Download 18. Port Phillip Bay and Bellarine Peninsula

18. Port Phillip Bay and Bellarine Peninsula
Information in the Ecological Character Description (ECD) (Hale 2009) and the latest version of the Ramsar Information Sheet (RIS) for the Port Phillip Bay
and Bellarine Peninsula 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 Port
Phillip Bay and Bellarine Peninsula 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:
Critical components, processes, benefits and services are as indicated in the ECD. Threats are from ECD and site management plan. The
management plan considered that urban and commercial development was a serious threat, but this was mostly due to stormwater and other
pollutants. This is captured in threat 9.1
Discussion with site managers (Parks Victoria) lead to the removal of dredging as a threat and inclusion of pest plants and animals.
The CSIRO Port Phillip Bay Study (Harris et al. 1996) identified the need to significantly reduce nitrogen loads to the Bay. The Western Treatment
Plant (WTP) is responsible for over 50% of nitrogen inputs. Melbourne Water developed an Environmental Improvement Plan with the aim of
reducing nutrient discharge. Actions under the plan include:
 An upgrade of the wastewater treatment process and a consequent reduction in the total nitrogen load to PPB (->Decreased nutrients);
 A reduction in retention times for water in some areas of the WTP (->decreased frequency of inundation);
 Decommissioning of some lagoons (which now receive treated effluent rather than sedimented sewage)
 A change to the patterns of irrigation in the grassland areas and a potential change in agricultural practices (-> Decreased nutrients and
decreased frequency of inundation).
Threats listed in the ECD, but not considered “imminent” are:
 Recreation – disturbance of migratory birds may be an issue, but this is unlikely to cause the magnitude of change in bird numbers that
would be considered a change in ecological character of the site.
 Water resource development – site was listed with a degree of water resource development and the character of Reedy lake is
maintained by the presence of artificial structures. There is no evidence that wide scale changes in water resource use are imminent.
 Climate change – the major impacts from climate change at this site are related to sea level rise and increased storm surges, these are
not predicted to be sufficient to change the character of the site within the next 10 years.
 Commercial fishing – much of the Ramsar site is protected marine waters and fishing is not permitted. While there is evidence that
commercial fishing may act as competition for seabirds, it is not considered that this alone is likely to result in a change in the ecological
character of the site in the next 10 years.
 Chytrid fungus – global scale threat not known to occur in the Ramsar site.
Following feedback from State representative (Yvette Baker) and Parks Victoria (Mark Rodrigue) Invasive species (foxes and Spartina) were
added as an imminent threat and the model and SSF updated to reflect this.
Table 2: Major categories and subcategories of current threats for the Ramsar site.
18. Port Phillip Bay and Bellarine Peninsula
1. Residential & Commercial Development
1.1. Housing & urban areas
7. Natural System Modifications
7.2. Dams & water management/use
2. Agriculture and Aquaculture
2.1. Annual & perennial non-timber crops
2.3. Livestock farming and ranching
8. Invasive & Other Problematic Species & Genes
8.1. Invasive Non-native/Alien Species
4. Transportation & Service Corridors
4.3. Shipping lanes
5. Biological Resource Use
5.1. Hunting & collecting terrestrial animals
5.4. Fishing & harvesting aquatic resources
6. Human Intrusion & Disturbance
6.1. Recreation activities
9. Pollution
9.1. Household sewage & urban waste water
9.3. Agricultural & forestry effluents
11. Climate Change & Severe Weather
11.4. Storms & flooding
IMM
Hydrology
Vegetation
Frogs
IMM
Fish
Waterbirds
IMM
IMM
Orange-bellied Parrot
IMM
IMM
Provisioning service: Water supply
Cultural service: Recreation
Cultural service: Tourism
Cultural service: Science and education
Cultural service: Spiritual and inspirational
Supporting service: Physical habitat
IMM
IMM
Supporting service: Biodiversity
IMM
Supporting service: Threatened wetland species,
habitat and ecosystems
IMM
IMM
Supporting service: Ecological connectivity
IMM
IMM
IMM
11.4. Storms & flooding
9.1. Household sewage
& urban waste water
IMM
Geomorphology
9.3. Agricultural &
forestry effluents
8.1. Invasive Nonnative/Alien Species
7.2. Dams & water
management/use
6.1. Recreation activities
5.4. Fishing & harvesting
aquatic resources
5.1. Hunting & collecting
terrestrial animals
4.3. Shipping lanes
2.3. Livestock farming
and ranching
1.1. Housing & urban
areas
Components (blue), Processes (green)
Services (yellow)
2.1. Annual & perennial
non-timber crops
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 Port Phillip Bay and Bellarine Peninsula Ramsar site (components shaded blue, processes green, services yellow).
Key to shapes used in conceptual model.
References
Hale, J., 2009, Ecological Character Description for the Port Phillip Bay (western shoreline) and Bellarine Peninsula Ramsar Site. Report to the Department of
Environment, Water, Heritage and the Arts, Canberra
18. Port Phillip Bay and Bellarine Peninsula
9. Pollution
9.1. Household sewage & urban
waste water (change in operation at
waste treatment plant)
Decreased nutrients
Indicator: Nitrogen
concentration (Total N
NOx, NH4)
2. Agriculture & Aquaculture
2.1. Annual & perennial non-timber
crops (change in operation at waste
treatment plant)
Decreased frequency
of inundation
8. Invasive & Other Problematic
Species & Genes
8.1. Invasive non-native/alien species
Invasive species
(foxes, cats)
Indicator: Abundance
9. Pollution
9.1. Household sewage & urban
waste water (urban stormwater)
Invasive species
(Spartina)
Indicator: Extent
Decreased light
Indicator: Secchi
depth
Increased nutrients
Indicator: Nitrogen
and phosphorus
concentrations (PO4,
NOx, NH4)
Reduced
primary
productivity
Indicator:
Chlorophyll
Disruption
of breeding
(Growling
Grass Frog)
Altered food
webs
(decreased
secondary
productivity)
Component:
Fish
Services: Biodiversity,
Ecological connectivity
Component:
Frogs
Service: Threatened
species
Increased
predation
(waterbirds)
Altered food
webs
Indicator:
No of Ibis
foraging
Component:
Waterbirds
Services: Physical
habitat, Biodiversity,
Threatened species,
Ecological connectivity
Altered
community
composition
(saltmarsh)
Component:
Vegetation (saltmarsh)
Service: Physical
habitat
Decreased
vegetation
health
Component:
Vegetation (freshwater
aquatic flora)
Service: Physical
habitat
Component:
Vegetation (seagrass)
Service: Physical
habitat