PROGRESS WITH THE EDCAT PROGRAMME

1
PROGRESS WITH THE EDCAT PROGRAMME RISKS OF
OESTROGENS FOR FISH POPULATIONS
Peter Matthiessen, Jan Balaam, Andrew Johnson,
Ioanna Katsiadaki, Tom Pottinger, Jim Readman,
John Sumpter, Charles Tyler and John Zhou
Centre for Ecology and Hydrology (CEH), UK
Centre for Environment, Fisheries and Aquaculture
Science (Cefas), UK Plymouth Marine
Laboratory (PML), UK Brunel University, UK
University of Exeter, UK University of Sussex

• ABSTRACT
• During its first year, EDCAT (Endocrine
  Disruption in Catchments) has shown that-
• Modelled oestrogen concentrations in the River
  Ray are similar to measured values at some times
  of year
• 2) However, in vitro oestrogenic activity and
  steroid concentrations in water are very
  variable, with highest activity just downstream
  of the STW discharge during October 2006
• 3) To date, stickleback (Gasterosteus aculeatus)
  populations have only shown minor vitellogenin
  (VTG) responses to oestrogens, but this may be
  due to the transience of exposure and to the lack
  of fish sampling during October.
• 4) Breeding experiments with roach (Rutilus
  rutilus) in semi-natural spawning groups have
  shown that weakly intersex fish are as successful
  as normal fish in fathering offspring
• 5) During 2007, we are aiming to improve our
  exposure modelling in order to correctly reflect
  seasonal and spatial variation, to continue
  studies of stickleback populations to establish
  true oestrogen exposure and populations
  variables, and to conduct further breeding
  experiments to assess the effects of intersex in
  more severely affected roach.

• INTRODUCTION
• Fish populations in many UK lowland rivers and
  estuaries are feminised (vitellogenin, ovotestis,
  feminised gonoducts, and/or feminised secondary
  sexual characteristics in males)
• The EDCAT programme is testing the hypothesis
  that oestrogen contamination in these rivers is a
  risk to fish populations.
• EDCAT (Endocrine Disruption in Catchments) is a
  multi-funder, multi-institute 6 year (Phases 1
  and 2) programme which is studying the River Ray
  in the United Kingdom. Current work is
  establishing the baseline situation prior to
  oestrogen removal from the Swindon (Rodbourne)
  sewage treatment works (STW) discharge.

Predicted E2-equivalent concentrations (ng/l) in
the River Ray throughout the year, at a range of
distances (1-13 km) downstream of the Rodbourne
STW discharge

• MODELLING AND EXPOSURE MEASUREMENTS
• EXAMS modelling of E1, E2 and EE2 in the R. Ray
  (see near right) predicts highest E2 equivalent
  concentrations (11 ng/l) immediately downstream
  of the STW discharge in summer.
• Predicted activity is higher than time-averaged
  values measured in spring with the Yeast Estrogen
  Screen (YES) (see far right), but similar to
  those measured in autumn. Most activity is
  attributable to estrone (E1), oestradiol (E2) and
  ethinylestradiol (EE2)
• To improve predictions, the model will be
  further developed, and re-run using measured
  values for discharge rates, river flow-rates, and
  biodegradation rates

E2-equivalent concentrations (ng/l) in the River
Ray at 5 sites and 4 sampling dates. Each
concentration represents a value time-averaged
over a month using POCIS passive samplers and
assay of POCIS extracts with the Yeast Estrogen
Screen (YES)
Reproductive success of freely-breeding male
roach from the River Bourne. The degree of
intersex was mild (intersex index up to 3.2), and
there was no difference between the success of
mildly intersex fish and normal males.

• FISH STUDIES
• The stickleback populations in the R. Ray are
  being monitored for their demographic
  characteristics. To date, plasma and whole-body
  VTG levels in males are low (see far left), but
  samples were not taken in October at the time of
  highest E2-equivalent activity.
• We have identified 6 variable DNA
  micro-satellites in roach that have been
  successfully used to identify the parentage of
  fry produced in freely-breeding spawning groups
  in the laboratory
• In the first breeding experiment, using fish
  from the R. Bourne, there was no difference in
  the breeding success of intersex and normal males
  (see near left). However, the intersex fish were
  only mildly abnormal (intersex indices up to
  3.2), and further experiments are now being
  performed with more severely affected fish

Male VTG levels in sticklebacks from the R. Ray
and the reference site (R. Ock)

• DISCUSSION AND CONCLUSIONS
• Model predictions of E2-equivalent
  concentrations in the Ray are in the right range,
  but do not yet reflect the fact that the level of
  oestrogenic activity is very variable, both
  between sites and between seasons. We intend to
  improve this situation by developing the model
  further, and by using more realistic input data
  for sewage and stream flow rates etc.
• Although oestrogenic activity in October 2006
  was high enough to produce a vitellogenin
  response in stickleback, little response was seen
  in samples taken earlier in the year. We
  therefore propose to coordinate the chemical and
  biological sampling more closely in the coming
  year. The degree of contamination in October
  should have been high enough to produce effects
  on sticklebacks, but it remains to be seen if
  reproduction, and ultimately population
  demographics, are indeed affected.
• We have developed a set of robust DNA
  microsatellite markers for identifying parentage
  in roach fry, allowing the reproductive success
  of freely-breeding male fish to be accurately
  assessed. An initial experiment, in which mildly
  intersex fish were allowed to compete with normal
  fish, showed no differences in reproductive
  success. We are now conducting further breeding
  experiments using roach populations containing
  more strongly intersex individuals.
• Overall, EDCAT is on target to establish
  baseline conditions in the River Ray before the
  Rodbourne STW is upgraded in 2008/09 to remove
  oestrogens.

EDCAT sponsors UK Department for Environment,
Fisheries and Rural Affairs (Defra) Environment
Agency of England and Wales (EA) United Kingdom
Water Industry Research Ltd (UKWIR)
For more information, please see the EDCAT
website www.ceh.ac.uk/edcat or contact Peter
Matthiessen, the programme leader
peter_at_matthiessen.freeserve.co.uk