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Habitat Type: Artificial littoral mud
Habitat Type: Artificial littoral mud
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Written by Oliver Lewis
Updated over 5 months ago

PHOTO COMING SOON

The following is a short summary of the habitat type and how to create/enhance it to a "good" condition. For an informed position, please refer to official up-to-date EUNIS documentation or the UK Government's Condition Assessment Sheet.

Aligns with the description provided by EUNIS ART_A2.3

Artificial sedimentary habitats will be those that cannot meet the general natural definition, particularly in respect to using substrate that is not of marine origin or that cannot remain in situation without significant engineering. Beneficial use & beach recharge or replenishment: Provided these use the same sediment type as originally present they fall into enhancement of existing habitats. In these situations, do not use the artificial habitat definition. Ensuring condition is as good as or better than originally and still requiring the 10% biodiversity unit gain. If it’s a different sediment type then it will be habitat creation – to be considered natural sediment creation the scheme must meet the natural habitat definition including an aim for biodiversity conservation. Otherwise, they will be considered artificial in the metric. Examples of artificial littoral sediment habitats: Sediments deposited around artificial islands, sediments

Shores of fine particulate sediment, mostly in the silt and clay fraction (particle size less than 0.063 mm in diameter), though sandy mud may contain up to 40% sand (mostly very fine and fine sand). Littoral mud typically forms extensive mudflats, though dry compacted mud can form steep and even vertical structures, particularly at the top of the shore adjacent to saltmarshes. Little oxygen penetrates these cohesive sediments, and an anoxic layer is often present within millimetres of the sediment surface. Littoral mud can support communities characterised by polychaetes, bivalves and oligochaetes. Most muddy shores are subject to some freshwater influence, as most of them occur along the shores of estuaries. Mudflats on sheltered lower estuarine shores can support a rich infauna, whereas muddy shores at the extreme upper end of estuaries and which are subject to very low salinity often support very little infauna.

Muddy shores are principally found along the shores of estuaries where there is enough shelter from wave action to allow fine sediment to settle. Muddy shores may also be present in sheltered inlets, straits and embayments which are not part of major estuarine systems.

Enteromorpha spp. and Ulva lactuca may form mats on the surface of the mud during the summer months, particularly in areas of nutrient enrichment or where there is significant freshwater influence.

How to Create / Enhance to a "Good" condition

⚠️ Important Note

The design and management of coastal habitats will have specific competency requirements which should be demonstrated where these habitats are targeted in the SSM.

There are a set of criteria that are used to judge the condition of this habitat. These are listed below.

Indicator

Good (3 points)

Moderate (2 points)

Poor (1 point)

A

Coastal processes

Coastal processes are functioning naturally. No evidence of human physical modifications which are clearly impacting the habitat.

Artificial structures present e.g. groynes, that are impeding the natural movement of sediments or water, affecting up to 25% of the habitat.

Artificial structures present e.g. groynes, that are impeding the natural movement of sediments or water, affecting more than 25% of the habitat.

B

Presence and abundance of invasive non-native species

Not more than one invasive non-native species is ‘Occasional’ on the SACFOR scale or is occupying more than 1% of the habitat. No high-risk species indicative of suboptimal condition present, see Footnote 1 for details.

No invasive non-native species are present above ‘Frequent’ on the SACFOR scale or they occupy between 1-10% of the habitat. No high-risk species indicative of suboptimal condition present, see Footnote 1 for details.

One or more invasive non-native species are present at an ‘Abundant’ level on the SACFOR scale; they occupy more than 10% of the habitat; or a high-risk species indicative of suboptimal condition is present – GB Non-native Species Secretariat should be notified, see Footnote 1 for details.

C

Water Quality

No visual evidence of pollution. There are no nuisance algal growths that are likely to be attributable to nutrient enrichment. Consider seasonality of survey timing2.

Visual evidence of low to moderate levels of pollution. Elevated algal growth with increases in cover that may indicate nutrient enrichment. Consider seasonality of survey timing2.

Visual evidence of high algal growth that is indicative of nutrient enrichment. Signs of eutrophication that would impede bird feeding. Consider seasonality of survey timing2.

D

Non-natural structures and direct human impacts

No evidence of impacts from direct human activities, or they occupy <1% of the habitat area (for example, pontoons, moorings, boats, crab tiles, bait digging or anchoring scars).

Evidence of impacts from direct human activities occupies 1-10% of the habitat area (for example, pontoons, moorings, boats, crab tiles, bait digging or anchoring scars).

Evidence of impacts from direct human activities occupies >10% of the habitat area (for example, pontoons, moorings, boats, crab tiles, bait digging or anchoring scars).

E

Litter (when examining a beach strandline, mean high water line or intertidal rocky shore)

Following the Marine Conservation Society (MCS) beach litter survey method, the number of items of litter does not exceed 0.0036 m−1 min−1 person−1, equivalent to up to 20 items per person per 100 m per hour. See Footnote 3 for details.

Following the MCS beach litter survey method, the number of items of litter does not exceed 0.0078 m−1 min−1 person−1, equivalent to between 21 and 47 items of litter per person per 100 m per hour. See Footnote 3 for details.

Following the MCS beach litter survey method, the number of items of litter exceeds 0.0078 m−1 min−1 person−1, equivalent to more than 47 items of litter per person per 100 m per hour. See Footnote 3 for details.

Condition Assessment Result

TOTAL SCORE 12-15 (75-100%) = GOOD CONDITION

TOTAL SCORE 8-11 (50-75%) = MODERATE CONDITION

TOTAL SCORE 5-7 (0-50%) = POOR CONDITION

Footnotes

Footnote 1 - Abundances estimated using SACFOR scales details available here: JNCC (No date) SACFOR abundance scale used for both littoral and sublittoral taxa from 1990 onwards [online]. Available from: sacfor.pdf (jncc.gov.uk)

Use the non-native species list available here: Microsoft Word - UK_Marine_NIS_priority_list_2020 (nonnativespecies.org)

DEFRA (2022) UK Marine Non-Indigenous Species Priority List (updated 2020) [online]. Available on: Marine Pathways Group » NNSS (nonnativespecies.org)

  • Ficopomatus enigmaticus - Trumpet tube worm

  • Styela clava - Asian tunicate; leathery sea squirt, club tunicate

  • Corella eumyota - Orange-tipped sea squirt

  • Grateloupia turuturu - Devil’s tongue weed, gracie, red menace and red tide

Intertidal mixed sediment A2.4

  • Ficopomatus enigmaticus - Trumpet tube worm Always check for updates of high-risk species.

Footnote 2 - Peak bloom time is July – September.

Footnote 3 - Please use the method as set out in Nelms et al (2017) to identify litter m−1 min−1 person−1, which is summarised below:
Collect litter along a linear transect parallel with the strandline, located between the back of the beach and the strandline. The transect should be 100 m long. Assign gathered items of litter to one of 101 item categories, and further classify them into 12 material groups (plastic, polystyrene, rubber, cloth, metal, medical, sanitary, faeces, paper, wood, glass, pottery or ceramic) using MCS classifications. Following this, record and sum all anthropogenic litter items and remove them from the beach. Litter identification guides may be useful, please see Nelms et al (2017) for more details on the method:

NELMS, S.E. ET AL. (2017) Marine anthropogenic litter on British beaches: A 10-year nationwide assessment using citizen science data. Science of The Total Environment [online], 579. Available from:

The indicator thresholds for litter are based on the methods in Van Loon et al (2020), which is guidance developed within the Common Implementation Strategy for the Marine Strategy Framework Directive (MSFD) by the MSFD Technical Group on Marine Litter.
VAN LOON, W. ET AL. (2020). A European Threshold Value and Assessment Method for Macro Litter on Coastlines. EUR 30347 EN, Publications Office of the European Union, Luxembourg. [online] Available from:

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