Sea Mere
Sea Mere in Essex Norfolk and Suffolk, England has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 140 µg/L. Chlorophyll-a (algae): 25 µg/L.
Why Sea Mere has no A–F grade
Sea Mere in England is published with the authority's own measurements, not a LakeQuality letter. official authority class; not a LakeQuality A–F letter Sampling here has recorded phosphorus and algae (chlorophyll-a), but not water clarity.
A letter on the LakeQuality scale would be an invention, not an official class. Everything below that has been measured is still reported on this page.
Monitoring: the Environment Agency (England).
Sea Mere is a lake in Essex Norfolk and Suffolk County, England.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2020-03-05. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Sea Mere
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 140 µg/L. Chlorophyll-a: 25 µg/L. Trophic State Index: 69.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 140 µg/L | Not graded |
| Chlorophyll-a (Algae) | 25 µg/L | Not graded |
| Trophic State Index (TSI) | 69 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Sea Mere
Compare lakeside cabins, hotels, and vacation rentals near Sea Mere in Essex Norfolk and Suffolk, England — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Sea Mere
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Fishing Sea Mere
Frequently asked questions about Sea Mere
What is the water quality of Sea Mere?
- Sea Mere in Essex Norfolk and Suffolk, England has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 140 µg/L. Chlorophyll-a (algae): 25 µg/L.
Is Sea Mere safe to swim in?
- Sea Mere has official nutrient and clarity measurements, not a bacteria swim class and not a safety clearance. Algal blooms, currents, and depth are not covered. Always check local notices before swimming.
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Where this data comes from
30 measurements from 1 monitoring station, 2016–2020. Retrieved from the Environment Agency (England; not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- Environment Agency (England)
ea-wqa30 samples · 2016–2020
Monitoring station identifiers (1)
AN-SEAMERE
Authority classifications are stored separately from LakeQuality A–F letters and are never blended. See methodology and data sources.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2020-03-05
Monitoring stations: 1