Flood Plain Lower Ringarooma River Ramsar site Ecological Character Description March 2012 Blank page Citation

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1.13Summary of the Key Threats

Although there are many other potential or less major threats (see sections 4.1 to 4.3, above), Table 12 focuses on the major threats confronting the site.

Table 12: Summary of the key threats to the site.

Threat	Details	Likelihood	Severity	Time frame
Sedimentation	Ongoing deposition of sand in the wetlands of the site, reducing habitat extent and diversity. Direct threat to estuary and freshwater zone.	Almost certain	Unknown	up to 50 years
Erosion	Indirect threat to freshwater zone - eventual scour of the river channel, when upstream sediment supply decreases. Result could be lowering of river bed and subsequent isolation of the wetlands from the river.	Possible	High	Unknown
Expansion of agriculture into natural/near natural vegetation communities	Expansion of grazed land into the currently ungrazed areas of the site could lead to loss of vegetation communities and soil structure of freshwater zone.	Possible	Potentially severe	Unknown
Weed invasion	Can occur through existing agricultural activities and any expansion of grazing at the site. Indirect threat to freshwater and estuarine zone, through loss of natural vegetation. Incursion of weeds brought downstream from higher in the catchment and the persistence of gorse (Ulex eurpaeus) are threats.	Likely	Unknown	Indefinite
Eutrophication	Inputs of excess nutrients, leading to problems with algal blooms in permanent and temporary waters of the site. Direct threat to water quality of freshwater and estuarine zones.	Possible	Potentially very severe	Indefinite
Climate Change	Most likely impact is through rising sea levels inundating the (currently) freshwater and estuarine zones of the site. Changes to precipitation also pose an indirect threat to freshwater zone.	Possible	Potentially very severe	Medium to long term (50 to 100 years)

lIMITS OF ACCEPTABLE CHANGE

LAC explanatory notes

1. Limits of Acceptable Change are a tool by which ecological change can be measured. However, Ecological Character Descriptions are not management plans and LACs do not constitute a management regime for the Ramsar site.

2. Exceeding or not meeting LACs does not necessarily indicate that there has been a change in ecological character within the meaning of the Ramsar Convention. However, exceeding or not meeting LACs may require investigation to determine whether there has been a change in ecological character.

3. While the best available information has been used to prepare this Ecological Character Description and define LACs for the site, a comprehensive understanding of site character may not be possible as in many cases only limited information and data is available for these purposes. The LACs may not accurately represent the variability of the critical components, processes, benefits or services under the management regime and natural conditions that prevailed at the time the site was listed as a Ramsar wetland.

4. Users should exercise their own skill and care with respect to their use of the information in this Ecological Character Description and carefully evaluate the suitability of the information for their own purposes.

5. LACs can be updated as new information becomes available to ensure they more accurately reflect the natural variability (or normal range for artificial sites) of critical components, processes, benefits or services of the Ramsar wetland.

The following components and processes were identified (Section 3.4) as critical to the ecological character of the Flood Plain Lower Ringarooma River Ramsar Site ecosystem:

wetland vegetation types
regionally rare plant species
nationally and regionally listed bird species
nationally listed fish species
green and gold frog
nesting shorebirds
listed migratory birds
migrating fish

Table 13 presents the limits of acceptable change for the critical components, processes and services, as identified within the ECD process. Limits are typically set for the time of listing and, if change in ecological character has occurred since listing, a second set of limits is provided. In the case of the Flood Plain Lower Ringarooma River Ramsar Site, there was one change to a critical component that did not constitute a change in ecological character but was worthy of a refinement of the limits. This change was the increase in area of freshwater aquatic sedgeland and rushland (Ramsar wetland type Ts). Rather than prepare two LAC for this component the LAC area was increased to accommodate the increase.

The confidence levels for the limits of acceptable change represent the degree to which the authors are confident that the LAC represents the point at which a change in character has occurred and follow the approach of Hale (2010):

High – Quantitative site specific data; good understanding linking the indicator to the ecological character of the site; LAC is objectively measureable.

Medium – Some site specific data or strong evidence for similar systems elsewhere derived from the scientific literature; or informed expert opinion; LAC is objectively measureable.

Low – no site specific data or reliable evidence from the scientific literature or expert opinion, LAC may not be objectively measurable and / or the importance of the indicator to the ecological character of the site is unknown.

Table 13: Limits of Acceptable Change for the Flood Plain Lower Ringarooma River Ramsar Site.

Critical Component, Process or Service	Baseline information	Limits of acceptable change*	Confidence level	Justification and Comments
All Ramsar wetland types identified as being present at time of listing except Freshwater aquatic sedgeland and rushland (Ts) (service = supports Ramsar wetland types).	Using a vegetation survey (DPIW 2006), aerial photographs, and a site inspection, the following areas were identified for each wetland type (hectares): E = 74 F = 33 G = 58 H = 44 J = 74 N = 5 Tp= 169 W = 13 Xf = 614 Xp = 1	Not more than a 20 percent loss in area of any wetland type in nine out of 10 years. So that is, no more than: 15 hectares for E 6.5 hectares for F 12 hectares for G 9 hectares for H 15 hectares for J 1 hectare for N 34 hectares for Tp 2.5 hectares for W 123 hectares for Xf 0.2 hectares for Xp	Medium – site specific measures of area are used: however, the 20 percent change is not quantitatively derived.	There are no data on the variability of the wetland habitat types and, until this ECD, there was no mapping of the wetland types. These limits have been set as a common sense approach to defining a significant change in the area of each wetland type. Monitoring into the future should incorporate changes to wetland type over time to refine this LAC.
Freshwater aquatic sedgeland and rushland (Ts) (service = supports Ramsar wetland types).	Using a vegetation survey (DPIW 2006), aerial photographs and a site inspection, an area of 257 hectares was identified as freshwater aquatic sedgeland and rushland at the time of listing.	No less than 298 hectares of freshwater aquatic sedgeland and rushland should be present at the site in nine out of 10 years. This represents 80 percent (for example a 20 percent loss) of the current area of this wetland type (373 hectares).	Medium – site specific measures of area are used: however, the 20 percent change is not quantitatively derived.	At listing, the site contained a large area of agricultural land (rough grazing) in Fosters Swamp. Grazing has subsequently ceased and the area allowed to regenerate into sedgeland and rushland, increasing the total area of this vegetation type to 373 hectares. There are no data on the variability of the wetland habitat type at the site and, until this ECD, there was no mapping of the wetland types. A limit of 20 percent has been set as a common sense approach to defining a significant change in the area of each wetland type. Monitoring into the future will refine this LAC.
Rare plant species (service = supporting populations important for regional biodiversity).	The only baseline information available is that four rare wetland dependent species were recorded as being at the site at the time of designation.	Presence in nine out of 10 years of: native gypsywort erect marshflower purple loosestrife ribbon weed	Low	There is no quantitative information on these species within the site. Therefore quantitative limits of acceptable change cannot be set and a qualitative LAC based on presence / absence of these four species is provided. Based on lack of data for the site, confidence in the LAC representing good indicator of change in ecological character is low.
Australian grayling and dwarf galaxias (service = support for rare or threatened species).	The only baseline information available is that these species were recorded as being at the site at the time of designation.	Presence in nine out of 10 years of: Australian grayling dwarf galaxias	Low	There is no quantitative information on any fish species at the site. Therefore quantitative limits of acceptable change cannot be set and a qualitative LAC based on presence / absence of the species is provided. Based on lack of data for the site, confidence in the LAC representing good indicator of change in ecological character is low.
Green and gold frog (service = support for rare or threatened species).	This species has been seen and heard at the site on different occasions. There are no quantitative data for this species.	Presence in nine out of 10 years of the green and gold frog	Low	There is no quantitative information on Litoria raniformis at the site. Therefore quantitative limits of acceptable change cannot be set and a qualitative LAC based on presence / absence of the species is provided. Based on lack of data for the site, confidence in the LAC representing good indicator of change in ecological character is low.
Migratory bird species (service = support for a population at a critical stage of its life cycle) and regionally rare bird species (service = supporting populations important for regional biodiversity).	The only baseline information available is that these eleven species were recorded as using the site at the time of designation.	Presence in 2 out of 3 years of: Latham’s snipe curlew sandpiper red-necked stint ruddy turnstone bar-tailed godwit caspian tern little tern greenshank cattle egret great egret white-bellied sea eagle	Low	There is no quantitative information on these species at the site. Therefore quantitative limits of acceptable change cannot be set and a qualitative LAC based on presence / absence of the species is provided. Based on lack of data for the site, confidence in the LAC representing good indicator of change in ecological character is low.
Nesting shorebird species (service = support for a population at a critical stage of its life cycle) and rare bird species (service = support for rare or threatened species).	The only baseline information available is that five species of shorebirds nest at the site, one of which (fairy tern) is listed on the IUCN redlist.	The presence of nesting populations in 2 out of 3 years for: little tern hooded plover fairy tern pied oystercatcher red-capped plover	Low	No quantitative information on these species at the site means that no quantitative limits of acceptable change can be set and a qualitative LAC based on presence / absence of the species is provided. Based on lack of data for the site, confidence in the LAC representing good indicator of change in ecological character is low.
Migratory fish species (service = support for a population at a critical stage of its life cycle).	The only baseline information available is that three migratory fish species occur at the site, one of which is the rare Australian grayling.	Presence in 2 out of 3 years of: Tasmanian mudfish Tasmanian whitebait Australian grayling	Low	Again, no quantitative information on these species at the site means that no quantitative limits of acceptable change can be set and a qualitative LAC based on presence / absence of the species is provided. Based on lack of data for the site, confidence in the LAC representing good indicator of change in ecological character is low.

* Exceeding or not meeting a LAC does not automatically indicate that there has been a change in ecological character.

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