How are some animals and plants responding to a warming world? Dr Anjani Ganase looks at some creatures’ adaptations to survive the changing climate.

We are in the anthropocene – the current geological era where human activities have significant impacts on the environment and climate. Indeed, humans are currently driving the sixth mass extinction. To date we are losing species to extinction at a rate of about 2,000 species every year (WWF est.). While many die off, other animals and plants are undergoing adaptation to survive either the warming conditions directly or changes in habitat conditions, food supply and environment. Scientists who have been monitoring and conducting genetic studies over the last 50 years have been able to match changes in animal physiology (body shape and size) or behaviour (migratory timing) to changes in temperature. There are a few creatures that do benefit from the warmer conditions, although the extent of such benefits remain to be seen in the future. Here are some examples of adaptations by creatures to their environment brought on by climate change.

Upgrading your buddy

Symbiosis refers to two organisms living together for their survival. Corals are known to have symbiont algae living in their tissues that provide food from photosynthesis, while the corals provide the algae with nutrients and remove waste. Unfortunately, the algae can be sensitive to warm conditions which results in coral bleaching. Scientists have observed that corals present on reefs with a history of frequent coral bleaching because of thermal stress appear to be less sensitive to subsequent bleaching because the coral host has swapped out their symbiotic algae for a more heat-tolerant variety that makes the coral more resistant to future warming events. Some scientists are even breeding these heat-tolerant strains to develop super corals able to withstand climate change and plant them out on the reef. Many of these strategies are done at a very small scale and for a handful of coral species.

Changing their timing

Scientists have observed that populations of pink salmon in Alaska returning to Auke Creek in Juneau for spawning arrive in two waves. Dark-coloured salmon arrived as early migrators in August, while brightly-coloured salmon would arrive in the late wave in September. Over time, scientists have observed significant shifts in the proportion of early and late migrators, and found later migrators reduced in their populations. Today, the average migration time for pink salmon to more upstream for spawning is about two weeks earlier compared to 40 years ago. Scientists also found that the early migrators were able to cope with warmer summer temperatures better than the late migrators.

Shifting ranges

The movements of about 26 species of commercial fish species in the Pacific, including salmon, herring, sharks, and sardines have been tracked over the years. Researchers found that patterns in fish movement have shifted northward, away from the warming tropical waters at a rate of about 25 mile