National Character Area 41

Humber Estuary - Natural Capital and Key Ecosystem Services

Introduction

The Humber Estuary NCA provides a wide range of benefits to society. Each is derived from the attributes and processes (both natural and cultural features) within the area. These benefits are known collectively as ‘ecosystem services’. The predominant services are summarised below. Further information on ecosystem services provided in the Humber Estuary NCA is contained in the ‘Analysis’ section of this website.

Note: The natural capital in this NCA is mapped below. This displays more recent national and publicly available data sets as used within Natural England’s 2020 Natural Capital Atlas Profiles.

The predominant ecosystem services in this NCA are also summarised below. The text contained in this section is based on the previous NCA profiles in 2014, and so is not entirely current. Further information on ecosystem services provided in the North Northumberland Coastal Plain NCA is contained in the Analysis: Ecosystem Services page of this website.

What is Natural Capital?

Natural capital means “the elements of nature that directly or indirectly produce value to people, including ecosystems, species, freshwater, land, minerals, the air and oceans, as well as natural processes and functions” (Natural Capital Committee, 2017).

It is helpful to consider natural capital in the form of a logic chain that represents the links between ecosystem assets, services, benefits and value to people. The figure below displays that logic chain. The quantity and quality of ecosystem assets (woodland, bogs, etc) support different types of ecosystem services, such as carbon sequestration or water filtration. These ecosystem services then provide different benefits to society, providing value for people. The figure also shows how management interventions, as well as pressures and drivers of change, influence this chain. Other capital inputs are also often needed for people to obtain the benefits from ecosystem services (a simple example is the processing of trees to produce wood products).

As an example, an area of woodland (ecosystem asset) may reduce air pollution created by traffic on a nearby road. This woodland is therefore improving air quality (ecosystem service) in the local area which results in cleaner air and improved health in the adjacent residential street (benefit). This cleaner air has a value because we know it impacts the health and wellbeing of communities.

Sometimes for ease of understanding, economic framing is used to give these benefits a monetary value. The figure below shows how natural capital assets support the provision of ecosystem services, benefits and value. The roots of the tree show how aspects of asset quality are critical to the provision of ecosystem services. The roots also show that geodiversity underpins the ecosystem assets and therefore the ecosystem services and benefits they can provide. It is important to remember that this diagram, and natural capital frameworks more generally, are a simplification of how nature works in practice.

Natural Capital within this NCA

In 2018, Natural England published ‘Natural Capital Indicators: for defining and measuring change in natural capital’ (Lusardi et al., 2018). This report identified key properties of the natural environment vital for the long-term sustainability of benefits, which can act as indicators of change.

These indicators are designed to inform our understanding of the state of our natural assets. The indicators highlight the importance of our natural assets for delivering which ecosystem service and the benefits they provide for society. The indicators and datasets identified in Natural England’s Natural Capital Indicators Project provide the foundation for the Natural Capital Atlas Profiles.

Natural England’s Natural Capital Atlas Profiles provide an “off the shelf” natural capital evidence base for each county or city region. They have a wide variety of uses with more information in the How to Start Using Your Natural Capital Atlas.

The Natural Capital indicators are presented on the map below by broad asset theme, displaying the natural capital within the NCA.

It is noted that not all indicators listed within the Natural Capital Atlas Profiles are included within the map as data is not yet available to measure them. Refer to the “Indicator Gaps and Limitations” of the Natural Capital Atlas Profiles for further information.

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated.

Provisioning services (food, fibre and water supply)

Food provision: With 37 per cent of the land at Grades 1 and 2, and 36 per cent at Grade 3, the area is highly productive. Arable farming is predominant, with high concentrations of cereals and oilseeds. The area is also important for pig rearing. The loamy and clayey soils of the coastal flats with naturally high groundwater have the potential to continue to support highly productive agriculture but this is dependent upon pump drainage and protection from floods. However, over-abstraction is increasing the risk of saline intrusion.

Regulating services (water purification, air quality maintenance and climate regulation)

Climate regulation: Significant carbon storage is provided by extensive areas of saltmarsh, reedbeds, mudflats and coastal marine sediments.

Regulating water quality:For information regarding the current state of water quality within this NCA, refer to the Environment Agency (Draft river basin management plan maps).

Regulating water flow (flooding): The entire NCA lies within the ‘floodable area’ of the Humber Estuary, at risk of being flooded by rising sea levels, and in particular by a storm surge in the North Sea combined with high river levels. Reflecting this risk, essentially the entire stretch of the estuarine shore is protected by flood defences. These give rise to ‘coastal squeeze’, as intertidal habitats are lost between rising sea levels and the flood banks, which needs to be addressed by managed realignment to enable the continued expansion of intertidal habitats.

The complex processes of deposition and erosion within the estuary are linked to the coastal processes. Sediments from the North Sea and from the eroding Holderness cliffs to the north are drawn in and out of the estuary and contribute to the continual changing patterns of deposition. In particular, these sediments form the Spurn Head peninsula at the mouth of the estuary which in turn provides shelter, encouraging the accretion of extensive mudflats on the east side. The supply of sediments thus needs to be maintained.

Cultural services (inspiration, education and wellbeing)

Sense of place/inspiration: Sense of place, inspiration and escapism are all provided by the expansive, flat, low-lying estuarine landscape dominated by the Humber, with large open skies, the exposed Spurn peninsula, and remote, quiet wetlands alongside the estuary. The tidal nature of the estuary provides an ever-changing scene, often with large flocks of birds wheeling past, and the Humber Bridge, industrial complexes and other iconic structures forming distinctive focal points.

Tranquillity: There are strong contrasts between the very busy areas of Hull and the industrial complexes along the south bank, and the tranquil areas of the mudflats and estuarine landscape on the north side, and the upper stretches of the estuary. Spurn Head retains an ‘other-worldly’ quality, all but cut off from the mainland.

Biodiversity: The Humber Estuary is of international significance, with most of it designated as a Ramsar site and as a Special Area of Conservation for its extensive intertidal habitats such as mudflats, sands, coastal lagoons and sand dunes, and its populations of grey seals and lampreys. It is also a Special Protection Area for its breeding, migratory and overwintering bird populations, and is the third largest Site of Special Scientific Interest in England.

Geodiversity: The Humber Estuary is of international importance for its complex patterns of erosion and accretion, with the Spurn Peninsula an outstanding example of a dynamic spit system, with a long historical map record.