North Queensland Naturalist 50: 73-79

Habitat features associated with newborn Giant Shovelnose Rays (Glaucostegus typus)

 

Leo C. Gaskins, Joseph P. Morton, Julianna J. Renzi, Stephanie R. Valdez and Brian R. Silliman

Abstract

Understanding patterns of habitat use by newborn-sized animals is critical to conserving threatened species and their potential nursery grounds. Giant Shovelnose Rays (Glaucostegus typus) are Critically Endangered but at least locally abundant in the Australian portion of their range, providing an opportunity in Australia to understand what types of habitat features are associated with newborn and young-of-the-year individuals in the absence of intense fishing pressure. To investigate this, we used replicated belt transects to study Giant Shovelnose habitat use and abundance in shallow (< 0.5 m), shoreline waters. 28 whole-island surveys were conducted at low tide over 2 years on Heron Island, Australia. In total, we counted 552 Giant Shovelnose Rays, 79% of which were newborn class (< 40 cm in length), in both sand flats and shallow areas with rock rubble. These habitat characteristics are consistent with other studies of Giant Shovelnose Rays in Australia, adding to the existing knowledge that these juvenile animals commonly use shallow waters. Studying newborn Giant Shovelnose habitat characteristics in a portion of their range where they are still locally abundant can offer a roadmap for managers to locate key regions to protect within imperiled portions of their range.