Factors affecting the recovery of soft-sediment mussel reefs in the Firth of Thames, New Zealand

2012 ◽  
Vol 63 (1) ◽  
pp. 78 ◽  
Author(s):  
Ian M. McLeod ◽  
Darren M. Parsons ◽  
Mark A. Morrison ◽  
Agnès Le Port ◽  
Richard B. Taylor

Bivalve reefs are vital ecosystem engineers but have declined or disappeared in many regions. In the Firth of Thames (FOT), north-east New Zealand, overfishing, sedimentation or both led to the virtual extinction of extensive reefs of green-lipped mussels (Perna canaliculus). The mussel reefs have not recovered since commercial fishing ceased in 1968, possibly because the muddy sediments that replaced the reefs are an unsuitable habitat for adult mussels. To test this hypothesis, we transplanted mussels into cages on the seafloor for 500 days at three sites along a turbidity gradient (average visibility 0.8–4.7 m) within the mussel reefs’ former range for 500 days. Results showed that 68% of individuals survived the experiment and grew an average of 19 mm in length. Survivorship and growth did not differ between sites. However, at the completion of the experiment, mussels from the least turbid site were in better condition (condition index = 15) than those from the most turbid site (condition index = 10). Our results suggest that the current lack of recovery of mussel reefs in the FOT is attributable to low recruitment and survivorship of juvenile mussels. Restoration of mussel reefs and the ecosystem services that they provide may therefore be possible.

Author(s):  
K. G. Mukerji

Abstract A description is provided for Peronospora destructor. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Affects species of Allium; common on A. cepa, rarer on A. ascalonicum, A. fistulosum, A. porrum, A. sativum, A. schoenoprasum, and a few wild species. DISEASE: Downy mildew (mildiou, falscher Mehitau) of onion. GEOGRAPHICAL DISTRIBUTION: On onion in all parts of Europe and America; north, east and south Africa, west, south and east Asia, Australia, New Zealand; and Tasmania. On other Allium crops in a few countries in Europe and on other continents (CMI Map 76. ed. 3, 1969).


1886 ◽  
Vol 3 (9) ◽  
pp. 398-402

The “Lake District” of the North Island is too well known to all students of volcanic phenomena, especially of that branch comprising hydrothermal action, to need a detailed description. It will be sufficient to say that it forms a belt, crossing the island from north-east to south-west, and forms a portion of the Middle and Upper Waikato Basins of Hochstetter. The district has been recently brought into prominent notice by the disastrous eruption of Mount Tarawera, very full accounts of which have appeared in New Zealand papers lately received. The eruption commenced in the early morning of Thursday, June 10th, but premonitory symptoms showed themselves a few days before in a tidal wave, three feet high, on Lake Tarawera, great uneasiness of the springs at Ohinemutu, and the reported appearance of smoke issuing from Euapehu, the highest of the great trachytic cones at the extreme south-westerly end of the system. The belt of activity extends from Mount Tongariro at the one end to White Island, in the Bay of Plenty, at the other, a distance of about 150 miles. White Island has undergone considerable change from volcanic action during recent years, and Tongariro was last in eruption in July, 1871; whilst its snowclad sister cone Euapehu has never manifested volcanic action within the historic period until now. This wide zone in the centre of the North Island has, ever since the arrival of the Maoris, been the scene of such extraordinary phenomena, that it has of late been the resort of visitors from all quarters of the globe.


1984 ◽  
Vol 18 (3) ◽  
pp. 367-377 ◽  
Author(s):  
W. N. Vant ◽  
R. J. Davies‐Colley

2021 ◽  
Author(s):  
◽  
Ellen Yarrow

<p>This study explores the relationship between professional contractors and the permanent employees they work with at organisations in New Zealand. This thesis uses two concepts, organisational socialisation and the psychological contract, as lenses through which the working relationship is explored. The 20th century notion of standard employment has largely been eroded, giving way to different forms of non-standard work. Professional contractors are now found performing a variety of roles in many organisations across this country. Many are doing the work of permanent employees, but they are neither employees nor permanent. Professional contractors are a type of non-standard, transient worker. As part of a blended workforce, professional contractors work alongside permanent employees, but little is known about how they work together.  This qualitative study involves 49 face-to-face interviews with professional contractors, permanent employees and managers working in the Information Technology (IT) divisions of 10 organisations in three major cities in New Zealand. This research design results in a rich data set. The data collected was subject to analysis using the software NVIVO. This data was analysed in relation to the literature on organisational socialisation and the psychological contract to further explain the working relationship between professional contractors and permanent employees.  The findings reveal professional contractors’ experience of Van Maanen’s (1979) socialisation tactics were: collective, informal, variable, random and serial. It was found that an organisation’s policy sets the tone for the treatment (induction, inclusion and management) of professional contractors. According to the professional contractors interviewed, the Chao, O'Leary-Kelly, Wolf, Klein, and Gardner (1994) socialisation content dimensions that are important are structure, culture and values and language but history was not considered important. According to the managers interviewed, contractors need to know about the processes and procedures of the client organisation, have strong technical skills and industry, sector or domain knowledge. It was found that the indicator of adjustment ‘acceptance by insiders’ (Bauer & Erdogan, 2012) may be a sign that the contractor is adjusting to their new role but it is not essential. A new indicator of adjustment for professional contractors – output – clearly emerged from the data. The notion of ‘time to productivity’ is highly relevant to professional contractors and three factors affecting it are identified (contractor capability, role complexity and organisation readiness). Another important finding is that permanent employees play a key role as socialisation agents (Feldman, 1994; Jones, 1983; Van Maanen, 1978) in the socialisation of professional contractors. Surprisingly, it was found that other professional contractors also act as socialisation agents assisting the newcomer to adjust. It was found that proactive socialisation is particularly important for professional contractors. Together these findings establish the need to reconceptualise organisational socialisation for professional contractors specifically.  The second part of this thesis explores the psychological contract by asking interviewees about their mutual expectations. The expectations of each of the three parties (managers, professional contractors, and permanent employees) are subtly different, potentially influencing the psychological contract they develop. Permanent employees expect great things, professionalism and independence from professional contractors. Managers expect speed, professionalism and value for money from contractors. On the other hand, professional contractors simply expect to be treated with respect by their colleagues. Professional contractors expect to be given autonomy by their managers and support or guidance, should they require it. This study was not able to ascertain what type of psychological contract a professional contractor may develop. It is possible that a professional contractor develops a hybrid psychological contract. Alternatively, it is possible that a professional contractor’s psychological contract moves between the types developed by Rousseau (1995) over the course of their term with the client organisation. The insights gained by exploring the expectations of professional contractors, permanent employees and their managers are two-fold. Firstly, these expectations provide a valuable insight into the working relationship. Secondly, the exploration of a breach or violation of the psychological contract indicates that a malleable psychological contract (one that will shift or adjust) is less likely to manifest a breach or violation. Therefore, it is better for a professional contractor to develop and maintain a malleable rather than rigid psychological contract.  This study’s findings highlight the interrelationship between organisational socialisation and the psychological contract. This thesis asserts that the working relationship between professional contractors and permanent employees is specifically influenced by the socialisation of contractors as newcomers and in the mutual expectations, which form the psychological contract. As a result, it contributes to theorising and understanding of the working relationship between professional contractors and permanent employees. It identifies several tensions in the co-dependent working relationship, which are: time, team, treatment and training. This study has implications for Human Resource practitioners and managers because there is a need for corporate or HR policy relating to the treatment professional contractors. The use of organisational socialisation and the psychological contract as lenses with which the working relationship is explored is both original and meaningful.</p>


2020 ◽  
Vol 21 (5) ◽  
Author(s):  
Malika Rached Kanouni ◽  
Alia ZERROUKI ◽  
Maroua LAHMAR ◽  
Amina Beldjazia ◽  
Karima Kara ◽  
...  

Abstract. Rached-Kanouni M, Zerrouki A, Lahmar M, Beldjazia A, Kara K, Ababsa. 2020. Assessment of the health status of the Sidi R'Ghies forest, Oum El Bouaghi, north-east Algerian. Biodiversitas 21: 1980-1988. In recent decades, the forest of Sidi R'Ghies has been degraded by human activity. The establishment of the state of the massif by a diagnosis on different forest plots is part of a project of monitoring and silvicultural management. The purpose of this study is to assess the health status of the Sidi R'Ghies forest. The methodology used was the visual assessment of the tree crown of the dominant species (i.e. Aleppo pine and holm oak) according to the protocols DEPEFEU, DEPERIS, and ICP Forests. These protocols were selected for adoption based on field observations and their applicability in record time. The results obtained indicate that the health status of the trees within the studied plots is declining. The DEPEFEU value index shows an average of 2.20 for Aleppo pine and 1.95 for holm oak while the DEPERIS has an average level of 4.56 in Aleppo pine and 3.07 in holm oak. ICP Forests has also contributed to providing clearer information on the consequences of this health situation by deducting an average visibility rate of 1.24 and 1.63; social status of 2.17 and 2.11 and competition of 1.71 and 2.49 for Aleppo pine and holm oak respectively. In general, the health status of the tree crown is average and almost adapted to the environmental conditions. In contrast, the carrying capacity of biodiversity is low and needs to be improved.


2021 ◽  
Author(s):  
◽  
Brenton Hodgson

<p>Globally, commercially exploited fish species are coming under more and more pressure as the population of humans grow. Protein from the sea has traditionally been available to coastal communities throughout history. In modern times however, traditional artisanal fisheries have been replaced by commercial fishing industries. It is estimated by some authorities that these modern fisheries have led to decreases in pre-exploitation biomass of desirable species of up to 90%. As desirable species decline, secondary species become more valuable and subject to exploitation. An issue with this exploitation is that management decisions of fish stocks are often based on political or commercial concerns rather than sound science focussed on preserving stocks, and ultimately, fishing industries. To investigate phylogenetic and phylogeographic relationships of fish, kahawai (Arripis trutta) was used as a proxy species. A. trutta is one of only four members of the genus Arripis, which in turn is the sole member of the family Arripidae. It was found that a single, highly connected population of A. trutta inhabit New Zealand waters, and approximately 15 migrants per generation make the journey between New Zealand and Australia, genetically linking these populations. A phylogeny of A. trutta was resolved using mitochondrial DNA, and while COX1 data supported the hypothesis that A. trutta forms a monophyletic clade within the Stromateoids (medusa fish, squaretails and drift fish) and the Scombrids (tuna, mackerel and their allies) suggesting a common ancestor, other data collected during the investigation does not support this hypothesis.</p>


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