6. Pittwater-Orielton Lagoon
Information in the Ecological Character Description (ECD) (Dunn 2009) and the latest version of the Ramsar Information Sheet (RIS) for the Pittwater-Orielton
Lagoon Ramsar site were reviewed to identify threats to the ecological character of the site. Terminology from these key Ramsar documents was aligned to
be consistent with the approach of the Ramsar Rolling Review (see Table 1 explanation notes).
The Ramsar Rolling Review uses the IUCN threat classification (reference) to standardise terminology across sites. All threat categories identified at the
Pittwater-Orielton Lagoon Ramsar site are listed in Table 2.
The critical components, processes and services (CPS) specified in the ECD are reproduced in Table 3. Threats which have the potential to change one or
more of the critical CPS within a 10 year timeframe are defined as imminent threats to the ecological character of the site (labelled IMM in Table 3). .
Consultation with site managers was undertaken to ensure the correct identification of current and imminent threats (see Table 1).
A stressor model is presented to illustrate the major pathways by which imminent threats effect the critical CPS. For clarity, the model does not attempt to
show non-imminent threats, weak linkages or feedbacks.
Table 1: Notes regarding alignment of terminology and additional information sourced from site managers to aid in the development of the sites
threat conceptual model.
Notes:
Threats in the ECD were matched to IUCN categories as follows:
 Loss of freshwater inputs = 7.2 Dams and water management/use
 Changes in sediment transport = 7.2 Dams and water management/use and 7.3 Other ecosystem modifications (changes to the tidal
movement)
 Agricultural services = 2.3 Livestock farming and ranching
 Waste products = 9.1. Household Sewage & Urban Waste Water and 9.2. Industrial & Military Effluents
 Urban development = 1.1 Housing and Urban Areas, 6.1 Recreational Activities and 9.1 Household Sewage & Urban Waste Water
 Invasive species = 8.1 Invasive alien species and genes
 Climate change = 11.1; 11,2, 11.3; 11.4 (various effects of climate change)
Model was updated and imminent threats re-assessed based on the advice of Parks Tasmania (Lynne Sparrow) as follows:
 Urban and commercial development was considered an imminent threat due to increased sediment discharge to the site and disturbance
of breeding and migratory birds;
 Recreation was expanded to include the Golf Course and associated impacts;

Human Intrusions and Disturbance (6.3 Work & Other Activities) was added to encompass disturbance to birds from the local airport,
commercial properties, roads, etc.
 Impacts of recreation are not limited to bird disturbance, but also trampling of littoral vegetation;
 Climate change (Habitat alteration and increased frequency and intensity of storms) was considered an imminent threat to littoral
vegetation communities;
 Invasive species (African Boxthorn) is a concern in part of the site, particularly on islands. However, is not considered likely to change the
ecological character of the Ramsar site in the short term.
Drought and reduced freshwater inflows is a threat to aquaculture (Provisioning service: Provision of aquatic foods for human consumption).
However this is not considered to be likely to change the ecological character of the site.
Table 2: Major categories and subcategories of current threats for the Ramsar site.
6. Pittwater-Orielton Lagoon
1. Residential & Commercial Development
1.1. Housing & urban areas
8. Invasive & Other Problematic Species & Genes
8.1. Invasive Non-native/Alien Species
2. Agriculture and Aquaculture
2.3. Livestock Farming and Ranching
9. Pollution
9.1. Household sewage & urban waste water
9.2. agricultural & forestry effluents
6. Human Intrusion & Disturbance
6.1. Recreation activities
6.3. Work & other activities
7. Natural System Modifications
7.2. Dams & water management/use
7.3. Other ecosystem modifications
11. Climate Change & Severe Weather
11.1. Habitat Shifting & Alteration
11.2. Droughts
11.3. Temperature Extremes
11.4. Storms & Flooding
Hydrology
Water quality
IMM
IMM
Littoral vegetation
IMM
IMM
Submerged vegetation
IMM
IMM
IMM
IMM
IMM
IMM
IMM
Geomorphology
IMM
Invertebrates
Fish
Birds
Provisioning service: Provision of aquatic
foods for human consumption
Regulating service: Pollution control and
detoxification through trapping, storage
and/or treatment of contaminants
Regulating service: Natural hazard
reduction
IMM
IMM
IMM
IMM
IMM
11.4. Storms & flooding
IMM
IMM
IMM
11.3. Temperature extremes
IMM
IMM
Climate
11.2. Droughts
9.2. Agricultural & forestry
effluent
IMM
11.1. Habitat shifting &
alteration
9.1. Household sewage &
urban waste water
IMM
8.1. Invasive nonnative/alien species
IMM
7.3. Other ecosystem
modifications
IMM
7.2. Dams and water
management/use
6.3. Work & other activities
6.1. Recreation activities
2.3. Livestock farming &
ranching
Components (blue), Processes (green),
Services (yellow)
1.1. Housing & urban areas
Table 3: Matrix of all current threats against critical components, processes, and services showing those considered to be an imminent threat to
the ecological character of the Pittwater-Orielton Lagoon Ramsar site (components shaded blue, processes green, services yellow).
IMM
IMM
Cultural service: Tourism
Cultural service: Science and education
Cultural service: Cultural heritage and
identity
Cultural service: Spiritual and inspirational
Supporting service: Nutrient cycling
IMM
Supporting service: Sediment trapping,
stabilisation and soil formation
Supporting service: Biodiversity
Key to shapes used in conceptual model.
IMM
IMM
IMM
IMM
11.4. Storms & flooding
IMM
Cultural service: Recreation
11.3. Temperature extremes
IMM
11.2. Droughts
9.2. Agricultural & forestry
effluent
IMM
11.1. Habitat shifting &
alteration
9.1. Household sewage &
urban waste water
IMM
8.1. Invasive nonnative/alien species
IMM
7.3. Other ecosystem
modifications
IMM
7.2. Dams and water
management/use
6.3. Work & other activities
6.1. Recreation activities
2.3. Livestock farming &
ranching
1.1. Housing & urban areas
Components (blue), Processes (green),
Services (yellow)
References:
Dunn, H., 2009, Pitt Water - Orielton Lagoon Tasmania Ecological Character Description, Draft 1 August 2009
6. Pittwater-Orielton Lagoon
7. Natural Systems Modification
7.2. Dams and Water
Management
Decreased high flows
Indicator:
Hydrograph
1. Residential & Commercial
Development
1.1. Housing & urban areas
Increased suspended
sediments
Indicator: Total
suspended solids
11. Climate Change & Severe
Weather
11.1. Habitat shifting & alteration
9. Pollution
9.1. Household sewage & urban
waste water
9.2. Agricultural & forestry effluents
6. Human Intrusions and
Disturbance
6.1. Recreational activities
6.3. Work & other activities
Increased erosion
Indicator: Area of
shoreline impacted
Increased nutrients
Indicator: Nutrient
concentrations (PO4,
NH4, NOx, Total N,
Total P)
Increased human
activity
Indicator: Numbers
of visitors/vehicles
Decreased
health
(saltmarsh
and
seagrass)
Increased
primary
productivity
Indicator:
chlorophyll
a
Disruption
of breeding
and
migration
(birds)
Increased salinity
Indicator: Salinity
Disruption
of breeding
(fish)
Component:
Hydrology
Component:
Water quality
Service: Nutrient
cycling
Altered
community
composition
(saltmarsh)
Component: Fish
Services:
Aquatic foods for
human consumption,
Biodiversity
Component:
Invertebrates
Service: Biodiversity
Component: Littoral
vegetation
Service: Biodiversity
Component:
Submerged
vegetation
Service: Biodiversity
Component: Birds
Service: Biodiversity