Hervey Bay Dugong and Seagrass Monitoring Program

Seagrass in Hervey Bay

Hervey Bay once had the second largest area of seagrass along the east coast of Australia.
Two floods and a cyclone in early 1992 resulted in more than 1000km(sq) of seagrass dieback from Hervey Bay. * Preen ,A., and Mangh,H,.(1995) * Preen ,A., Lee Long,W., and Coles R (1994).
Subsequent surveys found that virtually all the known seagrasses in Hervey Bay had disappeared.
Shallow water seagrasses may have suffered excavating and burial by the effects of high energy waves, swells and currents. * Preen,A., Lee Long,W., and Coles, R., (1993).
Flood water from the Mary and Burrum Rivers most likely caused widespread impacts in Hervey Bay. Associated sediment loads and high turbidities would have shaded the light demanding seagrasses, particularily in deeper areas. As a result of diminished light and reduced photo synthesis the seagrasses may have effectively starved. * Preen, A., Lee Long,W., and Coles, R., (1993).
Approximately six to eight months later, dead and dying dugongs began to strand in unprecedented numbers along the shores of Hervey Bay and the Great Sandy Straits. *Preen ,A., and Mangh ,H,.(1995) *Preen ,A., Lee Long,W., and Coles R (1994). *Preen ,A., and Mangh ,H,. (1995) * Preen ,A., Lee Long,W., and Coles R (1994) .

LOCATION MAP OF HERVEY BAY SHOWING FRASER ISLAND AND THE GREAT SANDY STRAITS.

Sampling sites in Hervey Bay

The distribution of sampling sites and the abundance of seagrass (percentage cover) in Hervey Bay in 1988. Stippling represents seagrass cover generalised from sampling sites. Dashed lines indicate the three arbitrarily defined sectors of the bay.

The distribution of sampling sites and the abundance of seagrass (percentage cover) in Hervey Bay in 1992. Stippling represents seagrass cover generalised from sampling sites. Dashed lines indicate the three arbitrarily defined sectors of the bay.

Hervey Bay Seagrasses

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Halophila ovalis
Photo courtesy of Ron Phillips - University of Hawaii

Zostera capricorni
Photo courtesy of Maree Mateer

Halophila spinulosa
Photo courtesy of Ron Phillips - University of Hawaii

Halophila decipiens
Photo courtesy of Ron Phillips - University of Hawaii