What is the role of deoxygenated water in fish deaths?

Question

Accepted Answer

Deoxygenated Water as a Primary Factor in Fish Mortality

Deoxygenated water played a significant role in the recent fish deaths in Teluk Bahang, creating a stressed environment that led to the mortality of an estimated 50,000 fish. While heavy metals were detected, the primary cause cited for the deaths was a severe lack of dissolved oxygen in the water. This condition, exacerbated by potential nutrient enrichment, created an environment where fish could not survive.
Low Dissolved Oxygen Levels Confirmed

Water quality assessments indicated that the oxygen levels in the affected area were lower than normal. A science officer from the Centre for Marine and Coastal Studies (Cemacs) confirmed these findings, noting that while other water parameters like temperature, salt, and pH were within normal ranges, the dissolved oxygen was critically depleted. This deficiency directly impacts the fish's ability to respire.
Eutrophication as a Contributing Factor

Experts suggest that eutrophication, a process driven by excessive nutrients such as phosphate and ammonia, may have contributed to the low dissolved oxygen levels. This enrichment can lead to algal blooms, and as these organisms die and decompose, they consume large amounts of oxygen, further depleting the water's dissolved oxygen content. This condition creates a hazardous environment for aquatic life in shallow bays.
Combined Stressors on Fish Populations

The fish deaths are believed to have resulted from a combination of factors, with low dissolved oxygen being the most direct cause. While heavy metals were present, they were reported to be within permissible levels, suggesting they were not the sole lethal agent. However, the presence of these metals, alongside the critically low oxygen, may have created a cumulative stress on the fish, making them more vulnerable to mortality. The situation is particularly concerning as this is the second major fish kill incident in Teluk Bahang since May, impacting breeders who have suffered substantial financial losses.

Reading history

Hide →

This history is cleared when the page is closed.

What is the role of deoxygenated water in fish deaths?

Loading

Was this article helpful?

Helpful

Not helpful

Report an issue

1

0

0

Share with friends