Local correspondents have advised Britannia P&I Club and Standard Club that loss or reduction in propulsion was continuing to occur in the Houston Ship Channel. An investigation of ships’ sea chests showed that the strainers were blocked with Menhadens, a smallish, flat, oily fish common to the Gulf of Mexico.
Menhaden can be present all year round, with the greatest presence between April to October.
The correspondents said that these fish could clog sea chest strainers and restrict the flow of sea water cooling, increasing the cooling water temperature and resulting in slowdown of the engines, not only while transiting, but also while the ship was alongside a berth. This had led to a loss of propulsion, manoeuvrability, generator power or other seawater safety systems.
US Coast Guard Sector Houston-Galveston issued USCG Marine Safety Information Bulletin MSIB 10-18, highlighting the issue and recommending best practices to reduce the risk.
https://britanniapandi.com/houston-fish-causing-sea-chest-clogging/