Wildlife and Conservation Review of 2000
Another winter task is to prepare and disseminate the results of previous survey work. The BTO
published the results of its 1999 Nightingale survey in January, comparing the results with the
previous survey of 1980. Overall, there was a contraction in its distribution towards the south-east,
but an increase in numbers (possibly attributable to better recording) in the core counties, from
Norfolk to Sussex, which now hold more than three-quarters of the UK breeding population. In
Essex, the number of recorded territories rose from 263 to 402, arise of 55%, amounting to nearly
10% of the total number.
Less positively, a Plantlife report drew attention to the threats to native plants arising from the
invasion of alien species. This is most noticeable in aquatic environments, with ongoing increases
in Swamp Stonecrop and Floating Pennywort, to give just two examples. One approach to dealing
with plant invaders is the application of herbicide, although this is particularly sensitive in waterside
locations. And even in terrestrial habitats, alarm bells started to ring, in particular over the use of
glyphosate (marketed as Roundup). This has long been considered a 'safe' herbicide, with low
toxicity to animals and little persistence as it was believed to break down rapidly in contact with soil.
Not so, according to new research; nitrogen-fixing bacteria, mycorrhizal fungi and beneficial insects
such as ladybirds have been shown to be more susceptible to glyphosate than previously believed; it
is more persistent in agricultural soils than hitherto realised, with a half-life of up to 140 days;
residues are detectable in crops to which it is applied; and resistance is developing in some target
species. Such findings have considerable relevance to the ongoing debate about the commercial
release of Genetically Modified crops, several of which are modified specifically to be resistant to
such herbicides.
Worse news was to come for Essex. When the Environment Agency announced the results of its
survey of our salt marshes, comparing aerial images in 1998 with those from 1988, there was no
indication that the previously recorded high rates of erosion between 1973 and 1988 were slowing.
The pattern of erosion seems to have shifted slightly, with Hamford Water performing worst in the
recent period, compared with the Stour in the former period. But the big picture is that Essex is
losing around 40 hectares of salt marsh each and every year to erosion, the result of relative
sea-level rise. This represents 1% of the 1973 area being lost every year, despite the implementation
in recent years of managed realignment schemes, allowing the sea to reclaim low-lying coastal
lands. Clearly we need to do a lot more of such realignment if we are to produce a sustainable
coastline, with gains balancing the losses, irrespective of the need to restore historic losses. So it is
particularly pleasing to report the purchase in January of Abbotts Hall farm at Great Wigborough
by the Essex Wildlife Trust. This 280 hectare holding, costing a reported £2.3 million, will allow a
considerable area of new salt marsh to be created, as well as providing a showpiece farm for EWT
to demonstrate the benefits of environmentally-friendly farming. Sadly, it came just too late for
inclusion in a new English Nature publication The Essex Coast beyond 2000, which extols the
virtues of our coastline and its wildlife, and highlights the important steps needed to secure its long-
term future.
Spring
As with 1999, March proved to be a mild (1.5°C above average) and dry (50% of average) month,
raising hopes of a long hot summer. Sadly it was not to be, and by the end of the month we were
plunged into wet, unsettled conditions, which persisted, if we are honest, almost continuously to
the end of the year and beyond. Nevertheless, March was lovely: a strong emergence of wintering
butterflies was complemented by Chiffchaffs in song across the county from the second week,
possibly singing overwinterers rather than new migrants. At least three records turned up - from
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Essex Naturalist (New Series) 18 (2001)