The San Antonio River Authority spent Wednesday afternoon trying to figure out what killed several fish in the Museum Reach of the River Walk.
The dead fish were spotted floating belly up on the surface between the Ninth Street Bridge and the lock and dam system.
Tourist Sarah Schulz and her family were checking out the new section of the river when they noticed several dead fish floating by.
"We saw several dead fish in the lock and as we progressed upstream we saw a lot more dead fish," Schulz said. "You expect to see one or two but to see as many as we've seen in just 50 feet, it's pretty surprising."
Maintenance crews working for the San Antonio River Authority used nets to collect the bloated carcasses from a barge.
Within minutes of contacting the River Authority, scientists were dispatched to investigate the kill and took water samples.
"Currently the water quality is fine," said Steven Schauer, a spokesman for S.A.R.A. "The dissolved oxygen levels are OK."
According to Schauer, the tests were inconclusive for contaminates. Schauer suspected the fish kill may be related to recent rains following a long dry spell.
"Often times things get washed into the river and there might have been something that washed into the river that had a temporary shocking effect," Schauer said. "The dissolved oxygen levels might have temporarily dropped because of the rain event.
Schauer said colder water temperatures could also be partly responsible.
"The colder water temperatures do have a negative impact on some of the species," Schauer said. "So some of the weaker fish of those species might have passed because of colder water."
Since the fish kill was concentrated in one small section of the river, Schauer said he isn't overly concerned by it. Schauer added overall the river is pretty healthy.
"There's thousands of healthy fish in the San Antonio River and a small kill of 15-20, while it's something we don't like to see, is really nothing to be completely alarmed by," Schauer said.
Scientists will continue to monitor the water in the Museum Reach just to be sure there's nothing more serious killing the fish.