Abstract
The use of Trojan Y chromosomes (TYC) for controlling invasive species involves manipulating the sex chromosomes of captive-raised individuals. Following release, the offspring of these individuals consist of only one sex, thereby skewing the sex ratio of the invasive population and potentially leading to eradication. Simulation models are needed that can inform managers about how to maximize the likelihood of invasive species eradication, since implementation of this novel management approach in the field is still rare. Here, we present the first spatially explicit, mechanistic simulation model of a real-world TYC program for invasive species eradication. Using a brook trout Salvelinus fontinalis system model, we investigated the effects of competitive and reproductive fitness of the captive-raised YY males, dispersal behaviour upon their release and landscape heterogeneity on eradication success. Likelihood of eradication was dependent on both the competitive and reproductive fitness of the Trojan individuals. Competitive fitness (i.e. survival) had a higher threshold for eradication, below which the invasive populations were not eradicated. Movement ecology of both the wild and YY male populations was important for eradication. Under a restricted dispersal scenario for YY males following their release, the wild population was not extirpated but maintained a stable, yet reduced, population size. Analysis of landscape configuration indicated that time to eradication of local patches increased with greater connectivity within the stream network. In addition to sex ratio distortion, density-dependent mortality resulting from outplantings made an important contribution to population decline and therefore may also affect native competitors. Synthesis and applications. The use of Trojan sex chromosomes to skew population sex ratios is a novel method for the suppression and eradication of aquatic invasive species. Results from our modelling work indicate that while eradication is possible, maximizing its likelihood requires an understanding of the fitness and movement ecology of both the wild and YY male populations of the invasive species. Both our model and the principles derived from this study related to fitness and behavioural landscape ecology can be broadly applied to other invaded species and systems.
| Original language | English |
|---|---|
| Pages (from-to) | 1413-1425 |
| Number of pages | 13 |
| Journal | Journal of Applied Ecology |
| Volume | 57 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1 2020 |
Funding
This work was supported by Seattle City Light and NASA grant NNX14AC91G. We thank Seattle City Light, West Fork Environmental, the Washington Department of Fish and Wildlife and the Kalispel Tribe of Indians for providing data for this study. We thank Al Solonsky and Harry Rich for their input on the model and manuscript. This work was supported by Seattle City Light and NASA grant NNX14AC91G. We thank Seattle City Light, West Fork Environmental, the Washington Department of Fish and Wildlife and the Kalispel Tribe of Indians for providing data for this study. We thank Al Solonsky and Harry Rich for their input on the model and manuscript.
| Funders | Funder number |
|---|---|
| Seattle City Light | |
| Washington State Department of Fish and Wildlife | |
| National Aeronautics and Space Administration | NNX14AC91G |
Keywords
- CDMetaPOP
- Salvelinus fontinalis
- YY males
- behavioural landscape ecology
- brook trout
- fisheries management
- relative fitness
- simulation modelling