Tens of Thousands of Dead Fish Wash Up on Texas Coast

US authorities have reported that a large number of fish have been found dead on the Texas Gulf Coast. This unfortunate event occurred because there was a shortage of oxygen dissolved in the warm water.

The incident of dead fish washing ashore began early on Friday morning (June 9th, 2023) and continued until Sunday (June 11th, 2023).

The Gulf menhaden, a type of fish, was particularly affected by this incident. Officials at Quintana Beach County Park have stated that the majority of the beach has been cleared of dead fish, although there are still a few scattered around that the machinery was unable to remove.

Causes of fish die-offs

According to officials from Quintana Beach County Park, fish die-offs like this are quite common during the summer months when temperatures rise. The main reason behind these incidents is a lack of sufficient oxygen in the water, preventing the fish from being able to breathe.

In a statement, the park officials described the situation as a “perfect storm” that resulted in reduced oxygen levels near the shore.

It’s important to note that warm water contains less oxygen compared to cold water, putting fish at a greater risk.  When the water temperature surpasses 21 degrees Celsius (70 degrees Fahrenheit), it becomes increasingly challenging for Gulf menhaden to obtain enough oxygen for their survival.

The issue is further compounded when these fish find themselves trapped in shallow waters as the temperature rises. Shallow areas tend to warm up more quickly than deeper regions.

As a consequence, if a group of Gulf menhaden gets stuck in the shallows as the water heats up, they will begin to experience a condition called hypoxia, which is a lack of oxygen that leads to their suffering.

Oxygen deficiency due to calm seas and cloudy skies

Typically, waves contribute to the oxygen levels in the water. When wind and waves interact with the air, there is an exchange that introduces oxygen into the water, which then mixes throughout the ocean. However, during this period, there was minimal wave activity, which limited this process of oxygenation.

Another way it is generated in the water is through the process of photosynthesis, carried out by tiny phytoplankton or larger macroalgae. This photosynthesis relies on sunlight as its energy source.

Dead fish showing up on the coast of Texas. See what gas stoves are doing? pic.twitter.com/eBPQMAayaB

— Dr. Jebra Faushay (@JebraFaushay) June 12, 2023

Unfortunately, the cloudy skies hindered the ability of these organisms to produce oxygen through photosynthesis.

Lerrin Johnson, a spokesperson from the Texas Parks and Wildlife’s Kills and Spills Team Region 3, explained that sunlight-driven photosynthesis leads to increased dissolved oxygen levels, especially during daylight hours.

However, due to the cloud cover, the production of oxygen through photosynthesis was negatively impacted.

Recent decomposition of dead fish

Photosynthesis ceases during the nighttime and may be less active on cloudy days. However, plants and animals in the water still engage in respiration and consume available oxygen, causing a decline in the concentration of dissolved oxygen.

According to the National Weather Service, Brazoria County experienced a high temperature of 33 degrees Celsius (92 degrees Fahrenheit) on Friday (June 9th, 2023).

Quintana Beach County Park provided an update on Sunday, stating that it seems all the fish have now washed ashore. The most recent arrivals are in such an advanced state of decomposition that they have become nothing more than skeletal remains, appearing shredded and deteriorated.