A Research and Monitoring Program to Mitigate the Impact of Harmful Algae Blooms on the Matagorda Bay and San Antonio Bay Ecosystems

Harmful algal blooms (HABs) are caused by the proliferation of phytoplankton species that have harmful effects on marine life and human health. Since 2008, shellfish harvesting in Matagorda Bay and San Antonio Bay has been closed no less than seven times and five times, respectively, due to the presence of the HAB species Karenia brevis and Dinophysis ovum. Fish kills have also been reported in response to blooms of the former. Aside from causing fish mortality events and leading to shellfish harvesting closures, a longer-term threat comes from potential impacts on the nascent commercial oyster aquaculture industry in both Matagorda Bay and San Antonio Bay.

Coastal HAB monitoring efforts in Texas are largely reactive, with efforts geared towards responding to an event as it develops or that has already developed. One of the important lessons learned from previous HAB events is that proactive, sustained monitoring efforts need to be expanded to give early enough warning for effective response. This will reduce economic loss and adverse health impacts that will more than pay for the cost of increased monitoring efforts. In the longer-term, data collected as part of sustained monitoring can inform resource managers and researchers as to the drivers of HAB events, leading to solutions to prevent future blooms. Dr. Michael Wetz, HRI Chair for Coastal Ecosystem Processes, has successfully done this in Baffin Bay.

Currently, the only sustained HAB monitoring in Texas is through use of automated HAB detection sensors that are limited to three locations along the 367 miles of coastline, none of which are near Matagorda or San Antonio Bay.

Using information gained from a synthesis of historical HAB events and results from recent sampling efforts led by Dr. Wetz, an analysis of water quality “hot spots” that have conditions conducive to HABs, and the distribution of key oyster reefs in these systems, the Harte Research Institute has developed a HAB research and monitoring program for Matagorda and San Antonio Bays. Once implemented, a key outcome will be enhanced mitigation of negative impacts from HABs on human, environmental, and economic health by facilitating greater early warning and increased awareness of the presence of HABs, assuring residents and visitors that their waters and seafood are safe. A longer-term outcome, facilitated by improved understanding of the relationship between HABs and environmental drivers, will be an increased likelihood for prevention of some HABs by reshaping the environment to no longer be conducive for them.

Specific objectives of the project are to:

1. Deploy a real-time automated HAB sensor at a strategic location to provide early warning of ocean-derived HAB events.
2. Couple data acquired from the sensor with data from targeted water sampling in both bays to understand drivers of HAB events in them.
3. Engage stakeholders to increase awareness of HABs and to seek solutions that will mitigate HAB impacts and potentially prevent their future occurrence.