The cold killed off a huge number of invasives. I saw it myself about a month ago...
I go to Myakka State Park in Sarasota, FL pretty regularly to perform fish surveys and remove invasives. About a month ago I went and the first thing I noticed was the smell. There were floating fish all around the banks, with some dead on the bottom as well. I literally saw thousands of dead tilapia, plecostomus, walking catfish, and brown hoplos (I had to wade through them). The water level was also about 3' higher than normal. I only saw one dead native, a decomposing sunfish.
The collection yielded hundreds of native sunfish, mollies, and killifish; as well as one invasive: a large tilapia. Normally we also see jewel cichlids, and tilapia usually outnumber sunfish 20:1. We didn't see the diversity we usually do, but the invasives definitely took most of the blow. 6 weeks before that we caught hundreds of plecos, tilapia, jewel cichlids, and brown hoplos. Then suddenly they were all gone.
I go to Myakka State Park in Sarasota, FL pretty regularly to perform fish surveys and remove invasives. About a month ago I went and the first thing I noticed was the smell. There were floating fish all around the banks, with some dead on the bottom as well. I literally saw thousands of dead tilapia, plecostomus, walking catfish, and brown hoplos (I had to wade through them). The water level was also about 3' higher than normal. I only saw one dead native, a decomposing sunfish.
The collection yielded hundreds of native sunfish, mollies, and killifish; as well as one invasive: a large tilapia. Normally we also see jewel cichlids, and tilapia usually outnumber sunfish 20:1. We didn't see the diversity we usually do, but the invasives definitely took most of the blow. 6 weeks before that we caught hundreds of plecos, tilapia, jewel cichlids, and brown hoplos. Then suddenly they were all gone.
As a general rule yes non natives are to be avoided in the wild but cernatly not allways. If you want I ll give some interesting examples that have poped up here and there
). Unfornatly like 30-40% of that group alongside all of the giant fligth less gosse group and some others went extinct after the polinesians reached Hawai and then afterwards another like 25% of that taxa went exctinct after the europeans came. Most are now exctinct and alongside with them most of the native polinators and seed dispersers of the hawaian forests. The few left are mostly restricted to very isolated locations in the mountains, so most of the lowland forests are basicly free of native polinators and seed dispersers. Why are they still triving? Because a long time ago the europeans brougth to the islands a hand full of non native small brids species wich as it turns out are doing a great job dispersing the seeds and polinating the flowers of the native plants and as such helping to preserve what´s left of the hawaian forests (they are NOT competing with the honey creepers and they didnt contributed to their decline wich was a deadly mix of habitat destruction, introduction of much more dangerous invasives and specialy avian malaria, brougth by the time of the polinesians colinization). And not only that. One of the "invasives" is the java sparow wich is greatly endangered in its native range, however its triving in the Hawai islands. Ho knows maybe in the future specimens from Hawai can be reolocated back to Java!