Packing Shed Marsh Island is a small island of shingle and shells sandwiched between Cobmarsh Island and Sunken Island half a mile south west of the town of West Mersea on Mersea Island. The Mersea Fleet flows to the east of the island and the Thorn Fleet flows to the west. The island is 300 metres long at low tide and at high tide most of the shingle is covered with water. The remains of oyster pits can still be seen in the middle of the island. These provide nesting sites for herring gulls and oystercatchers.
In the late 19th century huge quantities of oysters were sent from Mersea Island to Billingsgate Fish Market in London in barrels on Thames barges. They were also exported to Europe. The Packing Shed was built on the island, which later became known as Packing Marsh Island, by the Tollesbury & Mersea Native Oyster Fishery Company Limited c1890. It was used for cleaning, grading and packing the oysters, which had been dredged up from the local oyster beds. The island was owned by Willoughby John Bean, who also owned much of West Mersea, from 1887 until 1891 when he sold it to Albert Barker. Barker sold it on to the Tollesbury & Mersea Native Oyster Fishery Company Limited in 1914.
The original Packing Shed was blown away in a storm in the 1890s but a replacement was built in 1897. This shed was used continuously, apart from during the Second World War, until the late 1950s when the oyster industry collapsed, due to diseased oysters. An additional smaller shed was built to the north of the main Packing Shed in 1912, but it was destroyed during storms and floods in March 1949.
After the 1950s the Packing Shed was used occasionally by the Tollesbury & Mersea Native Oyster Fishery Company Limited for storing fishing gear, but it gradually fell into a derelict state. By the end of the 1980s all that remained of the Packing Shed was part of the roof and some wooden wall cladding. It was further damaged by two storms in September 1990. It was then restored by a group of local volunteers and it reopened to visitors in 1992. The island and the Packing Shed still belong to the Tollesbury & Mersea Native Oyster Fishery Company Limited but they now lease it to the Packing Shed Trust.
In the inter-war period American slipper limpets were competing for food with the oysters and so tons of limpets were dredged out of the oyster beds and dumped on the island, which helped to stabilise it. However, storms in 1987 and 1997 moved some of them and the island is gradually eroding away.
The Packing Shed Trust holds open days once a month during the summer and on those days they run a ferry service to and from the island from the hammerhead quay at West Mersea. A cream tea is included in the price of the trip, which in 2024 was £8.
