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Marron Production Enhancement

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Marron Production Enhancement A farmer s lessons learned by John Luckens Kangabbie Farm Fleurieu Peninsula South Australia July 2015 RIRDC Publication No 15/053 RIRDC Project No PRJ Rural Industries
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Marron Production Enhancement A farmer s lessons learned by John Luckens Kangabbie Farm Fleurieu Peninsula South Australia July 2015 RIRDC Publication No 15/053 RIRDC Project No PRJ 2015 Rural Industries Research and Development Corporation. All rights reserved. ISBN ISSN Marron Production Enhancement Publication No. 15/053 Project No. PRJ The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable regions. You must not rely on any information contained in this publication without taking specialist advice relevant to your particular circumstances. While reasonable care has been taken in preparing this publication to ensure that information is true and correct, the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication. The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the part of the Commonwealth of Australia, RIRDC, the authors or contributors. The Commonwealth of Australia does not necessarily endorse the views in this publication. This publication is copyright. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. However, wide dissemination is encouraged. Requests and inquiries concerning reproduction and rights should be addressed to RIRDC Communications on phone Researcher Contact Details John Luckens PO Box 89 Kangarilla SA 5157 Phone: In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. RIRDC Contact Details Rural Industries Research and Development Corporation Level 2, 15 National Circuit BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: Fax: Web: Electronically published by RIRDC in July 2015 Print-on-demand by Union Offset Printing, Canberra at or phone ii Foreword Australia is a highly urbanised mature economy with a diverse range of export industries, yet food production from agriculture, horticulture and increasingly aquaculture play a significant role. New and developing industries bring opportunity, diversity and strength to rural Australia. The sustainable management of Australia s non-urban landmass, through conservation and maintenance of biodiversity, industry and food production is critical to community wellbeing and prosperity. This Project extends RIRDC s commitment to researching improvements in production systems for developing industries, in this case freshwater crayfish. This industry has the potential to make a valuable contribution to Australia s food production and at the same time reduce pressure on our natural resources. Previous work funded by RIRDC has focused on Redclaw, a similar species, while this Project seeks improvements in marron production. Improved culture systems and yields will be a significant benefit to rural communities. This Project had two aims, firstly an improved pond system and secondly a family based breeding program following on from the development of genetic markers. Significant advances were made in both areas. The new pond systems have significant benefits on previous practices but are not yet fully proven. It is considered that the difficulties encountered in the early development of the new pond systems have now been overcome and the systems will demonstrate proven value in the next few years. The selective breeding program is ongoing, following the development of genetic markers to permit the assignment of parentage. In the course of this work it appears there are fertility problems in hybrids, and this problem will need to be addressed. This Project was funded through the RIRDC s New Animal Program, funded by the Australian Government. This report is an addition to RIRDC s diverse range of over 2000 research publications and it forms part of our New and Developing Animal Industries program which aims to enhance industry success through targeted industry-specific RD&E. Most of RIRDC s publications are available for viewing, free downloading or purchasing online at Purchases can also be made by phoning Craig Burns Managing Director Rural Industries Research and Development Corporation iii About the Author John Luckens has been a marron farmer at Kangarilla on the Fleurieu Peninsula in South Australia for the past 18 years. He is Secretary of the Australian Freshwater Crayfish Growers Association (SA) Inc. Acknowledgments Many people over the years have given valuable advice and shared their knowledge and experience with me on marron farming, and my better ideas reflect that contribution. I greatly appreciate all their help. This Project would not have been possible without their unsung efforts, and I hope this Report in some way repays the debt. I particularly wish to thank the Late Peter McInnes from RIRDC for his encouragement and support. I ve also heavily leaned on a few friends and colleagues whose help has been critical. Professor Graham Mair has twisted my arm on correct terminology in discussing genetics and listened to my worries over the years on marron breeding, and along with Dr Nick Robinson have been an invaluable help in the development of the genetic breeding program. Actually, it wouldn t have happened without them. Dr Shannon Loughnan in a previous day job used to purchase fish from our farm, but while doing his PhD provided inestimable support for this Project through the development of genetic markers. I m humbled. Dr Josie Mair is always enthusiasm exemplified and her help on things great and small is appreciated. Dr Alex Safari was an important fount of wisdom in the early stages of this Project before bigger things beckoned elsewhere. Yet without someone doing the hard yards it s not much more than talk. Philippa Dean and Charles Ford as students were a great help in the breeding room, and without Kieran Wenham doing the earthworks, Locky Loughron, Mash Miller, and Rata Luckens on all the other jobs, nothing would have happened. Doctor Diener, Emeritus Professor of Adaptive Technologies, RAG Institute, for all his help in converting something discarded into something useful. Shelia Saville and her mob, Mike Dickeson and many others for help when it was needed and Steve (More Fish in the Sea) Sangster for courage when all seemed lost. And my Partner Cathy Elston, for keeping it altogether. But as always, the mistakes are all mine. iv Contents Foreword... iii About the Author... iv Acknowledgments... iv Executive Summary... vii Introduction... 1 Objectives... 6 Methodology Pond infrastructure development Breeding systems and breeding program development Chapter 1 Pond System Chapter 2 Breeding systems and breeding program development Chapter 3 Breeding problems in marron, a case study at Kangabbie Farm Summary of Findings Implications Recommendations Appendix Microsatellite isolation for the smooth marron (Cherax tenuimanus) from next generation sequencing Appendix Proposal to initiate selected breeding for marron at Kangabbie Farm References Tables Table 1: Aquarium and tank spawning rates for the four breeding seasons, v Figures Figure 1: Figure 2: Figure 3: Figure 4: Figure 5: Figure 6: Figure 7: Figure 8: Figure 9: Figure 10: Figure 11: Figure 12: The round ponds, three of the five new prototype ponds constructed at the beginning of this Project to pilot key elements of the proposed new production system.... x Old pond system, showing pond prior to filling, floor hides of corrugated iron on legs, mesh hides on floating poly pipe, stand pipe aeration, and compacted floor. Compare the hide numbers with the round pond (which is twice the area) as shown in Figure The round pond radial aeration system showing the dual opposing paddlewheels churning water across the diameter of the pond which then circulates around the edge and back to the centre Round pond, which is twice the size of the traditional rectangular pond (Figure 2) but has 3 times the column/mesh hides and 10 times the floor/corro iron hides Preparing for draindown, showing set up of transportable tanks which can assist in separating stock (berried, juveniles) and allow marron immediate gill flush in clean flowing aerated water Marron collection, showing pick up of the last marron. Note the venturi aerated water (white pipe) and tap handle (above red cap) which allows easy control of water at this stage of draindown Pond cleaning showing the central sprinkler which reaches the pond floor edge. All hides are left in place, checked underneath for marron at draindown, then after a first sprinkle clean moved to a clean gap, and the pond again sprinkle cleaned. Some hand hosing at the centre is sometimes necessary. This is less effort than the traditional ponds Floating netting for predator control, showing floating radial hide lines supporting net, small cats eye open area for paddlewheel and exclusion walls Ingested pond floor fibre. The polyester fibre in the pond floor (silt barrier) fabric is about as thick as a human hair, can be a meter or more long and is indigestible. The initial construction plan was to leave this fabric partly exposed. However the marron ingested these fibres which spooled inside their stomach s (the grey shapes) between the gastroliths (the white shapes), which blocked the stomach, resulting in death by starvation Breeding room showing the wall mounted aquaria and two breeding tanks prior to commencement of the breeding Immature or undeveloped ovaries, showing very small eggs. These females were dissected in late October following the normal August/September spawning season to observe ovary size as a very poor spawning occurred in the breeding room as well as in the outdoor breeding ponds. These eggs are significantly smaller than eggs ready for spawning. This farmer/author does not know whether these marron are not yet sexually mature or if there is another cause for the poor spawning. Note, these eggs are very different to those shown in Figure 11, which are presumed to be in a process of reabsorption Reabsorbed ovaries. Some marron from the breeding aquaria and tanks did not spawn. This marron was split open to reveal reabsorption, perhaps indicating handling or confinement stress. Other marron opened showed small ovaries, (see Figure 11) vi Executive Summary Background The development of new food industries, particularly industries that provide a high commercial value will continue to play a significant role in Australia s social and economic success. Marron farming is one such potential industry. Marron is a large freshwater crayfish which will have significant economic value to the farming community when farming systems and brood stock constraints are understood and addressed. Although significant efforts have been made over the years to develop a commercially viable production system and improve brood stock quality, commercial production is not yet assured notwithstanding the efforts of many farmers. Marron is indigenous to south west Western Australia and this is still the major region for marron production. Kangaroo Island and Fleurieu Peninsula in South Australia also produce marron, contributing around one third of the national harvest. Earlier research indicated that a semi intensive farm system was commercially viable but this has not eventuated. Although some of these semiintensive systems are still operating, most production is by trapping in extensive systems. The natural resources for production (land, water, climate) are readily available and the life cycle is reasonably understood. The challenge is to better understand the farming requirements to increase production intensity and yields and breed a high quality aquaculture friendly strain of marron. This Report is written by a farmer outlining our endeavours for other farmers who have an interest in marron production, and contributes to the existing background knowledge. The technical language has been kept to a minimum except where my academic friends and collaborators have insisted. It is hoped this Report will also be of value by encouraging other researchers to contribute to the marron industry. Aims/objectives This Project sought to contribute to this industry through the building and monitoring of a new pond system designed to increase production intensity and the initiation of a family based selective breeding program. The objective of this research was to contribute to the development of an improved production system and to develop breeding systems and tools to facilitate the initiation of a genetic improvement program. The success of the production system described here is likely to be of benefit to new entrants to the industry while the adoption of the family based breeding program is likely to be more broadly based. The initial take up of these technologies is anticipated to be within the communities already having an interest in marron. Our work built upon the earlier work of numerous others, by improvements to current production methods through the development of a new round pond production system. A systematic long term family breeding program was developed to select for desired traits while using genetic markers as the means to avoid inbreeding. The successes and lessons learned in this Project will contribute to building a commercially viable industry. Methods used The conception of a new round pond system arose from recognition of the relatively low yields and high labour requirements of the traditional rectangular 1000 sq. meter marron ponds. Five prototype ponds were built, with this Project providing support for the development of some components of the system and to the monitoring of the process, with a view to supporting an enhanced system of marron production. The ponds were built in two stages, fully equipped, stocked and managed, water quality vii monitored, harvested, and results assessed. Pond yields were initially, unexpectedly very low. Eventually it was realised this was due to the marron ingesting fibre from the fabrics used on the pond floor. After this problem was diagnosed a complex remediation of the ponds over several years was undertaken and the ponds were restocked. The ponds are now satisfactory but not yet fully proven. A breeding facility was built with aquariums and tanks to establish the indoor breeding system as an essential precursor to the development of a breeding program. Breeding couples were selected from the farms ongoing mass selection breeding program and placed in the aquariums and tanks as the initial families, with an eventual target of 75 ongoing families to meet the requirements of a quantitative genetics program. Over the four year period, a cohort of family bred marron is now mature and will become the next generation of the program. A suite of genetic markers were developed through a PhD studies program at Flinders University and these will be used to assign parentage to the selected marron for the next generation of breeders. Results/key findings This Projects goal was to develop a commercially viable farming system. Disappointingly this goal has not been fully proven by this Project, but significant achievements have been made. The family based selective breeding program has been established and a suite of genetic markers has successfully been developed for ongoing use in a long term quantitative genetics breeding program. Many gains were made with this Project but not all ambitions were met. This Project has been successful in a number of key ways. We have developed a different farming system that allows for greater economies of scale, is easily replicated onto different sites, has standardised components, and is relatively easily managed. Genetic markers have been developed and a small scale family based selective breeding program has been established, enhancing the current mass selected selective breeding program. However, we have not yet had consistent yields in the new pond system and further pond infrastructure development is required. Our best pond yield has only been on par with the traditional pond system, but we believe this is likely to be bettered in the next few years as the initial teething problems are overcome. However, based on these results it remains premature to consider rolling out this new system. We believe the current disappointing results are predominantly due to the use of some manufactured components in the pond construction resulting in substantial mortality of marron, and we believe this problem is now substantially under control. Further annual production results are needed to confirm this expectation and as is often the case in the biological sciences, there is often another surprise in store. The indoor family based breeding program has been successfully established and is able to be continued. The methodologies to continue this indoor breeding program and the ability to bring forward the breeding season are understood. The breeding program has met all the Projects objectives, including the establishment of the genetic markers. However, an unexpected additional finding gives cause for some concern. Following the careful monitoring of the breeding pairs required for the program, and then the examination of breeding females within the normal breeding pond and growout pond system, it has become apparent that many females among the current brood stock are infertile. The rate of infertility appears to differ by breeding year cohorts, with each cohort taking three years to be sexually mature to produce the next generation. There were three different stocks introduced into the farm s ongoing breeding program over a four year period (2002-5), a step taken to improve the levels of genetic diversity in the farm stock and potentially induce hybrid vigour. These stocks included both juveniles and brood stock and were on grown and crossed with the original farm stock. The breeding year cohort with the highest infertility appears to coincide with the introduction of new marron in viii There are thus variable levels of introgression (an indeterminate mixing of genes between two species or strains) of the introduced stock with the original farm stock that can be traced back to the introduction and the breeding of subsequent generations of brood stock. Tracing back the lineage of stocks as reliably as is possible (given the lack of detailed pedigrees at the time) gives cause for concern that this introgression is resulting in significantly reduced fertility and possibly reduced levels of overall fitness, possibly as a result of outbreeding depression, that is, a loss of positive evolutionary endowments which have adapted the gene pool to its particular environment. This Project is the first to observe this phenomenon in farm breeding, but that may be due to the standard mass selection breeding program masking the problem. This issue may well go a long way to explaining the difficulties farmers have had in growing marron, with size and robustness also associated with reduced fertility in these introgressed stocks. The implication for this Project is that to breed through this problem may well take significantly more time and breeding pairs than the planned annual production of 75 families, and require larger facilities and significant costs in testing for genetic markers. Despite some of the setbacks encountered in the implementation of this Project the results are heartening from the producer s perspective. The new round pond system, while not yet proven, has demonstrated significant improvements on the previous system and is expected to yield good results. The indoor b
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