Non-native species and climate change are two of the most pressing issues facing Florida in the Anthropocene. Due to Florida’s extensive hydrological alteration, subtropical climate, and large population size, the state is a hotspot for non-native fish introductions. Of these introductions, the cichlids are the largest group, popular in aquaculture, and among anglers and aquarists, with many introduced species of cichlid having established in Florida. These species may cause various environmental and socioeconomic impacts to the state. This study is focused on the potential geographic distributions of three species: African Jewelfish (Hemichromis letourneuxi Sauvage, 1880), Blue Tilapia (Oreochromis aureus Steindachner, 1864), and Mayan Cichlid (Cichlasoma urophthalmus, Gunther, 1862). The research questions of this study are as follows: where is the current distribution of suitable habitat for these species in the state? Where will suitable habitat be distributed in the future? This study correlates the georeferenced presence points of the three different species and the current bioclimatic and hydrological variables at those sites using maximum entropy modeling (Maxent), in a species distribution modeling (SDM) framework. These relationships are then projected to two different representative concentration pathways (RCPs), further into the Anthropocene- the years 2050 and 2070.
The resulting maps of suitable habitat are reported at the finest resolution available- 1 square-kilometer. For the African Jewelfish, suitable habitat in the state is expected to stall in 2050 and 2070 under both RCPs. For the Blue Tilapia, an expansion of suitable habitat will occur throughout Florida, including in novel environmental space in the northwest of the state. Suitable habitat for the Mayan Cichlid is predicted to contract, only occurring within canals- themselves a novel habitat feature on the landscape. The strongest parameter in driving the distribution of suitable habitat was minimum temperature of the coldest month. For regions supporting rich fish diversity and endemism like the Southeastern United States, managers may use this SDM framework in prioritizing effort and limited resources in controlling those non-native species causing the most negative impacts. While in the case of the Blue Tilapia there are climate change risks predicted in this study, there are also management opportunities, as suggested by the Mayan Cichlid findings.