Citizen science to detect marine species’ range shifts

For some marine species, warmer temperatures are harmful. They disrupt physiology and behaviours, causing the deaths of individuals, and sometimes whole populations. Over time, this drives southward shifts in the ranges of a southern-hemisphere marine species into cooler waters. Scientists have so far measured these range shifts in 198 Australian marine species. There are thousands more that might also have shifted, but there is not enough data to know.

New approaches are required to acquire the vast volumes of information needed to facilitate understanding of range shifts across all marine species.

This project examined the usefulness of ‘citizen science’ for this purpose. It is a program that supports and guides scientific data collection by community members, for specific research goals. It is potentially very economical for marine research in particular, as it often uses existing tourism vessels and expeditions, and there are potentially thousands of available volunteer data-collectors.

Approach and findings

Approach

This project systematically searched and analysed three citizen science databases to find evidence of range shifts in 200 target marine species. The data sets were from:

• Redmap (Range Extension Database and Mapping Project) – photos by fishers and divers;
• iNaturalist Australasian Fishes Project – photos by various marine users; and
• Reef Life Survey – systematic surveys of inshore reefs by volunteer scuba divers.

Findings

From these databases, 76,000 individual records of 197 target species were detected, outside their historically-known range. For 77 of these species, verifiable photographic evidence accompanied the written records, confirming unequivocally, that the species had undergone range-shifts. Species on-the-move included anemones, corals, crabs, lobsters, sea urchins, sharks, rays, dolphins, and fish.

The average southern shift in range demonstrated within this data was 316 km. The maximum change was 1474 km by the Atlantic blue marlin (Makaira nigricans). The eight largest southward range extensions were on the Western Australian coast where the Leeuwin current channels warm waters southward.

Conclusions

Citizen science is clearly capable of providing valuable and unique data on species’ range shifts and is therefore highly complementary to traditionally collected science, for detecting and understanding climate-driven species redistributions in Australian marine systems.

With millions of Australians fishing, diving, and engaging in marine tourism and beach activities annually, considerable potential exists for expansion of marine citizen science. With around 48,000 marine animal species in Australian waters, most with little or no data collected, citizen science holds great promise for filling knowledge gaps.

Careful consideration will need to be given on how to effectively expand current programs and ensure that collected data is accessible to community members, scientists, and managers.

Outcomes

• Natural resource distribution assessment methods better understood.
• New monitoring methods to detect climate-driven species’ range shifts progressed.
• Improved understanding for better managed environmental resources.

Project location

Southern Australia (WA to QLD)