title: Long-term variations in fish assemblage, macrophyte community, and water quality in Lake Rotoroa (Hamilton Lake)

authors: Law, Duncan Robert Mckenzie

abstract: Lake Rotoroa (37º48’S, 175º16’E) is a small, shallow, polymictic lake located on the western side of Hamilton City. The lake covers an area of 0.54 km2 with a mean depth of 2.4 m, catchment and riparian margins have been significantly modified into a suburban park-like setting. Due to its urban location and recreational value, exotic flora and fauna have been intentionally and unintentionally introduced. This has resulted in fluctuations in water quality and changes in phytoplankton, fish, and macrophyte assemblages over the past 60 years. The overall aim of this thesis is to summarise the fluctuations in water quality and macrophyte community of Lake Rotoroa associated with introduction of exotic species, and to develop a general understanding of the ecosystem response. This study involved collating and analysing available information on fish assemblages, macrophyte community, and water quality in Lake Rotoroa. Data from nine fish surveys undertaken between 1976 and 2012 has been combined. Water quality and macrophyte data was supplied by NIWA, who have undertaken monitoring for Hamilton City Council as part of the national lakes monitoring programme.

Fishing methods have varied from gill, trap, and fyke netting between 1976 and 2001, with boat electrofishing surveys between 2003 and 2012. Lake Rotoroa has a relatively diverse freshwater fish fauna, comprising two native and six exotic fish species. The fish assemblage is now dominated by the native shortfin eel (Anguilla australis), European perch (Perca fluviatilis), brown bullhead catfish (Ameiurus nebulosus), and tench (Tinca tinca), with low densities of rudd (Scardinius erythrophthalmus) and goldfish (Carassius auratus). Fish density and biomass have varied throughout the survey period, to some extent related to the environmental conditions and macrophyte cover. 

Macrophyte coverage and water quality have undergone considerable changes in the last 30 years, with the collapses of macrophytes stimulating decreases in water quality and increased perch abundance. In 1990, the macrophyte community collapsed with an associated release of nutrients into the water column, causing the lake to become supertrophic. Between 1992 and 2010, water quality improved, with a decrease phosphorus concentrations that apparently limited phytoplankton biomass and improved water clarity. This allowed macrophytes to recolonise the lake to 30% lake bed coverage in 2005 and a consequent improvement from supertrophic to a eutrophic state. Since 2009, the macrophyte community has undergone another collapse, with only a few clumps of native charophytes and Egeria densa present in 2011. The reduction of macrophytes has been accompanied by a decrease in water clarity. The collapse has been attributed to disturbance by grazing from the herbivorous rudd and foraging benthic feeding fish, although other stresses such as decreased water clarity and microcystins may also have had an influence. 

Further research is needed on the selectivity between passive and active fish capture methods used to allow accurate comparisons between the two methods. This will allow for density and biomass estimates to be made for the passive fishing methods previously used and allow greater insight into changes in abundance of fish populations in Lake Rotoroa.

text: Long-term variations in fish assemblage, macrophyte community, and water quality in Lake Rotoroa (Hamilton Lake) Lake Rotoroa (37º48’S, 175º16’E) is a small, shallow, polymictic lake located on the western side of Hamilton City. The lake covers an area of 0.54 km2 with a mean depth of 2.4 m, catchment and riparian margins have been significantly modified into a suburban park-like setting. Due to its urban location and recreational value, exotic flora and fauna have been intentionally and unintentionally introduced. This has resulted in fluctuations in water quality and changes in phytoplankton, fish, and macrophyte assemblages over the past 60 years. The overall aim of this thesis is to summarise the fluctuations in water quality and macrophyte community of Lake Rotoroa associated with introduction of exotic species, and to develop a general understanding of the ecosystem response. This study involved collating and analysing available information on fish assemblages, macrophyte community, and water quality in Lake Rotoroa. Data from nine fish surveys undertaken between 1976 and 2012 has been combined. Water quality and macrophyte data was supplied by NIWA, who have undertaken monitoring for Hamilton City Council as part of the national lakes monitoring programme.

Fishing methods have varied from gill, trap, and fyke netting between 1976 and 2001, with boat electrofishing surveys between 2003 and 2012. Lake Rotoroa has a relatively diverse freshwater fish fauna, comprising two native and six exotic fish species. The fish assemblage is now dominated by the native shortfin eel (Anguilla australis), European perch (Perca fluviatilis), brown bullhead catfish (Ameiurus nebulosus), and tench (Tinca tinca), with low densities of rudd (Scardinius erythrophthalmus) and goldfish (Carassius auratus). Fish density and biomass have varied throughout the survey period, to some extent related to the environmental conditions and macrophyte cover. 

Macrophyte coverage and water quality have undergone considerable changes in the last 30 years, with the collapses of macrophytes stimulating decreases in water quality and increased perch abundance. In 1990, the macrophyte community collapsed with an associated release of nutrients into the water column, causing the lake to become supertrophic. Between 1992 and 2010, water quality improved, with a decrease phosphorus concentrations that apparently limited phytoplankton biomass and improved water clarity. This allowed macrophytes to recolonise the lake to 30% lake bed coverage in 2005 and a consequent improvement from supertrophic to a eutrophic state. Since 2009, the macrophyte community has undergone another collapse, with only a few clumps of native charophytes and Egeria densa present in 2011. The reduction of macrophytes has been accompanied by a decrease in water clarity. The collapse has been attributed to disturbance by grazing from the herbivorous rudd and foraging benthic feeding fish, although other stresses such as decreased water clarity and microcystins may also have had an influence. 

Further research is needed on the selectivity between passive and active fish capture methods used to allow accurate comparisons between the two methods. This will allow for density and biomass estimates to be made for the passive fishing methods previously used and allow greater insight into changes in abundance of fish populations in Lake Rotoroa.

year: 2012

title: Welcome ground for women faculty in academe: An international perspective

authors: Copper, Joanne

subjects: welcome ground

abstract: With the continued documentation of a persistent hostile or chilly climate for women in academe (Blum, 1991; Cooper, 2002; Curtis, 2005; Glazer-Raymo, 1999), questions arise about whether women faculty can find a home or welcome ground, both in the United States and around the world (Caplan, 1993; Cooper, Benham, Collay, Martinez-Aleman, & Scherr, 1999).  The literature identifies a number of differing ways of viewing the academy as home. For example, Jane Roland Martin (2000) refers to the academy as "the home of thought" (p. 41). In discussing this concept, many women academics talk about finding or forging, if not a home, then welcome ground or a neighborhood. Whatever the term, the connotation is one of a place that is friendly, rather than hostile; one that counters the chilly climate image that Sandler and Hall (1986) have written about.
This article explores the question of finding a home or welcome ground by asking if these concepts are relevant both in the new millennium and in the international arena.  We examine the experiences of women academics in three countries: the United States (US), Aotearoa/New Zealand (NZ), and Romania (Ro). We build on the recent exploration of US women's efforts to find or forge a home (Cooper, Ortiz, Benham, & Scherr, 2002; Cooper, et al., 1999), and explore this concept in three countries that are geographically distant from one another. They are vastly different in size, from the giant United States to the tiny New Zealand, as well as culturally, politically, and economically different. We share the stories of twelve women, four each from the US, NZ, and Romania. Because experiences are embedded in the particular socio-cultural, political conditions of the individual country, the next section will describe existing research about women's experiences in each country.

text: Welcome ground for women faculty in academe: An international perspective With the continued documentation of a persistent hostile or chilly climate for women in academe (Blum, 1991; Cooper, 2002; Curtis, 2005; Glazer-Raymo, 1999), questions arise about whether women faculty can find a home or welcome ground, both in the United States and around the world (Caplan, 1993; Cooper, Benham, Collay, Martinez-Aleman, & Scherr, 1999).  The literature identifies a number of differing ways of viewing the academy as home. For example, Jane Roland Martin (2000) refers to the academy as "the home of thought" (p. 41). In discussing this concept, many women academics talk about finding or forging, if not a home, then welcome ground or a neighborhood. Whatever the term, the connotation is one of a place that is friendly, rather than hostile; one that counters the chilly climate image that Sandler and Hall (1986) have written about.
This article explores the question of finding a home or welcome ground by asking if these concepts are relevant both in the new millennium and in the international arena.  We examine the experiences of women academics in three countries: the United States (US), Aotearoa/New Zealand (NZ), and Romania (Ro). We build on the recent exploration of US women's efforts to find or forge a home (Cooper, Ortiz, Benham, & Scherr, 2002; Cooper, et al., 1999), and explore this concept in three countries that are geographically distant from one another. They are vastly different in size, from the giant United States to the tiny New Zealand, as well as culturally, politically, and economically different. We share the stories of twelve women, four each from the US, NZ, and Romania. Because experiences are embedded in the particular socio-cultural, political conditions of the individual country, the next section will describe existing research about women's experiences in each country.

year: 2006

title: Whangai: remembering, understanding and experiencing

authors: McRae, Karyn Okeroa

subjects: adoption

abstract: The Māori customary practice of whangai is often equated with adoption or foster care.
There are, however, significant differences between the institutions. Adoption or foster care, tends to be mainly focused on the interests of the child. The institution of whangai, while being cognizant of the interests of the child, is weighted more towards establishing, nurturing and cementing relationships between individuals, families and broader relational networks. In this paper we draw on the lived experiences of six people who have been raised as whangai and/or have raised whangai. We were interested in their understanding of the cultural concept of whangai, how the customary practice of whangai has changed over time, and their projected thoughts on future generations’ experience of whangai. Findings suggest that the institution of whangai remains as a strong vehicle for both the care of children and for the nurturing of whangai kinship relationships. While participants recognised that contemporary Māori social environments have contributed toward multiple manifestations of whangai, most felt it to be an institution that will be valued and carried into the future.

text: Whangai: remembering, understanding and experiencing The Māori customary practice of whangai is often equated with adoption or foster care.
There are, however, significant differences between the institutions. Adoption or foster care, tends to be mainly focused on the interests of the child. The institution of whangai, while being cognizant of the interests of the child, is weighted more towards establishing, nurturing and cementing relationships between individuals, families and broader relational networks. In this paper we draw on the lived experiences of six people who have been raised as whangai and/or have raised whangai. We were interested in their understanding of the cultural concept of whangai, how the customary practice of whangai has changed over time, and their projected thoughts on future generations’ experience of whangai. Findings suggest that the institution of whangai remains as a strong vehicle for both the care of children and for the nurturing of whangai kinship relationships. While participants recognised that contemporary Māori social environments have contributed toward multiple manifestations of whangai, most felt it to be an institution that will be valued and carried into the future.

year: 2006