The Saltmarsh bushcare working bees have been removing weeds in the saltmarsh at Gough Whitlam Park since 2011. There have been quarterly monitoring sessions to document the changes to the saltmarsh in this time. These changes include weed abundance, saltmarsh plant distribution, and biodiversity indicators such as crabs.

The Saltmarsh monitoring bees use quadrants across a transect from the outer (landward) to the inner (river side) saltmarsh. This transect tracks changes in vegetation with the ground level. A major factor in vegetation spread is the level of tidal innudation with each high and king tide. 

The principal saltmarsh plants are Sarcarcornia quinqueflora, Suaeda australis, and Triglochin striatum. A recent arrival since working at the site is the native Creeping Brookweed (Samolus repens). We are also seeing the spread of Sarcarcornia toward the outer saltmash due to bushcare efforts. This indicates fantastic progress.

In general, the outer saltmarsh is more weedy. The weeds are mostly common couch, and occasionally flea bane, dock. The most serious weed is Juncus acutus. The monthly volunteer bushcare working bees have been vigilant in preventing it establishing.

The Gough Whitlam Saltmarsh on the Cooks River

Methodology: What do we do, and how?

1. A series of 1 m² quadrats are used along established points in the saltmarsh.
2. These quadrats are sampled at approximately 3 monthly intervals. All the plant species present in each quadrat are recorded and the percentage of the quadrat covered by each species noted.
3. Only the major species are plotted:
   (a) Streaked arrow grass (Troglochin striata)
   (b) Austral seablite (Suaeda australis)
   (c) Samphire, beaded glasswort (Sarcocornia quinqueflora)
   (d) Marine couch grass (Sporobolus virginicus)
   (e) Common couch grass (weed) (Cynodon dactylon)
   (f) Sea rush (Juncus kraussii)

Other points of interest such as the presence of crab holes are also noted. The data from 2012-13 and 2013-14 is available here, with a map sourced from google maps. This graphical data was compiled by Russell Cail.

Saltmarsh monitoring graph 2012-13

The inner (quadrant 1) and the outer quadrants ( 7 and 8 ) remained consistent across the yearly sampling period, however  changes to species occurrence can be seen in quadrant 2, 3 and 4. These quadrants represent a change to species distribution over a relatively small area of the saltmarsh, including Suaeda, marine couch and exotic couch.

Saltmarsh monitoring graph 2013-14

In this sampling period 2013-14, an increase in Sarcorcornia in quadrants 2 and 4 is seen. Changes in the occurrence of Triglochin is also noted in quadrant 5. A seasonal increase of Suaeda and marine couch is also evident in quadrant 10.

Saltmarsh monitoring graph 2014-15

In the sampling period 2014-15, continued increases of Sarcorcornia , Suaeda and marine couch are evident.

For more information, or If you would like to be involved in monitoring, please contact the Biodiversity Projects Officer on 97899750.