By Matt Keyse
OPAL Community Scientist, FSC Scotland
It was a cold but bright morning at St. Maurice’s pond in Cumbernauld. The weary February sun hovered just above the tree line, reflecting off of the thin layer of ice forming over the water.
With some trepidation a group of Greenfaulds High School students, currently studying the new Higher Environmental Science course, grabbed a variety of sampling equipment and made their way gingerly away from the car park towards the water.
The morning session was being delivered by an OPAL community scientist from the Field Studies Council Scotland, using OPAL surveys. For this young troop of scientists, the surveys had the added benefit of being directly relevant to their Higher Environmental Science course including modules like ‘investigating ecosystems and biodiversity’, ‘interdependence’ and ‘human influences on biodiversity’.
For example, the OPAL Water Survey uses a combination of characteristics to assess the health of the ecosystem including the invertebrates present as indicator species and various factors like pH and clarity (suspended sediment).
Lakes and ponds are not in short supply around Scotland – even in urban centres. Glasgow alone has more than 90 parks and gardens, many of which have ponds of different sizes, so finding a suitable site is often a case of going for a short walk.
After some initial work getting through a little ice to the watery world below, the students began to sample a shallow section of the pond from a wooden boardwalk.
Most people don’t entertain the thought that even in winter, freshwater ecosystems should be teeming with life – even under ice – from newts sheltering amongst the roots of plants to water hoglouse munching away on dead plant matter. St. Maurice's pond didn’t disappoint; within minutes we had identified freshwater shrimp, hoglouse, mayfly, ramshorn snail, daphnia and alderfly.
The Water Survey scores each family of invertebrates based on their tolerance to pollution, some animals like the alderfly need high levels of oxygen whereas other groups, such as the snails, can cope with much lower levels such that occur when the pond is polluted.
“I reckon it’s 6!” one student called out while measuring pH with a test strip. A little acidic but within a healthy pH range.
It was starting to look as if this pond was home to a pretty healthy ecosystem. We discussed all of the living and non-living factors that might be influencing the species present including competition within and between species, dissolved oxygen content and nutrient levels.
Ponds can act as real hubs for wildlife in urban areas acting as safe havens and hatcheries for a whole host of plants and animals (check out OPAL's top ten tips for a healthy pond, PDF, 134KB). This particular pond had a variety of habitats suitable for life including deeper gravel sections and shallower silty areas, dense vegetation and patches of woodland in the vicinity. Added to this was the benefit of a small channel entering the pond to the south, bringing a constant supply of fresh oxygenated water.
The students can now upload these results on to the OPAL network, improving our understanding of these important natural resources around the UK. What’s more they can write up the investigation for their course, aiding their personal understanding while developing our next generation of environmental scientists.