Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Data Files
• Supplemental Files
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

To test the ecological consequences of phenotypic variation in dogwhelk drilling, Nucella canaliculata dogwhelks were outplanted to field cages and the effects on mussel bed succession were quantified as changes in percent cover of sessile species. In May of 2020, sixteen large plots of mid-intertidal mussel bed were cleared to bare rock at the Mussel Point site in Bodega Marine Reserve. The communities were left to naturally develop for a year until they were at a mid-successional stage. Stainless steel mesh cages with removable lids were then placed in the 16 areas in May of 2021. Cages were attached by bolting the cage to the rock and sealing the edges with marine epoxy (Z-spar splash zone compound). Cages were in a block design with 5 cages placed in the 16 areas. In July of 2021, 5 adult dogwhelks were placed in each cage. Cages within each block received dogwhelks from the same family (dogwhelks from the same egg capsule cluster were considered a family of snails), with each cage getting dogwhelks from a given early-life diet treatment, plus one was a reference cage that did not get any dogwhelks. Mussel bed succession in the cages was quantified approximately every eight weeks for the next year (a total of 7 experimental checks, plus one check before the outplant of dogwhelks). The lids of the cages were removed, and photographs were taken of each plot. These photos are in the attached Supplemental File "Percent Cover Images.zip". Percent cover of sessile species was quantified from the photographs using image analysis by tracing polygons around individuals of a given species and dividing the total area by the area of the caged plot. Species were grouped into seven functional groups for analyses: bare rock, acorn barnacles, gooseneck barnacles, mussels, other sessile animals, coralline algae, and a final group of algae and surfgrass.

ImageJ was used to analyze photos of the plots. Species were grouped into seven functional groups for analyses: bare rock, acorn barnacles, gooseneck barnacles, mussels, other sessile animals, coralline algae, and a final group of algae and surfgrass. 

- Imported original file "Percent cover measure of mussel bed succession on rocky shores due to intra-population variation in dogwhelk drilling.xlsx" into the BCO-DMO system.
- Renamed fields/columns to comply with BCO-DMO naming conventions.
- Added columns for site Latitude and Longitude.
- Converted the Date column to YYYY-MM-DD format.
- Saved the final file as "918518_v1_pcnt_cover_mussel_bed_succession.csv".

NSF Award Abstract:
Historically, ecologists regarded evolution as a process that typically acts slowly over very long time scales. However, recent studies suggest that evolution might also shape the way species interact over much shorter timespans, ranging from weeks to years. Are these sorts of rapid feedbacks between evolution and ecology important in marine ecosystems? This project will address this question along the Pacific coast of the United States by studying predatory snails (Channeled Dogwhelks) that feed on California Mussels, an important habitat-forming species on rocky intertidal shores. Prior research shows that some dogwhelk populations are composed of an assortment of individuals that differ genetically in how effectively they can drill through mussel shells. This project will test whether short-term changes in the environment can impose rapid natural selection that favors some of these drilling variants over others, altering the effects that a dogwhelk population has on the surrounding mussel bed. At the same time, this project will examine whether regional differences in mussel shell thickness have influenced the evolution of drilling ability among dogwhelk populations distributed along >900 kilometers of the California and Oregon coasts. Overall, this study seeks to understand the dynamic feedbacks between evolution and ecology that might influence marine communities in the face of changing ocean conditions. This project will train diverse undergraduate and graduate students and will provide the foundation for a significant public outreach component, including the production of accessible video documentaries.

This project seeks to advance our understanding of eco-evolutionary dynamics in the sea by investigating links among oceanographic variation, natural selection, species interactions, and community succession. This project will use the interaction between the Channeled Dogwhelk (Nucella canaliculata) and the California Mussel (Mytilus californianus) as a model system to address two central objectives. (1) The research team will explore how spatial mosaics of selection drive adaptive differentiation among populations of consumers. Newly collected and archived mussels will be analyzed to characterize variation in shell thickness along the coasts of California and Oregon, and to evaluate whether this spatial mosaic has been consistent or variable over the past two decades. Laboratory experiments will test whether dogwhelk populations distributed across this mosaic have diverged in the thickness of shell that they can drill successfully. (2) The research team will examine whether temporal variation in selection on consumer phenotypes shapes predator-prey interactions, with cascading effects on ecological dynamics. In particular, the project will test whether short-term variation in prey recruitment and shell thickness can impose rapid selection on the frequency of drilling phenotypes within a dogwhelk population. A field experiment will also test whether selection on these predator phenotypes in turn alters the trajectory of mussel bed succession.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.