Foraminiferal record of ecological impact of deforestation and oyster farms, Mahurangi Harbour, New Zealand

2007 ◽  
Vol 58 (5) ◽  
pp. 475 ◽  
Author(s):  
Hugh R. Grenfell ◽  
Bruce W. Hayward ◽  
Mark Horrocks
Keyword(s):  
New Zealand ◽  
Sediment Cores ◽  
Ecological Impact ◽  
Rapid Change ◽  
Oyster Shell ◽  
Ecological Changes ◽  
Lower Oxygen ◽  
Oyster Farms ◽  
Foraminiferal Record ◽  
On Farm

The microfossils in eight short sediment cores in Mahurangi Harbour, northern New Zealand, record major ecological changes since colonisation by Europeans. During the period of catchment deforestation (1850s–1900) these changes include increased sedimentation rates, decline of soft-shore molluscs, increased diatoms and seaward migration of brackish, agglutinate-dominated, foraminiferal associations, inferred to be due to increased freshwater runoff and decreased pH. The interval of most rapid change (1950s–1980s) occurred before and during the establishment of oyster farms, which therefore are not implicated. Comparison of the microfossil content of surface sediment samples taken inside and outside of four oyster farms indicates variable effects dependent on farm location. In less saline sites, the presence of oyster-shell debris in sediment beneath oyster farms appears to have buffered the foraminiferal faunas from some of the impacts of lowered salinity and pH. At more tidally flushed, saline sites, the oyster farms influence a wider surrounding area that has lower relative abundance of three species of Elphidium and other calcareous Foraminifera, attributed to slightly muddier sediment, higher nutrients and consequently lower oxygen. A newly arrived exotic foraminifer, Elphidium vellai, appears to be an indicator species for the enhanced nutrient, carbonate-rich conditions beneath oyster farms.

scholarly journals Ewe Wastage in New Zealand Commercial Flocks: Extent, Timing, Association with Hogget Reproductive Outcomes and BCS

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 779
Author(s):  
Kate J. Flay ◽  
Anne L. Ridler ◽  
Chris W. R. Compton ◽  
Paul R. Kenyon
Keyword(s):  
New Zealand ◽  
Key Management ◽  
Body Condition Score ◽  
Survival Models ◽  
Reproductive Outcomes ◽  
Increase Risk ◽  
Interval Censored ◽  
Mortality Incidence ◽  
Condition Score ◽  
On Farm

Ewe wastage is the combination of on-farm mortality and premature culling. Internationally, there is limited research on actual wastage incidence and causes in commercial sheep flocks. To the authors’ knowledge, this is the first study that reports both lifetime wastage and detailed annual wastage in a sample of commercial New Zealand flocks. This study utilized data collected from 13,142 ewes from four cohorts on three commercial New Zealand farms (Farm A 2010-born, Farm A 2011-born, Farm B, Farm C), during the period 2011–2017, as they aged from replacement hoggets to 6-year-old ewes (Farm A and Farm B) or 3-year-old ewes (Farm C). Data collection visits occurred at three or four key management times each year, namely pre-mating, pregnancy diagnosis, pre-lambing and weaning. At each visit, body condition score (BCS) was assessed and any ewes that were culled or had died on farm were recorded. As this was a lifetime study, each ewe was assigned an outcome and corresponding ‘exit age’. By the end of the study, all ewes that had exited their respective flocks, were classified as either prematurely culled, or dead/missing, or if still in the flock, as censored, and either the exact date or interval in which they exited the flock was recorded. Semi-parametric competing risk (premature culling vs. dead/missing), interval-censored survival models were developed to: 1. describe the association between hogget reproductive outcomes and risk of subsequent wastage, and 2. assess pre-mating BCS as a predictor of wastage in that production year. Of the 13,142 enrolled ewes, 50.4% exited their respective flocks due to premature culling and 40.0% due to on-farm dead/missing, giving a total of 90.4% that exited due to wastage. Annual mortality incidence ranged from 3.5 to 40.2%. As a hogget, wastage incidence ranged from 7.6 to 45.4%. Pregnancy or rearing a lamb as a hogget did not increase risk of subsequent wastage. In all years, pre-mating BCS was a predictor of ewe wastage, with odds of wastage lower with increasing BCS. Therefore, farmers should focus on improving pre-mating BCS to 3.5/5.0 by assessing ewe BCS at weaning, allowing poorer-BCS ewes to be managed to gain BCS before re-breeding.

scholarly journals The Carbon Footprint of Energy Consumption in Pastoral and Barn Dairy Farming Systems: A Case Study from Canterbury, New Zealand

2019 ◽  
Vol 11 (17) ◽  
pp. 4809 ◽  
Author(s):  
Hafiz Muhammad Abrar Ilyas ◽  
Majeed Safa ◽  
Alison Bailey ◽  
Sara Rauf ◽  
Marvin Pangborn
Keyword(s):  
New Zealand ◽  
Carbon Footprint ◽  
Dairy Farming ◽  
Carbon Footprints ◽  
Energy Inputs ◽  
Study Results ◽  
Feed Supplements ◽  
Dairy Systems ◽  
Milk Solids ◽  
On Farm

Dairy farming is constantly evolving to more intensive systems of management, which involve more consumption of energy inputs. The consumption of these energy inputs in dairy farming contributes to climate change both with on-farm emissions from the combustion of fossil fuels, and by off-farm emissions due to production of farm inputs (such as fertilizer, feed supplements). The main purpose of this research study was to evaluate energy-related carbon dioxide emissions, the carbon footprint, of pastoral and barn dairy systems located in Canterbury, New Zealand. The carbon footprints were estimated based on direct and indirect energy sources. The study results showed that, on average, the carbon footprints of pastoral and barn dairy systems were 2857 kgCO2 ha−1 and 3379 kgCO2 ha−1, respectively. For the production of one tonne of milk solids, the carbon footprint was 1920 kgCO2 tMS−1 and 2129 kgCO2 tMS−1, respectively. The carbon emission difference between the two systems indicates that the barn system has 18% and 11% higher carbon footprint than the pastoral system, both per hectare of farm area and per tonne of milk solids, respectively. The greater carbon footprint of the barn system was due to more use of imported feed supplements, machinery usage and fossil fuel (diesel and petrol) consumption for on-farm activities.

Simplified methods for on-farm prediction of yield potential of grazed lucerne crops in New Zealand

2021 ◽  
pp. 1-19
Author(s):  
Derrick J. Moot ◽  
Xiumei Yang ◽  
Hung T. Ta ◽  
Hamish E. Brown ◽  
Edmar I. Teixeira ◽  
...  
Keyword(s):  
New Zealand ◽  
Yield Potential ◽  
On Farm

scholarly journals Ecological impact and spread of an invasive paper wasp in New Zealand (Hymenoptera: Vespidae)

2021 ◽  
Author(s):  
Matthew Howse
Keyword(s):  
At Risk ◽  
Invasive Species ◽  
New Zealand ◽  
Ecological Impact ◽  
Diet Analysis ◽  
Paper Wasp ◽  
Gut Contents ◽  
Suitable Habitat ◽  
The South ◽  
The North

<p><b>Social wasps are considered among the most successful and impactful invasive species in the world. One species, Polistes dominula has spread from its native Mediterranean range to every continent except Antarctica. This wasp reached New Zealand in the last decade where it has established in the north of the South Island, however, reports of its presence are increasing throughout the country. Due to its recent arrival in New Zealand, little is known about where this species is likely to establish or what impacts it may have on local insect communities. In this thesis, I conducted two studies to investigate these questions, providing valuable information that may inform future management of this invasive species. </b></p><p>In chapter 2, I used two bioclimatic modelling methods to predict areas of suitable habitat across four regions in the southern hemisphere. These models were informed by global temperature and precipitation data as well as global distribution occurrence data of P. dominula. These data were used to estimate conditions most highly correlated with the presence of this wasp. The models identified large areas across the target regions that were climatically suitable for the establishment of P. dominula. Many of these areas are not known to currently contain populations of this species, representing habitat potentially vulnerable to further invasion by P. dominula. Areas across South America, South Africa and Australia were predicted to be climatically suitable. In New Zealand, much of the North Island and eastern parts of the South Island were predicted to be suitable habitat for this wasp. These results suggest that P. dominula could potentially establish across more of the country and expand its invaded range. Information provided by these models may guide conservation and biosecurity management by highlighting key areas where prevention and mitigation should be prioritized. </p><p>In chapter 3, I used molecular diet analysis to investigate the range of prey being utilised by P. dominula in New Zealand. Using DNA barcoding, larval gut contents of P. dominula and another closely related species, Polistes chinensis, were analysed to identify what species were present in the diet of both wasps. Butterflies and moths (Lepidoptera) were found to be the most highly represented order in both species’ diets. True bugs (Hemiptera) and flies (Diptera) were also abundant. Both wasps were shown to consume a range of native and introduced species including a number of agricultural pests. P. dominula was found to utilise a wider range of prey than P. chinensis. This more diverse prey range, combined with known differences in nesting behaviour, suggest that P. dominula may represent a more significant threat to invertebrate diversity than the already well-established P. chinensis. These results may inform conservation and biosecurity managers on which species are most at risk where this new invasive wasp becomes established. </p><p>This thesis provides insights into the potential impacts of a new invasive species to New Zealand. Both chapters represent the first time that these methods have been used to study P. dominula. This work highlights the need for continued monitoring of wasp populations throughout New Zealand, especially in regions highlighted as vulnerable to P. dominula establishment. We also suggest the need to prioritise the conservation of ‘at-risk’ species in coastal and human-altered habitats. Increased public engagement through the citizen-science initiatives should be encouraged while more research into management and control methods is recommended.</p>

scholarly journals A new method of administering local anesthesia for calf disbudding: Findings from a comparative on-farm study in New Zealand

2019 ◽  
Vol 102 (3) ◽  
pp. 2492-2506 ◽  
Author(s):  
A.J. Bates ◽  
M.A. Sutherland ◽  
F. Chapple ◽  
S.K. Dowling ◽  
A.P. Johnson ◽  
...  
Keyword(s):  
New Zealand ◽  
Local Anesthesia ◽  
New Method ◽  
On Farm

Growth, morphometrics and size structure of the Diadematidae sea urchin Centrostephanus rodgersii in northern New Zealand

2012 ◽  
Vol 63 (7) ◽  
pp. 624 ◽  
Author(s):  
Danilo Pecorino ◽  
Miles D. Lamare ◽  
Mike F. Barker
Keyword(s):  
Growth Rate ◽  
New Zealand ◽  
Sea Urchin ◽  
Size Structure ◽  
Growth Line ◽  
Fluorescent Marker ◽  
Zealand Population ◽  
Ecological Changes ◽  
Eastern Australia ◽  
Size At Age

The sea urchin Centrostephanus rodgersii has increased its range in Eastern Australia resulting in important ecological changes. C. rodgersii may also have expanded its distribution range to northern New Zealand in the last five to six decades, although little is known about this process and of the biology of the species in New Zealand. We investigated morphometrics as well as growth using two techniques (growth line count in genital plates and tag–recapture using the fluorescent marker tetracycline). These methods allowed modelling of size at age of C. rodgersii in New Zealand, which we compared with populations recently established in Tasmania. The modelled growth rate was only slightly higher in the New Zealand population, and no differences in morphometrics were observed. The New Zealand population structure suggests that annual recruitment occurs regularly, with the population including a range of ages (3 to 10+ years).

scholarly journals Developing an Animal Welfare Assessment Protocol for Cows in Extensive Beef Cow–Calf Systems in New Zealand. Part 1: Assessing the Feasibility of Identified Animal Welfare Assessment Measures

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1597 ◽  
Author(s):  
Y. Baby Kaurivi ◽  
Richard Laven ◽  
Rebecca Hickson ◽  
Tim Parkinson ◽  
Kevin Stafford
Keyword(s):  
New Zealand ◽  
Animal Welfare ◽  
Welfare Assessment ◽  
Assessment Protocol ◽  
Beef Cow ◽  
Cattle Management ◽  
Assessment Measures ◽  
Animal Welfare Assessment ◽  
Cow Calf ◽  
On Farm

Potential measures suitable for assessing welfare in pasture-based beef cow–calf systems in New Zealand were identified from Welfare Quality and UC Davis Cow-Calf protocols. These were trialled on a single farm and a potential protocol of 50 measures created. The aim of this study was to assess the feasibility of the measures included in this protocol on multiple farms in order, to develop a credible animal welfare assessment protocol for pasture-based cow–calf farms systems in New Zealand. The assessment protocol was trialled on 25 farms over two visits and took a total of 2.5 h over both visits for a 100-cow herd. The first visit in autumn included an animal welfare assessment of 3366 cows during pregnancy scanning, while the second visit in winter included a questionnaire-guided interview to assess cattle management and health, and a farm resource evaluation. Through a process of eliminating unsuitable measures, adjustments of modifiable measures and retaining feasible measures, a protocol with 32 measures was created. The application of the protocol on the farms showed that not all measures are feasible for on-farm assessment, and categorisation of identified animal welfare measures into scores that indicate a threshold of acceptable and non-acceptable welfare standards is necessary.

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