Can oysters filter laby? Experiments and Models

Our group is focusing our project on the question of whether mitigation of laby outbreaks in eelgrass beds is possible via two methods, culling of disease or filtration by oysters.

Today we set up round two our oyster filtration experiments again in Lab 5. Our hypothesis is that oysters will filter laby out of the water, reducing the prevalence and/or severity of infection in exposed eelgrass.

cloudy_laby_setup2

I’ve been analyzing the data from our first round of experiments and the results are interesting. There is no difference in prevalence of infection between the eelgrass that was in the seawater+laby treatment versus the seawater+laby+oyster treatment (though both of those treatments had significantly higher prevalence that the treatments that we did not add laby to, so it appears we can infect eelgrass via exposure, which is pretty neat). There also does not seem to be a change in the severity of the infection (measured as total blade length/total lesion length) in the seawater+laby compared to the seawater+laby+oyster treatment. I’m interested to see if our results are the same the second time around.

Before we worked on our experiment, we spent some time with Maya learning about disease modelling and had a chance to play around with some software and a model she developed for oyster filtration of a pathogen. The first 20 or so times I ran the model the pathogen in the water was eliminated, but I wanted to see if I could get it to be filtered, but still present in the environment. It took some tinkering with the parameters, but I finally got the pathogen to persist at low levels. http://youtu.be/tT9Waxrwstk

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