So this evening I went to an event given at ZSL London Zoo about the future of beavers in Britain. I had heard about the reintroduction of beavers in Devon (after having been extinct from the UK for around 400 years due to hunting to extinction,as well as being hunted nearly to extinction in the rest of Europe) recently which made me interested in this event.
My initial thought of the beavers was positive and excited about the idea of them being native to this country again. but then as i thought about it i did wonder if it was a positive thing after all. beavers do have a huge impact of the environment around them. they are thought to be one of the only species (only with us) that drastically modify their environment according to what they need (i.e. building dams and canals to create deep, still water). I felt that going along to a event as this one I could find out more about the impacts of beavers and make an informed decision on my thoughts of the reintroduction of this species.
The reintroduction began in Scotland long before they reached devon. currently there are two populations of beavers in scotland which are both being carefully monitored to assess their impact on the environment around them. a report on the last 5 years of investigations ‘Beavers in Scotland’ (http://www.snh.gov.uk/publications-data-and-research/publications/search-the-catalogue/publication-detail/?id=2273) is currently being assessed to decide whether they should remain in britain or be removed.
It does look positive for them though. it has been shown that beavers do have a positive impact (or neutral) on many native species in the investigated area due to the creation of new habitats and diversity. this could be a great way to increase biodiversity! However, there are some native habitats (such as Aspen woodland) which are limited and could be damaged by the presence of beavers…
Equally in Devon they have seemed to have a positive impact on the environment, as in one location they created 13 ponds and a number of canals which both created a number of new habitats (huge increase in the amount of frog-spawn found) but also in the flow of water through the area. The dams created appeared to create a constant flow of water even after a high rain fall (when there would usually be a surge in water flow) the dams and ponds create a buffer, meaning that the overall flow is not affected. Equally the water leaving the area appeared to have less sediment in it, i.e. it was cleaner!
However, the dams, if build in the wrong place can interfere with monitoring systems set up by the Environment Agency to monitor the flow of water.This would need to be monitored if beavers became more widespread.
Additionally, looking at soco-economics, they have seen that generally most of the population would benefit or be unaffected by this reintroduction. however, those who would have problems (agriculture, forestry etc.) need to be considered as well. equally, some fishing industries (such as the atlantic salmon in scotland) could also be negatively affected by beavers, and need to be considered.
In Europe the beaver population was nearly destroyed. Hunting was widespread and had it not been controlled, the whole of europe could have ended up like Britain. however, now the overall beaver population of the whole of europe is back up again, to around 1 million! However, this genetic bottle-necking has had a slight damaging effect on the genetic diversity of the beaver population as a whole. there is also an issue with the genetic diversity of the UK populations. one of the populations in devon stem from just one breeding pair and so at the moment interbreeding is a serious problem. they are looking into importing a few more breeding pairs to the area to increase diversity as at the moment this is not a sustainable population.
The introduced beavers in Scotland where originally from Norway and were carefully quarantined and checked before being released. It is important when reintroducing a species in this way to insure that any diseases are not brought along with the animals! being an island we have the ability to eradicate a disease, but this needs to be maintained and importation of animals is a easy way for a disease to come back, or a new disease to be brought over.
some of the beavers now in the UK are from an unknown origin. this is a problem from a disease point of view as they then need to be caught and tested after having been in the environment for a while, which means they could already have brought in a new disease!
One of these diseases is infection of the parasite Echinococcus Multilocularis. It has been found to be in 5% of beavers in Bavaria but it has been confirmed that it is not present in the current british wild populations. This problem is that it has been seen in a captive beaver in this country and as no one knows where some of these wild beavers are coming from any new ones need to be tested to make sure that they cannot bring the parasite in to the environment (which is also a zoonotic parasite and so poses a public health risk).
Overall, it was a fascinating and very enjoyable evening and I do think that actually beavers in this country would not be such a bad thing. In the end they did used to be native here and if introduced carefully and slowly could really benefit our natural ecosystem. It is important to remember, however, that it is still early and this project could still fail. I will definitely be keeping an eye out for more developments.