Browsing by Supervisor "Duggan, Ian C."
Now showing items 1-20 of 26
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Long-term changes in Zooplankton community composition in North Island lakes: What are the drivers of change?
(The University of Waikato, 2023)Zooplankton are an important component of freshwater ecosystems, forming a trophic bridge between primary producers and higher trophic levels. They are highly responsive to changes in their environment and have therefore ... -
Dietary overlap between the non-native mosquitofish (Gambusia affinis) and native common bully (Gobiomorphus cotidianus): Evidence for interspecific competition?
(The University of Waikato, 2023)Since their establishment in New Zealand in the 1930s, the globally invasive western mosquitofish (Gambusia affinis) has become widespread throughout lowland freshwaters, primarily in the North Island. Despite co-occurring ... -
The potential for waterbirds to act as a vector for zooplankton dispersal in the North Island, New Zealand
(The University of Waikato, 2022)Zooplankton are essential components of freshwater ecosystems by controlling algal growth and sustaining higher trophic levels. Freshwater zooplankton are geographically isolated and are incapable of active dispersal to ... -
Responses of zooplankton assemblages to spatio-temporal variability in environmental conditions of brackish coastal ponds, Auckland, New Zealand
(The University of Waikato, 2022)Brackish waters, including estuaries, lagoons and coastal ponds, all experience fluctuations in their physicochemical properties, particularly their salt concentrations, due to the mixing of marine and freshwater inflows. ... -
Long-term zooplankton dynamics in Lake Taupō: 2000-2020
(The University of Waikato, 2021)Long-term monitoring is essential for distinguishing between natural and anthropogenically induced changes within ecosystems, particularly those with high degrees of natural fluctuation. In order to gain further understanding ... -
Interactions between freshwater mussels and non-native species
(The University of Waikato, 2020)Biological invasions contribute to ecosystem change globally, with a disproportionate and intensified impact in freshwaters. This process is exacerbated in modified systems such as hydrogeneration reservoirs that promote ... -
Zooplankton communities in small Waikato lakes and ponds: are natural waters and farm dams the same?
(The University of Waikato, 2019)Ponds have been identified as biodiversity ‘hotspots’ that play an important role in supporting and maintaining biodiversity. In freshwater ecosystems, zooplankton are an essential trophic link between algae and fish, and ... -
Community composition and distribution of macroinvertebrates on natural and artificial substrates in North Island lakes and ponds
(The University of Waikato, 2019)Artificial structures in freshwater ecosystems are becoming increasingly common. The introduction of these structures in marine systems lead to changes in the physical structure and the biotic assemblages. Even though ... -
Evaluating the implications of recent filter-feeding Daphnia invasions for kākahi (Echyridella menziesii)
(The University of Waikato, 2019)Freshwater mussels function as key ecosystem engineers due to their highly efficient filter feeding and bioturbating abilities, which enhance water clarity and promote nutrient cycling. Although they play a crucial role ... -
Constructed treatment wetlands: Tools to attenuate diffuse agricultural pollution and enhance the biodiversity of eutrophic peat lake ecosystems
(The University of Waikato, 2018)Agricultural land use is a major source of nitrogen (N), phosphorus (P) and suspended sediment (SS) to aquatic ecosystems. Elevated inputs of N, P and SS associated with agricultural expansion and intensification have led ... -
The effects of common carp on zooplankton communities using morphological and molecular techniques
(The University of Waikato, 2018)Understanding the factors causing a decline of water quality is important to ecologists, but particularly challenging given the complexity of natural systems. New Zealand’s freshwater ecosystems are under threat from ... -
Seasonal and spatial patterns in nitrogen cycling and food web interactions in Lake Taupō New Zealand
(The University of Waikato, 2018)Lakes with high water quality and low productivity, commonly referred to as ‘oligotrophic’, are often viewed as relatively pristine and highly aesthetic ecosystems, but may still require management of nutrient inputs and ... -
Zooplankton Dynamics in Wastewater Treatment High Rate Algal Ponds and development of effective control methods
(The University of Waikato, 2017)High Rate Algal Ponds (HRAPs) are effective and economical open pond to provide near tertiary-level wastewater (WW) treatment, with the nutrients recovered as algal biomass. However, WW treatment performance can be reduced ... -
A Study of the length weight relationships and diets of non-indigenous Poecillids in New Zealand geothermal Streams
(University of Waikato, 2016)Poecillids are highly specialised and well adapted to surviving in highly undesirable conditions. Because of this they have been able to establish populations in many areas where have been released. There are two species ... -
Spatio-temporal distribution and diversity of zooplankton in zoo ponds relative to water quality parameters
(University of Waikato, 2006)Little is known of the distribution and abundance of zooplankton in New Zealand, and the environmental variables that affect their spatial and temporal dynamics. Furthermore, smaller pond habitats have often been overlooked ... -
Grass carp and incidental invaders from aquaculture: a study of impacts on zooplankton communities and invader origins
(University of Waikato, 2016)The movement of fish from aquaculture facilities has led to invasions of non-native species globally, including of ‘hitch-hiking’ species, resulting in impacts on the composition of communities in recipient ecosystems. ... -
Genetic diversity and potential responses of New Zealand Rotifera and Antarctic Collembola to environmental changes
(University of Waikato, 2015)Environmental changes can impact the diversity and abundance of biotic communities as well as their dispersal among geographic regions. The availability of sensitive molecular techniques has enabled assessments of diversity ... -
The link between floodplain inundation and whitebait food supplies in the lower Waikato River
(University of Waikato, 2015)Globally, many large, lowland rivers are regulated due to the construction of stopbanks and flood protection schemes. Many of these changes now govern discharge regimes and lateral floodplain interactions. These modifications, ... -
Assessing the Diversity of New Zealand's Freshwater Copepods (Crustacea:Copepoda) using Mitochondrial DNA (COI) Sequences
(University of Waikato, 2014)The diversity of New Zealand’s freshwater copepods has been largely understudied. In order to enhance our understanding of this taxon, I used the mitochondrial cytochrome c oxidase subunit one (COI) gene sequences to examine ... -
When Two Worlds Collide: Mātauranga Māori, Science and Health of the Toreparu Wetland
(University of Waikato, 2014)Much of our understanding of wetland health and function comes from scientific-based monitoring and methodologies. However, there is a wealth of knowledge to be gained from Māori-value based assessment methods for monitoring ...
