Chalk streams

Chalk streams are globally rare and unique rivers, with the vast majority found in southern and eastern England.

Chalk streams are fed by pure, filtered groundwater from chalk aquifers. Their stable flow, cool, clear, mineral-rich water, and clean gravel beds create an exceptionally productive and specialized habitat for a diverse range of wildlife, including wild trout and water voles.

Associated species

12 species recorded from Greater Lincolnshire in the last 25 years 13 recorded from Greater Lincolnshire all time

Increasing

1 Stable

1 Declining

Extinct

Casual introduction

Natural vagrant

Established non-native

11 Data deficient

Unassessed

2 Key action species

Beetles

		common name	scientific name	occurrences	earliest	latest
		Drupenatus nasturtii	Drupenatus nasturtii (Germar, 1823)	21	1951	2018

Crustaceans

		common name	scientific name	occurrences	earliest	latest
		White-clawed Crayfish	Austropotamobius pallipes (Lereboullet, 1858)	1,116	1900	2024
		Trichoniscoides albidus	Trichoniscoides albidus (Budde-Lund, 1880)	9	1993	2023

Dragonflies and damselflies

		common name	scientific name	occurrences	earliest	latest
		White-legged Damselfly	Platycnemis pennipes (Pallas, 1771)	54	1984	2024
		Scarce Chaser	Libellula fulva Müller, 1764	13	1917	2021

True bugs

		common name	scientific name	occurrences	earliest	latest
		Sigara (Retrocorixa) venusta	Sigara venusta (Douglas & Scott, 1869)	143	1986	2015

True flies

common name	scientific name	occurrences	earliest	latest
Tipula marginella	Tipula marginella Theowald, 1980	2	2008	2008
Cheilotrichia imbuta	Cheilotrichia imbuta (Meigen, 1818)	1	1972	1972
Helius pallirostris	Helius pallirostris Edwards, 1921	9	1986	2015
Bright Four-spined Legionnaire	Chorisops nagatomii Rozkošný, 1979	6	2011	2022
Dark-winged Soldier	Oxycera analis Wiedemann in Meigen, 1822	2	2011	2011
White-barred Soldier	Oxycera morrisii Curtis, 1833	148	1971	2019
Silver Colonel	Odontomyia argentata (Fabricius, 1794)	9	2016	2022