Host traits and temperature predict biogeographic variation in seagrass disease prevalence

Diseases are ubiquitous in natural systems, with broad effects across populations, communities, and ecosystems. However, the drivers of many diseases remain poorly understood, particularly in marine environments, inhibiting effective conservation and management measures. We examined biogeographic patterns of infection in the foundational seagrass Zostera marina by the parasitic protist Labyrinthula zosterae, the causative agent of seagrass wasting disease, across >20° of latitude in two ocean basins. We then identified and characterized relationships among wasting disease prevalence and a suite of host traits and environmental variables. Host characteristics and transmission dynamics explained most of the variance in prevalence across our survey, yet the particular host traits underlying these relationships varied between oceans, with host size and nitrogen content important in the Pacific and host size and density most important in the Atlantic. Temperature was also a key predictor ..., Study sites: In the summer of 2015, we surveyed 17 discrete, monospecific eelgrass beds across the northern hemisphere, mostly along the coasts of North America (9 in the Atlantic Ocean, 8 in the Pacific Ocean). All of the surveyed sites were in protected, shallow waters (0 - 2 m depth at low tide).
Wasting disease survey: At each site, we collected a total of 20 individual vegetative eelgrass shoots at least two meters apart along two 10 meter transects running parallel to shore. We clipped shoots at the base in the field and placed them in individual plastic bags. We timed sampling to target peak wasting disease prevalence based on local knowledge of system dynamics, which resulted in most sites being surveyed in mid-summer near peak eelgrass biomass.
Within five hours of collection in the field, we scored the third youngest leaf of each shoot for signs of wasting disease (i.e., lesions). We focused on this leaf because it has been shown to harbor the highest intensity of wasting dise..., , # Host traits and temperature predict biogeographic variation in seagrass disease prevalence

[https://doi.org/10.5061/dryad.5qfttdzh8](https://doi.org/10.5061/dryad.5qfttdzh8)

## Description of the data and file structure

Dataset to reproduce analyses in \"Host traits and temperature predict biogeographic variation in seagrass disease prevalence\"

### Files and variables

#### File: Schenck\_etal\_data\_repository.csv

##### Variables

* site:
The site name.
* site.code:
The unique two digit abbreviation for each site name.
* region:
The geographic region where the site is located.
* ocean:
The ocean where the site is located.
* disease.prevalence:
The proportion of Zostera marina third leaf blades on which lesions characteristic of eelgrass wasting disease are present
* latitude:
The latitude of the site in decimal degrees.
* longitude:
The longitude of the site in decimal degrees.
* shoot.density:
Mean density of Zostera marina shoots per square meter (from sampling ...