Linking local ecological outcomes with basin-wide water planning: a case study of Yanga National Park,an important Australian inland forested wetland

Abstract

Maintaining and restoring the ecological integrity of floodplains remains a priority for many Australian federal and state government agencies. The Murray-Darling Basin Authority (MDBA) introduced the Proposed Basin Plan 2012, the Australian government’s latest basin-scale water planning instrument to promote a healthy, working river system. The proposal seeks to limit surface water (consumptive) use to 10 873 GL year^-1 on a long-term average. The controversy prompted by this proposed reduction has underscored a need for rigorous and transparent modelling of ecological benefits. In this paper, we investigate the likely ecological outcomes of the proposal for Yanga National Park, one of the most significant environmental assets in the Murray-Darling Basin, using a decision support system. Our results indicate that the proposal will increase the inundation extent with a 33% (or 7000 ha) increase in median flood. The increase in inundation would improve the hydrological conditions in most wetlands in terms of the frequency and duration of events and inter-flood dry periods and enhance the habitat quality for a range of biota, though benefits are not distributed evenly across the wetland.

Editor D. Koutsoyiannis; Guest editor M. Acreman

Citation Wen, L. and Saintilan, N., 2014. Linking local ecological outcomes with basin-wide water planning: a case study of Yanga National Park, an important Australian inland forested wetland. Hydrological Sciences Journal, 59 (3–4), 904–915.     

Marine protected areas in Australia: Towards a coordinated rock lobster industry position

Plans by government to accelerate the establishment of a national representative system of marine protected areas (NRSMPAs) in Australia have caused increasing disquiet within the fishing industry. Rock lobster fishers have raised concerns regarding plans to establish large “multiple‐use” MPAs that may or may not contain a substantial no‐take component in the continental shelf waters adjacent to the coast. Key industry concerns including the potential impacts on present and future harvest rates are examined. The industry response to government MPA policy in each of the major jurisdictions is outlined. An industry position developed at the National Rock Lobster Congress in Perth, Western Australia (September 2003) is put forward. The position advocates the need for an adjustment scheme to account for displaced effort, the need for government commitment to the development of management plans that include the long‐term monitoring of all MPAs, and the need for a thorough risk assessment process to be conducted before the establishment of an MPA. The issues raised in this paper should be relevant to the establishment of MPAs in an international context.     

Age verification,growth and life history of rubyfish Plagiogeneion rubiginosum

Age verification of rubyfish (Plagiogeneion rubiginosum) was sought using the bomb radiocarbon chronometer procedure. Stable isotopes were investigated for life history characteristics. Radiocarbon (¹⁴C) and stable isotope (δ¹⁸O and δ¹³C) levels were measured in micro-samples from five otoliths that had been aged using a zone count method. All the core ¹⁴C measurements were ‘pre-bomb’ indicating ages of at least 45 years, and the ¹⁴C measurements across the otolith sections suggested that the zone-count ageing method described herein is not biased. Maximum estimated age was 100 years. There was no significant between-sex difference in the von Bertalanffy growth curves. The δ¹⁸O values indicated that rubyfish are near-surface as juveniles, and move deeper with age. Adults appear to reside in 600–1000 m; this is deeper than most trawl-capture data suggest, but not implausible, and has stock assessment implications. The δ¹³C values reflect fish metabolic rates, trophic feeding levels and oceanographic conditions. The stable isotopes record the environmental life history of each fish, and have value in distinguishing stocks and/or indicating vertical and latitudinal migratory patterns.     

Isotopic mapping of groundwater perchlorate plumes

Analyses of stable isotope ratios of chlorine and oxygen in perchlorate can, in some cases, be used for mapping and source identification of groundwater perchlorate plumes. This is demonstrated here for large, intersecting perchlorate plumes in groundwater from a region having extensive groundwater perchlorate contamination and a large population dependent on groundwater resources. The region contains both synthetic perchlorate derived from rocket fuel manufacturing and testing activities and agricultural perchlorate derived predominantly from imported Chilean (Atacama) nitrate fertilizer, along with a likely component of indigenous natural background perchlorate from local wet and dry atmospheric deposition. Most samples within each plume reflect either a predominantly synthetic or a predominantly agricultural perchlorate source and there is apparently a minor contribution from the indigenous natural background perchlorate. The existence of isotopically distinct perchlorate plumes in this area is consistent with other lines of evidence, including groundwater levels and flow paths as well as the historical land use and areal distribution of potential perchlorate sources.     

A Paddock to reef monitoring and modelling framework for the Great Barrier Reef: Paddock and catchment component

Targets for improvements in water quality entering the Great Barrier Reef (GBR) have been set through the Reef Water Quality Protection Plan (Reef Plan). To measure and report on progress towards the targets set a program has been established that combines monitoring and modelling at paddock through to catchment and reef scales; the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef Program). This program aims to provide evidence of links between land management activities, water quality and reef health. Five lines of evidence are used: the effectiveness of management practices to improve water quality; the prevalence of management practice adoption and change in catchment indicators; long-term monitoring of catchment water quality; paddock & catchment modelling to provide a relative assessment of progress towards meeting targets; and finally marine monitoring of GBR water quality and reef ecosystem health. This paper outlines the first four lines of evidence.     

Assessing landslide movements in volcanic islands using near-shore marine geophysical data: south Pico island,Azores

Marine geophysical data from around the submarine flanks of volcanic islands can potentially help to resolve whether large-scale instability of an edifice has been geologically recently active. We use geophysical data to investigate part of the coast of Pico Island of the Azores where, above sea-level, a major slump of Topo volcano has been interpreted previously from arcuate escarpments and a rugged irregular topography seaward of them. Multibeam echo-sounder data collected offshore of this feature show remarkably little evidence for slump fault movements in the island's submarine slope. Mid-slope benches, like those associated with the Hilina Slump of Kilauea, are absent. The high-resolution data extends onto the island's shelf, allowing us to evaluate evidence for continuing activity there. In particular, as the shelf's rock platform will have been last modified by surf erosion during the postglacial period of sea-level transgression, it provides a reference surface of intermediate age (7–19 ka) that can potentially reveal whether any movements occurred in pre-historic times. Where the arcuate escarpments are continued offshore, the modern seabed shows no bathymetric evidence for active faults where the shelf rock platform crops out in the multibeam data. Elsewhere, mobile shelf sediments could be disguising evidence for active faulting so we examined boomer profiles able to image the rock platform beneath them. The data reveal a platform that is steep (6.6°) compared with the dips of platforms that we have studied previously around the coast of adjacent Faial Island and steeper than the platform outside the proposed slump. This suggests that it was created by coastal erosion over a shorter period and hence is consistent with a younger age of the coastline. As with the multibeam data, where escarpments are continued offshore onto the shelf, the rock surface imaged with these boomer data also shows no clear evidence of major slump-related fault displacements. This study therefore illustrates how high-resolution boomer seismic and multibeam data could usefully contribute to hazard assessment of volcanic islands, by helping to evaluate areas with no historical movements. Explanations to reconcile the onshore and offshore data here are also put forward.     

Lava penetrating water: the different behaviours of pāhoehoe and ‘a‘ā at the Nesjahraun, Tingvellir, Iceland

The Nesjahraun is a basaltic lava flow erupted from a subaerial fissure, extending NE along the Tingvellir graben from the Hengill central volcano that produced pāhoehoe lava followed by ‘a‘ā. The Nesjahraun entered Iceland’s largest lake, Tingvallavatn, along its southern shore during both phases of the eruption and exemplifies lava flowing into water in a lacustrine environment in the absence of powerful wave action. This study combines airborne light detection and ranging, sidescan sonar and Chirp seismic data with field observations to investigate the behaviour of the lava as it entered the water. Pāhoehoe sheet lava was formed during the early stages of the eruption. Along the shoreline, stacks of thin (5–20 cm thick), vesicular, flows rest upon and surround low (<5 m) piles of coarse, unconsolidated, variably oxidised spatter. Clefts within the lava run inland from the lake. These are 2–5 m wide, >2 m deep, ∼50 m long, spaced ∼50 m apart and have sub-horizontal striations on the walls. They likely represent channels or collapsed tubes along which lava was delivered into the water. A circular rootless cone, Eldborg, formed when water infiltrated a lava tube. Offshore from the pāhoehoe lavas, the gradient of the flow surface steepens, suggesting a change in flow regime and the development of a talus ramp. Later, the flow was focused into a channel of ‘a‘ā lava, ∼200–350 m wide. This split into individual flow lobes 20–50 m wide along the shore. ‘A‘ā clinker is exposed on the water’s edge, as well as glassy sand and gravel, which has been locally intruded by small (<1 m), irregularly shaped, lava bodies. The cores of the flow lobes contain coherent, but hackly fractured lava. Mounds consisting predominantly of scoria lapilli and the large paired half-cone of Grámelur were formed in phreatomagmatic explosions. The ‘a‘ā flow can be identified underwater over 1 km offshore, and the sidescan data suggest that the flow lobes remained coherent flowing down a gradient of <10°. The Nesjahraun demonstrates that, even in the absence of ocean waves, phreatomagmatic explosions are ubiquitous and that pāhoehoe flows are much more likely to break up on entering the water than ‘a‘ā flows, which, with a higher flux and shallow underlying surface gradient, can penetrate water and remain coherent over distances of at least 1 km.     

Measuring the benefits and costs of community education and outreach in marine protected areas

Conservation organizations often invest considerable resources in education and outreach activities in and around marine protected areas (MPAs). The expectation is that such efforts will change local knowledge, attitudes and ultimately behavior. This is one of the first studies to assess the efficacy of using education and outreach activities to improve community knowledge and attitudes about an MPA. Random sample surveys in 2005 and 2010 (n=1213) before and after education and outreach activities are compared. Program budgets for the same period give the investment levels. With an investment level averaging US$24 per capita/year, the result was an average increase of 33% in “yes” responses across 15 indicators of knowledge and attitudes towards marine conservation. The increase in knowledge and positive attitudes was associated with a large decrease in “not sure” responses, suggesting that community members with fewer initial preconceptions are the most effective target for education and outreach activities. This study demonstrates that investments in MPA education and outreach can generate increases in local knowledge and positive attitudes, and changing knowledge and attitudes is expected to contribute to the long-term compliance with MPA regulations.     

A sedimentary record of the rise and fall of the metal industry in Bergslagen,south central Sweden

Detailed stratigraphic analyses of sediments deposited in Lake Botjärnen, a small boreal forest lake in the shield terrain of central Sweden, clearly reflect progressively increasing human impact on terrestrial and aquatic ecosystems following settlement and establishment of an iron industry in the 17th century. Rising frequencies of pollen and spores from light-demanding plants provide evidence of extensive forest clearance for charcoal and timber production, which peaked in the early 20th century. An associated increase in catchment erosion is reflected by changing carbon and nitrogen elemental content and carbon–isotope composition of sediment organic matter and by increased magnetic susceptibility of the sediments. Records of air-borne pollutants (lead, zinc and sulphur) can be correlated to the development of local and regional mining and metal industry as inferred from historical accounts. Rapid recession of the iron industry led to re-forestation and recovery of the aquatic nutrient status to pre-industrial conditions over the past 100 years. The chronology of the sediment succession, which is based on ²¹⁰Pb and ¹³⁷Cs radionuclide data in combination with radiocarbon dating, is confirmed by historical lead pollution trends established for the region.