Over many years humans have put multiple barriers into our rivers and streams, these prevent fish migration
Weirs, sluices and other man-made structures prevent free movement for fish such as brown trout, salmon and eels that have different requirements throughout their life cycle and need to move between habitats to spawn, decrease chances of predation, isolation and disease.
Isolated populations of a species can mean less genetic diversity.
Water vole are also victims of habitat fragmentation. Unsympathetic riparian management can leave Britain’s largest vole with nowhere to live and nowhere for young to disperse.
Trusts are working with landowners to open up fish passage, through mapping and ground truthing barriers to removing or modifying barriers.
Trusts are surveying for water voles and carrying out river restoration habitat improvements to increase suitable habitats for Britain’s fastest declining mammal.