Working in science education, I get exposed to all sorts of myths and conspiracies regarding modern science. Mermaids are real, because we just don’t know that they’re not (thanks Animal Planet); AIDS is simply the result of malnutrition (phew, that makes things waaay easier); and climate change is caused by new order aliens who are altering the atmosphere to meet their reptilian needs (I love this one).
This last one is a personal favorite, not only because like, wow, but also because there actually is a closer connection between aliens and climate change than you might think. Ok, not those probey, X-Files aliens, but alien species aka invasive species that are here on earth.
So you have probably heard of invasive species before. They are also sometimes called exotic species, or non-native species. They are typically things like kudzu or zebra mussels that move into a new region and completely take off. They tend to be good dispersers (their pollen, seed, babies etc. go everywhere), are tolerant around environmental extremes or changes, and often have the advantage of growing quickly (1,2). Some of them live long and prosper, while others live hard, die young and leave a legacy of minions to take their place. Either way, they create a bit of a mess for whatever ecosystem they move into.
Invasive species end up in new areas through a variety of means. Sometimes they follow roads and rivers to new locations like in the case of Ragweed’s spread throughout Quebec (achoo!) (3), and sometimes they are escapees from homes, like in the case of exotic fish species released from aquariums (4) — Free Nemo!
It turns out that though, that aquatic systems are particularly sensitive to invasive species under climate change scenarios, as aquatic animals can be sensitive to changes in water temperature and acidity levels. Who wants to swim in hot acid anyway?
In aquatic systems, both native and non-native animal species are impacted by these changes to acidity and temperature, but the non-native species have a much stronger response overall. This means that if the conditions got better for them, the non-natives took off, but if it got worse the non-natives suffered more (5). This makes for a tricky situation for those native species, as not only do they have to deal with a changing environment, but also there are these jerk invaders coming in that might completely take over if conditions become a little more comfortable for them. At the same time though, if the environment becomes a little more inhospitable, the natives will be the ones to prosper.
This of course is a grand generalization, because there are so many components that can make invasive species succeed (growth rate, dispersal ability, reproduction time) and climate change can impact systems in so many different ways (temperature, acidity levels, even salinity). So there are still plenty of research questions to be answered in this field.
Not the worry though. As you are tucked peacefully in your bed at night scientists are working hard analyzing data, chasing down lion fish and developing models to better understand how these systems will respond to climate change. The truth is out there, and scientists are going to find it.
1. Rapid evolution in introduced species, ‘invasive traits’ and recipient communities: challenges for predicting invasive potential.
2. Do invasive species show higher phenotypic plasticity than native species and, if so, is it adaptive? A meta-analysis.
3. How did common ragweed (Ambrosia artemisiifolia L.) spread in Quebec? A historical analysis using herbarium records.
4. Beyond ballast water: aquarium and ornamental trades as sources of invasive species in aquatic ecosystems.
5. Poised to prosper? A cross-system comparison of climate change effects on native and non-native species performance.