Physical Sciences and Mathematics Commons^™

Research Note: Pcbs In The Acushnet River Estuary, Jacek Sulanowski

Bridgewater Review

Much media attention has recently been devoted to potentially toxic substances disseminated throughout various components of the environment. In almost every case these substances had been manufactured and distributed under the assumption that they did not pose a threat to man. Indeed when tested by methods current at the time of their initial introduction the substances were considered benign. It was only later when technologically advanced and more sensitive methods of analyses were developed that the presence of these substances was considered to be of real concern. Unfortunately, in the interval between introduction and detection, the accumulation of these substances …

Soil Testing For Acidity, I R. Wilson

Journal of the Department of Agriculture, Western Australia, Series 4

One of the most important aspects of the soil acidity research programme is the accurate analysis of soil and plant materials.

A soil acidity problem cannot be simply diagnosed with one test. Although the soil pH test is used for the initial evaluation of soil acidity, it does not measure the other factors which affect plant growth as a result of this acidity.

For example, plant growth on a coastal soil with pH 4.3 (in water) may not be affected by applying lime, but growth may improve markedly on a central wheatbelt soil of pH 4,8 (in water).

Another two …

Acid Rain: A Complex Issue For Minnesota

Journal of the Minnesota Academy of Science

No abstract provided.

The Response Of Invertebrates In Temporary Vernal Wetlands To Altosid Sr-10 As Used In Mosquito Abatement Programs, Ronald W. Lawrenz

Journal of the Minnesota Academy of Science

Three temporary vernal wetlands on the Bayport Wildlife Management Area in eastern Washington County, Minnesota, were divided by sandbag barrier into treatment and control areas. Designated areas were treated with Altosid® SR-10 briquets at standard mosquito control rates. Invertebrate populations were monitored weekly using net sweeps, column samples, and ocular estimates.

The development of Eubranchtpus bundyi, Lyncerus sp, and Daphnia sp., the three major components of the invertebrate fauna, was delayed by as much as one week in site 47. Similar developmental lags were noted for E. bundyi populations in the treated portions of sites 6 and 32. Delay of …

Rabbits North Of Carnarvon, D R. King

Journal of the Department of Agriculture, Western Australia, Series 4

In Westeern Australia rabbits are mainly a pest along the south-western coastal parts of the State, but there are populations north of the Tropic of Capricorn. Rabbits after crossing the Nullarbour plain from South Australia and colonising the South-West of the State, were reported to have reached the west coast near Geraldton by 1912 and then spread northwards.

There is little information on the biologhy of rabbits in the northan parts of their range, but pastoralists in some areas are concerned about erosion and damage to vegetation on their stations when rabbits reach high numbers.

The Agricultural Protection Board undertook …

Myxomatosis In Western Australia, D R. King, S. H. Wheeler

Journal of the Department of Agriculture, Western Australia, Series 4

Since myxomatosis was introduced to Western Australia in the early 1950s rabbit plagues have ceased. However, myxomatosis has not proven to be the whole answer to the rabit problem.

Rabits continue to damage crops and pastures in many areas and resurgences of rabbit populations are reported from time to time.

Drs D.R. King and S. H. Wheeler of the Agricultural Protection Board's research section have been studying the way myxomatosis epidemics occur and spread in rabbit populations in a range of Western Australian environments. This research will provide data for planning effective control strategies intergrating the various control options available …

Algal Problems Of The Estuary, E. P. Hodgkin, P. B. Birch

Journal of the Department of Agriculture, Western Australia, Series 4

The Peel-Harvey esturine system study began in 1976 because people living near Peel Inlet complained about the accumulation of water weeds and algae on the shores and the smell of hydrogen sulphide (rotton egg gas) that resulted from their decomposition. From 1974 efforts had been made to control this 'algal problem' by raking up the weed with tractors and carting it away. This 'cosmetic activity had little impact on the problem.

The immediate cause was obvious: a carpet of green algae covering about 20square kilometres of the bottom of Peel Inlet. From time to time this 'goat weed' floated to …

Modifying Fertiliser Practices, J S. Yeates, D. M. Deeley, M. F. Clarke, D. Allen

Journal of the Department of Agriculture, Western Australia, Series 4

If modified fertiliser practices are adopted phosphorus losses from the Peel-Harvey catchment can be reduced. Farmers can save money on fertiliser applications and the need for more expensive catchment management measures to reduce algal pollution of the estuary will be avoided.

Research data available so far indicate that, with farmer co-operation and the use of the new slow release fertiliser New Coastal Superphosphate, long-term phosphorus application rates can be reduced by 30-40 per cent - and possibly even halved - without lowering agricultural production. This will also reduce phosphorus loss to drainage water.

Although much of the research since 1982 …

Tackling The Problem Off The Farm, C M. Croft

Journal of the Department of Agriculture, Western Australia, Series 4

Methods of redusing phosphorus losses from the catchment soils of the Peel-Harvey esturine system have been discussed in other articles in this Journal.

This article briefly discusses a range of 'off the farm' techniques to improve phosphorus flushing from Peel Inlet or Harvey Estuary to the sea and to treat the phosphorus and the algae. These techniques were among more than 100 management options evaluated by the Peel-Harvey Study Group.

Causes Of Soil Acidity, W M. Porter

Journal of the Department of Agriculture, Western Australia, Series 4

The introduction of agriculture into australia has caused many of our soils to become more acid faster than they would have otherwise.

In Europe and other parts of the world, soil acidification is accepted as a normal by-product of a successful agricultural system. Lime* is widley used to neutralise the acids added as a result of agricultural practices.

In Western Australia, lime applications will be needed more frequently in the future, although maybe not in the same volumes as in Europe.

Rabbit Kitten Survival In The South-West, D R. King

Journal of the Department of Agriculture, Western Australia, Series 4

In the South-West of Western Australis reliable winter rains allow the rabbit breeding season to extend through winter and spring, and thus a large number of kittens are produced each year.

Studies on the biology of rabbits at Cape Naturaliste (270 kilometres south-west of Perth) and Chidlow (40 kilometres east of Perth in the Datling Range) have shown that at these sites each doe produces about 30 and 27 kittens respectively a year. If all these youg rabbits survived, there would be a 15-fold increase in numbers. Within a short time the State would be covered "wall to wall" by …

Algal Growth And The Phosphorus Cycle, Arthur J. Mccomb, K. S. Hamel, A. L. Huber, D. K. Kidby, R. J. Lukatelich

Journal of the Department of Agriculture, Western Australia, Series 4

Larger algae and microscopic phytoplankton foul the waters of the Peel-Harvey estuarine system, upsetting the fishery and polluting the beaches.

These aquatic plants grow in response to phosphorus runoff from drainage, trapping phosphorus in the estuary and using it in their growth. When they die this phosphorus remains in the system to be recycled for further plant growth.

Algal pollution in the estuary can be lessened by reducing the amount of phosphorus entering the system, increasing phosphorus losses to the ocean, or in some way blocking the trapping and recycling processes.

The Extension Programme, W K. Russell, G. K. Palmer

Journal of the Department of Agriculture, Western Australia, Series 4

From the start of the Peel-harvey study in 1976, scientific research and extension have been closely linked. Trials, some involving major drainage works, have been set up on about 30 farms and several field days and seminars have been held.

The Peel-Harvey Study Group anticipates that farmer acceptance of the Department of agriculture's recommendations will reduce the phosphorus input to the estuary by 30 to 40 per cent over the next three to five years. At the same time farmers will benefit from modified cultural practices better suited to the sandy soils of the coastal plain.

Soil Improvement With Bauxite Residues, W H. Tacey, S. C. Ward, K. J. Summers, N. J. Barrow

Journal of the Department of Agriculture, Western Australia, Series 4

The sandy soils of the Peel-Harvey catchment hold water and nutrients very poorly. The Gavin ridges dry out quickly during rainless periods and this severely limits pasture growth. These ridges and the lower lying Joel and Coolup sands also lose a large proportion of the phosphorus, sulfer and potash fertilisers applied to them. Normally the sands lack clay materials to bind and hold the nutrients so rainfall leaches them out.

The Peel-Harvey Study Group, CSIRO, Alcoa and Murdock University have studied the use of a residue from bauxite mining to help overcome these problems. The treated residue has a texture …

Soil Types And Drainage, Eric Bettenay, N. J. Schofield

Journal of the Department of Agriculture, Western Australia, Series 4

At least 90 per cent of the phosphorus entering the Peel-Harvey estuarine system comes from land cleared for agriculture, most of it from the coastal plain. These soils are naturally deficient on phosphorus and sulfur and this is supplied in superphosphate, which contains about 10 per cent phosphorus and 1 percent sulphur.

However, rain leaches some of this applied phosphorus from the land into drains and rivers which flow into the estuary. In 1981, farmers in the Harvey River-Mayfields Drain catchment lost the equivalent of 1,300 tonnes of superphosphate into the estuary. Between them they have in effect spent $120,000 …

Alternative Land Uses, D A. Morrison, B. C. Mattinson

Journal of the Department of Agriculture, Western Australia, Series 4

One aproach to minimise the high nutrient content and associated algal pollution of the Peel-Harvey estuarine system is to reduce phosphorus losses at their source. Farmers can do this by changing land use is such a way thar phosphorus run-off fromthe catchment soils into drainage is prevented or at least reduced.

The department of Agriculture is investigating the economics of alternative uses, particularly substituting forestry with Pinus pinaster or Eucalyptus globulus (Tasmanian blue gum) for present beef and sheep enterprises. P. pinaster is used for logging and E. globulus for pulping.

Research Objectives In Vertebrate Pest Control, A J. Oliver

Journal of the Department of Agriculture, Western Australia, Series 4

The European rabbit, introduced into Australia in 856 by an early settler for hunting, caused massive losses to agricultural production in Western Australia in 1940s and 1950s.

In those years most of the country's recources and efforts allocated to vertebrate pest problems were aimed at controlling this animal.

Research and control measures by Commonwealth and State agencies, including the introduction of myxomatosis, were largely responsible for reducing the rabbit problem to the comparatively minor one it is now.

Today, the Agricultural Protection Board is involved in the control of a much wider range of mammals and birds which cause losses …

Feral Donkeys : An Assessment Of Control In The Kimberley, S H. Wheeler

Journal of the Department of Agriculture, Western Australia, Series 4

Feral donkeys are one of the major limitations to increased pastoral production in many parts of the Kimberley area of Western Australia, where they compete with cattle for food. In addition donkeys are aggressive animals, driving cattle from watering points and better grazing areas. They eliminate perenial plants by overgrazing and therefore reduce the carrying capacity of the range.

Originally introduced as draught animals, donkeys were released when cars arrived; since then they have bred up to large numbers in many areas.

For several years the Agricultural Protection Board has undertaken a programme of donkey shooting from helicopters. Since this …

The Soil Phosphorus Store, G S P Ritchie, D. M. Weaver

Journal of the Department of Agriculture, Western Australia, Series 4

The management of the soil phosphorus store, or 'super bank' to minimise phosphorus leaching losses is a vital part of any strategy to reduce algal pollution of the Peel-Harvey estuary.

Phosphorus can exist in the soil in four main 'pools'. it may occur in the soil solution or in one of the three pools that contain phosphorus in solid forms. This phosphorus can be in compounds (fertilisers, dead plant material); adsorbed (attached) to soil particles such as organic matter, clay and iron oxide; or as constituents of micro-organisms.