Small creatures are vital for the food chain.

Here are some fine photos by Barry Curwen showing what happens:

Sid Valley Biodiversity Group | Images of a Dipper helping with the surveying of the invertebrates in the River Sid (The Byes) this morning | Facebook

Invertebrates are also an indication of the health of any habitat.

The Environment Agency has looked at the status of the River Sid, including invertebrates: 

Sid | Catchment Data Explorer | Catchment Data Explorer

The  Devon Wildlife Trust / Sid Vale Association survey of 2013 looked at the health of the Sid – which covered most layers of life in the river, including:

Taking surveys of invertebrate life (typically mayflies and waterbugs) from along the river as a means of evaluating its water quality status.

Looking after the River Sid – the restoration project making a splash in East Devon | The Exeter Daily

Here’s a report from 2021 from Ed Dolphin – together with a photo of a mayfly nymph – as part of a ‘kick-sampling’ survey:

In a 2014 survey by the SVA, the invertebrate population indicated The Sid was free from major pollution. Children from St John’s School found the same thing when they kick sampled with the Science Festival in 2018. One thing that the 2014 survey did highlight was that the Woolbrook supported hardly any invertebrates, perhaps because of pollution from road runoff. We are pleased to report that the Woolbrook seems to have recovered.

When volunteers kick sampled in the Woolbrook recently, there was plenty of life hiding in the gravel. There were lots and lots of the freshwater shrimp Gammarus. Gliding smoothly across the bottom of the inspection dish there were tiny water snails and planarians, a type of primitive flatworm. Most significantly, there were also mayfly and caddisfly nymphs, these are only found in relatively unpolluted water.

Initial findings show town’s waterways are healthy | Sidmouth Herald

In February 2022, Buglife looked at Research which revealed that insects in British fresh waters are potentially at risk from climate change: 

Aquatic insects in hot water – Buglife latest news

In autumn 2023, the River was surveyed specifically for invertebrates – with a further report from Ed Dolphin:

One important survey involves the nymphs and larvae of various river flies, particularly mayflies, stoneflies and caddisflies. These small invertebrates are rather like the canaries once used in coal mines. If the canaries stopped singing the miners knew there was a dangerous build up of methane gas. If there isn’t a healthy population of river flies, we know there is probably something wrong with the river environment.

Ed Dolphin of Sid Vale Biodiversity Group on river canaries | Sidmouth Herald

With photos of the ‘canaries’ here, courtesy of Ed Dolphin:

With a lot more here on the SVBG social media pages:

Sid Valley Biodiversity Group | The SVBG has been monitoring the water quality in the River Sid and its tributaries since 2020 ( | Facebook  [September 2023]

Sid Valley Biodiversity Group | Plenty of invertebrate life in the Woolbrook but a very different spectrum to what was found in the main river up near its source at the Hare and Houn… | Facebook  [October 2023]