Marazion Marsh facts for kids

Marazion Marsh is a special place for nature, managed by the Royal Society for the Protection of Birds (RSPB). It's located in a shallow river valley, about half a kilometre west of Marazion in Cornwall, UK. A natural shingle bar and small sand dunes separate it from the coast. This marsh is home to Cornwall's biggest reed bed, which is like a giant field of tall reeds.

Where is Marazion Marsh?

Marazion Marsh is found west of the town of Marazion and about 3.5 kilometres (2.2 miles) east of Penzance. It sits in a type of bay-shaped estuary. A natural barrier of old sand and gravel separates the marsh from Mount's Bay. This barrier usually stops the sea from reaching the marsh, except during very extreme weather. The main road from Penzance to Marazion (the A394) crosses a broken line of sand dunes here.

The marsh is drained by the Red River, also called the Marazion River. This river flows through the marsh, which is mostly covered by Phragmites reeds.

One of the biggest challenges for the marsh today is soil washing into it from nearby farms. Because of this, the area around the marsh is part of a "Catchment Sensitive Farming Area." The UK government works with local farmers to help control soil erosion and protect this important wetland.

How Marazion Marsh Formed

Scientists have drilled deep into the marsh to study its past. They found up to 10 metres (33 feet) of loose soil and rock on top of older, weathered bedrock. They found materials from the Holocene period, which is the last 11,700 years of Earth's history.

By studying these layers, scientists can learn about the marsh's ancient environment. They look at things like the size of soil particles, the layers of sediment (called stratigraphy), and tiny plant and algae remains like pollen and diatoms. Pollen helps them figure out what plants grew there long ago. Samples were even sent to the Godwin Laboratory, University of Cambridge, for radiocarbon dating to find out how old they were. Different types of diatoms show how salty the water was over time. All these clues help us understand how Marazion Marsh changed through history.

Between 5,500 and 4,500 years ago, there's strong evidence that the water table was rising, the water was getting saltier, and organic material was building up in the marsh. This suggests that the sea was having a bigger impact, even though a natural barrier protected the marsh from the open sea. Sometimes, the sea water would temporarily wash over or seep through this barrier, showing that sea levels were rising. A major rise in sea level happened after about 4,500 years ago. This caused a lot of marine sediments to be quickly deposited on top of the older organic layers. Similar changes happened in nearby areas too.

The oldest layers of the marsh show a lot of herbaceous (non-woody) plant pollen. As you look at newer layers, there's more tree and shrub pollen. These changes in plants tell us that the area got wetter as the lower organic layers formed. Later, Phragmites reeds became common, and the number of tree species decreased. This led to the marsh becoming mostly an alder-dominated fen-carr (a type of wet woodland) and a reed-marsh environment. Above the organic layers, there are layers of sand with some gravel, silt, and traces of organic matter.

History of Marazion Marsh

In May 1793, a doctor named Richard Moyle successfully drained about 63 acres (25 hectares) of the marsh for farming. He laid the first drainage pipes. About 36 acres (15 hectares) of this area was tidal marsh, located between the sandy embankment from the sea and the farmland.

In June, open ditches were dug across the marsh. In one of these drains, about three feet deep, workers found a pot containing around a thousand copper coins! These coins were very corroded, but some were clear enough to show they were from the Roman Emperor Victorinus, who ruled from 268 to 270 or 271 AD.

The Red River, which used to be called the Ponsandean stream, was also used for "streaming" tin. This means people would wash the river gravel to find tin ore, all the way up to its source at Tregilliowe.

In 1951, Marazion Marsh was officially named a Site of Special Scientific Interest (SSSI). This means it's a very important place for its wildlife. It's recognized for several reasons:

• It's a feeding ground for wading birds that are passing through and for birds that spend the winter there.
• A pair of the rare Cetti's warbler (Cettia cetti) breeds here.
• Rare plants like pillwort (Pilularia globulifera) grow in the marsh.
• It has a high number of different dragonfly species.

The land is owned by the St Aubyn Estates. In 1990, they met with the RSPB to create a plan for managing the site. At that time, the reed bed was drying out because of dead leaves and stems building up. It was also changing naturally into willow scrub. That year, the reed bed was in poor condition due to a hot, dry summer. Emergency steps were taken to flood the site. Within three days, a large pool appeared, and in the following weeks, 154 individual dragonflies of 11 different species were counted!

Wildlife and Habitats

Important Habitats

Reed beds are one of the rarest habitats in the UK. Only about fifty of them are larger than 20 hectares (49 acres). Marazion Marsh has the largest reed bed in Cornwall, covering 16.8 hectares (41.5 acres). It's also the most westerly reed bed on mainland Britain. This makes it a very important reserve for birds that breed there, birds that spend the winter, and birds that are just passing through.

The reed bed is carefully managed to help the Eurasian bittern (Botaurus stellaris). This involves cutting the Phragmites australis reeds, removing dead leaves and stems, and cutting back plants that spread too much, like willow (Salix cinerea var atrocinerea). The reserve also includes 3 hectares (7.4 acres) of natural grassland, open water areas, woodlands, and willow scrub.

Notable Birds

Marazion Marsh Nature Reserve

Up to five bitterns spend the winter at the reserve. Even though the reed bed is smaller than the 20 hectares (49 acres) usually needed for bitterns to breed, it's still a vital place for them. The reserve has received money from the EU LIFE Programme's Bittern Project (from 2001 to 2007) to help manage the habitat for these special birds.

Images for kids

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  Marazion Marsh Nature Reserve