scholarly journals Resource specialisation among suspension-feeding invertebrates on rock walls in Fiordland, New Zealand, is driven by water column structure and feeding mode

2012 ◽  
Vol 452 ◽  
pp. 109-118 ◽  
Author(s):  
S Wing ◽  
L Jack
Keyword(s):  
New Zealand ◽  
Water Column ◽  
Suspension Feeding ◽  
Feeding Mode ◽  
Column Structure

scholarly journals Water column structure and statistics of Denmark Strait Overflow Water cyclones

2014 ◽  
Vol 84 ◽  
pp. 110-126 ◽  
Author(s):  
Wilken-Jon von Appen ◽  
Robert S. Pickart ◽  
Kenneth H. Brink ◽  
Thomas W.N. Haine
Keyword(s):  
Water Column ◽  
Column Structure ◽  
Denmark Strait

Oceanography of the New Zealand subantarctic region

2021 ◽  
Author(s):  
◽  
Aitana Forcén-Vázquez
Keyword(s):  
New Zealand ◽  
Interannual Variability ◽  
Water Column ◽  
Large Scale ◽  
Southern Oscillation ◽  
Complex Structure ◽  
Positive Trend ◽  
Intermediate Water ◽  
Subantarctic Region

<p>Subantarctic New Zealand is an oceanographycally dynamic region with the Subtropical Front (STF) to the north and the Subantarctic Front (SAF) to the south. This thesis investigates the ocean structure of the Campbell Plateau and the surrounding New Zealand subantarctic, including the spatial, seasonal, interannual and longer term variability over the ocean properties, and their connection to atmospheric variability using a combination of in-situ oceanographic measurements and remote sensing data.  The spatial and seasonal oceanographic structure in the New Zealand subantarctic region was investigated by analysing ten high resolution Conductivity Temperature and Depth (CTD) datasets, sampled during oceanographic cruises from May 1998 to February 2013. Position of fronts, water mass structure and changes over the seasons show a complex structure around the Campbell Plateau combining the influence of subtropical and subantarctic waters.  The spatial and interannual variability on the Campbell Plateau was described by analysing approximately 70 low resolution CTD profiles collected each year in December between 2002 and 2009. Conservative temperature and absolute salinity profiles reveal high variability in the upper 200m of the water column and a homogeneous water column from 200 to 600m depth. Temperature variability of about 0.7 °C, on occasions between consecutive years, is observed down to 900m depth. The presence of Subantarctic Mode Water (SAMW) on the Campbell Plateau is confirmed and Antarctic Intermediate Water (AAIW) reported for the first time in the deeper regions around the edges of the plateau.  Long-term trends and variability over the Campbell Plateau were investigated by analysing satellite derived Sea Level Anomalies (SLA) and Sea Surface Temperature (SST) time series. Links to large scale atmospheric processes are also explored through correlation with the Southern Oscillation Index (SOI) and Southern Annular Mode (SAM). SST shows a strong seasonality and interannual variability which is linked to local winds, but no significant trend is found. The SLA over the Campbell Plateau has increased at a rate of 5.2 cm decade⁻¹ in the last two decades. The strong positive trend in SLA appears to be a combination of the response of the ocean to wind stress curl (Ekman pumping), thermal expansion and ocean mass redistribution via advection amongst others.  These results suggest that the variability on the Campbell Plateau is influenced by the interaction of the STF and the SAF. The STF influence reaches the limit of the SAF over the western Campbell Plateau and the SAF influence extends all around the plateau. Results also suggest different connections between the plateau with the surrounding oceans, e.g., along the northern edge with the Bounty Trough and via the southwest edge with the SAF. A significant correlation with SOI and little correlation with SAM suggest a stronger response to tropically driven processes in the long-term variability on the Campbell Plateau.  The results of this thesis provide a new definitive assessment of the circulation, water masses and variability of the Campbell Plateau on mean, annual, and interannual time scales which will support research in other disciplines such as palaeoceanography, fisheries management and climate.</p>

scholarly journals A note on modeling mixing in the upper layers of the Bay of Bengal: Importance of water type, water column structure and precipitation

2019 ◽  
Vol 168 ◽  
pp. 104643
Author(s):  
Lakshmi Kantha ◽  
Robert A. Weller ◽  
J. Thomas Farrar ◽  
Hasibur Rahaman ◽  
Venkata Jampana
Keyword(s):  
Water Column ◽  
Bay Of Bengal ◽  
Water Type ◽  
Column Structure ◽  
Type Water

scholarly journals Polymorphy and extinction of the Late Cretaceous burrowing shrimp Protocallianassa faujasi and first record of the genera Corallianassa and Calliax (Crustacea, Decapoda, Thalassinoidea) from the Cretaceous

2001 ◽  
Vol 70 (2) ◽  
pp. 85-98 ◽  
Author(s):  
Krista Swen ◽  
René H.B. Fraaije ◽  
Gijsbert J. van der Zwaan
Keyword(s):  
New Species ◽  
First Record ◽  
Suspension Feeding ◽  
Feeding Mode ◽  
Male And Female ◽  
Immature Male ◽  
Type Area ◽  
Mode Of Life ◽  
Burrow Morphology

A biometric study of chelae of the burrowing shrimp Protocallianassa faujasi ( Desmarest, 1822), from the late Maastrichtian of the Maastrichtian type area, The Netherlands, has revealed three morphotypes. These types are interpreted as sexual dimorphs (male and female) and earliest ecdysis stages (immature male). Among the studied material are fifteen specimens of a new Cretaceous callianassid, Corallianassa acucurvata new species, one specimen provisionally assigned to the genus Calliax and a callianassid from the Danian. Burrows preserving callianassid chelae in situ are discussed. Based on burrow morphology a suspension feeding mode of life for P.faujasi is inferred, whereas C. acucurvata n. sp. probably was an active omnivorous analogue of its closest Recent relatives. The extinction of P. faujasi in the Meerssen Member appears to correspond to the increase in seagrass vegetation. The Protocallianassa-Corallianassa faunal changeover took place about 100,000 yrs before the K/T boundary in this region.

Redox speciation of chromium in the oceanic water column of the Lesser Antilles and offshore Otago Peninsula, New Zealand

2003 ◽  
Vol 54 (6) ◽  
pp. 745 ◽  
Author(s):  
Sylvia Sander ◽  
Andrea Koschinsky ◽  
Peter Halbach
Keyword(s):  
New Zealand ◽  
Water Column ◽  
Effective Means ◽  
Stripping Voltammetry ◽  
Speciation Analysis ◽  
Hydrothermal Activity ◽  
Lesser Antilles ◽  
Species Determination ◽  
Seafloor Hydrothermal Activity ◽  
Redox Speciation

Chromium redox speciation analysis was carried out onboard ship in several water column profiles off the islands of Dominica, St Lucia and Grenada (Lesser Antilles), and at two stations offshore from the Otago Peninsula (New Zealand). The catalytic adsorptive stripping voltammetry with diethylenetriaminepentaacetic acid as complexing reagent and a hanging mercury drop as a working electrode were used. In the samples from the Lesser Antilles, Cr(VI) concentrations ranged around a relatively constant background of 1.5–2.5 nM, except for one higher value of 4.3 nM, whereas Cr(III) was highly variable and reached maximum concentrations of 12 nM. Variable environmental influences, such as hydrothermal activity and atmospheric input, are probable sources for reduced chromium species. In contrast, the Cr(III) contribution was less than 50% of total Cr in subantarctic non-hydrothermal water offshore from the Otago Peninsula and the presence of Cr(III) was restricted to the upper 100 m of the water column. In these depth profiles, Cr (VI) (up to 3.7 nM) was clearly the dominating species.Onboard ship redox speciation was shown to be an effective means to avoid storing artefacts in species determination. We conclude that seafloor hydrothermal activity contributes significantly to the reduced Cr species chemistry of the surrounding seawater.

Infaunal benthic community structure and function in the Gulf of Carpentaria, northern Australia

1994 ◽  
Vol 45 (3) ◽  
pp. 293 ◽  
Author(s):  
BG Long ◽  
IR Poiner
Keyword(s):  
Species Richness ◽  
Species Density ◽  
Physical Factors ◽  
Suspension Feeding ◽  
Sediment Texture ◽  
Surface Deposit ◽  
Feeding Mode ◽  
Sediment Grain Size ◽  
South Eastern ◽  
Deposit Feeders

The infaunal benthos (>20 m) of the Gulf of Carpentaria was surveyed during November and December 1990. In all, 684 taxa were collected from 105 stations, each with three replicate 0.1-m2 grab samples (Smith-McIntyre grab). Trends in abundance and species richness were correlated with gulf-wide trends in sediment texture and depth. Highest abundance (20-153 individuals per 0.1 m2), wet-weight biomass (X=7.6 g per 0.1 m2) and species density (X=25.8 taxa per 0.1 m2) occurred in the sands and muddy sands along the eastern and south-eastern margins of the gulf. Lowest abundance (3.3-20.0 individuals per 0.1 m2), biomass (X=3.0 g per 0.1 m2) and species density (X=9.5 taxa per 0.1 m2) occurred in the muds and sandy muds in the centra, western and north-western gulf. Infaunal abundance and biomass were similar to those of other tropical continental shelves but were lower than those of some temperate-region shelves and upwelling areas. Species richness was also lower than in temperate areas of upwelling or high production. Scavengers/carnivores (44%) and deposit feeders (43%) numerically dominated throughout the gulf. Suspension feeding was less prevalent (13%), and few herbivores were found (< 1%). There was a trend in the proportion of deposit and suspension feeders that was related to sediment texture. Suspension feeding was highest in the muddy sands of the eastern and south-eastern gulf and lowest in the muds of the north-west. The proportion of deposit feeders was highest in muddy sediments and lowest in sandy sediments. Small (<5 mm) surface deposit feeders numerically dominated within this feeding mode. The 15 numerically dominant taxa were comprised mainly of opportunistic or second-stage colonizing taxa. Most had gulf-wide distribution patterns, but levels of abundance were correlated with sediment and depth. The infaunal benthic communities in the Gulf of Carpentaria appear to be regulated by physical factors of the environment that correlate with sediment grain size and depth.

Water Column Structure and Circulation In The Main channel, Twin Cays, Belize

2005 ◽  
Vol 535 ◽  
pp. 136-156
Author(s):  
S. R. Kibler ◽  
Maria A. Faust ◽  
M. V. Vandersea ◽  
S. M. Varnam ◽  
R. Wayne Litaker ◽  
...  
Keyword(s):  
Water Column ◽  
Main Channel ◽  
Column Structure
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