How to Prevent Fish Dying in Your Dam

What Fish Are Found in Australia’s Dams?

A variety of fish species are commonly found in dams across Australia. Native fish include the Murray Cod, the Golden Perch, and the Australian Bass. You might also find an Eel-tailed Catfish if you’re lucky!

Introduced species of fish that also find a home in Australia’s dams include the rainbow Trout and Brown Trout varieties, along with the Common Carp and the Redfin Perch.

What Causes a Fish to Die in a Dam?

Fish die in dams because of a variety of reasons. Here are some of the most common causes that can be prevented with good maintenance and care:

Low Oxygen Levels

The most common reason why fish die in dams is because of low oxygen levels. Fish need dissolved oxygen that is present in the water, otherwise they can’t survive. 

If the level of oxygen in the water decreases to very low levels, the fish will suffocate and die. So, what causes low oxygen levels? 

The quality of dam water decreases rapidly if there’s significant algae growth or aquatic weed growth. Eventually, algae and weeds die and decompose, requiring a large amount of oxygen which decreases oxygen levels rapidly. Further decaying debris adds to this.

Additionally, if dam water is not circulated, water stratification can occur. This is when water temperatures are divided in layers, with the bottom layer much colder than the top layer. A middle layer acts as a barrier between the two.

Algae Growth

As well as causing low oxygen levels when decomposing, large growths of algae blooms can produce toxins that are harmful to fish. The blue-green cyanobacteria algae is the main culprit, poisoning fish with toxins. 

Of course, large algae growth will also block sunlight from reaching the water, reducing oxygen levels further. Both adult fish and small fish might be vulnerable to low oxygen levels, which is why some fish die.

Diseases

Low levels of water quality are a perfect breeding ground for fish diseases. Fish may be vulnerable to some types of disease and may die in large numbers, particularly if there are too many fish in the dam. How many fish die will depend on the fish disease and the health of all the fish.

Keeping your dam water clean and well oxygenated is the best prevention for disease along with minimising fish waste. Uneaten food will also decompose and harm the remaining fish population. 

How Can I Prevent Fish Dying in My Dam?

Prevent fish dying in your dam by actively managing and maintaining the dam water and ensuring your ecosystem is healthy. Here are the best ways to prevent fish dying in your dam:

Improving Oxygen Levels

Fish need dissolved oxygen in the dam water. Ensuring enough dissolved oxygen in the water is one way to prevent fish from dying. So, how do you oxygenate your dam water?

The first way to improve oxygen levels in your dam water is to prevent decomposition. So, clear up algae, weeds, and debris on a regular basis, before it begins to decompose. 

Use aerator systems to add air or oxygen into your dam. You can opt for surface aerators, bottom diffusers, or nanobubble aerators to oxygenate your water and help your dam fish to breathe. The force of the aerator will also force the water to circulate, mixing low oxygenated water with highly oxygenated water.

If you don’t want to use an aerator, install a water circulator instead. A water circulator makes the dam water move and mix without adding air or new water. 

Prevent Algae Growth

Eliminate algae blooms and prevent further growth by treating the water. Use Biostim Probiotic to feed the good bacteria in the water and leave little for algae to consume. With a lack of food, algae won’t grow! It’s safe for fish and will help keep the ecosystem healthy. Water quality will be great for the fish and they will thrive in a well-maintained dam.

Remove Aquatic Weeds

Eradicating aquatic weeds from the dam will improve water quality and give fish more room to swim. Remove emergent weeds from their roots in the dam bed with the Beachroller Aquatic Weed & Muck Removal Tool

A Lake Bottom Blanket can be anchored under the surface to block sunlight and kill submerged weeds.

The Best Products to Prevent Fish Dying

Prevent fish dying by using a combination of products and tools from Love My Dam! Here are our pick of the products for a healthy dam:

Air-O-Lator Carnival Aerating Fountain

The Air-O-Lator Carnival Aerating Fountain injects air into your dam water to fully aerate and oxygenate your dam. This aerator system also doubles-up as a water feature as you can enjoy a fountain in the middle of your dam. This is a perfect option for dam sizes up to 2.5 surface acres and depths of up to 5m. 

Benefits:

  • Aerate dam water and increase oxygen levels
  • Enjoy a fountain feature
  • Reaches depths of up to 5m
  • Suitable for up to 2.5 surface acres.

Biostim Probiotics

Biostim Probiotics is a probiotic that feeds the beneficial bacteria and decreases food for weeds and algae to consume. You can purchase the Biostim Probiotic in powder, liquid, or pellet form and there’s a selection of sizes on offer. 

You can treat the entire water body with the Biostim Probiotic, or target smaller areas. Use the Biostim Accelerator for optimum results and to create the best conditions for your fish, preventing poor water quality. 

Benefits:

  • Choose the type of probiotic to suit your dam
  • Treat the entire water body or target specific areas
  • Use in conjunction with the Biostim Accelerator for the best results.