The Environmental Sciences Department is continuing to monitor the sightings, and officials said the dead fish are not caused by poor water quality.
Anyone who spots dead fish along the river is asked to contact the River Authority’s Environmental Investigations team online or by calling 866-345-7272.
The Texas Parks and Wildlife Department said fish on the Texas coast first started dying off on Feb. 14.
Among the fish species impacted were spotted seatrout, red drum, sheepshead, grey snapper, snook, black drum and tarpon.
Other wildlife species impacted by the storm include axis deer, blackbuck, nilgai antelope and multiple bird species, according to TPWD.