Sampling dormant bryozoan from lake mud! – a field trip around the Broads 12th-15th March 2015

The Lake BESS team has just spent four full days on the water to collect bryozoans statoblasts from 14 different Norfolk broads. You will find more information about our work on bryozoans in this previous post.

The aim of this sampling is to gather evidence regarding how connectivity between lakes influences the movement of aquatic biodiversity, in particular bryozoan population genetics.

We were extremely privileged to be shown around by Geoff Philips, who greatly facilitated this field work with his knowledge of the area and of the people managing The Broads – at the Broads Authority, the Norfolk Wildlife trust, etc.

Last summer, we collected similar samples from the Upper Lough Erne region, Northern Ireland. With this trip in the Broads we completed the sampling of bryozoans for our project. We used an Ekman grab from our boat to retrieve lake surface sediment, i.e. oozy mud.

We collected bags and bags of oozy mud, from which we are isolating the tiny bryozoans statoblast (less a 1 mm!), from which DNA will be extracted.

But collecting the mud is only the first step of the sampling. Back on the shore, our bryozoans expert Beth screened the sediments through a microscope to pick out individuals statoblasts (the dormant phase of bryozoans measuring less than 1 mm in diameter). These individual statoblasts are going to be sent off for their DNA to be extracted.

We are expecting to find out that isolated broads have bryozoans population with more distinct genetics than those from broads connected to the river systems. But we are really not sure how the gene flow within the Broads will compare with that experienced within the Upper Lough Erne region, so we are looking forward to get our results – and we are hope to be surprised!

Many thanks for the many people who helped making this sampling possible!

Ponds and aquatic plants near Catcliffe and Treeton, East of Sheffield, UK

Last August, I was fortunate to be shown several ponds near Catcliffe and Treeton, East of Sheffield, UK, by Bob Croxton, form Sorby Natural History Society. The area is full of history and is a fascinating example of nature recovering following industrialisation.OLYMPUS DIGITAL CAMERAFor instance, one of the ponds visited was formed in a lost piece of land amongst spoil heaps and three railway line! At this site Persicaria maculata and Nymphoides peltata were in full bloom (see picture) and two Potamogeton species were observed, now confirmed as P. pectinatus and P. pusillus. However only one shore was prospected and other nice aquatic plants are likely to be present in the rest of the pond.

On the whole, too many of the water bodies in the area were absolutely dominated by Elodea nuttallii, an invasive species that colonised the UK from the 1970s. It’s phenomenal spread in Britain and Ireland is summarised in a paper by Simpson that can be read from the BSBI archives. It remains unclear whether this spread has caused arm to aquatic biodiversity or whether it was simply facilitated by degraded habitats.

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Persicaria amphibia (amphibious bistort) in full bloom! East Sheffield, UK

Back from the field!

We’re just back from our very successful field work around the Upper Lough Erne, Co. Fermanagh, Northern Ireland. We managed to survey nearly 20 satellite loughs for aquatic plants, water chemistry and bryozoans (see this previous post).

Corracoach Lough
Access to some of the lough was sometimes tough but always rewarding. Photography by Helen Bennion.

The help we received from volunteers and project partners was absolutely tremendous! Over the two week we have been a dozen of us actively involved in this research campaign. We’d particularly like to thank Hannah, Robert, Tim and Stephen for joining our team at this occasion and also all the land owners who were kind enough to grant us access to the lakes we had targeted.

Battling through reed beds to get onto some of the lough with our boats was one of the striking aspects of this field work! But it was worth the effort and the diversity of aquatic plant observed over the two week is very impressive. For instance we have sightings for at least ten different Potamogeton species (see this previous post), an extremely good score!

We’ll post more picture and reports from this field work in the coming weeks.

P. perfoliatus
Potamogeton perfoliatus (Photograph by Ben Goldsmith)

Rediscovery of Festuca altissima in Sheffield, UK

The little article below is to be published in the next Sorby Record, Sheffield.

“As a contribution to the South-west Yorkshire (v.c. 63) Vascular Plant Red Data List, a population of Festuca altissima (wood fescue) was re-found at Forge Dam in the Porter Brook Valley, Sheffield, UK.

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A plant of wood fescue hiding among wood mercury at Forge Dam, Sheffield, UK

This population was first observed in 1991, when it was seen on “On steep shady bank by path” by Ian Rotherham with the grid reference SK303849. This record for F. altissima had remained overlooked by O. Gilbert who completed ecological work in the valley (Gilbert, 2001; 2003) as well as during the field recording undertaken in the area for the South Yorkshire Plant Atlas by Wilmore et al. (2010)(Ken Balkow, personal communication, 2013).

F. altissima is a rare grass in South-west Yorkshire where it is only know from four other sites, one in the same valley, two in the Sheffield area and one between Sheffield and Barnsley (Wilmore et al 2010).

It is not rare nationally but restricted in distribution by its narrow ecological preferences. It grows exclusively on steep slopes in shaded valleys on neutral to mildly alkaline soils and is believed to regenerate very slowly, i.e. to be sensitive to mechanical disturbance (Cope and Gray, 2009; Richards, 2013).

The Porter Dam population is located in or adjacent to SK30378492, on the South bank of the Porter Brook. There are approximately 40 individual plants, large and small, suggesting a healthy and dynamic population but, unfortunately, there is no indication of abundance associated with the 1991 record and as a consequence, it is not possible to ascertain any population dynamic through time.

The 40 plants are split equally into two groups by a large specimen of Prunus laurocerasus (Cherry Laurel) and there is no regeneration under the canopy of this shrub. Cherry Laurel appears to increasingly encroach this bank of the river, potentially threatening the local population of F. altissima.

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The volunteers of the Friends of Porter Valley have now cleared some of the cherry laurel so the wood fescue can re-colonise parts of its habitat

In order to minimise the risk of extinction for this localised population, I contacted the concerned environmental stakeholders, the Sheffield City Council Ecology Unit and the Friends of Porter Valley. As a result the Friends of Porter Valley have volunteered to cut back the encroaching Cherry Laurel and monitoring will be undertaken in the coming years by myself.

The rest of the valley has not been searched for systematically for other populations of F. altissima and it cannot be excluded that other locality will be found in the future. The picture below shows the vegetative diagnostic character for the identification of F. altissima. These reduced leaf blades called cataphylls are of variable length and can be observed towards the base of the stem. Please refer to Cope and Gray (2009) or to Hubbart (1986) for a full description of the plant.

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The diagnostic cataphyll of Festuca altissima.

I am very grateful to John Poland, BSBI (Botanical Society of Britain and Ireland) referee for vegetative identifications, to confirm the identification of the plant material sent and to Ziggy Senkar and Ann Le Sage for taking interest in this botanical findings.

References cited in the text:

Cope, T. & Gray, A. (2009) Grasses of the British Isles, BSBI Handbook no. 13, Botanical Society of the British Isles.

Gilbert, O.L. (2001). Ecological survey of the Porter Valley. Sheffield : Friends of the Porter Valley.

Gilbert, O.L. (2003). Plants in the Porter Valley and their Ecology. Sheffield : Friends of the Porter Valley.

Hubbard, C.E. (1954) Grasses, Penguin: Middlesex.

Richards, A.J. (2013). Species account: Festuca altissima. Botanical Society of the British isles, www.bsbi.org.uk.

Wilmore, G.T.D., Lunn, J., Rodwell, J.S. (eds.) (2011). South Yorkshire plant atlas. Yorkshire Naturalists’ Union.”

Pondweeds

Pondweeds

The islands of Britain and Ireland have over 40 species or hybrids of pondweeds (genus Potamogeton). This diversity in pondweed is one of the highest in Europe with most European species being represented. Unfortunately local diversity and abundance of pondweeds have declined over the 20th Century, as a result of habitat destruction and pollution. The Upper Lough Erne region and The Broads are two areas of importance for the conservation of pondweed – but “what can we learn from these strongholds?” and “what measure could enhance their recovery nationally?” are questions we are trying to address part of the Lake BESS project. (Photo by Ambroise Baker: P. polygonifolius in full bloom).

Fissidens rivularis

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Tom Ottley brought us to Old Roar Ghyll, in the middle of Hastings, Sussex, UK, during the British Bryological Society spring meeting in April 2014 and showed this beautiful and rare species of Pocket-moss. The ghyll had many more unusual species especially on the sandstone rock faces with dripping water.

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LakeBESS start-up

Lakes are inspirational places for people enjoying outdoor activities and they are cherished by local communities and holiday-makers alike. However, lake ecosystems are threatened by environmental change and loss of biodiversity that can have cascading and catastrophic effects.

The LakeBESS project, run from the Environmental Change Research Centre (ECRC) at UCL, is focussed on two lake districts, the Broads in East Anglia and the Upper Lough Erne district in Northern Ireland.

debarcadaireWe are looking into how biodiversity regulates ecological balance within lakes and would like to assess the consequences of biodiversity loss for the provision of ecosystem services. Ecosystem services from lakes are extremely diverse: recreation, tourism, water purification, flood prevention, provision of fish for anglers and fisheries and other supporting services such as carbon storage for climate mitigation.

Because of this variety, changes in lake ecological functioning may affect the different services in different ways, rendering best practices for restoration and management difficult to establish.

One aspect we are particularly interested to develop in LakeBESS is the importance of ecological connectivity between lakes for their biodiversity. Connectivity may be a major factor determining lake ecosystem resilience because it counter-balances the negative effect of local extinction by increasing species re-colonisation.

Another aspect of interest is the consequences of biological invasions by organisms such as zebra mussel and Canadian pondweed.

We have just started this project as part of the Biodiveristy, Ecosystem Services and Sustainablility (BESS) research programme funded by the UK Natural Environment Research Council (NERC).

Our team is composed of Carl Sayer, Helen Bennion, Jorge Salgado and Ambroise Baker at UCL, Tom Davidson at the University of Aarhus (Denmark), Beth Okamura at the Natural History Museum and Nigel Willby at Stirling University. We are looking forward to a field campaign this summer and to presenting the result of our work to the numerous stakeholders in both lake districts.

We also would love to hear your take on how changes in lakes, or in a particular lake, can affect people’s lives.