Biodiversity action in the North York Moors

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New arrivals: alcathoe bats and Montagu's harriers

In 2010 alcathoe bats were discovered in woodland in the North York Moors National Park in April – one of only two places in the UK where this tiny flying mammal has so far been spotted. Park staff are hoping the area's rich woodland habitat will mean the little fella will stick around!

The second species is that was a new arrival in 2010 was a pair of Montagu’s harriers. The couple chose to set up home in the park this year for the first time in 50 years. They fledged three chicks and staff and birdwatchers are keeping their fingers crossed that they return again in 2011.

Esk pearl mussel and salmon recovery project

Why are pearl mussels important?

The Esk is the only river in Yorkshire with a population of freshwater pearl mussels and one of only 11 rivers in England that is home to the species which:

  • Can live for more than 100 years
  • Is an important indicator of the health of river eco-systems

In the Esk, only a small number of mussels are left (around 1,000). The vast majority are old (60+ years old). Without action, within 30 years there will be no pearl mussels left in the Esk.

Aims of the project

Started in January 2008, the four-year £260,000 Esk Pearl Mussel and Salmon Recovery Project was set up to save the freshwater pearl mussel from extinction and to halt the decline of Atlantic salmon and brown/sea trout populations (which act as hosts for the larval stage of the mussel’s lifecycle).

What work has been done?

A wide variety of river restoration work is being carried out along the Esk to restore the river habitat for these species including:

  • Installation of 24 kilometres of riverbank fences to prevent bank erosion by livestock and allow a natural buffer strip of native flora to establish
  • Nine new cattle crossing points created to prevent nutrient and sediment input to the river system
  • 13 new drinking troughs and cattle drinking bays along watercourses created
  • One new wetland created to trap sediment and nutrients and prevent these from reaching the river as well as providing a valuable habitat for a host of plants and animals
  • Three small-scale bank revetments (reinforcements) installed to stabilise the riverbanks
  • Around 1,000 broad-leaved trees planted along the river to restore the natural woodland corridor along the river banks
  • Control of non-native and invasive plant species (including Japanese knotweed, Himalayan balsam and Himalayan knotweed) along 12 kilometres of the river
  • Management of bankside vegetation including, coppicing and pollarding of diseased trees and removal of trees that are causing bank erosion

In addition to the above, a number of mussels from the Esk are also in a breeding programme in the Lake District. They bred successfully in 2008 and there are currently around 500 juveniles growing and developing. These will be reintroduced to the Esk once conditions have improved.