An analysis of water specimens from Oso Bay collected by Dr. David McKee’s marine biology classes over the last 18 years has given one of the most underappreciated bodies of water along the Texas Gulf Coast a clean bill of health.

According to McKee, the finding is good news because Oso Bay is an important nursery area for many species of fish, crabs and shrimp. Without the Bay’s protection during the early stages of development, much of the young marine life would not survive long enough to develop and move into open the open waters of the Gulf of Mexico.

“The entire body of data we’ve collected shows that Oso Bay is a very healthy body of water,” said McKee. “The same kinds of organisms are represented each year in similar abundances indicating that few, if any, changes have occurred despite increasing development along the bay’s shorelines.”

Monitoring of Oso Bay is essential, says McKee, because three sewage plants discharge their treated water into the bay. Despite that fact, the tests conducted by McKee’s classes show that the water remains pristine and an excellent nursery for developing organisms. Much of the credit, he points out, must go to the treatment plants which have effectively recycled the cleaned water.

Oso Bay hasn’t always enjoyed such excellent health. Prior to the construction of the Barney Davis power plant in 1976, waters from the upper Laguna Madre to Oso Bay suffered from a lack of oxygen due to stagnation. But as the power plant takes in and discharges water to cool its pumps, circulation is increased, which leads to more plant growth where young fish, crabs and shrimp can survive until they reach maturity.

Unfortunately, the power plant is due to close within the next couple of years, which could very well affect Oso Bay’s future health. The power plant has already reduced its water flow which may lead to a reversal of its positive effects.

 “When the plant shuts down it will be very important to continue monitoring the bay, The 18 years’ worth of data we’ve collected can be used to compare future changes in plant and fish life as well as saline content.”

One night each year McKee’s marine ecology classes spend a night camping on the beach of Oso Bay to gather and study water specimens. Over a 24-hour period, students gather samples to determine the presence and abundance of large and small fish and invertebrates. The students also measure water quality. While the annual 24-hour study gives students valuable hands-on experience working with tools they’ll need in their careers as scientists, McKee cautions against relying too much on its findings.

“The study is just a one-day glimpse, so we must be careful about the trends we see in the data,” he pointed out. “The oxygen levels could be impaired by a summer without much rain or by a temporary change in dissolved oxygen levels. The main purpose of the exercise is to give the students experience and to get them to pose questions and look for answers.”
After the results are tallied and analyzed the students are required to write an extensive research paper to describe the collections made and to compare this year with previous studies.

“Writing papers helps prepare the students for careers as scientists,” McKee said. “Quite a few of our students will go on to become field biologists employed by state or federal agencies while others will go to graduate school and will do field research. In addition to knowing about different sampling gears and techniques, they will be expected to collect and analyze data and write in a technical format.”