Author: Molly Grew
Drone shot of Stingrays in Burrill Lake, NSW.
Stingrays, often admired for their graceful movements, play a vital role in maintaining marine ecosystems. One of their key contributions is bioturbation, the process of reworking sediments in their environment. As stingrays forage for food, such as polychaetes, molluscs, and crustaceans, they disturb the sediment, creating feeding pits that can last for weeks. This activity not only enhances oxygen penetration into deeper sediment layers but also recycles nutrients into the water column and much more.
Quantifying the impact of stingray bioturbation is challenging, but recent research has advanced our understanding. My recent PhD research, published in Remote Sensing in Ecology and Conservation, is the first to combine drones, aerial imagery, and 3D modelling to map benthic topography and identify stingray feeding pits on intertidal and subtidal sandflats. By conducting daily drone surveys in the Brisbane Water estuary, we measured the volume of sediment displaced by stingrays, revealing that these small creatures move an impressive 21,000 tonnes of sediment annually – a greater mass than the Great Sphinx of Giza.
However, declining ray populations due to overfishing, habitat loss, and climate change threaten this important ecological process. With many species at risk of extinction, the reduction in bioturbation could lead to a loss of essential ecosystem services, potentially causing cascading effects throughout the food web. Understanding and protecting the ecological roles of stingrays is crucial for maintaining the health of our marine environments.
Link to my publication below: https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1002/rse2.411
Stingray in Wallis Lake.
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