot-equivalent units (TEUs) in March, down 11% compared to the year-earlier period. Officials said the port also saw seven blank sailings during the month.

Despite the monthly decline, first-quarter volume through the port remained strong; as of March, full year volume to date was up 11% compared to the first quarter of 2019.

“We must remain open for business to help international commerce continue during this difficult period,” the port’s Executive Director Roger Guenther said in a statement Tuesday. “We also must support the economy with the necessary infrastructure to rebound when this global pandemic is brought under control.”