Richard T. Kingsford

Scientific Foundations for an IUCN Red List of Ecosystems

An understanding of risks to biodiversity is needed for planning action to slow current rates of decline and secure ecosystem services for future human use. Although the IUCN Red List criteria provide an effective assessment protocol for species, a standard global assessment of risks to higher levels of biodiversity is currently limited. In 2008, IUCN initiated development of risk assessment criteria to support a global Red List of ecosystems. We present a new conceptual model for ecosystem risk assessment founded on a synthesis of relevant ecological theories. To support the model, we review key elements of ecosystem definition and introduce the concept of ecosystem collapse, an analogue of species extinction. The model identifies four distributional and functional symptoms of ecosystem risk as a basis for assessment criteria: A) rates of decline in ecosystem distribution; B) restricted distributions with continuing declines or threats; C) rates of environmental (abiotic) degradation; and D) rates of disruption to biotic processes. A fifth criterion, E) quantitative estimates of the risk of ecosystem collapse, enables integrated assessment of multiple processes and provides a conceptual anchor for the other criteria. We present the theoretical rationale for the construction and interpretation of each criterion. The assessment protocol and threat categories mirror those of the IUCN Red List of species. A trial of the protocol on terrestrial, subterranean, freshwater and marine ecosystems from around the world shows that its concepts are workable and its outcomes are robust, that required data are available, and that results are consistent with assessments carried out by local experts and authorities. The new protocol provides a consistent, practical and theoretically grounded framework for establishing a systematic Red List of the world’s ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity

The Macquarie Marshes in Arid Australia and their waterbirds: A 50-year history of decline

We investigated the relationship between total annual flow of water in the Macquarie River and the extent of flooding in the northern part of the Macquarie Marshes and trends in waterbird populations from 1983 to 1993. The amount of water in the Macquarie River measured each year within the Macquarie Marshes explained about 86% of the variation in area flooded in the northern part of this wetland. This allowed use of long-term data on flow at Oxley, a gauge within the Macquarie Marshes, as an index to flooding. Annual flows at Oxley have decreased significantly for high and medium rainfall events in the catchment, despite no trend in rainfall between 1944 and 1993. The area flooded by large floods has contracted by at least 40–50% during the last 50 years (1944–1993). Water use has progressively increased upstream in the period, depriving the Macquarie Marshes of water: 51% of all water passing Dubbo each year, a gauge 100 km upstream, reached the Macquarie Marshes in the period 1944–1953, but by 1984–1993 this had declined to 21%. Numbers of species and density of waterbirds on the northern part of the Macquarie Marshes declined between 1983 and 1993. Three other wetlands, not affected by water abstractions, showed no declines. We believe the decline was due to wetland degradation as a result of decreased flooding. We estimated more than 88,000 waterbirds in the Macquarie Marshes in October 1984, establishing the site as an important wetland site in Australia. The extent and viability of this wetland will depend on maintaining or increasing the water supply.

Water flows on Cooper Creek in arid Australia determine 'boom' and 'bust' periods for waterbirds

Abstract Cooper Creek is probably the longest and most important dryland river in Australia and one of the largest endorheic catchments in the world. Long dry periods (‘busts’) are punctuated by floods of high productivity (‘boom’ periods). Data on waterbird distribution and abundance were collected during a boom period (1989/1990 flood) when Cooper Creek ran into Lake Eyre and overflowed into Strzelecki Creek to fill Lake Blanche. There were about 500 000 waterbirds in December 1990: Lower Cooper (138 000), Lake Eyre (325 000), Lake Blanche (40 000). Given underestimates of aerial surveys, conceivably there were one million waterbirds, making the area one of the most important for waterbirds in Australia. Colonies of Australian pelicans, cormorants, black swans, terns and silver gulls established during this flood. We used flow data and rainfall to estimate how often such habitat (boom periods) is created over a 100-year period, 1885–1995. Rainfall (cumulative index of four rainfall stations—Muttaburra, Tangorin, Isisford and Innamincka), was significantly related to total annual flow (ML), measured at Cullamurra (R2=0.86). We estimated that the Lower Cooper (south of Lake Hope) receives water about every 4.5 years but these floods seldom reach Lake Eyre (8 years in 100 years). There is water in Lake Hope and the Lower Cooper Creek: respectively, 62% and 39% of the time. Cooper Creek overflowed into Strzelecki Creek when there were large floods (1906, 1950, 1974) or two or more consecutive years of high flows (1916–1918, 1955–1956, 1989–1990). Lake Blanche filled six times and Lake Callabonna filled four times in 100 years. Occasionally, local rainfall also fills lakes (e.g. Lake Callabonna in 1931). Like all terminal river systems, these wetlands depend predominantly on upstream flows of water. Potential irrigation developments in the catchment will divert water from the river and decrease the frequency and flooding of wetlands of the Lower Cooper. There will be fewer feeding areas and less breeding opportunities for waterbirds. Boom periods will be shorter and bust periods longer. ©

Major conservation policy issues for biodiversity in oceania

Oceania is a diverse region encompassing Australia, Melanesia, Micronesia, New Zealand, and Polynesia, and it contains six of the worlds 39 hotspots of diversity. It has a poor record for extinctions, particularly for birds on islands and mammals. Major causes include habitat loss and degradation, invasive species, and overexploitation. We identified six major threatening processes (habitat loss and degradation, invasive species, climate change, overexploitation, pollution, and disease) based on a comprehensive review of the literature and for each developed a set of conservation policies. Many policies reflect the urgent need to deal with the effects of burgeoning human populations (expected to increase significantly in the region) on biodiversity. There is considerable difference in resources for conservation, including people and available scientific information, which are heavily biased toward more developed countries in Oceania. Most scientific publications analyzed for four threats (habitat loss, invasive species, overexploitation, and pollution) are from developed countries: 88.6% of Web of Science publications were from Australia (53.7%), New Zealand (24.3%), and Hawaiian Islands (10.5%). Many island states have limited resources or expertise. Even countries that do (e.g., Australia, New Zealand) have ongoing and emerging significant challenges, particularly with the interactive effects of climate change. Oceania will require the implementation of effective policies for conservation if the regions poor record on extinctions is not to continue.

A Ramsar wetland in crisis – the Coorong, Lower Lakes and Murray Mouth, Australia

The state of global freshwater ecosystems is increasingly parlous with water resource development degrading high-conservation wetlands. Rehabilitation is challenging because necessary increases in environmental flows have concomitant social impacts, complicated because many rivers flow between jurisdictions or countries. Australia’s Murray–Darling Basin is a large river basin with such problems encapsulated in the crisis of its Ramsar-listed terminal wetland, the Coorong, Lower Lakes and Murray Mouth. Prolonged drought and upstream diversion of water dropped water levels in the Lakes below sea level (2009–2010), exposing hazardous acid sulfate soils. Salinities increased dramatically (e.g. South Lagoon of Coorong >200 g L–1, cf. modelled natural 80 g L–1), reducing populations of waterbirds, fish, macroinvertebrates and littoral plants. Calcareous masses of estuarine tubeworms (Ficopomatus enigmaticus) killed freshwater turtles (Chelidae) and other fauna. Management primarily focussed on treating symptoms (e.g. acidification), rather than reduced flows, at considerable expense (>AU

Responses of waterbirds to flooding in an arid region of Australia and implications for conservation

2 billion). We modelled a scenario that increased annual flows during low-flow periods from current levels up to one-third of what the natural flow would have been, potentially delivering substantial environmental benefits and avoiding future crises. Realisation of this outcome depends on increasing environmental flows and implementing sophisticated river management during dry periods, both highly contentious options.

Australian waterbirds—products of the continent's ecology

Floods are a frequent but irregular feature of Australias dryland river catchments. We investigated changes in abundances of waterbirds in north western New South Wales with changes in wetland distribution at local, catchment and broad scales. The abundance of most functional groups of waterbirds changed in response to broad scale changes in wetland distribution, while local abundance remained highly variable. Patterns of abundance varied among functional groups of waterbirds, with some immediately responding to changes in wetland distribution and area flooded, and others apparently responding to sequences of wetting and drying. In Australia, the main conservation issue for waterbirds is water and its use across the landscape and not the spatial arrangement of any fixed array of reserves established to protect them.

IMPOSED HYDROLOGICAL STABILITY ON LAKES IN ARID AUSTRALIA AND EFFECTS ON WATERBIRDS

Abstract Some aspects of the ecology of 93 waterbird species, found predominantly on freshwater ecosystems, are reviewed. These species, belonging to six major orders—Anseriformes (ducks, geese and Black Swan), Podicipediformes (grebes), Pelecaniformes (Australian Pelican and cormorants), Ciconiiformes (herons, ibis, spoonbills and bitterns), Gruiformes (cranes, rails, crakes and gallinules), and Charadriiformes (waders and terns)—use a wide range of habitats and about half occur throughout the continent. Knowledge of their ecology remains poor for many waterbirds, particularly cryptic and rare species, and is moderate to good for hunted species. Life histories of Australian waterbirds differ from their counterparts elsewhere. Australias highly variable climate and river-flooding patterns create wetland habitats, the spatial and temporal variability of which strongly influence the ecology of local waterbirds. Many waterbirds respond to newly generated habitats to feed and/or breed and then disperse or die as wetlands dry. Regular movements are not common in most Australian species although some, particularly waders, migrate between Northern Hemisphere breeding grounds and non-breeding habitat in Australia. Breeding of Australian waterbirds coincides with food abundance in the southern spring, the wet season in the tropics and following floods inland. Habitat loss through draining of wetlands, regulation of rivers, diversion of water for irrigation and floodplain development are currently the major threats to waterbirds. Other potentially threatening processes include exotic plants and animals, pollution, climate change and over-harvesting but evidence for the impact of these factors remains poor. Understanding of waterbird, particularly waterfowl, ecology has contributed significantly to the conservation management of wetlands in Australia. Research on single species, studies of movements using satellite technology, further investigation of the effects of hunting, long-term monitoring and large-scale analyses of the availability of wetland habitat should be future research priorities.

Continental-scale interactions with temporary resources may explain the paradox of large populations of desert waterbirds in Australia

Hydrological disturbances, usually floods and drying, govern the distribution and abundance of biota and ecological processes in freshwater ecosystems. Reducing hydrological variability should reduce biodiversity and affect ecological processes. Many of Australias rivers have reduced variability with river regulation, but some remain free flowing. We tested the variability hypothesis using waterbird communities on 12 floodplain lakes, paired into six systems distributed across half of the continent, over the period from 1983 to 2001. Half of the floodplain lakes were regulated (reservoirs) with stable water levels, while the remainder had unaltered hydrology. We analyzed in more detail the waterbird community within the Menindee system, using eight floodplain lakes, paired into four groups of flow regimes. Similar but less marked patterns occurred within the Menindee system. Overall, mean density (±1 se) on unregulated floodplain lakes was significantly higher (6.04 ± 1.64 waterbirds/ha), compared with r...

Impact of water diversions on colonially-nesting waterbirds in the Macquarie Marshes of arid Australia

Arid Australia supports extraordinary numbers of waterbirds. We show that the solution to this seeming paradox lies in considering the availability of temporary wetland habitat in the context of the birds dispersal capability and fluctuations in the abundance of wetlands in time and space. For species with large dispersal capabilities, the Lake Eyre Basin of central Australia, amongst the driest regions on the continent, has the highest habitat availability for waterbirds. Analyses of landscape structure show that the wetlands of the Lake Eyre Basin are highly inter-connected and linked by broad pathways to wetter parts of south-eastern Australia. These analyses illustrate that organism traits and patch dynamics affect realised habitat availability and indicate that the processes that structure populations may operate at much larger spatial scales than those at which humans usually seek to manage the landscape.