Prof Steve Ormerod - MSc, PhD, FIEEM
Photo of the Himalayan Mountains.
I first came to Cardiff in 1980 for the UWIST MSc in Applied Hydrobiology, from there completing a PhD on interactions between hydrochemistry and community invertebrate ecology in the Wye river-system. Simultaneously, I developed an interest in the ecology of river birds, showing for the first time how this group was affected by acid rain. These major themes — freshwaters, invertebrates and birds in aquatic habitats — have continued to provide my major research models.
Field work on the Tibetan Plateau, 1999.
From 1984, I led a post-doctoral group investigating the ecological effects of surface-water acidification using surveys, models and a series of ecosystem-scale experiments that have now run for over 25 years. That group became the current Catchment Research Group, applying the same blend of methods to large-scale ecological problems in the UK, the Himalayan Mountains, the Andes and mainland Europe. Under my leadership, and since its formation in 1988, the group’s research income now approaches £2 million, and over 200 scientific papers have been produced.
Complementing the perspectives of other members of the Biodiversity and Ecological Processes Group, my research is explicitly ecological. Unified by the theme of ecosystem-scale dynamics in rivers and wetlands, activities focus on:
1. Ecosystem quality and the distribution of aquatic organisms
Photo of the common toad.
This theme links the use of aquatic organisms as bio-indicators of freshwater quality with research to understand the ecological processes affecting assemblage composition and species pattern.
Current projects examine factors affecting globally endangered molluscs; zooplankton ecology in an artificial lake (Cardiff Bay; Faye Merrix); the ecological consequences of lake invasion by exotic bivalves (Muriel Alix), and the development of biodiagnostic tools to assess sedimentation effects in rivers (Stefano Larsen). A significant project led by Dr Ian Vaughan is appraising interactions between river hydrogeomorphology and the distribution of river organisms, with support from a PhD studentship on the importance of habitat complexity (Jacqui Platt). Links between river geomorphology and endangered coleopterans are being investigated in a project co-supervised by Dr Hefin Jones and involving the Brecon Beacons National Park. (Paul Sinnadurai).
2. The ecology of surface water acidification and recovery
Catchment liming ameliorates acidity.....
... but places some wetland organisms at risk.
Research into the causes, consequences and mitigation of surface water acidification has formed a long-term theme, moving more recently to an assessment of factors affecting biological recovery. Working in the experimental catchments at Llyn Brianne and elsewhere in Britain and Europe, recent work revealed the pivotal importance of episodic acidification and continued metal mobilisation as major constraints (Kowalik et al. 2007). Recovery experiments established in replicate catchments in 1981 are continuing, but increasingly providing information on other long-term problems such as climate change (see below). An ongoing project with CEH Bangor and the National Museum, Wales, is examining acidification and its management in the Wye Special Area of Conservation (Dr Esther Clews).
3. The ecology of river and wetland birds
Checking the contents of a Dipper nest (Photo by Andrew Lucas).
White-throated dipper, Morocco.
Long-term studies on the dipper Cinclus cinclus and Grey Wagtail Motacilla cinerea have shown how these contrasting species respond to variations in river quality. The work on the dipper provided the first ever evidence that birds were affected adversely by acidification (Ormerod et al. 1985), with the causal mechanisms now clear. The concept of using dippers as indicators of acidity led to studies also of their role as indicators of river contamination by xenobiotic compounds. These themes – resource scarcity during egg formation and contaminant acquisition – are now being linked by Dr Christy Morrissey in a Royal Society Fellowship in which Cinclus cinclus and Cinclus mexicanus both figure.
4. Climatic effects on upland river ecosystems
Storm event in a mountain river, Nepal.
The Middle Hills and Langtang Himal, Nepal.
Long-term data collected in the Llyn Brianne experimental catchments (1981-2005) recently showed that climate has had surprising and major effects on the abundance and assemblage composition of stream invertebrates (Bradley & Ormerod 2001; Durance & Ormerod 2007). Work led by Dr Isabelle Durance is now attempting to identify and model the processes involved, to identify the organisms at risk, and to assess the likely biological outcomes. Parallel studies on northern (Prince Project), southern (Theres project) and eastern rivers (Max Carstairs) continue these investigations. New work is investigating stream-scale resistance to climatic effects, and drawing lessons for adaptive management. In collaboration with Cardiff School of Engineering (Dr Catherine Wilson), flume experiments are being used to assess hydraulic effects on aquatic invertebrates under varying flow conditions (Laura Trodden).
Current and recent sponsors of work by the Catchment Research Group include:
The Royal Society
Natural Environment Research Council
Swiss Foundation for Scientific Research
The Welsh Assembly
The Environment Agency
Freshwater Biological Association
Royal Geographical Society
National Geographic Society (USA)
National Museum of Wales
SMEs (Shawater Ltd, Ambient Hydro, APEM Ltd, ENSIS Ltd, Cascade Consulting)
Wye and Usk Foundation
Scottish Environmental Protection Agency
Cardiff City Council
Affiliated Staff and Students
Current Group Members
Dr Ian Vaughan (RCUK Fellow)
Hydrogeomorphology and the distribution of river organisms
Dr Christy Morrissey (Royal Society Incoming Fellow)
Nutrient sources and contaminant acquisition in river birds
Dr Isabelle Durance (NERC/Daphne Jackson Trust Fellow)
Climatic effects on headwater stream ecological function
Dr Esther Clews (Wye and Usk Foundation)
The effects of hydrochemical restoration on river organisms
Low flow effects on lowland stream organisms
Faye Merrix (Cardiff City Council; Jointly supervised by Dr Steve Thackaeray, CEH Lancaster)
Zooplankton ecology in Cardiff Bay
Stefano Larsen (Wye and Usk Foundation)
Effects of sediment deposition on upland stream organisms
(Cardiff School of Engineering; jointly supervised with Dr Catherine Wilson)
Climate change, stream hydraulics and stream invertebrates
Muriel Alix (Cardiff City Council)
The ecology of invasive zebra mussels in Cardiff Bay
(NERC; joint supervision with Dr Ian Vaughan)
Habitat complexity and river biodiversity
Paul Sinnadurai (Jointly supervised with Dr Hefin Jones) Dispersal and distribution in riparian Coleoptera
Successful past PhD students include:
Dr Seb Buckton
The ecology of Himalayan River Birds
Dr Richard Jenkins
The ecology of Water Rail Rallus aquaticus
Dr Heike Hirst
Ecological influences on diatom responses to water quality
Dr Hem Sagar Bharal (Joint with the University of Amsterdam)
Community structure and habitat associations of lowland grassland birds of Nepal.
Dr Zoe Masters (FBA/Cardiff University Ray Beverton Memorial Studentship)
The effects of geographical isolation on stream recovery from acidification
Dr Dave Bradley (PhD studentship funded by Defra)
Dynamic processes in acid senstitive streams
Dr Alisa Watson (NERC CASE studentship with WWT)
The ecology of two scarce molluscs
Dr Liz Chadwick (Cardiff University/Llysdinam Trust; co-supervised with Dr Fred Slater)
The influence of climatic variation on the ecology of common toads
Dr Fabio Lepori (PhD studentship funded by the Swiss Foundation for Scientific Research)
The ecological effects of acid episodes in the Swiss Italian Alps
Dr H. Ceri Williams (NERC studentship; co-supervised with Prof Mike Bruford)
Dispersal and genetic variation in Baetis mayflies
Dr Ian Vaughan (PhD Studentship funded by the Environment Agency)
Modelling the distribution of river birds using habitat data
Dr Renata Kowalik (PhD studentship funded by Defra)
Detecting and modelling the effects of acid episodes on stream fauna
Dr Emma Durward (Cardiff University/Llysdinam Trust; co-supervised with Dr Fred Slater)
Dr Beth Lewis (Wye and Usk Foundation; co-supervised with Dr Brian Reynbolds, CEH Bangor)
The effects of liming on invertebrate recovery from acidification
(NERC; jointly supervised with Dr Sian Griffiths)
Behavioural avoidance and sheltering behaviour of salmonids during acid episodes