
%0 Journal Article
%A Lee Long, WJ 
%A Mellors, JE 
%A Coles, RG 
%T Seagrasses between Cape York and Hervey Bay, Queensland, Australia
%J Marine and Freshwater Research
%D 1993/02/01
%V 44
%N 1
%P 19-31
%K 
%R https://doi.org/10.1071/MF9930019
%U https://www.publish.csiro.au/paper/MF9930019 
%X The area of seagrasses in waters adjacent to the Queensland coast between Cape York and  Hervey Bay is approximately 4000 km2. Seagrasses were found near estuaries, in coastal  bays and associated with islands, at sites that provided shelter from the south-easterly trade  winds and Pacific Ocean swells. Of the seagrass meadows mapped, 37% had a bottom  vegetation cover greater than 50%. Two large continuous areas (total of approximately 2500 km2)  of seagrass of predominantly Halophila species were found in deep water in Hervey Bay  and between Barrow Point and Lookout Point and may be part of a much larger area of  deep-water seagrass habitat not yet surveyed in the Great Barrier Reef province. Fourteen  seagrass species were found in the surveyed region, and most were typical of the northern  Australian and Indo-West Pacific region. The opportunistic Halophila and Halodule species  were most common, with Halophila ovalis (R. Br.) Hook. f. and Halodule uninervis (Forsk.) Aschers.  each being found in more than 15% of samples. High species richness occurred at depths of less  than 6 m, predominantly in sheltered bays at coastal and island locations.  Low species richness at estuary- associated sites may be due to stresses caused by low salinity  during monsoonal runoff periods or exposure at low tides. Zostera capricorni Aschers. was restricted  to these areas and may have a competitive advantage over other species with lesser tolerance to  varying salinity. Species richness decreased with an increase in both latitude and depth.  The latitudinal limits of recorded distributions for some of these tropical seagrasses were confirmed.  Seagrass biomass decreased with increasing depth, but parameters of seagrass abundance showed  no correlation with latitude, being dependent on a complex of site-related factors.  High seagrass biomass occurred at sheltered sites, including estuary-associated, coastal-bay and island-associated sites. The maximum recorded above-ground biomass was 102.9 g m-2 for Zostera  capricorni at Upstart Bay. Shoot densities reached 13 806 shoots m-2 for Halophila ovalis at  Escape River, and the highest leaf area index was 1.81 for Zostera capricorni at Upstart Bay. 
