To assess the ecological status of a river, watchdogs use several metrics, including the analysis of invertebrates in samples collected from watercourses, such as mayfly larvae, worms, snails, dragonflies or shrimps Source link : https://www.dailystar.co.uk/news/latest-news/health-checks-englands-rivers-could-36675071 Author : [email protected] (Rebecca Speare-Cole) Publish date : 2026-02-06 00:01:00 Copyright for syndicated content belongs to the linked Source.