Population structure, growth and longevity of Placostylus hongii (Pulmonata: Bulimulidae) on Tawhiti Rahi Island, Poor Knights Islands, New Zealand

2003 ◽  
Vol 9 (4) ◽  
pp. 241 ◽  
Author(s):  
I. A. N. Stringer ◽  
Karl E. C. Brennan ◽  
Melinda L. Moir ◽  
G. R. Parrish ◽  
Jonathan D. Majer ◽  
...  
Keyword(s):  
Population Structure ◽  
New Zealand ◽  
Shell Length ◽  
East Coast ◽  
Snail Species ◽  
Snail Population ◽  
Predator Control ◽  
Juvenile Period ◽  
Harmonic Radar ◽  
The Poor

Placostylus hongii, a threatened snail species, was studied on Tawhiti Rahi Island in the Poor Knights Islands group off the east coast of northern New Zealand between 1998 and 2000. Most live snails and empty shells were adults (83% and 85% respectively) and the low proportion of empty adult shells (36%) compared with live adult snails found in an area last burnt in the late 1950s suggests that the population there is still recovering. Growth was measured using snails recaptured with the aid of harmonic radar transponders attached to their shells. Increase in shell length varied from 6 to 25 mm per year in juveniles with shells >38 mm long, but it slowed when juveniles approached maturity (adult shell length 55-89 mm). The juvenile period is greater than three years and growth in shell length virtually stops when a thick aperture lip develops. This lip continues to thicken at 0.1-0.4 mm per year and can reach a maximum thickness of 15.5 mm, indicating that adults may live 10 years and possibly more than 30 years. A comparison of our data with two previous studies on the same population and on Aorangi Island, in the Poor Knights Islands group, confirms that these snails are slow developing, have low recruitment of adults, and that populations are probably maintained by a pool of long-lived adults. Our results indicate that following predator control on the mainland, the recovery of a snail population is likely to be slow. Once a population has recovered it could be maintained by intensively controlling rodents for periods of greater than three years (to allow recruitment of adults into the population) alternating with longer periods without control.

The Recent Cypraeidae of Northern New Zealand from the Kermadec Islands to the Poor Knights Islands, Southwest Pacific Ocean (Mollusca: Gastropoda: Cypraeidae)

The Festivus ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 36-54
Author(s):  
John Daughenbaugh
Keyword(s):  
New Zealand ◽  
Pacific Ocean ◽  
Continental Shelf ◽  
East Coast ◽  
Species Distributions ◽  
East Side ◽  
Tropical Eastern Pacific ◽  
The North ◽  
The Poor ◽  
Coastal Shelf

For researchers, isolated regions at the periphery of species’ distributions hold a peculiar fascination. The causes of their remoteness vary based on: distance (e.g. the Tropical Eastern Pacific), distance and countervailing currents (e.g. the Marquesas), location in a present day gyre (e.g. the Pitcairn Group) or the absence of present day means of veliger transport (e.g. the Vema Seamount). (Daughenbaugh & Beals 2013; Daughenbaugh 2015a & b, 2017). The northern New Zealand Region from the Kermadec Islands (Kermadecs) to the coastal and shelf areas in the northernmost part of New Zealand’s North Island (Northland), including the Poor Knights Islands (PKI), constitute the distributional boundaries for a number of Cypraeidae species. The boundaries are the result of the absence of coastal shelves along the east side of the Kermadec Ridge (Ridge) and precipitous drops to abyssal depths along Northland’s east coast continental shelf. Tropical waters, with their potential to transport Cypraeidae larvae, flow eastward from southern Queensland, Australia, entrained in the Tasman Front which terminates when reaching North Cape, the northernmost tip of Northland. There, the North Cape Eddy captures most of this flow while the remainder, the East Auckland Current (EAUC), flows intermittently southward along the eastern coastal, shelf and offshore areas of Northland into waters incapable of supporting Cypraeidae populations.

scholarly journals Population structure, temporal stability and seascape genetics of two endemic New Zealand Pleuronectiformes, Rhombosolea plebeia (sand flounder) and R. leporina (yellowbelly flounder)

2021 ◽  
Author(s):  
◽  
Heather B. Constable
Keyword(s):  
Population Structure ◽  
New Zealand ◽  
Coastal Waters ◽  
Population Genetic ◽  
East Coast ◽  
Temporal Stability ◽  
Soft Bottom ◽  
The South ◽  
Management Options ◽  
Genetic Patterns

<p>New Zealand’s coastal waters are an integral part of the social, economic and environmental heritage of this Pacific archipelago. Evolving in isolation for 82 million years under volatile tectonic action and volcanism, the marine biogeography of New Zealand is complex and diverse. Many hypotheses have been proposed to explain the subdivisions of biogeographic areas based on species distributions, habitat and population genetics. In this study, I test whether there is differentiation in coastal population connectivity between northern and southern provinces, the location of the break and what environmental factors may explain the patterns observed.  Sandy, soft bottom and estuarine ecosystems make up a large proportion of the coastline, but are not well-represented in population genetic studies in New Zealand and internationally. I chose Rhombosolea leporina (sand flounder) and Rhombosolea plebeia (yellowbelly flounder) as endemic, commercially and traditionally important inhabitants of the shallow coastal waters and estuaries to explore levels of gene flow among most of the marine biogeographic regions of the New Zealand mainland.  The goal of this thesis research was to (1) develop polymorphic DNA microsatellite markers and (2) investigate the population genetic patterns at multiple spatial scales. Although these species have a relatively long pelagic larval duration (PLD) of ~70 days, I found a significant level of population structure for both species. There was a pattern of isolation by distance and a north to south break in connectivity on the east coast for R. plebeia, but an east to west disjunction in R. leporina. There was no evidence of a north to south genetic break in R. leporina, however populations on the south east coast of the South Island were significantly differentiated in both species.  A test for temporal effects (3) of genetic variation was conducted to determine whether spatial patterns of differentiation were consistent across multiple sampling seasons and age classes. Aspects of the sweepstakes recruitment success (SRS) hypothesis were tested by examining differences in allele frequencies and levels of genetic diversity as a function of time. The analyses found evidence of temporal stability between years and between juveniles and adults.  Lastly, (4) the coastal and estuarine environmental variables were modelled using information from two public GIS datasets and several measures of genetic differentiation. The aim of this chapter was to determine which environmental and geospatial factors showed a significant level of correlation with the spatial genetic patterns reported in the earlier studies. For R. leporina, latitude, sediment and current speeds were significantly correlated with the genetic estimates of FST, F’ST and Jost’s D. In R. plebeia, a correlation was found between latitude, longitude, sediment, current speeds, sea surface temperature and width of the estuary mouth. The results of the modelling study suggest avenues for further research using candidate genes, such as heat shock proteins and rhodopsin.  This was the first study of New Zealand pleuronectids using a multidisciplinary approach with microsatellite DNA markers, GIS, and an array of bioinformatics software to study coastal connectivity on multiple spatial and temporal scales. Significant genetic structuring was found among populations of animals that are potentially well connected through continuous sandy, soft bottom environments and a long PLD. Despite similar life histories and ecologies, the two species were quite divergent in that there was little cross amplification of markers, different patterns of genetic structure and separate outcomes from environmental modelling. These results suggest that managing several species under one management plan may be an oversimplification of the complexities of the population dynamics and evolutionary histories of these species. Conservation and management options for coastal fisheries and possible avenues for future research are proposed.</p>

scholarly journals Population structure, temporal stability and seascape genetics of two endemic New Zealand Pleuronectiformes, Rhombosolea plebeia (sand flounder) and R. leporina (yellowbelly flounder)

2021 ◽  
Author(s):  
◽  
Heather B. Constable
Keyword(s):  
Population Structure ◽  
New Zealand ◽  
Coastal Waters ◽  
Population Genetic ◽  
East Coast ◽  
Temporal Stability ◽  
Soft Bottom ◽  
The South ◽  
Management Options ◽  
Genetic Patterns

<p>New Zealand’s coastal waters are an integral part of the social, economic and environmental heritage of this Pacific archipelago. Evolving in isolation for 82 million years under volatile tectonic action and volcanism, the marine biogeography of New Zealand is complex and diverse. Many hypotheses have been proposed to explain the subdivisions of biogeographic areas based on species distributions, habitat and population genetics. In this study, I test whether there is differentiation in coastal population connectivity between northern and southern provinces, the location of the break and what environmental factors may explain the patterns observed.  Sandy, soft bottom and estuarine ecosystems make up a large proportion of the coastline, but are not well-represented in population genetic studies in New Zealand and internationally. I chose Rhombosolea leporina (sand flounder) and Rhombosolea plebeia (yellowbelly flounder) as endemic, commercially and traditionally important inhabitants of the shallow coastal waters and estuaries to explore levels of gene flow among most of the marine biogeographic regions of the New Zealand mainland.  The goal of this thesis research was to (1) develop polymorphic DNA microsatellite markers and (2) investigate the population genetic patterns at multiple spatial scales. Although these species have a relatively long pelagic larval duration (PLD) of ~70 days, I found a significant level of population structure for both species. There was a pattern of isolation by distance and a north to south break in connectivity on the east coast for R. plebeia, but an east to west disjunction in R. leporina. There was no evidence of a north to south genetic break in R. leporina, however populations on the south east coast of the South Island were significantly differentiated in both species.  A test for temporal effects (3) of genetic variation was conducted to determine whether spatial patterns of differentiation were consistent across multiple sampling seasons and age classes. Aspects of the sweepstakes recruitment success (SRS) hypothesis were tested by examining differences in allele frequencies and levels of genetic diversity as a function of time. The analyses found evidence of temporal stability between years and between juveniles and adults.  Lastly, (4) the coastal and estuarine environmental variables were modelled using information from two public GIS datasets and several measures of genetic differentiation. The aim of this chapter was to determine which environmental and geospatial factors showed a significant level of correlation with the spatial genetic patterns reported in the earlier studies. For R. leporina, latitude, sediment and current speeds were significantly correlated with the genetic estimates of FST, F’ST and Jost’s D. In R. plebeia, a correlation was found between latitude, longitude, sediment, current speeds, sea surface temperature and width of the estuary mouth. The results of the modelling study suggest avenues for further research using candidate genes, such as heat shock proteins and rhodopsin.  This was the first study of New Zealand pleuronectids using a multidisciplinary approach with microsatellite DNA markers, GIS, and an array of bioinformatics software to study coastal connectivity on multiple spatial and temporal scales. Significant genetic structuring was found among populations of animals that are potentially well connected through continuous sandy, soft bottom environments and a long PLD. Despite similar life histories and ecologies, the two species were quite divergent in that there was little cross amplification of markers, different patterns of genetic structure and separate outcomes from environmental modelling. These results suggest that managing several species under one management plan may be an oversimplification of the complexities of the population dynamics and evolutionary histories of these species. Conservation and management options for coastal fisheries and possible avenues for future research are proposed.</p>

Tectonic and paleoclimatic significance of Quaternary river terraces of the Waipaoa river, east coast, North Island, New Zealand

2000 ◽  
Vol 43 (2) ◽  
pp. 229-245 ◽  
Author(s):  
Kelvin Berryman ◽  
Michael Marden ◽  
Dennis Eden ◽  
Colin Mazengarb ◽  
Yoko Ota ◽  
...  
Keyword(s):  
New Zealand ◽  
East Coast ◽  
River Terraces ◽  
Paleoclimatic Significance

LUCERNE IN THE WELLINGTON, TARANAKI, AND EAST COAST DISTRICTS

1936 ◽  
pp. 92-95
Author(s):  
A.G. Elliott ◽  
T.W. Lonsdale
Keyword(s):  
New Zealand ◽  
West Coast ◽  
East Coast ◽  
General Trend ◽  
Present Position ◽  
Department Of Agriculture ◽  
Forage Crop ◽  
High Rainfall ◽  
The North ◽  
Subsequent Discussion

IN two papers read by officers of the Department of Agriculture at the 1936 conference of the New Zealand Grassland Association, the growing of lucernc as a forage crop in districts of relatively high rainfall was dealt with. The area covered by the papers included the Manawatu and west coast from Paraparaumu to the Patea River(I) and Taranaki(n). During the subsequent discussion on these and other papers the present position and general trend in regard to lucernegrowing in the Wairarapa, Eiawke's Eay, and Poverty Bay districts were also touched on. It is the intention here. to review briefly some of the more important points in regard to the cultivation of lucerne in the southern portion of the North Island as discussed at the conference.

Geodetic strain and the deformational history of the North Island of New Zealand during the late Cainozoic

1987 ◽  
Vol 321 (1557) ◽  
pp. 163-181 ◽  
Keyword(s):  
New Zealand ◽  
Subduction Zone ◽  
East Coast ◽  
Late Quaternary ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Metamorphic Belt ◽  
Volcanic Region ◽  
The North ◽  
Plate Boundary Zone

The subduction zone under the east coast of the North Island of New Zealand comprises, from east to west, a frontal wedge, a fore-arc basin, uplifted basement forming the arc and the Central Volcanic Region. Reconstructions of the plate boundary zone for the Cainozoic from seafloor spreading data require the fore-arc basin to have rotated through 60° in the last 20 Ma which is confirmed by palaeomagnetic declination studies. Estimates of shear strain from geodetic data show that the fore-arc basin is rotating today and that it is under extension in the direction normal to the trend of the plate boundary zone. The extension is apparently achieved by normal faulting. Estimates of the amount of sediments accreted to the subduction zone exceed the volume of the frontal wedge: underplating by the excess sediments is suggested to be the cause of late Quaternary uplift of the fore-arc basin. Low-temperature—high-pressure metamorphism may therefore be occurring at depth on the east coast and high-temperature—low-pressure metamorphism is probable in the Central Volcanic Region. The North Island of New Zealand is therefore a likely setting for a paired metamorphic belt in the making.

scholarly journals 3. Remarks upon the Footprints of the Dinornis in the Sand Rock at Poverty Bay, New Zealand, and upon its recent extinction

1875 ◽  
Vol 8 ◽  
pp. 236-240
Author(s):  
T. H. Cockburn-Hood
Keyword(s):  
New Zealand ◽  
East Coast ◽  
The North

Impressions of the tracks of large birds from this locality have lately been objects of attraction to visitors to the museum at Wellington, New Zealand. To these Dr Hector, F.R.S., has affixed a label, stating that they are from the “Sea shore sand” at Poverty bay, a harbour on the east coast of the north island. “Sand rock” would have been a preferable term, as to most observers the description is calculated to convey the idea that these footprints are but of yesterday's date.

Sign in / Sign up

Export Citation Format

Share Document