Sites & Activites, Information, Authors

Students of the Plant Anatomy and Physiology course are expected to visit one of the sites recommended in the Sydney area and carry out the simple set of observations described. This material may be examined.

Activities

As part of this weeks practical work, you are expected to visit a mangove site and carry out the following activities.
Select a time for your visit when the tide will be less than half tide.

Aim to observe the following:

  • The relative positions of the different species with relation to the highest tide mark.
  • The species which are present.
  • The density of pneumatophores and their distribution, especially related to position in the tidal range.
  • The occurrence of algae growing on pneumatophores.
  • Try to identify the osmoticum used by Suaeda and Sarcocornia . A taste test will suffice if the plants are growing in a 'clean' area, such as one in which you might swim.
  • Look at the distribution and abundance of seedlings of mangroves. Where are they most common? What is the size distribution? In a representative sample, count the number of leaves (or better nodes) per individual.
  • Look for evidence of recruitment of new individuals which have grown past the 6 leaf stage. What does this tell you about the strategies used by the mangrove for its distribution?
  • Test for salt secretion by mangroves by tasting salt on leaves.
  • Observe flowering and fruiting of mangroves.
  • Look for evidence of human interference eg 'reclamation', clearing, rubbish dumping, oil spills.
  • Do the mangroves appear to be expanding their area? If so, at the expense of what?

Students of the Plant Anatomy and Physiology course are expected to visit one of the sites recommended in the Sydney area and carry out the simple set of observations described. This material may be examined.

Sites

There are many sites round Sydney where it is possible to gain easy access to mangroves however sites which also show the full range of salt marsh plants are uncommon.

Possible sites include:

Pittwater - Careel Bay off Hitchcock Park. Few Aegiceras but good for most other activities.

Bayview - Both sides of marina. Site of an attempt to regenerate a mangrove stand killed by an unknown agency (probably diesel oil). Few Aegiceras , most salt marsh plants present, limited zonation.

Roseville under Roseville Bridge. Enter from Earls Cr. Avicennia and other salt marsh species. (Also look on other side of the river in Garingal National Park).

Hunters Hill - Boronia Park . Tipperary Falls Picnic area off Princess St. A good site with limited salt marsh zonation.

Concord - Brays Bay. Enter park at end of Killoola St. (Rotary Club Picnic Area). A good site with salt marsh zonation to the right of the walkway. Aegiceras rare or absent.

Homebush Bay - Bicentennial Park. Good Avicennia with walkways . Some salt marsh zonation. Field study centre. Waterbird refuge.

Earlwood. Cooks River, Gough Whitlam Park. This was originally an extensive salt marsh which was 'reclaimed'. Regenerated site with Avicennia and salt marsh species in pond near change rooms (north side) and mangroves colonizing along river. (This site is within walking distance of Tempe railway station). Also Wolli Creek Enter from Waterworth Park below Unwin St. Make way along N side of creek under sewer line. Skirt mangrove stand (track) to north to find unusual salt marsh of mixed Sarcocornia and Phragmites.

Padstow. Salt Pan Creek - Stuart St. Reserve off Stuart St. Good Avicennia , some Aegiceras along creek at S.E. corner of reserve. Salt marsh species along creek but little zonation.

Riverwood. Salt Pan Creek Bridge, Henry Lawson Drive. Good Avicennia and salt marsh species under bridge. Look for large Aegiceras under cliff to the north of the bridge.

Grays Point. Shallow Rock Reserve. Excellent for mangroves. Salt marsh zonation fair. Also Grays Point at the end of Grays Point Rd. Excellent for mangroves. Salt marsh species present but zonation poor. A very pleasant site.

Organizing your excursion

Select a day when the tidal range is more than 1 metre and aim to arrive at the site an hour before low tide. You will inevitably get muddy and dirty, so wear old clothes (overalls, jeans, long sleeved shirts, hat) and take suitable footwear (gum boots or old joggers). Remember that it can be quite cold by the water. A bottle of water for drinking and washing hands can be useful and a simple first aid kit for cuts and scratches is a sensible precaution as is a supply of insect repellent and sun screen lotion.

Remember that mangrove and, especially, salt marsh communities are fragile and easily damaged by human intervention. Care must be taken to avoid excessive trampling, especially in Sarcocornia areas. Holes made to examine root systems must be filled in and rubbish removed. Respect the regulations concerning reserves and National Parks. Restrict your collections to the minimum necessary for plant identification and do not denude areas of seeds. As salt marshes are sometimes in lonely locations, it would be safer (and more interesting) to go in a group.


Production Information

"Mangrove and Salt Marsh, An excursion to Towra Point in Botany Bay"

This program was prepared as a 'virtual excursion' to replace an actual excursion which, for many years, had formed part of the second year course in Plant Anatomy and Physiology presented by the School of Biological Sciences at Sydney University. Changes in resource allocation within the school and the possibility that the excursion activities might cause damage to the area (which was previously held as a sand mining lease but which has recently become part of a national park), made it difficult to justify the continued presentation of the excursion in its original form.

In the writing of this program, an attempt has been made to maintain the 'linear' nature of an excursion. 'Links' are provided where supplementary information may be required. This program is designed to be used on an 'intranet' rather than the Internet. As a consequence, some illustrations may take time to download if being accessed through the Internet. This virtual excursion is best viewed with your monitor set to 'thousands of colours'.

The experimental and observational data presented was collected by students during excursions carried in 1996, and these students appear in the photos.

The material presented forms part of course work in the School of Biological Sciences but all others are welcome to access and use the information for interest or study, however, if it is reused or republished in any way, the source must be acknowledged.

We hope that you find the 'excursion' interesting and useful and would appreciate your constructive comments. This excursion is available on CD. If you are interested in a copy, please contact Mark Curran.

The Teachers of Plant Physiology, School of Biological Sciences A12, University of Sydney 2006. Australia.
Corresponding Author Mark Curran. If you are using this course on a networked computer you can click on the email address to send an email

Authors

This 'virtual excursion' was derived form material developed for the original mangrove excursion over a long period of time by a number of contributors including Mss F.E. (Penny) Goulter and Barbara Sanders, Michael Cole, Bill Allaway, Luke Grant and Mark Curran.

The concept and script was developed and written by Mark Curran with the help of Bill Allaway and Nick Skelton. Revised in 2004 by Mark Curran.

Images were prepared by Nick Skelton, who also gave advice on layout and solved the many computing problems which arose.

Photography by Malcolm Ricketts.