This week we are fortunate to have a guest blog from Richard Mason - Site Manager for the RSPB's Sutton Fen reserve. I say fortunate but, as you will read, the neighbouring Catfield Fen - which we manage on behalf of Butterfly Conservation - is under threat and Sutton Fen could be affected too. Read on and find out how you can help save the Jewel of the Broads....

I have worked in the Ant valley fens for five years managing our Sutton Fen nature reserve. I am often told by colleagues from our headquarters that of the RSPBs 210 reserves, Sutton Fen is right up at the top of the list amongst iconic places like Minsmere, Abernethy and Dungeness for the conservation importance and sheer diversity it supports. I am proud to look after such a place and I feel great reward from our achievements. Alongside many other successes cranes have returned to breed, we have seen the most swallowtails of any site in the UK for 4 years running and all 7 of our rarest plants have increased. I know that the work we do here makes a difference - every early morning and every hard day’s work by the volunteers helps to improve the site for nature.

Sutton Fen  - Photo by Ben Hall (rspb-images.com)

Four years ago, Butterfly Conservation approached us to ask if we would like to help them manage their nearby reserve at Catfield Fen. Part of the same SSSI and with a very similar suite of species, we jumped at the chance. I became aware of the local abstractions in 2010 when I flagged my own concern about dropping water levels at Sutton Fen. Through our own surveys and consultation with expert hydrologists and ecologists, we now realise that there is already a huge problem at Catfield Fen and that Sutton Fen may also be at risk in the longer term. Changes of pH and possibly water level are fundamentally changing the ecology of Catfield Fen, gradually eating away at the diversity. Worryingly, many now think that further damage will be irreparable.

The process is complicated, but the theory is that abstraction of ground water is reducing the amount of alkaline water reaching Catfield; this not only threatens a reduction in water level, but shifts the balance of pH, leaving a disproportionately high level of acidic water (largely from rain and run-off) behind. This acid water is good for a few species, such as the Sphagnum moss, sundew and crested buckler fern, but cannot be tolerated by the majority of both common and rare fenland plants. Milk parsley, fen orchid, greater water parsnip, cowbane are all red data book plants and are all being affected by surface acidification. These changes have a knock on impact on the sites exceptional invertebrate fauna, certainly one of the UK’s most important sites for moths, water beetles and water bugs. There are species that when found at Catfield, they were new to science. Catfield has the highest possible level of environmental protection for a reason, it is an exceptional place for nature and currently that nature is under imminent threat of irreparable damage.

Five years after moving to Sutton Fen, I get a great buzz when I walk around the reserve, it is flourishing, I know that the reserve is healthier as a result of our hard work. Four years after starting work at Catfield Fen, whenever I visit that site I feel disappointed that despite our great efforts, there is little we can do to halt the changes brought about by an outside influence - we continue to do our all, but it is not within our control. However, I am reassured that there is a groundswell building that the abstractions that may be causing the changes should not be renewed, if they are stopped then I know that over time we can repair the damage at Catfield and make it flourish once again.

You can help us make Catfield Fen flourish again by writing to the Environment Agency as they are now consulting on whether to renew two licenses adjacent to Catfield Fen. Follow the link to go straight to our briefing which will give you all the background information and key points you need to help save this unique Fen for future generations to enjoy.

Catfield Fen Briefing