Pond Dipping Pleasures

Sophie Lewis, an undergraduate at the University of Liverpool, has been carrying out research on ponds, including the one at New Ferry Butterfly Park. Here's a short report into her findings.

I really enjoy pond dipping because you never know what you will find. You can take the net out of the water and put the contents in a tray and then just wait. So many things will start wiggling and some are quite similar to ones we find on land!

Water hog louse (Asellus aquaticus) looks very similar to a woodlouse or pea bug 

Damselfly larvae (Lestidae family)

Male smooth newt (Lissotriton vulgaris)

The Wirral is home to lots of freshwater ponds that are vital for our landscape because they provide habitats for rare aquatic species and can store carbon. However, my recent dissertation research project at the University of Liverpool reveals that many of our local ponds are declining and some ponds are being lost altogether.

The ponds I looked at were extremely varied. I looked at 10 ponds on the Wirral: Arrowe Brook Farm, Caldy and Heswall Golf Courses, Lees Lane, New Ferry Butterfly Park, Ness Gardens, Thornton Common, Thurstaston Country Park, Upton Meadows, and Willaston Meadow. I observed all their characteristics including water chemistry, aquatic macroinvertebrate species, aquatic and marginal plant species and greenhouse gas emissions.

Data collection at New Ferry Butterfly Park

I found that some sites were “zombie ponds” which are ponds that have very few species present and are not healthy. They are identifiable by measurable characteristics: over 50% shade, low species diversity, low oxygen concentrations, and high greenhouse gas emissions. However, the zombie pond state is reversible and can be managed by:

• Thinning out overhanging trees allows light to hit the water, kickstarting photosynthesis and oxygenating the pond.

• Protecting small, connected pond networks rather than just focusing on large ones.

• Actively managing and recording what you find in the pond to keep track of its status. My research showed that sites that are managed by volunteers like New Ferry Butterfly Park had some of the highest ecological quality in the study.

Upton Meadows, an example of a zombie pond with lots of tree cover

I also found that smaller ponds have higher macroinvertebrate richness than larger ones. This shows how vital the small ponds that we create in our gardens and on our local nature reserve sites are, even if they are not very big. I also found that newer ponds had more diversity than older ones so digging new ponds is a great way to boost aquatic biodiversity and you will be surprised how quickly species will arrive!

By using statistical models, I identified Dissolved Oxygen (DO) as the single most important predictor of a pond’s health. When oxygen is high, we see a diverse community of beetles and dragonflies. When it’s low, we are left with only "specialist" survivors, like Daphnia (water fleas) that turn red to survive the harsh conditions or rat-tailed maggots that use "snorkels" to breathe air.

Daphnia in Jacksons Pond, Willaston Meadow. (Daphnia sp.)

Rat Tailed Maggot Fly at Ness Gardens (Eristalini tribe)

I really enjoy pond dipping, especially at New Ferry Butterfly Park because there are so many different species you can find, especially the newts! You can go pond dipping there on Sunday afternoons (12-4) from May to mid-September, or come and visit on our open day on Sunday 3rd May from 11am to 4pm.

New Ferry Butterfly Park Pond

If you would like any more information about this research or a copy of the full dissertation, please get in touch with me at: sophielewis5303@gmail.com