If you happen to be among the shrinking group of our planet’s inhabitants that do not want to do anything about climate change, you may have a new swarm of allies: mosquitoes.
A study published recently in the journal Proceedings of the Royal Society B: Biological Sciences examined the effects of warmer temperatures on ecosystems in the Arctic, with particular attention to mosquito and caribou populations. The results show that mosquito numbers will likely increase alongside global temperatures. While that’s good news for mosquitoes and their predators, it bodes poorly for other species.
Temperatures Up, Mosquitoes Up
The team, led by postdoctoral researcher Lauren Culler from the Dickey Center’s Institute of Arctic Studies at Dartmouth College, used both field and lab studies to develop models for evaluating the impact that rising temperatures in the Arctic will have on the development and death rates of mosquitoes in western Greenland. They then considered the relationship between mosquitoes, caribou, people and other species in the area’s ecosystem.
In the Arctic, mosquitoes appear in the spring when increasing temperatures begin to melt the frozen ground. The melting snow and ice form shallow ponds where mosquito eggs laid during the previous year can hatch. In warmer years, the melts occur earlier. Earlier melts mean that not only do the mosquitoes hatch ahead of schedule, but they also spend less time developing in the larval and pupal stages. The insects are particularly vulnerable to predation during those developmental stages. So, a shortened developmental period decreases their exposure to predators and ultimately increases their chances of survival.
Culler’s team determined a ten percent decrease in development time for every one degree (Celsius) increase in temperature. They estimate that if the temperature rises by two degrees Celsius, the mosquito population would experience a 53% increase in chances of survival.
Mosquitoes Up, Caribou Down?
An increase in the local mosquito populations isn’t all bad. Several species feed on or otherwise benefit from mosquitoes, such as birds, diving beetles, and pollinating plants.
But Arctic caribou, which are the primary targets of Arctic mosquitoes, would experience higher rates and risks of irritation, wounds, and disease transmission, among other negatives. As mosquito populations increase, caribou are more likely to migrate away from mosquito-heavy areas, which usually means moving away from nutrient-rich locations. The move will cost them energy, food, and ultimately numbers. And as many humans in the region depend on caribou for food and livelihood, surrounding communities might find themselves similarly suffering.
Beyond the Arctic
Although the Arctic has experienced warming at twice the global rate of temperature increase in the past 100 years, climate change is a global phenomenon that will disrupt all ecosystems, not just Greenland’s. Researchers like Cullen are working to determine what those disruptions will look like in order to prepare for them. But scientists agree that continued increases in temperature bode poorly for many species and especially for humans. The most important step is to curb the warming.
