Basin Notes - July 2009

Global Changes

The Montrose Basin is a Local Nature Reserve and, as such, provides facilities for humans and wildlife alike. The designations of SPA, SSSI and Ramsar all show how significant the Basin is for the wildlife that uses it. However, the world and its wildlife is changing so what happens to the LNR?

Some recent research (British Wildlife, April 2009) has investigated the effects that global warming might have on the way that we have to think about nature reserves and about whether they are the most viable way of protecting wildlife.

The basic thinking behind the establishment of any nature reserve is that one or more species of plant or animal is surviving in a small geographical area that has survived relatively untouched by man and unless it is protected then man will do something that makes it untenable to those species that call it home.

The Basin is fortunate to have avoided that fate as that the need to travel from Arbroath to Montrose and Aberdeen led to the building of the road and rail bridges which effectively blocked off shipping from entering the relative haven of the inner estuary. This meant that docks were not built along the shore and the channels were not dredged to accommodate large vessels. Clearly, the pier at Old Montrose demonstrates that it was used at one time to bring ashore goods for onward transport by road to inland destinations and only by an accident of history avoided further development.

However, global warming means that, as average temperatures rise, more of the birds that winter in the UK are going to survive, which is good news, but there is an additional subtle effect as well. The south-west of the UK is currently warmer in winter than the north east, so migrating waders have preferred to settle in the estuaries down there even though they are less productive than north-eastern ones like the Basin. They are gambling that the relative paucity of invertebrates in the mud is more than compensated for by the gentler conditions. However, with winter temperatures rising there is likely to be an expansion of wintering flocks towards the North Sea coastal estuaries where the balance of plenty of food and amenable temperatures will allow birds to survive just as well as those on the Atlantic coasts of Devon and Cornwall.

These conclusions have been drawn from the data collected by the BTO in their national monthly Wetland Bird Survey counts and show evolution in action as birds respond to the changing conditions. As might be expected, this north easterly drift is more noticeable in the smaller waders like dunlin and ringed plover, which, because of their size, are more sensitive to the hazardous effects of low temperatures.

So, the conundrum for conservationists is that current nature reserves may become less important for their current species as global conditions force those species to move to more favourable locations. While the prospects for the Basin seem good for the foreseeable future as more waders may decide to winter here to feast on the invertebrate food source flourishing in the muddy sediments, other reserves further to the south west may not be as lucky and their future may be in the hands of global warming.