Survey Resources - Rivers and Ponds

Alien Invaders in Estuaries: A guide to Invasive Non Native species

To learn more about how you can help stop the spread of invasive species in our estuaries please take a look at this leaflet, which has been developed for estuaries in France, The Netherlands, Belgium and the UK by the European project 'SE-FINS'.

Not all the species featured here are currently found in Essex estuaries, but this guide contains useful information on how to recognise invasive species and prevent them from spreading.

Further online resources

More resources for River Wardens and Riverfly surveyors can be found on the Essex Rivers Hub or on the Riverfly website: To enquire about becoming a River warden please contact us.

More volunteer recording resources and citizen science packs can be found on the Catchment Based Approach CaBA website

Guide to the Larger Aquatic Bugs

A photo guide for freshwater invertebrate recorders, kindly supplied by Adrian Chalkley, Suffolk County Recorder for aquatic invertebrates.

Guide to Water Vole Field Signs

Key to Great Diving Beetles

A photographic guide to Great Diving beetles, aimed at the non specialist. This key was kindly supplied to us by the developer Adrian Chalkley, Suffolk County Recorder for aquatic invertebrates.

Riversearch how to survey

Details on how to survey for otters, water voles, harvest mice and water shrews.

Riversearch Otter Survey information sheet

Riversearch survey form

The Riversearch otter and water vole survey form can be downloaded below. Please send completed forms to: Darren Tansley, Water for Wildlife Officer, Essex Wildlife Trust, Abbotts Hall Farm, Gt Wigborough, Colchester, CO5 7RZ.

Riversearch survey points

A list of the Riversearch survey points, highlighting those that are lacking surveyors. If you can help survey a Riversearch point near you please contact us for details.

White Clawed Crayfish Guide

A guide to our only native crayfish species, Authored by Nick Mott of Staffordshire Wildlife Trust.