title: The microbiome of colonial ascidians

authors: Livne Fadlon, Shir

abstract: Colonial ascidians are prolific and successful marine invertebrates worldwide. Colonial ascidians harbour a diverse assemblage of microorganisms, some of which are known to produce secondary metabolites (bioactives) that contribute to the ascidians’ ecological success. However, little is known about the microbial ecology of the putative symbionts associated with colonial ascidians and whether they consistently contribute to host competitiveness. We hypothesise that the colonial ascidian microbiome is host-specific and enables host ecological success in interacting with proximate competitor(s) through chemical competition facilitated by inducible microbially synthesised metabolites. We further theorise that, during invasion events, non-native colonial ascidians outcompete native ones using allelochemical capacities conferred by their microbiome and that nonnative colonial ascidians, which are globally successful invaders, harbour unique microorganism assemblages. 
To examine our hypotheses, it is necessary to characterise the relationship between ascidian ecological status (i.e., native, non-native, monospecific, or interacting) and the ascidian microbiome. We systematically sampled colonial ascidian specimens (both native and non-native species) engaged in competitive interactions as well as monospecific specimens. Microbiome analysis was conducted using 16S rRNA gene PCR amplicon sequencing to characterise baseline variability and identify microbial response patterns linked to the ecological status of host species. 
Our findings revealed a high degree of species-specificity in the ascidian microbiome, and native and non-native species exhibited distinct microbial patterns linked with their ecological state. However, interacting ascidian species did not appear to harbour dominant unique microbial assemblages compared to their monospecific counterparts. We also conducted the first microbiome comparison for zooids and tunics of colonial ascidians and found that, contrary to common assumptions, zooids and tunics generally harbour similar microorganisms. 
This study provides the first systematic characterisation of the colonial ascidian microbiome. We generated statistically informative baselines for the colonial ascidian microbiome and novel insight on its potential roles in mediating host ecology. Findings from this study form a robust foundation for future chemical characterisation of potential bioactive compounds (using the same specimens) and shotgun metagenomic analyses of these unique microbial communities.

text: The microbiome of colonial ascidians Colonial ascidians are prolific and successful marine invertebrates worldwide. Colonial ascidians harbour a diverse assemblage of microorganisms, some of which are known to produce secondary metabolites (bioactives) that contribute to the ascidians’ ecological success. However, little is known about the microbial ecology of the putative symbionts associated with colonial ascidians and whether they consistently contribute to host competitiveness. We hypothesise that the colonial ascidian microbiome is host-specific and enables host ecological success in interacting with proximate competitor(s) through chemical competition facilitated by inducible microbially synthesised metabolites. We further theorise that, during invasion events, non-native colonial ascidians outcompete native ones using allelochemical capacities conferred by their microbiome and that nonnative colonial ascidians, which are globally successful invaders, harbour unique microorganism assemblages. 
To examine our hypotheses, it is necessary to characterise the relationship between ascidian ecological status (i.e., native, non-native, monospecific, or interacting) and the ascidian microbiome. We systematically sampled colonial ascidian specimens (both native and non-native species) engaged in competitive interactions as well as monospecific specimens. Microbiome analysis was conducted using 16S rRNA gene PCR amplicon sequencing to characterise baseline variability and identify microbial response patterns linked to the ecological status of host species. 
Our findings revealed a high degree of species-specificity in the ascidian microbiome, and native and non-native species exhibited distinct microbial patterns linked with their ecological state. However, interacting ascidian species did not appear to harbour dominant unique microbial assemblages compared to their monospecific counterparts. We also conducted the first microbiome comparison for zooids and tunics of colonial ascidians and found that, contrary to common assumptions, zooids and tunics generally harbour similar microorganisms. 
This study provides the first systematic characterisation of the colonial ascidian microbiome. We generated statistically informative baselines for the colonial ascidian microbiome and novel insight on its potential roles in mediating host ecology. Findings from this study form a robust foundation for future chemical characterisation of potential bioactive compounds (using the same specimens) and shotgun metagenomic analyses of these unique microbial communities.

year: 2022

title: Boat electrofishing survey of five Waitakere City ponds

authors: Hicks, Brendan J.

subjects: New Zealand

abstract: We conducted a fish survey of five ponds (Lake Panorama, Paremuka Pond 1 & 2, Danica Esplanade and Longbush Pond) in the Waitakere District by single-pass boat electrofishing on 18 and 19 of July 2007. We caught 337 fish comprising four introduced and two native fish species in 2.89 km of fished distance from all 5 ponds. Assuming that each of the two bow-mounted anodes caught fish within a 1 m radius, the width fished was 4 m, and the total area fished was 11,537 m² or 1.154 ha. The water temperature for the 5 different ponds ranged between 10.8°C and 14.9°C.
In Lake Panorama, shortfinned eel (Anguilla australis) were the most numerous species caught (130 fish ha⁻¹ ), followed by perch (Perca fluviatilis) (100 fish ha⁻¹) and tench (Tinca tinca) (40 fish ha⁻¹).
In Paremuka Pond 1, koi carp (Cyprinus carpio) were the most numerous species caught (120 fish ha⁻¹), followed by shortfinned eels (50 fish ha⁻¹).

In Paremuka Pond 2, koi carp were again the most numerous species caught (340 fish ha⁻¹), followed by tench (250 fish ha⁻¹) and shortfinned eels (70 fish ha⁻¹).

In Danica Esplanade and Longbush Pond, shortfinned eels were the most numerous species caught (140 and 550 fish ha⁻¹respectively), followed by mosquitofish (Gambusia affinis). There was more macrophyte cover around the edges of Danica Esplanade compared to Longbush Pond and this decreased the catch rate as a large number of eels in Danica Esplanade were sighted but were unable to be captured. 

Koi carp were only caught in the Paremuka ponds. The majority of koi carp were caught on the edges of the lake in macrophytes and rushes. Koi carp biomasses were highest in Paremuka Pond 2 at 261 kg ha⁻¹ compared to 106 kg ha⁻¹ in Paremuka Pond 1. Biomass is a more accurate reflection of the potential ecological impact of koi carp than their density. Previous results suggest that 21-73% of the total population is caught on the first removal, depending on water visibility. As we fished the area at each site only once, the estimates in this survey represent a minimum abundance, and true population sizes are likely to be 1.4-4.8 times greater. The density of eels in both the Paremuka ponds is also likely to be higher as a large proportion of eels were able to escape into the macrophytes before they could be captured in the nets. Mosquitofish were also observed to be living in both the Paremuka ponds. Of ecological concern for the Paremuka ponds is the dominance of the fish biomass by introduced koi carp, which have a deleterious impact on aquatic habitats. Another concern for these ponds is the presence of small koi carp (<200 mm), which suggests that natural spawning is most likely occurring, although recent releases of carp into the ponds in another possibility.

The fate of the introduced fish varied depending on what species they were. Perch and tench were released back into the ponds after captures as they are classified as sports fish. Koi carp and mosquitofish are classified as unwanted organisms and were humanely destroyed with an anaesthetic overdose (benzocaine), and retained for further analysis.

text: Boat electrofishing survey of five Waitakere City ponds We conducted a fish survey of five ponds (Lake Panorama, Paremuka Pond 1 & 2, Danica Esplanade and Longbush Pond) in the Waitakere District by single-pass boat electrofishing on 18 and 19 of July 2007. We caught 337 fish comprising four introduced and two native fish species in 2.89 km of fished distance from all 5 ponds. Assuming that each of the two bow-mounted anodes caught fish within a 1 m radius, the width fished was 4 m, and the total area fished was 11,537 m² or 1.154 ha. The water temperature for the 5 different ponds ranged between 10.8°C and 14.9°C.
In Lake Panorama, shortfinned eel (Anguilla australis) were the most numerous species caught (130 fish ha⁻¹ ), followed by perch (Perca fluviatilis) (100 fish ha⁻¹) and tench (Tinca tinca) (40 fish ha⁻¹).
In Paremuka Pond 1, koi carp (Cyprinus carpio) were the most numerous species caught (120 fish ha⁻¹), followed by shortfinned eels (50 fish ha⁻¹).

In Paremuka Pond 2, koi carp were again the most numerous species caught (340 fish ha⁻¹), followed by tench (250 fish ha⁻¹) and shortfinned eels (70 fish ha⁻¹).

In Danica Esplanade and Longbush Pond, shortfinned eels were the most numerous species caught (140 and 550 fish ha⁻¹respectively), followed by mosquitofish (Gambusia affinis). There was more macrophyte cover around the edges of Danica Esplanade compared to Longbush Pond and this decreased the catch rate as a large number of eels in Danica Esplanade were sighted but were unable to be captured. 

Koi carp were only caught in the Paremuka ponds. The majority of koi carp were caught on the edges of the lake in macrophytes and rushes. Koi carp biomasses were highest in Paremuka Pond 2 at 261 kg ha⁻¹ compared to 106 kg ha⁻¹ in Paremuka Pond 1. Biomass is a more accurate reflection of the potential ecological impact of koi carp than their density. Previous results suggest that 21-73% of the total population is caught on the first removal, depending on water visibility. As we fished the area at each site only once, the estimates in this survey represent a minimum abundance, and true population sizes are likely to be 1.4-4.8 times greater. The density of eels in both the Paremuka ponds is also likely to be higher as a large proportion of eels were able to escape into the macrophytes before they could be captured in the nets. Mosquitofish were also observed to be living in both the Paremuka ponds. Of ecological concern for the Paremuka ponds is the dominance of the fish biomass by introduced koi carp, which have a deleterious impact on aquatic habitats. Another concern for these ponds is the presence of small koi carp (<200 mm), which suggests that natural spawning is most likely occurring, although recent releases of carp into the ponds in another possibility.

The fate of the introduced fish varied depending on what species they were. Perch and tench were released back into the ponds after captures as they are classified as sports fish. Koi carp and mosquitofish are classified as unwanted organisms and were humanely destroyed with an anaesthetic overdose (benzocaine), and retained for further analysis.

year: 2007

title: KAUMĀTUATANGA  Supporting School Leaders To Develop Cultural Values While Resisting The Dominance of Colonialism

authors: Nuri, Ngahuia

subjects: Kaumātua

abstract: In an education system that is asserting to the importance of Māori (indigenous people of Aotearoa) language, culture, identity and the history of Aotearoa  (New Zealand) into the curriculum, there is direction from the Ministry of Education (MOE) for schools to reach out to iwi. What this looks like and how this can be achieved is not an easy task. This thesis follows the journey of three kaumātua (respected, knowledgeable elders, both female and male) working alongside the Senior Leadership Team (SLT) of a decile 10 kura auraki (mainstream primary school) where ākonga Māori (Māori students) were in the minority. The research examines what role kaumātua might have in guiding other schools to help tamariki Māori (Māori children) enjoy and achieve education success as Māori. It highlights the coming together of leaders from two different worldviews with this vision as a common purpose. 

Kaumātua in te ao Māori (the Māori world) are respected elders. Kaumātua are leaders, respected for their wisdom, knowledge and models of behaviour among other attributes. The Māui narratives are one example of demonstrating the characteristics of kaumātua. It was through his respected elders that Maui achieved so much. It was his grandfather who rescued him and taught him all he knew. It was his grandmother Mahuika who gave him fire and it was his kuia (female elder) Murirangiwhenua from whom he received the magic jawbone. The wisdom of Māori kaumātua has been recognised for centuries by Māori and yet kaumātua are often an untapped resource in the mainstream sector of education. In this thesis the kaumātua and members of the SLT share their experiences of working together and the learning and unlearning that has taken place over a period of four years from 2016 through 2019. They share their vulnerability, humility and strength in the goals they have worked towards over this period of time.

text: KAUMĀTUATANGA  Supporting School Leaders To Develop Cultural Values While Resisting The Dominance of Colonialism In an education system that is asserting to the importance of Māori (indigenous people of Aotearoa) language, culture, identity and the history of Aotearoa  (New Zealand) into the curriculum, there is direction from the Ministry of Education (MOE) for schools to reach out to iwi. What this looks like and how this can be achieved is not an easy task. This thesis follows the journey of three kaumātua (respected, knowledgeable elders, both female and male) working alongside the Senior Leadership Team (SLT) of a decile 10 kura auraki (mainstream primary school) where ākonga Māori (Māori students) were in the minority. The research examines what role kaumātua might have in guiding other schools to help tamariki Māori (Māori children) enjoy and achieve education success as Māori. It highlights the coming together of leaders from two different worldviews with this vision as a common purpose. 

Kaumātua in te ao Māori (the Māori world) are respected elders. Kaumātua are leaders, respected for their wisdom, knowledge and models of behaviour among other attributes. The Māui narratives are one example of demonstrating the characteristics of kaumātua. It was through his respected elders that Maui achieved so much. It was his grandfather who rescued him and taught him all he knew. It was his grandmother Mahuika who gave him fire and it was his kuia (female elder) Murirangiwhenua from whom he received the magic jawbone. The wisdom of Māori kaumātua has been recognised for centuries by Māori and yet kaumātua are often an untapped resource in the mainstream sector of education. In this thesis the kaumātua and members of the SLT share their experiences of working together and the learning and unlearning that has taken place over a period of four years from 2016 through 2019. They share their vulnerability, humility and strength in the goals they have worked towards over this period of time.

year: 2024