Category: Natural swimming pools

feral fish eradication

Feral Thoughts: The devastating toll invasive Carp have on WA’s Lakes and Wetlands

There is a consensus among the scientific community that the common Carp (Cyprinus carpio) poses the greatest ecological threat out of all feral fish species in Australian waters. Given the nickname ‘River rabbits’, Carp have the ability to reproduce rapidly with females capable of produce upwards of 1,000,000 eggs per year.

Carp are omnivorous feeders and have broad habitat requirements, meaning they are capable of persisting in many environments, particularly degraded water bodies. When this species feeds, it ‘hoovers’ up the sediment, uprooting vegetation, releasing phosphorus by a process called bioturbination, and consuming the eggs of native species.

Ecological impacts of feral carp on natural and man-made wetlands include:

  • Increased nutrient levels and incidence of eutrophication and algal blooms.
  • Increased turbidity and mobilisation of phosphorous in from lake sediment.
  • Reduction of aquatic macrophyte biomass which play key roles in nutrient cycling.
  • Localised native fish extinctions through predation and competition.
  • Disease transmission into native fish.
  • Reduction in native macro invertebrate (insect) abundance and diversity including filter feeders (ie. Daphnia, Paramecium, Rotifers).

What are we doing about it?

All feral fish must be eradicated, but each problem must be assessed on a case-by-case basis taking into consideration the species, habitat and environmental characteristics of the affected system. Because each case offers a different series of challenges there are a number of efficient and humane feral fish control techniques hc

  • Electrofishing
    – Electrofishing involves stunning fish with a short burst electric field so they can be retrieved.
  • Seine Netting
    – The most efficient method for large species i.e Carp & Goldfish in open wetland environments.
  • Fyke Netting and Fish Traps
    – Used for smaller species including Mosquitofish, Pearl Cichlids, Tilapia smaller goldfish and koi
  • Spearfishing
    – Spearfishing is useful in targeting large invasive species in wetlands where the conditions, layout or features e.g submerged obstacles prevents netting.
  •  Biological control *Coming Soon*
    – We are currently working on the development of biological control methods to aid in the control smaller feral fish such as Mosquitofish, One Spot Livebearers, Rosy barbs and Swordtails.

    What can you do?
  • Never release aquarium fish or plants into our waterways – there are other options for your unwanted fish.
  • If you have a pond, why not stock it with native fish for mosquito control?
  • If you spot or catch a suspected feral fish species, do not return it to the waterway, dispose of it humanely, and report it to the Department of Fisheries Biosecurity team via the WA Pest Watch Portal.

If you think you have a feral fish problem or simply wish to improve the overall health of your wetland, lake or dam please contact us on 08 94571235


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Natural Swimming Pool Builders

Have you ever heard of a Backyard Billabong or a Natural Swimming Pool?

Natural swimming pools are a new and innovative concept using mother nature as the blueprint for creating stunning, eco-friendly swimming pools for your backyard. Natural swimming pools use a submerged vegetation zone which acts as a natural filtration system, purifying and stripping the
water of excess nutrients just like natural wetlands and rivers. Combining the best of nature and technology these advanced filtration systems remove harmful bacteria and pathogens and maintains clear water so there is no need to use chlorine, salts or other chemical additives that are traditionally
used in backyard swimming pools.

The benefits of natural pools:

It’s Eco-Friendly! Here at PASES Aqua we are passionate about nature and the environment. When designed correctly natural swimming pools provide shelter and sanctuary for small populations of non-harmful native wildlife such as butterflies, dragonflies, birds and frogs – Tadpoles (baby frogs) and Western Pygmy Perch can be a great addition to natural swimming pools due to their algae eating habits. It is the old saying “Build it well and they will come”.

  • Health Benefits: The sound of water whether it be rain drops, the crashing of waves in the ocean, or a trickling stream has a soothing, zen like effect on the mind and body and can positively impact ones mental health by reducing stress and anxiety. Similarly, a natural swimming pool can provide you and your family with a place of sanctuary and relaxation to escape from the rest of the world and recharge, promoting calmness, focus and creativity.
  • Visual and auditory aesthetic: WOW FACTOR! This is perhaps the most obvious benefit of natural swimming pools; they are a focal point of your backyard bringing an eye-catching
    slice of natural paradise to your home. Natural swimming pools offer a beautiful, serene place to swim, relax or host guests and the addition of water features will help to mask the sounds of street traffic or loud neighbours giving your home a greater sense of privacy.
  • Water conservation: One of the biggest environmental benefits of natural swimming pools
    is water conservation. In Perth, more than 40% of the residential water demand is used outside of our home in the garden. Plus, if you experience a lower-than-normal season of rainfall, you can always position drainpipes from your rooftop to empty directly into your pond, to create a natural reservoir. All this water conservation can be an effective way to reduce utility costs.
  • Financial benefits: When designed and executed correctly natural swimming pools are cheaper to maintain than traditional swimming pools. This is because there is no need to buy chlorine, salts or expensive water conditioners to maintain crystal clear water. Low energy pond pumps are used instead of standard pool pumps which are often expensive and require higher energy demands. Another added benefit of natural swimming pools is that it can help reduce the air temperature around your home, through evaporative cooling and acting as a natural outdoor air conditioner so you can enjoy being outdoors instead of being trapped inside with AC on.
  • Education and interaction : A natural swimming pool is not just a pool it can be a functioning ecosystem too! Watch as your pets or native wildlife grow, interact and breed. The whole family can get involved recording and photographing different wildlife and learn about ecosystems and nature. Getting kids involved and thinking about nature at a young age introduces your children to different learning experiences and is important in fostering environmental awareness among the next generation. Plant an appreciation for nature in them and watch it grow as they can begin to gain an understanding of nature and the importance of natural ecosystems.
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