The weedy seadragon is primarily threatened by habitat degradation and loss due to pollution and sedimentation, especially in urban areas.
The weedy seadragon is primarily threatened by habitat degradation and loss due to pollution and sedimentation, especially in urban areas. The loss of suitable seagrass beds, coupled with natural history traits that make them poor dispersers, put the future of seadragon populations at risk.
Weedy seadragons are killed by pollution and fertilizer run-off in their shallow, coastal habitats. Both algae-covered reefs and seagrass meadows have been adversely affected by human activities and loss in quality and quantity of habitat has been documented within its range.
The degradation of habitat is worst near major urban centers, such as Sydney, Adelaide, Melbourne, Perth, and Hobart, where discharge of storm water and treated sewage leads to eutrophication and increased sedimentation. Losses of seagrass have been particularly severe along the metropolitan coasts and are well documented. Reefs have been more strongly affected by increased rates of sedimentation resulting from human activities such as sand dredging, land reclamation and coastal urban development.
It is suspected that habitat degradation is playing a role in declines in weedy seadragons being observed along urban coasts, but further research is needed in order to confirm this. Further population and habitat monitoring are needed to decisively link habitat degradation to population declines.
• Image | © Klaus Stiefel, Some Rights Reserved (CC BY-NC 2.0)
• Sources | (Frostic, 2000; Pollom, 2017; Sanchez-Camara, Martin-Smith, Booth, Fritschi, & Turon, 2011; Short & Wyllie-Echeverria, 1996; The Wikimedia Foundation, 2019)