Two Saturdays ago Chris Kelley and I were down on Lavaca Bay trying to get a feel for the area. We are involved in an oyster reef restoration project at the Bay, using our methods of multicriteria analysis to select the best areas to create new oyster reefs for eventual harvesting. Lavaca Bay is a secondary bay of Matagorda Bay, halfway between Corpus Christi and Galveston. Secondary and tertiary bays of Texas are justly famous for being highly productive estuarine systems, and Lavaca has long been known for its harvests of shrimp, blue crabs, oysters, and red and black drum . Jim Simons took us around in a small boat. Jim is a coastal ecologist with Texas Parks and Wildlife (TPWD), and we have been talking about working together on projects ever since my former student, Helen Cortes-Burns, introduced us more than a year ago. Figuring out how to best restore habitats for biodiversity has long been among my goals, but even restoring a commercial fishery has its attractions.
We started early, and it was a relatively quiet morning on the bay, mercifully with very little wind. The water was virtually still in the northern half, and only slightly choppier towards the southern end which is closest to Matagorda and the Gulf of Mexico. Bottlenose dolphins (Tursiops truncatus) swam along the boat during several stretches. Recent work from the University of St. Andrews suggests that these animals know how to distinguish between individuals based on the sounds they make—in other words, they have names for themselves. Brown Pelicans (Pelecanus occidentalis) were everywhere, on channel markers, platforms—wherever there were places to perch. A few terns were around, though keeping too much distance for reliable identification to be possible. There was plenty of fish but it was mainly a morning for basking in the weak sun, still not strong enough to make you uncomfortable.
The task at hand was simple enough. We were trying to digitize a paper map of the areas recommended for oyster farming within the bay and the areas that are excluded. All we had to do was to get to the various markers and take GPS readings. What made it all more interesting is that some of the shore markers had peculiar descriptions: “Calhoun Easternmost house,” “Brown house with blue roof,” “East end of crabbing bridge.” Wonder what will happen if a local builder changes a few structures here and there? Markers on the water were also occasionally mismarked but, over a few hours, we managed to sort these out. (Later we discovered that accurate longitude-latitude data were already available for at least half of the markers we’d surveyed. It was wasted workj—but, then, that’s what you often expect with ecological fieldwork.) The next step will be to gather data, model the criteria, and select areas which optimize depth, flow, salinity, and hardness for the establishment of new oyster reefs. Luckily, TPWD already has most of the data we need, and many of the models have already been run.
People have been eating oysters along the Texas coast at least since the time of the Karankawas. The species in question is the Eastern Oyster (Crassotrea virginica), quite common to the American coast (though, bizarrely, there was an attempt to list it as an endangered or threatened species last year). The harvesting season is from 1 November to 1 May. During the open season anyone with a TPWD harvester’s license may harvest oysters but can only sell to dealers certified by the Texas Department of Health (TDH). During the rest of the year harvesting occurs on private leases, mainly in Galveston Bay, which produces 60 -70 % of the state’s oyster catch. By and large, until recently, the state seems to have managed its harvest well. It is the only state in the country that has maintained its harvest without significant planting . But all that has changed during the last decade. The large number of fishermen who have entered the industry is putting serious pressure on stocks. In 2005 the Legislature established a commercial moratorium on oyster and gulf shrimp licenses, hoping to decrease the number of fishing boats by gradual attrition. It is probably a wise move.
Historically, harvesting oysters for food is not the only factor to take its toll on Texas oyster reefs. Between 1922 and 1983 almost 270 million cubic meters of reef material was taken from Texas bays by shell dredging operations for use as roadbed material and in the manufacture of concrete . Most of this was probably buried shell, not living communities but, nevertheless, large quantities of exposed shell (cultch) was also removed. In 1953 shell dredging was banned within 457.2 meters of living reef but, in 1963, this distance was decreased to 91.4 meters. This practice probably explains why reefs have not regenerated as fast as they should have—hence, come projects such as our own to encourage regeneration.
Completing the rather limited scientific component of our project—the multicriteria analysis on depth, flow, salinity, and hardness—will not be that difficult. The next stage, incorporating the population biology of oysters will be more challenging. And interesting. However, the issue that I could not remove from the back of my mind that Saturday morning was that Lavaca Bay is home to what is arguably the worst environmental disaster on the Texas Gulf Coast . Two corporations have contributed to this distinction, Formosa Plastics, and the world’s largest aluminum company, Alcoa. In the mid-1980s, Formosa planned a $ 2 billion expansion of its plant in the northeast of the bay, and attempted to do so (with the EPA’s agreement) without an environmental impact statement (EIS). This led to a series of confrontations with local environmentalists, led by the redoubtable Diane Wilson . Ultimately, a compromise was worked out that was grudgingly accepted by most environmentalists: it included independent monitoring of air and water quality, hazardous waste, emergency planning, and worker safety. Formosa presumably constructed the plastic birdwatching boardwalk in Lighthouse Beach (Port Lavaca), made to look like wood, because of this compromise. However, I strongly suspect it is toxic—when Chris caught a splinter in his arm, it bothered him for the rest of the night. By and large, Formosa is believed to have lived up to its commitments.
Alcoa’s involvement in Lavaca Bay, in contrast, is a complete disaster. In 1970, the TDH found elevated levels of mercury in oysters, crabs, and finfish from the bay, and immediately notified the public that levels were much higher than the Food and Drug Administration (FDA) permitted guidelines . The reason for the mercury contamination was that, between 1966 and 1970, Alcoa’s Point Comfort plant legally released mercury into Lavaca Bay. Even conservative estimates put the amount at about 67 pounds a day. Unlike much of the pollution along the Texas coast, this mercury contamination did not get flushed out into the ocean. Rather, it settled into the sediment, increasing in concentration, and remaining at dangerous levels even today.
Following the TDH finding, state officials ordered Alcoa to stop dumping mercury. By 1971, at least in oysters, the mercury level fell below the then legal 1.0 ppm (parts per million) level and is now consistently below 0.5 ppm which is the new FDA guideline. Oysters have continued to be harvested from the region. One nagging question is whether the FDA guideline is sufficiently strict, especially given that it has already required downward revision once. Beyond oysters, in 1988 a section of the bay was completely closed off to fish and crab harvesting and part of it remains so to this day (though the extent of the area was decreased in 2000). Mercury concentrations in the Blue Crab (Callinectes sapidas) continued to be unacceptably high into the late 1990s . (Shrimp harvesting has never been banned—apparently shrimp do not accumulate mercury very well.)
Alcoa’s Point Comfort plant continues to dominate the skyline northeast coast of the bay, a continutal reminder of environmental degradation. In 1994, thanks to Alcoa’s activities, Lavaca Bay became a federally designated Superfund site. Alcoa then became legally responsible for paying for the cleanup of mercury and other dangerous pollutants originating its plant. So far it is believed to have spent about $ 40 million . In December 2004, after years of negotiation, federal and state agencies reached a settlement with Alcoa that will require to spend at least another $ 11.4 million to restore the bay and to reimburse government agencies. Alcoa also agreed to donate 729 acres of adjoining land to the Aransas National Wildlife Refuge (just a few miles south of Lavaca Bay), create 70 acres of intertidal salt marsh within the refuge, create 11 acres of oyster reefs in Lavaca Bay, and build boat ramps and fishing piers to compensate recreational users.
The trouble is that these actions do not even address prehaps the most crucial ethical issue created by Alcoa’s misbehavior: health problems that local residents are facing presumably because of eating contaminated seafood. Many of those who live around the bay have continued to eat catch from all parts of the bay irrespective of the ban. Fish, also, are not stationary organisms, and a ban cannot preclude contaminated fist from being caught elsewhere in the bay. There has been an explosion of health problems in the region which are widely believed to be mercury-related, especially autism. (Strangely, even though Alcoa and other entities have occasionally monitored mercury levels in the food, no one seems to have tested mercury levels in the affected humans! At leas, even if some such tests may have been done, I have so far found no data anywhere.) In 2005, with the assistance of two south Texas law firms, all three fishing communities from the region, Anglo, Hispanic, and Vietnamese, normally separated by racial tensions, decided to take on Alcoa jointly. With luck they will prevail, and we will finally get some environmental justice in Texas.
What worries me most is that the areas recommended for the new oyster reefs include those immediately adjacent to the area that continues to be closed to fishing and crab harvesting, even after the reduced boundary of 2000. I just hope that the data on mercury accumulation in oysters is accurate and FDA level has been set properly. Perhaps, before plans are implemented in the field, we’ll have to do our own measurements.
 Sager, D. R. 2002. “Long-Term Variation in Mercury Concentrations in Estuarine Organisms with Changes in Releases into Lavaca Bay, Texas.” Marine Pollution Bulletin 44: 807 -815.
 MacKenzie Jr., C. L. 1996 “Management of Natural Populations.” In Kennedy, V. S., Newell, R. I. E., and Eble, A. F. Eds. The Eastern Oyster: Crassotrea virginica. College Park: Maryland Sea Grant College, pp. 707 -721.
 Quast, W. D., Johns, M. A., Pitts Jr., D. E., Matlock, G. C., and Clark, J. E. 1988. Texas Oyster Fishery Management Plan. Austin: Texas Parks and Wildlife Deparment.
 Claitor, D. 2005. “Letter from Lavaca Bay.” Texas Observer, 7 August 2005.
 Blackburn, J. 2004. The Book of Texas Bays. College Station: Texas A&M Press.