Balaclava Island seagrass and marine plants baseline survey. A Report for Gladstone Ports Corporation

1. Seagrasses at Balaclava Island were surveyed between 4th –6th of November 2021. A total of 379 sites were surveyed including 82 where seagrass was recorded. 2. Seagrass was present in three meadows covering a total area of 189.08 ± 6.32 ha. Mean seagrass biomass across the meadows ranged from 1.01 g DW m‐2 in the smallest meadow to 18.58 ± 2.11 g DW m‐2 in the largest meadow. 3. Macroalgae was largely absent from the survey area with the exception of ephemeral filamentous green algae on some intertidal banks. 4. A range of fauna was observed during the survey including green turtles, snub nosed dolphins, sea eagles, sea snake and shorebirds such as pelicans, egrets and terns. 5. Seagrass meadows at Balaclava Island comprised of two species (Zostera muelleri, Halophila ovalis) that are common throughout Port Curtis and Rodds Bay including in the Western Basin at Fishermans Landing. 6. Seagrass meadow area at Balaclava Island (189 ha) was greater than meadow area within the Southern Reclamation Area of the Northern Land Expansion Project at Fishermans Landing (42 ha in November 2020) and had much greater biomass within its footprint (9.15 g DW m‐2 compared with 1.34 g DW m‐2)