Variation in mussel and barnacle recruitment parallels a shift in intertidal community structure in the Cook Strait region of New Zealand

2011 ◽  
Vol 62 (10) ◽  
pp. 1221 ◽  
Author(s):  
Rahul Demello ◽  
Nicole E. Phillips
Keyword(s):  
New Zealand ◽  
Intertidal Zone ◽  
Spatial Scales ◽  
South Coast ◽  
The South ◽  
Sessile Invertebrates ◽  
High Zone ◽  
Species Specific ◽  
High Intertidal Zone

Recruitment influences populations and communities of marine organisms to varying degrees and across a range of spatial scales. We hypothesised that recruitment plays a role in maintaining different intertidal invertebrate assemblages between two nearby locations in New Zealand (Wellington Harbour and the south coast), long reported to have dramatically different communities (with greater cover of sessile invertebrates in the Harbour). Sites in Wellington Harbour were hypothesised to have higher monthly recruitment rates of mussels and barnacles and greater barnacle colonisation after 1 year. Surveys were conducted to quantify community differences. In Wellington Harbour, the mid-intertidal zone was dominated by the mussel Mytilus galloprovincialis and the barnacle Chamaesipho columna and the high intertidal zone by C. columna. In contrast, on the south coast mussels were almost completely absent from both tidal heights and barnacles (predominantly Chamaesipho brunnea) were sparse. In the high zone, monthly recruitment and long term colonisation (over 1 year) of barnacles was much greater in the Harbour; in the mid-intertidal zone, mussel recruitment was up to two orders of magnitude greater in the Harbour than the south coast. Species-specific recruitment patterns differed between the locations, however and were consistent with those of adult abundance.

Surface erosion assessment in the South-Canterbury downlands, New Zealand using 137Cs distribution

Soil Research ◽  
1995 ◽  
Vol 33 (5) ◽  
pp. 787 ◽  
Author(s):  
LR Basher ◽  
KM Matthews ◽  
L Zhi
Keyword(s):  
New Zealand ◽  
Mean Value ◽  
Slope Position ◽  
Surface Erosion ◽  
The South ◽  
Erosion And Deposition ◽  
Erosion Rates ◽  
Land Use Types ◽  
Radionuclide Tracer

Redistribution of the radionuclide tracer 137Cs was used to examine the pattern of erosion and deposition at two sites with contrasting long-term land uses (pasture and cropping) in the South Canterbury downlands, New Zealand. There were clear differences between the two land use types in variation in 137Cs concentrations and areal activity, erosion rates and topsoil depth variability. Erosion and deposition have resulted in greater variability and lower mean levels of 137Cs areal activity under cropping (46.3 mBq cm-2) than pasture (55.0 mBq cm-2). At the cropping site, erosion and deposition roughly balanced with the mean value over all sampling sites, suggesting no net soil loss, but considerable redistribution of soil within paddocks. At the pasture site results suggested slight net deposition. There was evidence for both sheet/rill and wind erosion being important in soil redistribution. While there was no difference in mean topsoil depth between pasture and cropping, there were significant differences with slope position. At the pasture site, there was little variation of topsoil depth with slope position, except for swales which tended to be deeper, whereas at the cropping site there was considerable variation in topsoil depth with slope position. Topsoil depth was a poor indicator of erosion status.

scholarly journals The Subhabitat Dependence of Biogeographic Pattern

2020 ◽  
Vol 8 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Matthew J. Freeman ◽  
Julius A. Ellrich
Keyword(s):  
Intertidal Zone ◽  
Abiotic Factors ◽  
Species Abundance ◽  
Biological Surveys ◽  
Biogeographic Patterns ◽  
Abundance Data ◽  
Biogeographic Pattern ◽  
Sessile Invertebrates ◽  
High Intertidal Zone ◽  
Species Abundance Data

We introduce and test the subhabitat dependence hypothesis (SDH) in biogeography. This hypothesis posits that biogeographic pattern within a region differs when determined with species abundance data from different subhabitat types. It stems from the notion that the main abiotic factors that drive species distribution in different subhabitat types across a biogeographic region often vary differently across space. To test the SDH, we measured the abundance of algae and sessile invertebrates in two different subhabitats (high intertidal zone and mid-intertidal zone) at eight locations along the Atlantic Canadian coast. We conducted multivariate analyses of the species abundance data to compare alongshore biogeographic pattern between both zones. For both subhabitat types, location groupings based on community similarity not always responded to geographic proximity, leading to biogeographic patchiness to some extent. Nonetheless, both biogeographic patterns were statistically unrelated, thus supporting the SDH. This lack of concordance was most evident for southern locations, which clustered together based on high-intertidal data but showed considerable alongshore patchiness based on mid-intertidal data. We also found that the ordination pattern of these eight locations based on sea surface temperature data was significantly related to biogeographic pattern for the mid-intertidal zone but not for the high intertidal zone. This finding supports the rationale behind the SDH due to the longer periods of submergence experienced by the mid-intertidal zone. Overall, we conclude that biogeographic pattern within a region can depend on the surveyed subhabitat type. Thus, biological surveys restricted to specific subhabitats may not properly reveal biogeographic pattern for a biota as a whole or even just for other subhabitats. As many studies generate biogeographic information with data only for specific subhabitats, we recommend testing the SDH in other systems to determine its domain of application.

scholarly journals Marked variations in reproductive characteristics of snapper (Chrysophrys auratus, Sparidae) and their relationship with temperature over a wide latitudinal range

2015 ◽  
Vol 72 (8) ◽  
pp. 2341-2349 ◽  
Author(s):  
Corey B. Wakefield ◽  
Ian C. Potter ◽  
Norman G. Hall ◽  
Rodney C. J. Lenanton ◽  
Sybrand A. Hesp
Keyword(s):  
Climate Change ◽  
West Coast ◽  
Spatial Scales ◽  
Early Summer ◽  
South Coast ◽  
Late Winter ◽  
Published Data ◽  
The South ◽  
Reproductive Characteristics ◽  
Latitudinal Range

Abstract The timing and duration of spawning and maturation schedules of Chrysophrys auratus were determined for populations in one subtropical (∼25°S on the upper west coast) and two temperate regions (∼32°S on the lower west and ∼35°S on the south coasts) over >2000 km of coastline along the west coast of Australia. This study thus encompassed the wide latitudinal range of this recreationally and commercially important sparid in this region. The results were used, in conjunction with previously published data, to explore traditional paradigms regarding the relationships between the reproductive characteristics and variations in water temperature. Spawning at each latitude occurred mainly at 19–21°C, but following a decline in temperature in the subtropical region and after a rise in temperature in the two temperate regions. Spawning on the upper west coast thus occurred between mid-autumn and early spring (∼7 months) as opposed to late winter to early summer on the lower west coast (∼6 months). Spawning on the south coast was mainly restricted to mid-spring to early summer (∼2–3 months) in 2003 and 2004 and did not occur in 2005 when temperatures in this period were the coldest on record. Thus, marked interannual differences in the prevalence of mature fish on the south coast probably reflect the “marginality” of the population. The length (L50) and age (A50) at which C. auratus matured increased markedly from 25 to 32°S. Studies such as this allow for latitudinal variations in reproductive characteristics to be incorporated into population models to optimize fisheries sustainable yield, and contribute towards appropriate spatial scales for sustainable management strategies (e.g. minimum legal lengths consistent with latitudinal variation in length-based maturity schedules). The narrow temperature range over which this species spawns accounts for its current latitudinal distribution and enables predictions of how this distribution might alter with climate change. This study provides relevant information for management and climate change implications for similar subtropical and temperate marine teleosts.

scholarly journals Long-Term Trends of PM2.5 and its Carbon Content in the South Coast Air Basin: A Focus on the Impact of Wildfires

2021 ◽  
pp. 118431
Author(s):  
Faraz Enayati Ahangar ◽  
Payam Pakbin ◽  
Sina Hasheminassab ◽  
Scott A. Epstein ◽  
Xiang Li ◽  
...  
Keyword(s):  
Carbon Content ◽  
South Coast ◽  
The South ◽  
Long Term Trends ◽  
South Coast Air Basin ◽  
The Impact

scholarly journals Analysis of a 39-year continuous atmospheric CO<sub>2</sub> record from Baring Head, New Zealand

2013 ◽  
Vol 10 (4) ◽  
pp. 2683-2697 ◽  
Author(s):  
B. B. Stephens ◽  
G. W. Brailsford ◽  
A. J. Gomez ◽  
K. Riedel ◽  
S. E. Mikaloff Fletcher ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Seasonal Cycle ◽  
Southern Oscillation ◽  
Atmospheric Co2 ◽  
Co2 Uptake ◽  
South Pole ◽  
The South ◽  
Wide Range

Abstract. We present an analysis of a 39-year record of continuous atmospheric CO2 observations made at Baring Head, New Zealand, filtered for steady background CO2 mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO2 time series and regional to global carbon cycling. Baring Head is well situated to sample air that has been isolated from terrestrial influences over the Southern Ocean, and experiences extended episodes of strong southerly winds with low CO2 variability. The filtered Baring Head CO2 record reveals an average seasonal cycle with amplitude of 0.95 ppm that is 13% smaller and 3 weeks earlier in phase than that at the South Pole. Seasonal variations in a given year are sensitive to the timing and magnitude of the combined influences of Southern Ocean CO2 fluxes and terrestrial fluxes from both hemispheres. The amplitude of the seasonal cycle varies throughout the record, but we find no significant long-term seasonal changes with respect to the South Pole. Interannual variations in CO2 growth rate in the Baring Head record closely match the El Niño-Southern Oscillation, reflecting the global reach of CO2 mole fraction anomalies associated with this cycle. We use atmospheric transport model results to investigate contributions to seasonal and annual-mean components of the observed CO2 record. Long-term trends in mean gradients between Baring Head and other stations are predominately due to increases in Northern Hemisphere fossil-fuel burning and Southern Ocean CO2 uptake, for which there remains a wide range of future estimates. We find that the postulated recent reduction in the efficiency of Southern Ocean anthropogenic CO2 uptake, as a result of increased zonal winds, is too small to be detectable as significant differences in atmospheric CO2 between mid to high latitude Southern Hemisphere observing stations.

scholarly journals Turning bandits into ‘good citizens’: Coastal violence on the south coast of the Ming Empire in the fifteenth century

2020 ◽  
Vol 32 (3) ◽  
pp. 681-696
Author(s):  
Sander Molenaar
Keyword(s):  
International Trade ◽  
Sixteenth Century ◽  
Fifteenth Century ◽  
Coastal Communities ◽  
South Coast ◽  
The South

Banditry was a recurring problem on the mountainous, island-dotted south coast of the Ming Empire (1368–1644). Scholars mainly discuss banditry on the south coast in the context of growing international trade and focus on the sixteenth century while largely ignoring endemic forms of banditry. This article studies the interaction of bandit groups, coastal communities and Ming officials during the fifteenth century to show that banditry was an integral part of life on the south coast of the Ming Empire. Furthermore, it argues that the inability of Ming officials to understand how banditry was integrated in coastal society limited their capacity to secure long-term solutions.

scholarly journals Analysis of a 39-yr continuous atmospheric CO<sub>2</sub> record from Baring Head, New Zealand

2012 ◽  
Vol 9 (10) ◽  
pp. 15237-15277 ◽  
Author(s):  
B. B. Stephens ◽  
G. W. Brailsford ◽  
A. J. Gomez ◽  
K. Riedel ◽  
S. E. Mikaloff Fletcher ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Seasonal Cycle ◽  
Southern Oscillation ◽  
Atmospheric Co2 ◽  
Co2 Uptake ◽  
South Pole ◽  
The South ◽  
Wide Range

Abstract. We present an analysis of a 39-yr record of continuous atmospheric CO2 observations made at Baring Head, New Zealand, filtered for steady CO2 mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO2 time series and regional to global carbon cycling. Baring Head is well situated to sample air that has been isolated from terrestrial influences over the Southern Ocean, and experiences extended periods of strong southerly winds with low CO2 variability. The filtered Baring Head CO2 record reveals an average seasonal cycle with amplitude of 0.95 ppm that is 13% smaller and 3 weeks earlier in phase than that at the South Pole. Seasonal variations in a given year are sensitive to the timing and magnitude of the combined influences of Southern Ocean CO2 fluxes and terrestrial fluxes from both hemispheres. The amplitude of the seasonal cycle varies throughout the record, but we find no significant long-term seasonal changes with respect to the South Pole. Interannual variations in CO2 growth rate in the Baring Head record closely match the El Niño/Southern Oscillation, reflecting the global reach of CO2 mole fraction anomalies associated with this cycle. We use atmospheric transport model results to investigate contributions to seasonal and annual-mean components of the observed CO2 record. Long-term trends in mean gradients between Baring Head and other stations are predominately due to increases in Northern-Hemisphere fossil-fuel burning and Southern Ocean CO2 uptake, for which there remains a wide range of future estimates. We find that the postulated recent reduction in the efficiency of Southern Ocean anthropogenic CO2 uptake as a result of increased zonal winds is too small to be detectable as significant differences in atmospheric CO2 between mid- to high-latitude Southern Hemisphere observing stations.

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