title: Commentary: Women’s violence to children

authors: Ritchie, Jane

subjects: women’s violence

abstract: Feminists often feel uncomfortable about talking about, or even acknowledging, women's violence, whether it be women's violence to men, women's violence to other women, or women's violence to children. It is now generally recognised that women can be violent to their male partners, but that women's violence is often in self-defence, and does not usually result in the same degree of hurt and injury as does men's violence to women. As someone who, for many years, has been concerned about parental use of physical punishment, I have long been aware that women can also be violent towards their children.

text: Commentary: Women’s violence to children Feminists often feel uncomfortable about talking about, or even acknowledging, women's violence, whether it be women's violence to men, women's violence to other women, or women's violence to children. It is now generally recognised that women can be violent to their male partners, but that women's violence is often in self-defence, and does not usually result in the same degree of hurt and injury as does men's violence to women. As someone who, for many years, has been concerned about parental use of physical punishment, I have long been aware that women can also be violent towards their children.

year: 2005

title: The influence of water quality and sediment geochemistry on the horizontal and vertical distribution of phosphorus and nitrogen in sediments of a large, shallow lake

authors: Trolle, Dennis

subjects: Lake Taihu

abstract: Distinct horizontal water column concentration gradients of nutrients and chlorophyll a (Chl a) occur within large, shallow, eutrophic Lake Taihu, China. Concentrations are high in the north, where some of the major polluted tributaries enter the lake, and relatively low in the south, where macrophytes generally are abundant. It is not clear, however, whether these water column concentration gradients are similarly reflected in spatial heterogeneity of nutrient concentrations within the bottom sediments. The main objective of this study was therefore to test if horizontal and vertical variations in the phosphorus and nitrogen content in bottom sediments of Lake Taihu are significantly related to (1) horizontal variations in overlying water column nutrient concentrations and (2) other sediment geochemical constituents. We measured the concentration of total phosphorus (TP) and total nitrogen (TN) in surficial sediments (0–2 cm) and TP, TN and Chl a concentrations in water column samples, collected from 32 sites in 2005. In 2006 sediment, TP, TN, carbon, iron and manganese concentrations were measured vertically at 2 cm intervals, extending to a depth of approximately 20 cm, at an additional eight sites. Linear correlation analysis revealed that surficial sediment TP concentrations across the 32 stations were related significantly, though weakly, to annual mean water column concentrations of TP, TN as well as Chl a. Correlations of surficial sediment TN with water column variables were, however, not significant (P[0.05).Amongst the geochemical variables tested, the vertical variability of sediment TP concentrations was most strongly related to sediment manganese and carbon concentrations. A multiple stepwise linear regression revealed that the combination of sediment manganese and carbon concentrations explained 91% of the horizontal variability in sediment TP concentrations and 65% of the vertical variability.

text: The influence of water quality and sediment geochemistry on the horizontal and vertical distribution of phosphorus and nitrogen in sediments of a large, shallow lake Distinct horizontal water column concentration gradients of nutrients and chlorophyll a (Chl a) occur within large, shallow, eutrophic Lake Taihu, China. Concentrations are high in the north, where some of the major polluted tributaries enter the lake, and relatively low in the south, where macrophytes generally are abundant. It is not clear, however, whether these water column concentration gradients are similarly reflected in spatial heterogeneity of nutrient concentrations within the bottom sediments. The main objective of this study was therefore to test if horizontal and vertical variations in the phosphorus and nitrogen content in bottom sediments of Lake Taihu are significantly related to (1) horizontal variations in overlying water column nutrient concentrations and (2) other sediment geochemical constituents. We measured the concentration of total phosphorus (TP) and total nitrogen (TN) in surficial sediments (0–2 cm) and TP, TN and Chl a concentrations in water column samples, collected from 32 sites in 2005. In 2006 sediment, TP, TN, carbon, iron and manganese concentrations were measured vertically at 2 cm intervals, extending to a depth of approximately 20 cm, at an additional eight sites. Linear correlation analysis revealed that surficial sediment TP concentrations across the 32 stations were related significantly, though weakly, to annual mean water column concentrations of TP, TN as well as Chl a. Correlations of surficial sediment TN with water column variables were, however, not significant (P[0.05).Amongst the geochemical variables tested, the vertical variability of sediment TP concentrations was most strongly related to sediment manganese and carbon concentrations. A multiple stepwise linear regression revealed that the combination of sediment manganese and carbon concentrations explained 91% of the horizontal variability in sediment TP concentrations and 65% of the vertical variability.

year: 2009

title: Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2013

authors: Hicks, Brendan J.

abstract: The aim of this survey was to provide on-going monitoring of the fish communities and abundance in the Ohau Channel, especially fish species that are taonga to Maori (eels, goldfish, and koura). In the current study we present the findings from the seventh year of sampling (2013) in view of previous surveys using boat electrofishing in the Ohau Channel. 
We used the University of Waikato's 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of 1,025 fish (20.3 kg) from 11 sites comprising 2,817 lineal m and 11,484 m² in area on 27 November 2013. Common bully were the most abundant fish species (57% of the catch) followed by common smelt (36% of the catch).
Goldfish had their highest biomasses in the lower channel, especially at site 10 near Lake Rotoiti (up to 7.25 g m⁻²). Catch per unit effort (CPUE) for common bullies exceeded smelt CPUE at all sites except site 1, reflecting their greater densities. CPUE for rainbow trout was variable between the sites, and greatest at site 3. 
The abundance of common bullies in 2013 reversed the apparent trend of reducing abundance since these surveys started in 2007. The cause of fluctuating bully abundance is not known, and was not accounted for by water clarity expressed as black disc distance (BDD) or water conductivity. Poor water clarity can reduce the efficiency of electrofishing, but BDD was greater in 2012 than in 2011 when common bully densities were lower. In 2013, the apparent decline in smelt abundance was also reversed, but the relatively inefficient sampling resulting from boat electrofishing for these two species should be considered. 
The increased goldfish biomass in 2011-2013 arose because of targeted fishing in the excavated side branch, which clearly offers good habitat for goldfish. Removal of goldfish in the previous years may have reduced the density in the excavated side channel (site 11) compared to previous years. In 2013, a shortfin eel was caught, following the first shortfin eel encountered in the Ohau Channel in 2012.

text: Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2013 The aim of this survey was to provide on-going monitoring of the fish communities and abundance in the Ohau Channel, especially fish species that are taonga to Maori (eels, goldfish, and koura). In the current study we present the findings from the seventh year of sampling (2013) in view of previous surveys using boat electrofishing in the Ohau Channel. 
We used the University of Waikato's 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of 1,025 fish (20.3 kg) from 11 sites comprising 2,817 lineal m and 11,484 m² in area on 27 November 2013. Common bully were the most abundant fish species (57% of the catch) followed by common smelt (36% of the catch).
Goldfish had their highest biomasses in the lower channel, especially at site 10 near Lake Rotoiti (up to 7.25 g m⁻²). Catch per unit effort (CPUE) for common bullies exceeded smelt CPUE at all sites except site 1, reflecting their greater densities. CPUE for rainbow trout was variable between the sites, and greatest at site 3. 
The abundance of common bullies in 2013 reversed the apparent trend of reducing abundance since these surveys started in 2007. The cause of fluctuating bully abundance is not known, and was not accounted for by water clarity expressed as black disc distance (BDD) or water conductivity. Poor water clarity can reduce the efficiency of electrofishing, but BDD was greater in 2012 than in 2011 when common bully densities were lower. In 2013, the apparent decline in smelt abundance was also reversed, but the relatively inefficient sampling resulting from boat electrofishing for these two species should be considered. 
The increased goldfish biomass in 2011-2013 arose because of targeted fishing in the excavated side branch, which clearly offers good habitat for goldfish. Removal of goldfish in the previous years may have reduced the density in the excavated side channel (site 11) compared to previous years. In 2013, a shortfin eel was caught, following the first shortfin eel encountered in the Ohau Channel in 2012.

year: 2014