(Reuters) - The number of vessels that transited the Panama Canal, the world's second-busiest waterway, fell to an average of 33.7 per day in March for a total of 1,045 ships that month, according to a bulletin on Thursday by its administrative authority.

In February, an average of 34.8 vessels per day crossed the waterway, an increase from 32.6 per day in January, but still below the maximum number of ships authorized.

Transits this year have remained below the maximum of 36 vessels allowed to pass per day since the waterway lifted drought-related restrictions in the third quarter last year, despite lower fees. Transit fees in Panama this year have been 15% below last year's levels, according to figures from its authority.

A severe drought between late 2023 and early 2024 forced the waterway that connects the Atlantic and Pacific oceans to impose passage restrictions that prompted long waiting lines and higher transit fees.

The fees have been closely monitored since U.S. President Donald Trump complained about them earlier this year, adding that Washington would take over the canal if it determines that the presence of firms from China and Hong Kong near the waterway constitutes a security risk.

In late March, the canal's authority announced it would offer a net-zero weekly passage slot starting in October for dual-fuel vessels operating at low carbon intensity. The plan is part of an initiative to reward and encourage investments in energy efficiency and low-carbon fuels.