Baffin’s Bounty: Preserving Baffin’s Vital Underwater Habitat

You don’t have to be an angler to know that worms and fishing go together like brisket and BBQs. Many-a-Texan’s first encounter with fishing involves threading an earthworm on a hook for bait. Lesser known is the relationship anglers have with a special species of worm found in the salty waters of south Texas. These worms serve as a foundation for biodiversity and provide key habitat rather than being a fish sacrifice. The area where these worms reside has drawn anglers from all over the world for over a century and is now gaining attention from researchers.

Baffin Bay, anecdotally referred to as Jurassic Park by local fishermen, holds a special place in the heart of many anglers. Located roughly 20 nautical miles south of Corpus Christi, Texas, Baffin gives anglers the opportunity to catch trophy speckled trout, black drum, and massive redfish (locally referred to as the ghosts of Baffin). Now before you race down to Baffin to wet a line, know that no good treasure goes unguarded. Many parts of Baffin are lined with rock reef structures that are unique to the area and make navigation a challenge.

The reefs are the accrual of millions of small calcareous tubes. The creature responsible for these tubes is Hydroides dianthus, a species of serpulid polychaete, which is scientific speak for marine worm. Baffin is the only place on the Texas coast with active serpulid reefs and one of the few places in the world. Each reef is a magnet for marine life and the epicenter of food webs. H. dianthus feeds by filtering the surrounding water with a colorful bouquet of feathery appendages. Many species of crabs and other crustaceans take shelter on the reefs. Barnacles, algae, and other encrusting organisms attach themselves to the hard tubes. Baitfish take shelter around the structures and larger gamefish use the reefs as cover for ambushing prey. Most of the reefs in Baffin are relic, meaning they no longer have live worms. However, despite being inactive many organisms still live on and around the reefs. To learn more about the history of these reefs check out a previous TPWD Field Note written in 2009 titled "The Rocks of Baffin Bay”.

Boat collisions and heavy-footed wade fishermen have caused a lot of damage to the reefs. In recent decades, water quality issues have plagued Baffin Bay threatening the worms and their architecture. Polluted runoff and freshwater inflow with higher nutrient loads are causing harmful algal blooms. The aftermath of the blooms suffocates the worms and other slow moving or sensitive critters.

In 2012, local stakeholders gathered with experts from the Harte Research Institute (HRI) at Texas A&M University - Corpus Christi and Coastal Bend Bays and Estuaries Program (CBBEP) to address the health of the bay system. By 2013, a water quality monitoring program was formed utilizing a team of citizen scientists led by researchers at HRI. With the help of generous donations from multiple partners to fund the efforts, sources of nutrient pollution have been identified. The success of this program led to the formation of the Baffin Bay Stakeholder Group (BBSG) in 2018, the Bringing Baffin Back Initiative in 2022, and the creation of a Watershed Protection Plan which was reviewed and accepted by the U.S. Environmental Protection Agency in March of 2023. The Bringing Back Baffin project is applying a three-phase approach: Phase 1, continued monitoring; Phase 2, reducing the nutrient pollution; Phase 3, restoring habitat.

While the BBSG seeks to secure funding ($300M+) to address the sources of pollution, other researchers have taken interest in the rare serpulid reefs. The Coastal Conservation and Restoration Ecology Lab (CCREL) at HRI is studying recruitment dynamics of the serpulid worms in Baffin to gain insight into best practices for restoration efforts. In a recently published study by CCREL, recruitment tiles were deployed next to three different serpulid reefs. The tiles were retrieved quarterly, and a small section of the adjacent reef was collected as reference. The study found new settlement on the tiles year-round with seasonal variability. Peak recruitment for H. dianthus occurred between September and December. Seasonal variability appeared to have a greater effect on settlement than changes in salinity. Although lower recruitment occurred on the higher and lower ends of the salinity range experienced during the study period. Recruitment on the tiles did not correlate with growth on the natural reefs indicating that new growth on existing reefs is not limited by H. dianthus larvae. Interestingly, the worms preferred the lower surfaces of the tiles while Ivory barnacles dominated the upper surfaces.

 Another worm-curious team, the Habitat Assessment Team (HAT) at Texas Parks and Wildlife Department – Coastal Fisheries (TPWD), specializes in sonar surveys and producing map products. As a pilot study to test the efficiency of a bow mounted sidescan transducer, HAT will use the bow mounted sonar to map the serpulid reefs. This preliminary mapping effort could provide a baseline understanding of the reefs to compare changes over time and steer restoration efforts.

There is hope for a better Baffin. Fresh worm tubes coating trays and other materials used for sampling by the CCREL give researchers encouragement for future restoration projects. Long thought to be not worthy of study, let us recognize the importance of this humble worm, not as bait but as architect. For those that hold Baffin Bay near and dear, let the good fight continue to be fought. Collaborations such as the Baffin Bay Stakeholder Group and the Bringing Baffin Back Initiative are leading the charge towards reduced pollution and a healthier bay system. CBBEP, HRI, TPWD, and many other groups and individuals have heeded the call to coordinate monitoring, mapping, research, restoration, education, and outreach efforts of this beloved Baffin Bay to ensure that future generations will have clean water, active reefs, and dinosaur-sized fish to catch. Those interested in getting involved or donating to the cause should visit the Bringing Baffin Back website or attend the next Baffin Bay Stakeholder Group meeting.