Comments on: Link between ocean acidification and declining mussels? http://theoystersgarter.com/2008/11/25/link-between-ocean-acidification-and-declining-mussels/ Science served wet and salty Wed, 23 May 2012 15:12:53 +0000 hourly 1 http://wordpress.com/ By: Karen James http://theoystersgarter.com/2008/11/25/link-between-ocean-acidification-and-declining-mussels/#comment-2492 Wed, 26 Nov 2008 17:40:38 +0000 http://theoystersgarter.wordpress.com/?p=948#comment-2492 I feel indirectly connected to Tatoosh Island. When I was doing my PhD in Seattle, one of my roommates was Mar Wonham, who did her field work out there on invasive mussels. I remember her packing to go on field sessions: waders, tent, serious cold-weather gear, emergency generators, things like that. I was terribly impressed (and still am).
http://www.math.ualberta.ca/~mwonham/

]]> By: Miriam Goldstein http://theoystersgarter.com/2008/11/25/link-between-ocean-acidification-and-declining-mussels/#comment-2491 Wed, 26 Nov 2008 14:59:53 +0000 http://theoystersgarter.wordpress.com/?p=948#comment-2491 Yes, that was the part I was confused about – there could be any number of reasons that the composition of the rocky intertidal changed. Temperature (maybe correlated with ENSO), bad mussel recruitment, increased predation, human trampling…though it is interesting that they have documented a decrease in pH. (Of course, pH alone does not control the availability of carbonate ions.)

]]> By: jebyrnes http://theoystersgarter.com/2008/11/25/link-between-ocean-acidification-and-declining-mussels/#comment-2490 Tue, 25 Nov 2008 22:40:36 +0000 http://theoystersgarter.wordpress.com/?p=948#comment-2490 N.B. The one critical thing I’ll say here about the model is that it does not use pH as a parameter. Rather, it uses observed transition probabilities to predict dynamics. This was then correlated with changes in pH. The patterns matched, but it does not rule out other causal agents that are correlated with the observed changes in pH.

Using Pearson correlation coefficients, we probed whether any detected variation in transition patterns was related to pH change by correlating the annual variation in each transition probability with the average annual pH measured in the intervening year.

Others who know more how this was done, correct me if I’m wrong.

]]> By: jebyrnes http://theoystersgarter.com/2008/11/25/link-between-ocean-acidification-and-declining-mussels/#comment-2489 Tue, 25 Nov 2008 22:27:13 +0000 http://theoystersgarter.wordpress.com/?p=948#comment-2489 Indeed, the Markov chain approach is pretty solid as a means of temporal forecasting, as Wootton has shown in the past. I’ve always really admired it, and am excited to see its application here. It’s something I admittedly don’t understand well as I haven’t studied it. But, it’s a great way to get at temporal trends.

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