Water Pollution's Impact On Galveston's Marine Life

Galveston Bay is a vital natural resource that has faced water quality issues due to human activity. The health of the bay is threatened by pollution, habitat loss, and climate change, with a long history of industrial activity contributing to the release of pollutants. Oil spills, toxic contamination, and nutrient runoff all impact the bay's water quality and the marine life within it. While there have been improvements, primarily due to federal regulations and initiatives, water pollution continues to be a concern for Galveston Bay and the surrounding ecosystem.

Oil spills and toxic contamination

On March 22, 2014, a collision between an oil barge and a ship resulted in over 150,000 gallons of heavy fuel oil being spilled into the Houston Ship Channel. The spill had a devastating impact on the local wildlife, with the Coast Guard recovering 329 oiled birds, most of which were dead. The spill also threatened the local fishing industry, with concerns that fish embryos in the area were left vulnerable to deformities, as had been seen in the aftermath of the 2010 BP Oil Spill.

The Texas Oil Spill Prevention and Response Program is known for its proactive initiatives to keep oil out of the water, but oil spills remain a persistent issue, with an average of 197 spills reported annually in Galveston Bay since 2008. Most spills are small, but larger spills can have devastating consequences for marine life and the local ecosystem.

In addition to oil spills, toxic chemicals also pose a significant threat to the health of the bay and those who rely on it for seafood. Elevated concentrations of metals such as mercury, and organic compounds such as PCBs and polycyclic aromatic hydrocarbons (PAHs), have been found in the sediment of the bay and the Houston Ship Channel. These legacy pollutants can persist in the sediments for decades and work their way up the food web, potentially affecting both marine life and humans who consume seafood from the area.

To address these issues, local officials and residents are urged to prioritize the cleanup and preservation of the bay. This includes proper waste disposal, the use of natural cleaning products, and the reporting of any observed pollution or oil spills to the appropriate authorities.

Nutrient and oxygen levels

Dissolved oxygen is mainly added to water bodies from the atmosphere and, in smaller amounts, from groundwater discharge. It is breathed by fish and zooplankton and is essential for their survival. The amount of dissolved oxygen in a body of water is influenced by factors such as temperature, water flow rate, and organic material content.

Cold water can hold more dissolved oxygen than warm water. Therefore, dissolved oxygen concentrations are typically higher in winter and early spring and lower in summer and fall. Rapidly moving water, such as in mountain streams or large rivers, tends to have higher levels of dissolved oxygen compared to stagnant water.

Excess organic material in lakes and rivers can lead to eutrophic conditions, characterised by oxygen deficiency, which can cause a water body to "die". Stagnant water with high levels of rotting organic material, especially during the summer when dissolved oxygen levels are naturally lower, can be challenging for aquatic life.

Algal blooms can also deplete oxygen levels in water. High levels of nutrients in the water stimulate the growth of algae, which is then consumed by bacteria, resulting in oxygen depletion. This can lead to the death of many fish and the creation of hypoxic or "dead zones" where most life cannot be supported.

In Galveston Bay, nutrient and oxygen levels are primarily affected by human activities, such as runoff and wastewater. Nitrogen and phosphorus, which stimulate plant growth, are of particular concern. While these nutrients are essential for the bay's food web, excess amounts can cause harmful algal blooms that deplete oxygen and harm aquatic life.

In 2022, nine percent of nitrogen concentrations in regional waterways were above water quality standards, and 28 percent of phosphorus concentrations in the rivers and bayous surrounding Galveston Bay were above state screening levels. Despite these issues, the levels of nutrients and dissolved oxygen in Galveston Bay in 2022 were considered acceptable for supporting diverse and healthy aquatic life.

Invasive species

Galveston Bay is home to a wide variety of animals, including shellfish, finfish, and birds, which play an important role in maintaining the health of the bay's ecosystems. However, the bay has also become a habitat for numerous invasive species, which have detrimental effects on the native flora and fauna.

Galveston Bay is particularly susceptible to invasive species due to its location and human activities. As of 2022, over 100 species of invasive plants and animals have been found in the Galveston Bay watershed, with 75% of these being terrestrial plants. Examples of invasive species in the region include water hyacinth, privet, Chinese tallow, fire ants, feral hogs, armored catfish, and the zebra mussel. The introduction of these species has negatively impacted native species and altered the bay's ecosystems.

The management and prevention of invasive species are crucial for maintaining the health of Galveston Bay. Early detection and rapid response are key strategies, along with control and eradication methods such as the use of pesticides. Prevention and education are also essential, with community involvement and awareness campaigns playing a vital role in stopping the spread of invasive species and protecting the bay's delicate ecosystems.

Wetland destruction

Galveston Bay has a long history of industrial activity, which has resulted in the release of pollutants into the bay. Despite federal regulations, the destruction of wetlands in the area continues to be a critical issue. Between 1953 and 1989, Galveston Bay lost 30,000 acres of freshwater and saltwater wetlands, with an additional loss of 13,538 acres of freshwater wetlands between 1996 and 2010. This loss of wetlands has had a detrimental effect on the health of the watershed, as wetlands act as a natural filter for polluted runoff, absorbing rainfall, and providing flood control.

The disappearance of wetlands has made the area more vulnerable to flooding and water quality issues. Wetlands provide essential habitats for wildlife and are particularly important for fish species. They also play a crucial role in maintaining water quality by filtering out pollutants. The loss of wetlands in Galveston Bay has led to a decrease in water quality and a reduction in fish populations, which has impacted recreation, businesses, and local economies.

In addition to the loss of wetlands, invasive species, such as the Chinese tallow plant, pose a threat to the bay. These invasive species can inhibit the natural abilities of wetlands for drainage and flood protection. Furthermore, the bay continues to face threats from rising sea levels, subsidence, and increasing demands for freshwater.

The Galveston Bay Foundation and other organizations are working to restore and protect the bay's natural resources. Efforts include programs to restore shorelines, remove potentially toxic substances, and reintroduce lost habitats. However, with a growing regional population, development pressures, and relative sea-level rise, the cumulative impact of wetland loss in Galveston Bay has reached a critical tipping point.

The destruction of wetlands in Galveston Bay has had far-reaching consequences for the local environment and economy. The loss of these vital ecosystems has led to decreased water quality, reduced fish populations, and increased vulnerability to flooding. Protecting and restoring wetlands is essential to preserving the health and productivity of the bay for future generations.

Bacterial contamination

Galveston Bay has a long history of industrial activity, and while environmental regulations have since been put in place to control the release of pollution, industrial activities still result in the release of pollutants, which are predominantly found in the Bay's sediment.

One of the biggest threats to the bay is habitat loss, and the destruction of wetlands, which play a crucial role in the health of the watershed by acting as a natural filter for pollution. Despite their protected status, Galveston Bay lost 30,000 acres of freshwater and saltwater wetlands from 1953 to 1989, and a further 13,538 acres of freshwater wetlands between 1996 and 2010.

The bay's water quality is also threatened by bacterial contamination. A 2023 report by Environment Texas found that 90% of Texas beaches were contaminated with bacterial pathogens on at least one day in the previous year. Seawall Boulevard in Galveston was found to have exceeded safe levels of fecal bacteria on over a quarter of days in the same year.

The primary source of bacterial contamination in Texas waters is leaking sewage pipes. Rain frequently washes animal and human waste into waterways, causing a spike in enterococcus levels. This type of bacteria can cause serious gastrointestinal problems that could lead to hospitalisation.

To protect public health, the Galveston County Health District routinely tests 52 beach sites for the presence of enterococcus. When levels are found to exceed the EPA standard for safe swimming, an advisory is issued. However, the beach is not closed, and the advisory is simply a warning for people to make an informed choice about swimming in the affected waters.

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