Mapping acid groundwater in Western Australia’s wheatbelt

The extent of the area affected by deep drains in Western Australia (more than 11 000 km of drains installed as of 2002: Australian Bureau of Statistics 2002) and their continuing installation by land managers make understanding the distribution of naturally occurring acid groundwater a priority for land managers working toward sustainable agricultural production in the wheatbelt. This report describes development of a map of the likelihood of acid groundwater occurrence. It is meant to guide state agencies, natural resource management groups, landholders, and community stakeholders on where acid groundwater may occur

The use of zebrafish embryos as an alternative approach for ecotoxicity testing

The use of fish embryos for acute ecotoxicity tests has been widely documented and over recent years there has been significant progress in the use of zebrafish embryos as an alternative approach to juvenile fish. However, there are still some questions preventing the unilateral adoption of this surrogate life stage as an alternative to the use of juvenile fish for regulatory testing purposes. Many of the concerns that have been raised include the absolute sensitivity of fish embryos. For example, published work has shown that fish embryos are not as sensitive as other more developed life-stages (such as the eleutheroembryos) to certain classes of compounds including, but not exclusively, cationic polymers. However, there is limited understanding of why fish embryos do not behave similarly and exhibit a toxic response to these classes of chemicals. One possible reason is that fish embryos have a protective envelope called a chorion, which could prevent these certain chemicals from passing into the embryo. The research described within this thesis has focussed on understanding the need for alternative approaches in ecotoxicity testing, particularly regarding the use of fish embryos. In addition, the developmental ontogeny of zebrafish embryos has also been studied. Finally, the research investigated whether the chorion is indeed a barrier to entry to certain chemicals, and a technique for quantifying the proportion of bio-available chemical within the different components of the embryo was developed.Astrazenec

Groundwater chemistry and salinity processes in the Myalup region

The Myalup region, which incorporates the Myalup Irrigated Agriculture Precinct (MIAP), is located about 100 kilometres south of Perth between the southern end of Lake Clifton and the northern tip of the Leschenault Inlet. It covers 17 800 hectares, with about 2100ha being irrigated. The precinct produces mainly carrots, onions, potatoes and leafy vegetables. In 2016–17, the total value of agricultural production for the MIAP, including on-farm processing and packaging, was more than $120 million. Irrigation water is mainly from the surficial Myalup aquifer, with limited abstraction from the underlying Leederville aquifer. Average annual rainfall is about 800 millimetres, but rainfall has been declining since the 1970s and has reduced by about 13% since 2000. Salinity levels were increasing in some irrigated areas with ions, such as sulfate and chloride, reaching levels of concern to growers and regulators. There was also concerned about the saltwater intrusion risk into the superficial aquifer from salt lakes and the ocean to the west, and the source of increasing salinity in areas to the east. There is a growing water demand in the MIAP as a result of horticultural relocation to the area from Perth and other areas. Diversifying existing sources of fresh food and vegetable production and securing the long-term sustainability of water supplies are essential to maintaining and growing food production. Salinisation of the superficial aquifer poses a risk to production and a potential constraint on the future development of agriculture in the area. As part of the Water for Food program funded through Royalties for Regions, DPIRD investigated the likely causes of salinisation in the MIAP. Previous investigations showed there was considerable spatial and temporal variability of salinity in the superficial aquifer, with the origins of the salinity poorly understood. To better understand the controls on salinity in the Myalup aquifer, licensee water quality data from 200 sites were collated in a database. The database analysis was complemented with two phases of groundwater sampling across the Myalup region, covering a broader range of water quality parameters than the licensee data. The licensee and groundwater data showed there were multiple geochemical processes contributing to the increased salinity along the groundwater flow path in the Myalup aquifer. Salinity trends at sites with irrigated agriculture were statistically analysed using groundwater licensee data (140 sites out of 200) to determine the extent of increased salinity in the Myalup aquifer. Only 30 of the 140 sites showed increased salinity, while six sites showed decreased salinity. Within the sites showing an increase in salinity, oxidation of pyrite in acid sulfate soils was the dominant source of salinity at 19 sites (63% of 30 sites). In two localised areas (nine sites), recirculation was the main salinity process, and intrusion of saline groundwater was the main process in just one locality (two sites)

Groundwater chemistry of the Weaber Plain: preliminary results

In 2008, the Ord Irrigation Expansion Project was approved by the Western Australian Government to develop irrigated agriculture on the Weaber Plain. Construction of the M2 supply channel connecting the ORIA and the Weaber Plain, and the final period of irrigation design, environmental management and related approval processes, commenced later in 2009. This process followed a protracted period of public and private industry planning and environmental assessment (Kinhill 2000). This report summarises an analysis of groundwater salinity trends on the Ivanhoe and Weaber plains and the preliminary results of an intensive water-quality sampling program carried out in 2010 as part of Phase 1 of the project. The purpose of this report is to provide interim results to inform groundwater management plans required as part of the approval process for the development of the Weaber Plain

Groundwater chemistry of the Weaber Plain (Goomig Farmlands): baseline results 2010–13

The Ord River Irrigation Area (ORIA) is located in the north-east of the Kimberley region of Western Australia, near the town of Kununurra. The irrigation area was established in 1963 and over time developed to the current extent of 14 000 hectares (ha). The Weaber Plain (Goomig Farmlands) area is located north-north-east of the existing irrigation area, 30km from Kununurra, and has been identified as being suitable for irrigated agriculture for many decades. However, it was not until 2009, with state government support, that the 7400ha project commenced, with construction starting in 2010. State and Australian government environmental approvals required the proponent to install a groundwater monitoring network and develop a groundwater management plan. The environmental approvals required seasonal monitoring of groundwater to establish baseline groundwater chemistry conditions. The monitoring bores were sampled for up to three years and showed a large variation in water type and water quality across the Weaber and Knox Creek plains

Ciona spp. and ascidians as bioindicator organisms for evaluating effects of endocrine disrupting chemicals: A discussion paper

In context of testing, screening and monitoring of endocrine-disrupting (ED) type of environmental pollutants, tunicates could possibly represent a particularly interesting group of bioindicator organisms. These primitive chordates are already important model organisms within developmental and genomics research due to their central position in evolution and close relationship to vertebrates. The solitary ascidians, such as the genus Ciona spp. (vase tunicates), could possibly be extra feasible as ED bioindicators. They have a free-swimming, tadpole-like larval stage that develops extremely quickly (<20 h under favorable conditions), has a short life cycle (typically 2–3 months), are relatively easy to maintain in laboratory culture, have fully sequenced genomes, and transgenic embryos with 3D course data of the embryo ontogeny are available. In this article, we discuss possible roles of Ciona spp. (and other solitary ascidians) as ecotoxicological bioindicator organisms in general but perhaps especially for effect studies of contaminants with presumed endocrine disrupting modes of action.publishedVersio