Tuesday 22 October 2013

Invasive species, not all that bad!

I read an article by Chris D. Thomas in Nature this week titled 'The Anthropocene could raise biological diversity' and I liked it!

The article begins by explaining how the distribution of plants and animals is changing in response to the warming temperatures of our changing climate. So far nothing I’ve not heard before; nothing worth writing home about. Next I read of the ‘irrational’ response of those who find themselves ‘invaded’ by such ‘displaced’ species, and that the ‘persecution of the new – just because it is new – is no longer sustainable in a world of rapid global change’.  This I find refreshing and interesting. It fills me with a certain confidence and reassures me that my thoughts and opinions regarding introduced species are perhaps not all that ignorant and taboo.

As I mentioned in my previous post, I have never understood why native species are always given conservation priority over introduced species. In an increasingly globalized world, it seems that the flow of species is the only ‘flow’ that is not being actively encouraged. I can’t help but draw parallels to ethnic diversity, something that is greatly celebrated and promoted in globalized countries today, and without entering into these debates (human geography does not interest me), I wonder why it is that mixing of species is not seen in the same light.

One reader who has commented on the article, reminded me of the conventional stance taken by commentators of introduced species… He argued that populations living “on the edge” are not being irrational in seeking to eliminate potential threats to crops. In order to at least appear impartial, I decided to research (briefly) the adverse effects introduced species can have on ecosystems.  Who better to fight in the corner of the ‘anti-invasives’ than fishzilla himself - the snakehead fish. This fish is monstrous! It has many adaptations that make it an expert invader and it can even survive on land for up to four days! It has had decimated native food chains in the US.


In the red corner: ‘fishzilla’ – the snakehead fish

Snakehead fish, meet the Japanese white-eye. This non-native bird is actually helping to prevent the extinction of native rainforest shrubs in Hawaii by propagating their seeds.


And in the blue corner: Japanese white-eye (show them what you’ve got)

The article concludes that our default attitude to introduced species is ‘antagonism or ambivalence’. Introduced species are demonized often having caused no damage to their host ecosystems. All species should be given equal conservation value, irrespective of where they originate. I do recognize that some introduced species do damage ecosystems, and efforts should be concentrated on preventing the invasion of these species.

I am eager to discuss further the issue of invasive species as well as the other ways Chris D. Thomas says the Anthropocene is raising biodiversity.


2 comments:

  1. I think you've hit the nail on the head here. There is definitely a bias in the literature towards the negative impacts of invasive species, the term itself seems to imply 'oh, that's not from round here, ergo, it must be bad!' (Though is it any wonder with stuff like that ghastly fish branded as invasive and thrust in peoples faces!)

    Completely agree with your point about concentrating efforts on those invasive species which we know to have negative impacts too, instead of all invasive species, which would quite frankly be pointless!

    Maybe if we could somehow make the Japanese white eye the face of all invasive species, people would be more impartial to them!

    ReplyDelete
    Replies
    1. I am glad you agree Rob. I find the literature so frustrating! It's almost impossible to find articles (both academic and non-academic) that discuss invasive species objectively without that deep embedded bias that you mentioned. I saw a photograph of a Japanese White-Eye and the caption read "Photograph of the day: Japanese White-Eye adorable yet invasive". This says it all doesn't it!

      Delete