Seagrass Impact Assessment
Analyzed pre- and post-dredging data along the Northern Adelaide Coast, providing a scientifically robust evaluation of potential impacts on seagrass meadows and supporting government coastal management decisions.
Location: Northern Adelaide Coast (North Haven, Tennyson, West Beach), South Australia
Client/Sector: Department for Environment and Water (Government coastal management)
Challenge:
The South Australian Government conducted a dredging trial as part of the Adelaide Beach Management Review to investigate long-term sand recycling as a strategy for maintaining Adelaide’s beaches. Given the ecological importance of seagrass meadows in Gulf St Vincent, an independent assessment was required to determine whether dredging activities had caused measurable impacts on seagrass cover, density, or community composition.
Aquatic Assessments Role:
Aquatic Assessments undertook a comprehensive desk-based scientific analysis of pre- and post-dredging monitoring data using EPA-approved methodologies. Underwater video transects were reviewed to quantify seagrass cover, density, species composition, and epiphyte load across three Areas of Interest. Detailed statistical analyses were applied to detect changes in seagrass communities and distinguish potential dredging impacts from natural spatial and seasonal variability.
Outcome:
The study provided government decision-makers with a scientifically robust evaluation of potential environmental impacts in consideration with spatial and seasonal variation and provided scientifically defensible recommendations on monitoring to detect any delayed ecological responses.