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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 UKHAB documentation or the UK Government's Condition Assessment Sheet.
Coastal Lagoons are expanses of shallow coastal salt water, of varying salinity and water volume, wholly or partially separated from the sea by sand banks or shingle, or, less frequently, by rocks.
Landscape and Ecological Context
Salinity may vary from brackish water to hypersalinity depending on rainfall, evaporation and through the addition of fresh seawater from storms, temporary flooding of the sea in winter or tidal exchange. With or without vegetation of seagrasses or charophytes. Salt basins and salt ponds may also be considered as lagoons, providing they had their origin on a transformed natural old lagoon or on a saltmarsh, and are characterised by a minor impact from exploitation
How to Create / Enhance to a "Good" condition
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 | Presence and abundance of invasive non-native species | Not more than one invasive non-native species is ‘Occasional’ on the SACFOR scale3; or is occupying more than 1% of the habitat. No high-risk species indicative of suboptimal condition present, see Footnote 4. | No invasive non-native species are present above ‘Frequent’ on the SACFOR scale3; or they occupy between 1-10% of the habitat. No high-risk species indicative of suboptimal condition present, see Footnote 4. | One or more invasive non-native species ‘Abundant’ on the SACFOR scale3; 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 4. |
B | 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 timing5. | 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 timing5. | Visual evidence of high algal growth that is indicative of nutrient enrichment. Signs of eutrophication that would impede bird feeding. Consider seasonality of survey timing5. |
C | 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). |
D | 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 6 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 per person per 100 m per hour. See Footnote 6 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 per person per 100 m per hour. See Footnote 6 for details. |
E | Salinity | Salinity is between 15 - 40 ppt. | Salinity values are close to (but still within) the ends of range acceptable for lagoons (15 - 40 ppt). | Salinity values are either hypersaline >40 ppt or hyposaline <15 ppt. |
F | Isolating barrier | Fully functional and permitting tidal exchange. | Slightly damaged but some water exchange still occurring. | Not functioning. No water exchange occurring making the lagoon hyposaline. |
G | Physical damage of lagoon banks | No physical damage present7. | Only small, isolated patches of physical damage present7. | Evidence of significant physical damage7. |
H | Water clarity | Water is clear. | Water clarity is reduced. | Water is turbid and water clarity is poor (not just after heavy rain). |
TOTAL SCORE 18-24 (75-100%) = GOOD CONDITION |
TOTAL SCORE 12-17 (50-75%) = MODERATE CONDITION |
TOTAL SCORE 8-11 (0-50%) = POOR CONDITION |
Footnotes |
Footnote 1 – The extent of the lagoon waterbody should be recorded at high tide. This should be assessed at the end of the summer (late August – early September) and gives an indication of the amount of water that is present at all times of year. It should be noted that some lagoons are naturally very shallow. |
Footnote 2 - Examples of species adapted to lagoons can be found in Bamber (2010): BAMBER, R.N. (2010) Coastal saline lagoons and the Water Framework Directive [online]. Natural England Commissioned Reports, Number 039. Available from: |
For assessment of species characteristic of anoxic environments, for example presence of Capitellid worms, further information on the SACFOR scale can be found on the JNCC website at: JNCC (No date) SACFOR abundance scale used for both littoral and sublittoral taxa from 1990 onwards [online]. Available from: |
Footnote 3 - 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: |
Use the non-native species list available here: |
DEFRA (2022) UK Marine Non-Indigenous Species Priority List (updated 2020) [online]. Available on: |
Footnote 4 - High-risk species indicative of suboptimal condition at time of publication include: |
Footnote 5 - Peak bloom time is July – September. |
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. |
Footnote 7 - Sources of physical damage include: excessive poaching, damage from machinery use, damaging management or public access activities. |