Sometimes discoveries in biology don't start with an expedition, but with old data

This is what happened in Italy. The researchers collected and collated more than 40 years of unpublished data on marine amphipods, small crustaceans that live in the seas and play an important role in ecosystems. As a result, they processed 4,344 records from 1980 to 2025 and confirmed 302 species of amphipods in the Adriatic, Tyrrhenian and Ionian Seas. The work is published in the Biodiversity Data Journal.

This does not mean that the scientists discovered 302 species new to science. The important thing is different: they showed that much of the useful information about marine life had already been collected, but remained almost invisible until it was pooled and made available to other specialists.

Details

Amphipods are small crustaceans, often only a few millimetres long. To the average person they are almost invisible, but to the sea they are important. They recycle organic matter, provide food for fish, birds and marine mammals, and react quickly to pollution and changes in the environment.

That's why amphipods help scientists understand what's happening to the marine ecosystem. If the composition of these small species changes, it could be an early warning sign of problems: pollution, warming, alien species or changing conditions on the bottom.

Before this work, data on the amphipods of Italy were scattered in different sources. Some information was held by universities, conservation organisations, environmental agencies and research groups. Some was collected during monitoring, some during localised surveys, but not everything made it to public databases and scientific publications.

The new work brought these records together into a coherent system. It found that the Tyrrhenian Sea had the highest species richness, with 258 species, while the Adriatic Sea yielded the most records, probably due to more historical sampling.

The scientists also noted 11 alien species. They were found more often in harbours, lagoons and aquaculture areas. This is expected: marine species can move with ships, ballast water, equipment and human activities.

Why it matters

To protect the sea, we must first understand who lives in it and where. Without accurate species distribution maps, it is difficult to spot biodiversity loss, assess habitat condition, or understand where alien species are coming in.

This work shows an important problem with science: data can be collected but not work for common knowledge. If they lie in closed reports or localised archives, other researchers can't see them. So the same work has to be repeated, and the big picture remains incomplete.

When old data are brought to a common format and published openly, they become useful again. They can be used for monitoring, conservation decisions, assessing the effects of pollution and comparing with future observations.

Background

The Mediterranean Sea is considered an important centre of marine biodiversity, but at the same time it is under strong pressure: shipping, tourism, fishing, warming waters, pollution and the emergence of alien species.

Italy is in this sense at the centre of events: its coasts are connected to several Mediterranean marine areas at once. The updated data on amphipods are therefore important not only for Italian science, but also for a broader picture of the state of the Mediterranean Sea.

The authors emphasise that the collected dataset is published according to FAIR principles - that is, it should be findable, accessible, compatible with other databases and reusable. The dataset is also hosted through GBIF, a global biodiversity data platform.

Source

Antonina Badalucco et al., "A contribution to the inventory of marine amphipod species from Italian waters based on unpublished sources and FAIR principles", Biodiversity Data Journal, 2026.