The tiny inhabitants and overlooked plants that flourish in rainwater could provide us with the early-warning signs of climate change, local research shows.

The findings, part of continuous research on rock pools by a university student, make a strong case for the preservation of such ponds that are disappearing despite being declared as an EU priority habitat.

Rock pools are ponds that form between October and April when rainwater collects in rock cavities. They are home to unique plants and animals programmed to flourish within weeks and are survived by seeds that germinate with the next rain cycle.

Triops cancriformis. Photo: Lara Grima

These include the Mediterranean starfruit, the tadpole shrimp and the Maltese horned pondweed (Zannichellia melitensis), which is only found in Malta.

The tadpole shrimp (Triops cancriformis) is very rare and elusive and its hatching depends on rain patterns, with the eggs able to lie dormant for years. It is often called a “living fossil” because the species does not appear to have changed much over millions of years.

Unfortunately, these rainwater pools are becoming rarer, so the flora and fauna that grow in them are also uncommon, biology lecturer Sandro Lanfranco told this newspaper.

We don’t know whether their destruction would be the straw that breaks the camel’s back. They might be a very important link in the chain that we don’t yet know of

Asked what would happen if such flora and fauna became extinct, Dr Lanfranco admitted that scientists knew little about such habitats.

“We don’t know whether their destruction would be the straw that breaks the camel’s back. They might be a very important link in the chain that we don’t yet know of.”

The effect might not be immediate but cumulative, or even indirect. “Even if their existence is not important to the man in the street, creatures such as the tadpole shrimp help scientists understand evolution better and such knowledge may be useful in other fields, like understanding antibiotic resistance in bacteria,” Dr Lanfranco pointed out.

The Mediterranean starfruit. Photo: Claire Grima

Despite being situated in protected areas, these habitats have been making way for new buildings for years. The ponds also fall victim to the dumping of tyres, unwanted appliances or at times are just covered with soil.

Recent research by Claire Grima, who is reading for a Master’s at the University of Malta, makes a strong case for the preservation and even restoration of rock pools that have been filled with soil.

This is because there is higher biological diversity in rock pools when compared to the surrounding countryside. Thus, if the pools are lost because they get filled with soil, then more species would have been lost than would have been gained.

Ms Grima has taken the research on local rock pools to “a completely new level”, according to Dr Lanfranco, her supervisor, with the findings being presented at an international conference in Sardinia. The study has also been submitted to an international scientific journal and is in the process of peer review.

Hers is the first study that focuses on the whole landscape rather than individual pools, and Ms Grima has identified a number of distinct zones in pools. She traced the phylogenetic relationships of different species and which particular part of the pond they would grow in.

This information is not only useful for those who want to restore rock pools but also comes in handy as a monitoring tool.

The rock pools could specifically be used as an early-warning system for climate change.

Scientists could monitor the relationships between different plants and, when the genetic characteristics start to vary, it would indicate that the plants are responding to changes in climate, as opposed to simply changes in weather.

“We have developed several devices, as people are continuously looking for patterns of climate change, but these rock pools are natural gauges.

“Changes in rock pools are quick, so they help us detect predicted climate change quicker. Detecting such changes at a complex ecosystem like Buskett, for example, would take centuries,” Dr Lanfranco said.