Narr_Data_JAE_11_26_18.xlsx

We examined the relationship between nutrient availability and an abundant parasite capable of both horizontal and vertical transmission (<i>Hamiltosporidium tvaerminnensis</i>) of a planktonic crustacean, <i>Daphnia magna</i>, in rock pools on Baltic Sea Skerry islands. We found that the relative availability of nutrients directly affected infection prevalence; parasite prevalence was higher in pools with higher particulate N:P ratios. Infection prevalence was not related to <i>Daphnia</i> population densities. A complementary experiment that examined host responses to an N:P gradient in mesocosms indicated that high N:P ratios can increase spore load in the hosts.