Meeting Abstract
Parasites can exacerbate or buffer host response to environmental conditions, and thus hosting a parasite can affect host performance. Likewise, environmental context can alter parasite performance directly, creating a range of host-parasite interactions across environmental gradients. Extant variation in species interactions across environmental gradients could give us insight into how species will respond to climate change. Using field outplants, we examine growth of a shell-boring endolithic cyanobacteria and its mussel host, ““Mytilus californianus”” across an intertidal gradient. To isolate erosion rate from mussel growth rates, we paired dead shells with living mussels across the intertidal. To evaluate mussel defense we sequenced the microbial communities associated with the mussel shells. The proportion of mussels that are eroded by endolithic cyanobacteria varies across the intertidal, with high levels of erosion in the upper intertidal and low levels in the lower intertidal. We found that mussel growth rates were highest in the lower intertidal, and that erosion rates were highest in the upper intertidal. Live mussels had lower erosion rates then dead mussels, but only in the lower intertidal. Microbial communities varied across the intertidal and between live and dead mussel shells, suggesting that shell microbial communities could be related to mussel defense against biotic erosion.
