Policy paper

Highly Protected Marine Areas: Allonby Bay

Published 5 July 2023

Applies to England

This page outlines why Allonby Bay has been designated as a Highly Protected Marine Area (HPMA). It provides an overview of its ecological importance, where this area is located and our current knowledge of the activities within the area.

HPMAs have the highest levels of protection in our seas. All extractive, destructive and depositional uses are prohibited. This helps the ecosystem to fully recover.

This site became a HPMA on 14 June 2023.

Location

Allonby Bay is an inshore HPMA situated in the Irish Sea, covering the southern region at the mouth of the Solway Firth and extends approximately 5.6km seaward from the shoreline between Maryport and Mawbray.

At 27.6 km² it follows the mean high-water mark along the length of the enclosed shoreline, out to a maximum depth of 6.6 metres.

This HPMA is within both the Allonby Bay Marine Conservation Zone (MCZ) and the Solway Firth Special Protection Area (SPA).

Conservation objective

The Allonby Bay Highly Protected Marine Area (Marine Conservation Zone) Designation Order 2023 sets out the protected feature and the conservation objective applicable within the HPMA site boundary.

The conservation objective of Allonby Bay HPMA is to:

• achieve full recovery of the protected feature, including its structure and functions, its qualities and the composition of its characteristic biological communities present within the Allonby Bay Highly Protected Marine Area, to a natural state
• prevent further degradation and damage to the protected feature, subject to natural change

Why we have designated this site as a HPMA

Allonby Bay consists of a mix of habitats, characteristic of an environment that is subject to dramatic currents and tides. The seabed here consists of a range of rocky habitats and sediment dominated habitats.

The nutrient-rich sediments, dense mussel beds and intertidal rocky habitats in this area attract large densities of shore birds including species such as curlew and oystercatcher. The biodiverse subtidal habitats provide a food source for fish species, such as flat fish, and nursery areas for other species. In turn, these fish species attract diving, foraging seabirds including guillemots, gannets and razorbills.

One of the best examples of honeycomb worm reefs in the UK is found here. Honeycomb worms create a complex sediment network of tubes attached to rock, providing vital habitat for a range of species including crabs and molluscs.

Allonby Bay’s habitats and species provide many ecosystem services. The area contains 13km² (47% of the HPMA) of ‘blue carbon’ habitats which capture and store carbon and includes intertidal sand, muddy sand and subtidal sands. Overall, in English waters, seabed sediments (such as mud and sand) have been identified to have a large stock of organic carbon, highlighting the importance of protecting this habitat as a nature-based solution to tackling climate change. Furthermore, the extensive honeycomb reefs and blue mussel beds can provide both water purification and important coastal erosion protection.

The rich sediments and intertidal rock habitats attract important migratory, non-breeding bird species with large groups of around 16 different species congregating along the shoreline. Allonby Bay provides suitable spawning grounds for sole, thornback ray and bass, and a nursery area for cod, herring, plaice, sole and thornback ray.

Overlapping with an existing MCZ of the same name, and partial overlap with Solway Firth SPA, the designation of Allonby Bay as a HPMA would allow us to understand the added benefits the protection of a HPMA can provide in these scenarios. Furthermore, with limited disturbance identified, this area is considered to represent a more natural ecosystem providing an important opportunity to safeguard biodiversity and to help us further understand the ecological impact of the removal of any remaining pressures. Protected features which exist both within the HPMA and existing MCZ and SPA will be subject to the higher conservation objective for HPMAs in the overlapping area.

The consultation also showed high levels of support for the site. The boundary proposed for designation has been modified to allow for an area of recreational angling, including access for disabled anglers, and for other activities to continue due to its importance to the community and takes account of the needs of Maryport Harbour and the Port of Silloth while still delivering important biodiversity benefits.

Protecting the whole site

HPMAs take a ‘whole site approach’, therefore the entire marine ecosystem within the HPMA boundary is designated for protection.

The protected feature of the Allonby Bay HPMA is listed in the Designation Order as ‘the marine ecosystem of the area’.

‘The marine ecosystem’ means all marine flora and fauna, all marine habitats and all geological or geomorphological interests, including all abiotic elements and supporting ecosystem functions and processes, in or on the seabed, water column and the sea surface.

Some of the broadscale habitats including blue carbon habitats, together with their associated communities are listed below, but the list is not exhaustive.

• moderate energy littoral rock
• low energy littoral rock
• features of littoral rock (rockpools and ephemeral algae)
• littoral sand and muddy sand
• features of littoral sediment (ephemeral algae)
• high energy infralittoral rock
• moderate energy infralittoral rock
• moderate energy circalittoral rock
• sublittoral coarse sediment
• sublittoral sand
• sublittoral mud
• sublittoral mixed sediments
• sublittoral biogenic reefs

As well as these habitats, a range of mobile species, including birds, marine mammals and multiple species of fish and shellfish are also likely to use this area and form part of the protected feature when within the designated site. For further information, please refer to the ecological narrative developed for the candidate HPMA boundaries ahead of consultation.

Management of the site

A more precautionary approach to the management of activities is advised for HPMAs than is the case for existing MCZs. The government’s vision for HPMAs is that these will be areas of the sea that allow the protection and recovery of marine ecosystems by prohibiting extractive, destructive and depositional uses and allowing only nondamaging levels of other activities to the extent permitted by international law.

Allonby Bay HPMA is designated as an MCZ under the Marine and Coastal Access Act (MCAA). The MCAA Section 125 places a general duty on public authorities to carry out their functions in the manner that they consider best furthers – or least hinders – the conservation objectives set for MCZs. Activities should only be permitted if the public authority is satisfied that there is no significant risk that the activity will hinder the achievement of the conservation objectives or if certain conditions are met (MCAA 126 (5)-(7)).

Regulators, including the Marine Management Organisation (MMO) and Inshore Fisheries and Conservation Authorities (IFCAs), will aim to introduce necessary management measures in due course.

Management can take several different forms, including use of the existing planning and licensing regimes, specific byelaws and orders. Public consultation will be carried out as required for permanent byelaws and orders. For activities that require authorisation, public authorities must consider the site in their decision as soon as the site is consulted on.

High level and site-specific conservation advice by statutory nature conservation bodies (SNCBs), JNCC and Natural England, will provide further guidance related to management of HPMAs to meet the conservation objective.

Other guidance documents will also be available to support public authorities in their duties in relation to the management of HPMAs under the MCAA.