The first snail of Spring
The first daffodils bloomed on 1st January in my garden, but the snails
Cantareus (Helix aspersa as was) under the ivy
were deep in hibernation in mid-February and look unlikely to emerge
any earlier than normal. The mild winter could be more serious for hibernating
bats and hedgehogs if their fat reserves run out before there are enough
invertebrates to feed on.
The obvious consequences of climate change are to length of growing
seasons and times of breeding, migration and flowering. There will be
major consequences for species ranges, for farmers' choice of agricultural
crops, and an alteration to the balance between crop pests and biocontrol
agents. The range of parasites may also change - the snail hosts of
human blood fluke may find areas of Europe, Asia and the Americas more
to their liking while parts of Africa become too hot. If Southern Ocean
temperatures increase two degrees further, locomotion of marine molluscs
will be impaired,. Moreover, the landmass of Antarctica is a barrier
to their poleward migration.
Secondary effects include increased precipitation and cloud cover, thawing
of glaciers and permafrost, more frequent fires, sea levels rising 1-2
mm per year, and the increasing frequency and intensity of extreme events
such as storm surges, leading to flooding of low lying areas and coastal
erosion. The seas have absorbed 50% of carbon dioxide produced by human
activities in the last 200 y, but by the end of this century, pH is
predicted to fall from 8.2 to 7.7, causing problems in shell formation
for molluscs and crustaceans - and for plankters such as coccolithophores,
which form a literal carbon sink as their shells fall to the sea bed.
The changes in the next few decades are the unstoppable consequences
of our past and present activities. Although events such as climate
change may be regarded as having the inevitability of gradualness, they
are fast enough that we can see the effects over a generation, as species
ranges drift northward at 6 Km per decade and migration, flowering and
egg-laying advance by 2-3 days per decade.
I am grateful to all, especially Villie Flari and Laurence Cook, who
have contributed material for this issue. Please send contributions
for the next (August) issue to me by mid-July. Contributions of articles,
brief reviews, and news items (including items from non-malacological
journals) are especially welcome. Please keep articles and abstracts
'as short as possible but as long as necessary' and avoid or explain
specialist terms. Where appropriate, include a reference to a more detailed
account, and an illustration.
Bill Bailey
Dr S E R Bailey
Faculty of Life Sciences, 3.614 Stopford Building, University of Manchester,
Oxford Rd, Manchester M13 9PT, UK.
Email: bill...@manchester.ac.uk.
Tel: 0161 962 2573.