offered by most of the Forest ponds have proved tolerable, if not ideal, for most of these fish that can
withstand low levels of dissolved oxygen. The Crucian Carp is perhaps the most tolerant of these
conditions and has been captured in the dense root mass of Typha beds in a few inches of very muddy
water in winter (Fairmead Bottom Pond. November, 1989).
Several other fishes have been introduced by persons releasing fish from garden ponds or aquaria.
This accounts for the presence of Goldfish in many ponds, the Golden Orfe, the two records of the
Pumpkinseed and Koi.
Although a number of species are well established, their numbers often fluctuate in the ponds. In
the case of the Stickleback, seasonal mortality has already been referred to, but other fluctuations may
be due to parasitic infestation. In the 1950s these fish in Blackweir Pond were extremely common,
but later they suffered an almost 100% infestation by the cestode Schistocephalus solidus (Muller)
and declined greatly in numbers. Sticklebacks in the pond on Theydon Green were also abundant in
the 1960s but suffered from heavy parasitization by the fish louse Argutus foliaceus (L.), after which
they became much less common. In the case of the Gudgeon and Perch, which were common in
Connaught Water in the 1940s and are now much rarer, no certain explanation can be advanced to
account for the change. These variations do, however, show that there are natural fluctuations in fish
numbers, some of which may simply be related to vegetational succession and eutrophication in the
ponds concerned.
Because the catchment area for many of the Forest ponds is primarily woodland, pollution such as
that from agricultural run-off or spray-drift has never been a problem, as it can be in other areas.
However, the Forest trees do create the problem of excessive leaf fall into the ponds, the decay of
which depletes oxygen supply in the water and can ultimately create substances toxic to fish. Leaves,
particularly in some of the smaller ponds, can accelerate the process of infilling and drying out of the
ponds, again making them unsuitable for fish. Some of the ponds very close to roads, such as the
Wake Valley pond and the Whipps Cross Pond, may suffer from the run-off of pollutants originating
from cars using the adjacent road, and possibly from the road salt in winter; the possible effects of
these substances need to be investigated. One notable exception to the general lack of pollution from
external sources has been the Ornamental Water in Wanstead Park. The 183 acres of woodland,
grassland and lakes was added to the Forest in 1882. The Ornamental Water at this time was often
polluted with sewage from the River Roding, the principal source of water for the lake. The
Ornamental Water, despite its 15 acres of open water, in the early 1970s was thought to be devoid of
fish (Addison). Analysis of water samples failed to reveal any specific cause for this, but eventually
it was suggested that silting up and excessive leaf fall into the pond were causing the impoverishment
of fish life, as well as possible pollution from the Roding. As a result, in 1972 a scheme was initiated
to clear silt from the pond, clear tree growth from the margins and to only pump water from the Roding
when it was safe to do so. Today (1991) the Ornamental Water has a flourishing fish population.
Species recorded from here include Common and Crucian Carp, Pike, Roach and Tench.
Acknowledgements
I am grateful to Mrs. C. Gocke and Mr. P. M. Cooper, Department of Library Services, The Natural
History Museum, and Mr. Kevin Clifford for finding obscure literary references. Mr. G. Seddon,
Curator of the Queen Elizabeth Hunting Lodge Museum, confirmed details of the cased specimens
of Carp in the Museum; Mr. G. Rutter and Mr. N. Sanderson (E.F.C.C.) reported fish caught in several
ponds. Mrs. Georgina Green provided information on the history of Forest ponds. Mr. P. A. Moxey,
Warden and Director of Studies of the Epping Forest Conservation Centre, provided facilities and
space at the Centre. I also thank Mrs. Carol Boyce-Mears for typing this note.
References
Addison, W. (n.d.) Wanstead Park. Corporarion of London
Harris. M. T. (Ms) A study of the helminth parasites of fishes from a pond in Essex. (Copy in E.F.C.C. Library)
Qvist, A. (1958) Epping Forest. Corporation of London. 43 pp.
Ward, B.T.( 1951) A giant carp at Chingford. Essex Naturalist. Vol. XXV1I1: 299.
Wheeler, A. (1958) The fishes of the London Area. London Naturalist (1957): 80-101.
Wheeler, A. (1990) The population of three-spined sticklebacks Gasterosteus aculcatus in an Epping Forest pond. London Naturalist. 69:
77-78.
Wheeler. A. (1991) Carr formation and vegetation zones at Baldwins Pond, Epping Forest. London Naturalist (in press).
154