Interest in the field of environmental DNA (eDNA) is growing rapidly and eDNA surveys are becoming an important consideration for aquatic resource managers dealing with invasive species. However, in order for eDNA monitoring to mature as a research and management tool, there are several critical knowledge gaps that must be filled. One such gap is the fate of eDNA materials in the aquatic environment. Understanding the environmental factors that influence the decay of eDNA and how these factors impact detection probabilities over time and space could have significant implications for eDNA survey design and data interpretation. Here we experimentally explore eDNA decay in waste materials and reproductive cells obtained from captive stocks of the invasive bigheaded carps, Hypophthalmichthys nobilis and H. molitrix, as well as the influence of differing levels of water turbulence, temperature, microbial load, and pH on rates of eDNA decay. We found that the decay patterns of eDNA associated with both H. nobilis biological waste and H. molitrix milt significantly fit monophasic exponential decay curves. Secondly, we observed that the highest temperature we tested resulted in decay half-life as much as 5.5X more rapid than the lowest temperature we tested. When we suppressed microbial loads in eDNA samples, we observed that overall losses of eDNA were reduced by about 2.5X. When we amended eDNA samples with pond water the half-life of eDNA was reduced by about 2.25X, despite relatively little apparent increase in the overall microbial load, indicating the microbial sources, not only loads, might play a critical role in eDNA degradation. A shift in pH from 6.5 to 8.0 in the samples resulted in a 1.6X reduction in eDNA half-life. Water turbulence in our study had no apparent effect on eDNA decay. When we combined different temperature, pH, and microbial load treatments to create a rapid decay conditions and a slow decay conditions, and tracked eDNA decay over 91 days, we observed a 5.0X greater loss of eDNA by Day 5 under rapid decay conditions than under slow decay conditions. At the end of the trials, the differences in eDNA loss between the rapid decay and baseline and slow decay conditions were 0.1X and 3.3X, respectively. Our results strongly demonstrate the potential for environmental factors to influence eDNA fate, and thus the interpretation of eDNA survey results.