Spotted Seatrout, Cynoscion nebulosus, are among the most sought after fish by recreational fishers throughout the Gulf of Mexico. In Texas, seatrout averaged 40% of the annual recreational catch over the last six years. While seatrout are generally known to aggregate and spawn in estuaries and bays along the coast of Texas from April through September each year, the specific locations and distribution of critical spawning habitats have not been identified or characterized. Obtaining this kind of knowledge will help us understand the impacts of climate change, increased coastal development and expansion, increased shipping traffic, or oil spills on spawning habitat and the productivity of the trout fishery.
Given the importance of this species to regional fisheries and coastal ecosystems, mapping spawning sites for spotted seatrout will be invaluable to state and federal agencies tasked with maintaining healthy, sustainable fisheries and ecosystems that benefit local communities and livelihoods. The project also provides a unique opportunity to get local fishers directly involved in the project, thereby increasing their support and contributions to scientific research that seeks to improve fisheries management.
Objectives and Goals
- Map spawning locations and habitat of spotted seatrout in Corpus Christi Bay, Redfish Bay and Aransas Bay, Texas
- Monitor activity and abundance of spawning seatrout throughout the spawning season
- Work with local anglers to collect data on frequency and seasonality of seatrout spawning
Parts 1 & 2 – Mapping of Spawning habitat using passive acoustics
Seatrout are members of the croaker or drum family (Sciaenidae) that make vocalizations as part of their courtship rituals and spawning. The drumming sounds of seatrout are only produced during the spawning event, just before and after sunset. Therefore, spawning aggregations can be identified using mobile hydrophones (underwater microphones) to record sound produced by male seatrout during spawning. Once a spawning location has been identified, the frequency and intensity of spawning can be monitored over the entire spawning season by placing a fixed hydrophone at the site.
Currently, our study area spans from Corpus Christi Bay to Aransas Bay. We have identified spawning in 176 locations and are monitoring 16 sites in various habitat types.
Part 3. Cooperative Research with Recreational Fishers and Guides
Spawning female seatrout are easy to identify due to their enlarged abdomens and clear visual cues of eggs in the ovaries. Therefore, fishing guides and anglers can easily participate in the project by simply sending photos of fish ovaries along with information on location and time of collection (click the link to see how you can help! Spotted Seatrout Fyler).
Figure 2. Female spotted Seatrout caught in Texas with ovaries ready to spawn and a close up of the cells inside of the ovary.