Edging along a Warming Coast: A Range Extension for a Common Sandy Beach Crab

Area of Science:

• Marine biology
• Climate change ecology
• Zoology

Background:

• Understanding species' range shifts is crucial for predicting ecological and evolutionary responses to climate change.
• The ghost crab Ocypode cordimanus is common along Australia's east coast.
• Defining range edges is the first step in studying climate change impacts on species.

Purpose of the Study:

• To determine the poleward range edge of the adult ghost crab Ocypode cordimanus.
• To assess larval dispersal and recruitment patterns relative to the adult range edge.
• To evaluate the potential for range expansion in response to ocean warming.

Main Methods:

• Field surveys to establish the southernmost adult distribution of Ocypode cordimanus.
• Analysis of museum records to compare with current distribution.
• Oceanographic data analysis to identify warming trends and hotspots.

Main Results:

• The poleward range edge for adult Ocypode cordimanus was established at Merimbula, Australia, 270 km south of previous records.
• Pelagic larvae recruit to beaches 248 km beyond the documented adult range.
• The current range edge is located within an ocean warming hotspot with southward-moving isotherms.

Conclusions:

• Ocypode cordimanus exhibits significant larval dispersal beyond its adult range.
• The species' range edge is situated in a region experiencing rapid ocean warming, indicating potential for future poleward shifts.
• Ghost crabs like Ocypode cordimanus are proposed as valuable model organisms for studying climate change impacts due to their ecology and the correspondence of warming hotspots with their range edges globally.