4.1    Arguments for and against the taxon approach

4.2    Status evaluation and threatened species lists

4.2.1   International status evaluation: IUCN categories
4.2.2   Other criteria

4.3    The threatened species approach in Australia

4.3.1   Criteria and the listing process
4.3.2   Recovery plans and plans of management
4.3.3   Difficulties with invertebrate lists and current criteria for status evaluation

4.4    Characteristics of marine invertebrates likely to be at risk

4.4.1   Restricted geographic range
4.4.2   Habitat specialisation
4.4.3   Limited dispersal
4.4.4   Reproductive vulnerability
4.4.5   Overexploitation
4.4.6   Rarity

4.5    Some examples of threatened or potentially threatened Australian marine invertebrates

4.5.1   Porifera
4.5.2   Cnidaria
4.5.3   Polychaeta
4.5.4   Mollusca
4.5.5   Crustacea
4.5.6   Bryozoa
4.5.7   Echinodermata
4.5.8   Tunicata: Ascidiacea
4.5.9   Cephalochordata
4.5.10  Other phyla

4.6    Management options for species conservation

4.7    Main issues and recommended actions