Mersea Island and the estuaries
Seven square miles of land between two estuaries, joined to Essex by a single causeway that the sea covers every week. About ten minutes by car from the campsite, when the tide allows.
An island with one road
Mersea covers around seven square miles, eighteen square kilometres, nine miles south of Colchester, sitting in the mouths of the Blackwater and the Colne. It is the most easterly inhabited and publicly accessible island in the United Kingdom, a title it holds on a technicality: Horsey Island is further east but has nothing on it except farm buildings.
One road goes on and off, the B1025 across the Strood, and the sea takes it back regularly. The causeway can be covered for up to an hour at high water, particularly on spring tides, and on average it floods at some point in every week of the month. This is worth knowing before setting out for supper on the island. Tide tables are not optional here; they are the timetable.
The island divides in two. West Mersea holds the main settlement, the jetty and the marina, and is where the boats and the seafood are. East Mersea is largely farmland, and holds Cudmore Grove Country Park on the point, where the walk out through the park to the sea is the best of the island for anyone with children and an afternoon.
The coastline of Mersea Island with the Strood marked at its north-western corner. Drawn from Ordnance Survey data by way of OpenStreetMap.
Oysters
Oysters have been taken off Mersea since Roman times and are shipped from here worldwide. The modern trade works largely on introduced Pacific oysters, and the Essex fishery is still opened ceremonially each September by the Mayor of Colchester. The Roman connection is literal: a mosaic floor found in 1730 beneath the church of St Peter and St Paul at West Mersea suggests the place was already somewhere Romans came to enjoy themselves.
Tide tables are not optional here; they are the timetable.
On crossing the Strood
The Blackwater
The estuary west of the island is one of the more heavily protected pieces of water in England. Five thousand five hundred and thirty-eight hectares are notified as a biological Site of Special Scientific Interest; four thousand three hundred and ninety-five of those are also a Ramsar wetland of international importance and a Special Protection Area; and one thousand and ninety-nine hectares are a National Nature Reserve.
What that protects is mud, and what the mud feeds is birds. Overwintering species here include pied avocet, black-tailed godwit, dark-bellied brent goose, dunlin and ringed plover, and the area is notable as a breeding ground for little tern and a staging post for ringed plover on passage. Oysters have been harvested from the estuary for over a thousand years, and the remains of Anglo-Saxon fish weirs are still out on the flats.
Some of the thinking about how to defend this coast was done here. Northey Island, up the estuary towards Maldon, was where the first British experiments in managed retreat were carried out, deliberately setting sea walls back and letting saltmarsh form in front of them.
Between the two waters, the ground the campsite stands on is about as good a base as this stretch of coast offers: fresh water and forty thousand wintering duck to the north, salt water and the brent geese to the south, and four miles between them.
Figures are from published reference sources on Mersea Island and the Blackwater Estuary. Tide behaviour on the Strood varies; check a tide table rather than relying on an average.
| Island area | About 7 square miles (18 km²) |
|---|---|
| Distance from Colchester | 9 miles (14 km) south |
| Standing | Most easterly inhabited and publicly accessible island in the UK |
| Access | The Strood causeway, B1025; covered up to an hour at high tide, on average weekly |
| Settlements | West Mersea (jetty, marina) and East Mersea (farmland, Cudmore Grove) |
| Oysters | Harvested since Roman times; Essex fishery opened each September by the Mayor of Colchester |
| Roman mosaic | Found 1730 beneath St Peter and St Paul, West Mersea |
| Blackwater SSSI | 5,538 hectares |
| Ramsar and SPA | 4,395 hectares |
| National Nature Reserve | 1,099 hectares |
| Overwintering birds | Pied avocet, black-tailed godwit, dark-bellied brent goose, dunlin, ringed plover |
| Breeding | Little tern |
Figures from published reference sources on Mersea Island and the Blackwater Estuary. Tide behaviour on the Strood varies; check a tide table rather than relying on an average.