Pond Life

Introduction
A selection of organisms from a local pond or rock pool
Useful information
Kit List: 

For Crash, Bang, Squelch! the specimens are acquired by pond dipping around Cambridge
For the summer roadshow and other events, specimens may be acquired from ponds (freshwater) or rock pools (saltwater) locally
Identification charts (sourced from the field studies council)
Pond dipping net and bucket (see Microscopy UK guide to pond dipping)
White trays
Aeration pump, tube and stone
Plastic pasteur pipettes
Possibly a microscope and some petri dishes
Possibly also pH paper, or water testing sticks

Packing Away: 

Empty pond life back into suitable habitat
Thoroughly wash trays/nets

Explanation
Explanation: 

Using identification charts to look at and identify pond life (either with the naked eye or with the aid of a microscope). Can be extended to testing water quality, using invertebrates as indicator species.

You'll have the pond/rock pool water and creatures in a white tray to make it easy to see them. Let the kids choose a creature to identify then use the pictures/flow charts on the identification sheets to help you.
There are lots of different things you could talk about - predators and prey, how animals breathe under water (see lesser water boatman, frogs), metamorphosis and life cycles (see dragonflies, frogs).

FACTS ABOUT COMMONLY FOUND PONDLIFE

Great Diving Beetle - a very large diving beetle, blackish-green in colour, with a yellow border to the thorax and around the wing cases. They predate smaller invertebrates, tadpoles and even small fish. FUN FACT males have suction pads on their front feet in order to grip the females when mating.

Caddis Fly larvae - moth-like insects with hairy wings. There are almost 200 species of caddisfly in the UK. The largest species is over 3cm long. The larvae live underwater where they make cases by spinning together fragments of stone, sand, plant material, even tiny, old snail shells with a silk they secrete from glands around the mouth.

Lesser Water Boatman - a herbivorous insect with legs like oars that help it swim.
FUN FACT Water boatman need air to breathe so they have a clever trick that allows them to stay under water for a long time: they collect air from the water's surface and then carry it around as a bubble on their body

Common backswimmer, aka the 'Water Boatman' - a fearsome predator that hunts small invertebrates, tadpoles and fish. It has strong oar-like legs and swims upside-down, near the water's surface. It injects toxic saliva into its prey so it can suck out the prey's insides.

Dragonfly and damselfly nymphs - Dragonflies and damselflies are part of the Odonata order, which means 'toothed ones', reflecting their predatory habit. There are 57 species of Odonata in the UK: 36 dragonflies and 21 damselflies. Although we're familiar with these insects in their adult, winged forms, they spend most of their lives as nymphs (larvae). Dragonfly nymphs metamorphose gradually - they shed their skins 5-14 times before they emerge from the water. When they do emerge, they shed for a final time, becoming adult dragonflies. They then wait for about an hour until their wings harden and they can fly. Note this is very different from butterflies, which only undergo a single metamorphosis step. The nymph stage lasts up to 4 years, whereas the adult stage lasts only a few weeks.
FUN FACT - The nymphs are ferocious predators - they have a hinged jaw that they can shoot out to catch their prey.
ID TIP - you can tell the difference between adult mayflies and dragonflies by how their winds are positioned when they land - dragonflies sit with their wings open (horizontal) whereas mayfly have their wings closed together.

Mayfly larvae - these are flying insects that look a little bit like damselflies, but they have broader wings and long tails. Their larvae also live underwater. Often the adults hatch out and take flight simultaneously and in their hundreds. Once they reach adulthood, they may only live for a matter of hours - just enough time to mate and lay eggs before they die
FUN FACT - The adults of many mayfly species don't eat at all as their sole purpose is to reproduce (they die soon after).
ID TIP - the larvae are long and slender with three distinctive "tails"

Common frog (demo may have frogspawn or tadpoles in it) - Common frogs are amphibians. They feed on invertebrates and sometimes smaller amphibians. They lay their eggs in rafts of jelly-like frog spawn that hatch into black tadpoles. A single female lays up to 4,000 eggs in one spring! When the tadpoles hatch they look like small black blobs with tales. As they get older they start growing legs and get bigger until they resemble tiny versions of the adult frogs. This is an example of metamorphoses (you could compare this to dragonflies and butterflies, also see resources for life-cycles demo). Male common frogs have 'nuptial pads' on their front feet to help them grip on to females during the breeding season (note this is similar to the great diving beetle). The male frog wraps himself around the female and fertilises her eggs as she deposits them.
FUN FACT - frogs breathe through their skin, allowing them to stay underwater without drowning. Their skin is thin, with an extensive network of blood vessels under its surface. Oxygen is absorbed through the skin and goes into the blood stream which transports it around the body. (compare to the lesser water boatman)

WILD ABOUT GARDENS CAMPAIGN
If people are interested about how they can encourage wildlife, you can direct them to the Wild About Gardens Campaign, run by the Wildlife Trusts and Royal Horticulture Society https://www.wildaboutgardens.org.uk/. It has loads of useful tips on wildlife gardening and their focus this year (2020) is on ponds!

Some info from their booklet:
"We’re losing our ponds, rivers and streams at a rapid rate. The loss or degradation of these places – to development, drainage and intensive farming
– is linked to a huge decline in wildlife, from frogs and toads, to water voles and insects. "
"There is a lot we can do in our own gardens and communities to help. Even a small pond can be home to an interesting range of wildlife, including damsel and dragonflies, frogs and newts. It could also become a feeding ground for birds, hedgehogs and bats – the best natural garden pest controllers!"
"Your pond needn’t be big. A washing-up bowl, a large plant pot, or a disused sink could all be repurposed as ponds, providing you make sure
creatures can get in and out."

Risk Assessment
Date risk assesment last checked: 
Fri, 24/01/2020
Risk assesment checked by: 
Polly Hooton
Date risk assesment double checked: 
Sat, 25/01/2020
Risk assesment double-checked by: 
by250
Risk Assessment: 

Demonstrate and identify aquatic life using a light microscope.

Hazard Risk Affected Person(s) Likelihood Severity Overall Mitigation Likelihood Severity Overall
Specimen collection Risk of slipping/tripping/falling or getting caught by the tide when collecting specimens from pond or rock pool. Demonstrator 3 3 9 Send two demonstrators to collect specimens and exercise caution when choosing location (e.g. make sure there is something solid to stand on near the edge of the water). Check tide tables/observe the tide movement before going to rock pools to collect specimens.
In case of injury, call first aider.
2 2 4
Microbes in water Possible infection from infectious microbes in water. All 2 3 6 Encourage hand washing after touching experiment. Hand washing facilities made available. Cover up any cuts whilst handling water.
Call first aider in case of injury. If child ingests anything from the aquarium, advise parents to take child to GP if child becomes ill.
1 3 3
Spillages Slipping on a wet floor. All 2 3 6 Clear up spills immediately. In case of injury, call first aider. Use wet floor sign. 1 3 3
Microscope Electrical hazard from microscope, especially in conjunction with water. All 2 4 8 If water is spilled on microscope, turn it off, clear up, then turn it on again. Ensure microscope has been PAT tested within the past 2 years. See separate electrical parts risk assessment. In case of injury, call first aider. 1 4 4
This experiment contains mains electrical parts, see separate risk assessment.
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Images
Publicity photo: 
Experiment photos: