sundial

Sundial spotlight: freshwater shrimp

Freshwater shrimp

The third in a series of blogs celebrating the flora and fauna of our local river. 

By Jenny Figueiredo

The Freshwater Shrimp, Gammarus pulex, is one of those fairly self-explanatory names for a creature – simply a shrimp that lives in fresh water.  The common freshwater shrimp has a robust appearance, and is typically greyish with markings in dark brown or green. Seafood fans will be disappointed to hear that it’s unlikely you would throw any of Osney’s shrimps ‘on the barbie’ – most common freshwater shrimp vary in length between a pretty tiny 14mm for females to 21mm for males. 

As well as rivers and canals, freshwater shrimp can sometimes be found in garden ponds as well as in rivers and canals, as they are frequently carried as eggs or tiny babies on the feet of birds. 

These miniature marvels played a starring role in the campaign back in the 1880s to provide fresh water to Oxford.   When a new pumping station was installed in Oxford (in Lake Street, where South Oxford Community Centre now stands), local social campaigner and famous photographer Henry Taunt challenged the mayor to prove that the water pumped from New Hinksey Lake was fit to drink.  Taunt himself had claimed that in less than three hours of running the city water from his household tap, he had caught no fewer than 37 freshwater shrimps, which he later displayed at Oxford Town Hall under a microscope.

Photo credit: AJ Cann

Photo credit: AJ Cann

In recent years our friendly native freshwater shrimps are being increasingly challenged by invasive, non-native species.  These include the rather ominously named ‘Demon Shrimp’ (Dikerogammarus haemobaphes), which is one of the 15 invasive non-native species of most concern to the Environment Agency to be found here in Oxfordshire (according to Wild Oxfordshire’s ‘State of Nature’ report in 2016).  These invasive species tend to reproduce more quickly, are omnivorous and have a better tolerance for a range of temperature, salt and pollution levels than the native kinds.   As a result they are highly successful invaders and can be sadly very disruptive to ecosystems.

This mosaic has been commissioned in celebration of our centuries old relationship with the river. Local artist Josie Webber has created designs featuring native species nominated by local residents, and incorporating pottery fragments found in West Oxford. The marker stones will form part of a human sundial to be installed on the site. This project has been made possible thanks to the support of the National Lottery Heritage Fund.mosaic1_white

The sundial takes shape

Members of the OLH team met recently with artist Josie Webber, and our local sundial technical adviser Greg Birdseye, to work out the final layout of the sundial at the Osney Lock Hydro site.  It was eleven am when we met in case you were wondering, although as no one was standing on the proposed location the centre board, you can’t tell from our shadows if our calculations are correct….

Thanks as ever to the National Lottery Heritage Fund, without whom this project would not have been possible

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Sundial spotlight: The Grey Heron

The Grey Heron

Osney Lock Hydro has commissioned a mosaic in celebration of our centuries old relationship with the river. Local artist Josie Webber has created designs featuring native species nominated by local residents, and incorporating pottery fragments found in West Oxford. The marker stones will form part of a human sundial to be installed on the site. This project has been made possible thanks to the support of the National Lottery Heritage Fund.mosaic1_white

Each month we’ll shine a spotlight onto one of the species featured in the mosaic, thanks to a series of blogs written by local residents.

The first in the series is by Jenny Figueiredo and celebrates the Grey Heron.

The stately and solitary Grey Heron (Ardea Cinerea) is one of the UK’s biggest and most unmistakable birds, and is a familiar sight to Osney residents. They are graceful and gangly in equal measure, with long legs, long beak and grey, black and white feathers.  

Herons feed mainly on fish, but also eat waterbirds, crayfish and small mammals – even moles. They don’t migrate, and so can be seen at any time of year looking for food in rivers, lakes and even garden ponds.  If you see a heron standing in a field, it is probably digesting rather than hunting, because they sometimes eat very large prey such as eels, which can take a long time to go down.  

heron-4353038_1920Herons nest in colonies called ‘heronries’, often in the tops of trees. Here, they make their large and slightly clumsy nests out of twigs and lay 3-4 eggs. The young will fledge from the nest after about one and a half months. 

Herons have special feathers on their breast called ‘powder down’, which they crush with their feet and spread over themselves to keep clean. The powder soaks up the muck and grime from their feathers, and also helps to keep them waterproof. 

Despite this cleanliness, anglers once believed that herons’ feet gave off a scent that attracted fish, and often carried a heron’s foot to bring them luck (although not much luck for the poor heron). Once a regular dish on the medieval banqueting table, the heron is now thankfully a protected species under the Wildlife and Countryside Act 1981, with hefty fines or prison sentences awaiting anyone attempting to kill one. 

Osney Island’s very own resident heron can often be found under the footbridge to the island, staring intently into the water for his next meal.  His name is Eddie, and he even has his own Facebook profile – search for Eddie Heron and send him a friend request.TNLHLF_Colour_Logo_English_RGB_0_0