Sydney Harbour - 3000 species and counting!

These are questions that piqued the curiosity of 5 scientists at the Australian Museum who have published the first extensive list of Sydney Harbour animals.  The work is based on analyses of records from the Australian Museum's vast collections that date back over 150 years.

The project brought together all the museum's database records of fishes, crustaceans, molluscs, worms and echinoderms that have been collected in the harbour.  The records were plotted onto maps of the harbour to give a picture of what has been collected from different areas.

The authors, each a specialist on one of the groups of animals, examined the rate of accumulation of museum records and species numbers since the 1860s. The results revealed an interesting but not surprising picture: knowledge of Sydney Harbour's fauna has peaked at times when harbour-centred research programs were conducted and when more research taxonomists were employed at the Australian Museum.

Comparisons:

Sydney Harbour has between double to triple the number of polychaete, crustacean and mollusc species (2355) than that of the neighbouring estuaries: Botany Bay (1636), Hawkesbury River (1335) and Port Hacking (981). The high species richness of Sydney Harbour is probably the result of multiple factors, including significant tidal flushing and the high diversity of habitats.

What's next:

The project was the main contribution on biodiversity for a Sydney Harbour review that will soon be published by the Sydney Insititute of Marine Science. The research provides an excellent guide for future management and research decisions, and highlights the value of museum collections. There is so much more to learn. Potential areas of future work include:

• targeted sampling in poorly sampled areas and habitats (e.g. upper Middle Harbour, deep holes)
• examination of targeted specimens in the collection to confirm their identification.
• expansion of the work to include more animal groups (e.g. mammals, sponges - see top image on this page!, soft corals, ascidians etc.)

What can you do?

• Please report unusual sightings to the museum and/or Redmap.
• Please do not pour toxic liquids down the drain.
• If you live in Sydney, delight in the fact that you live near one of the world’s mega-diverse waterways.
• Recognise that Sydney Harbour is unique and worth preserving.