Holderness - Natural History

Natural History

For the purpose of describing the natural history the area can be divided into three parts:-

• The valley of the River Hull

The River Hull valley dominates the western landscape of Holderness. The river and its associated wetland habitats support a diverse range of plants and animals. The upper tributaries of the river originate on the edge of the Yorkshire Wolds before entering the area of glacial and alluvial deposits of Holderness. The river bed varies in composition reflecting the underlying geology. In the upper reaches of the river water crowfoot, lesser water parsnip, mares tail and spiked water milfoil may be found in the main channel whilst the marginal vegetation is composed of branched bur-reed, common reed and reed sweetgrass.

Otters have recently recolonised the upper reaches of the river, however the water vole is now confined to a few isolated populations. Notable species of invertebrates include uncommon mayflies. There is a diverse breeding bird community including lapwing, snipe and redshank. Wildfowl such as mallard and mute swans may also be seen, along with yellow wagtail, sedge warbler, reed warbler and reed bunting.

Further south towards Beverley and Hull the river becomes tidal and saline. In the lower reaches it is enclosed by flood banks with little associated natural habitat remaining. The majority of the formerly extensive wetlands have been subject to drainage schemes and agricultural improvement. However some small remnants remain along the Hull valley between Driffield and Wansford. Plants that are typical of these habitats including a variety of reeds, rushes and sedges as well as yellow flag, valerian and meadowsweet may be found.

There are few surviving areas of woodland among the open farmland which supports golden plover and lapwing and a flora of arable weeds.

• The Coast

The coast from Bridlington in the north to Spurn Point is an interesting complex of coastal processes. The soft cliffs of Holderness are subject to rapid erosion whilst the eroded material is being deposited on the Spurn peninsula. The speed of erosion along the glacial till cliffs prohibits colonisation of anything but sparse ruderal vegetation. Coltsfoot is particularly common and sand martin colonies have become established in places.

Hornsea Mere is the largest natural lake in Yorkshire at 120 hectares. It has, besides the open fresh water habitat, marginal habitats of reed swamp, species-rich fen and carr woodland. It regularly supports populations of wintering wildfowl and the reed beds provide breeding sites for reed warblers. Characteristic plants include milk parsley, greater water parsnip and lesser reedmace.

• The Humber Estuary

The intertidal system of the estuary of the River Humber has local seagrass beds that provide feeding and wintering areas for over 133,000 waders and wildfowl. It is rich in invertebrate communities. The estuary also provides for breeding birds, grey seals and natterjack toads.

Spurn Point at the tip of the Spurn peninsula is made of hard glacial moraine so is less liable to erosion than areas further north on the Holderness coast. The Spurn peninsula is a beach with dunes which moves in response to the action of the waves. The wave action removes sand from the east of the beach and deposits it on the western side. The coast is influenced mainly by wave action but in the estuary the processes are driven by the power of the tides. The incoming tidal currents carry more sediment into the estuary than the ebb tides carry out. The estuary is shallow because of this constant deposition. Isostatic recoil is, however, causing the area to sink at the rate of 3 mm annually and global warming is making the sea level rise. The combined effects of these processes mean that the sea in the estuary may be half a metre higher by the year 2050. A large area around the estuary consists of land which lies below the present high water mark. Flood defences offer only a short term and local answer and may actually increase the long term risks. Managed realignment of the coast by setting back the coastal defences will provide new intertidal habitats and harness natural equalising processes and is the preferred long term solution.