title: Characterizing heart rate differences across rugby union competition levels

authors: Koumandarakis, Nikolas

subjects: Internal load

abstract: Heart rate (HR) monitoring provides insight into the demands of rugby union and may be able to help discriminate between different levels of competition. There is limited data examining the differences in physiological responses among different levels of rugby union. Rugby union athletes from different levels of competition (n=15 School, n=15 Club, n=15 Professional, and n=15 International) were included in the study. HR was measured via chest straps worn during the game with specific variables compared between levels of competition (e.g. Average (Avg) HR (bpm), and HR during worst-case scenario (WCS) periods of play (1, 2, 3, 4 and 5 minutes). Data was collected from eight matches for International, six matches for Professional and Club, and with School only able to play four due to season constraints. A one-way ANOVA revealed statistically significant differences in Avg HR across the four competition levels (p < 0.05). School players recorded the highest Avg HR (175 ± 10 bpm), while International players had the lowest (159 ± 9 bpm). Club and Professional teams had similar values, with no significant difference between them (p = 0.72). This trend was consistent across both forwards and backs. WCS HRs over rolling 1–5-minute intervals followed the same pattern, with School players consistently recording the highest values and International players the lowest. The largest WCS difference was observed at the 2-minute interval between School (191 ± 9 bpm) and International (179 ± 6 bpm) teams. Tukey post-hoc tests confirmed that School and International were significantly different from all other groups, while Club and Professional teams did not differ significantly. To the authors knowledge, this study is the first to compare heart rate metrics through different levels of competition in rugby union and is timely as the age of professional players is getting lower. Coaches should consider accurately tailor training to prepare athletes for optimal performance across different levels of competition as HR provides an accurate measure of internal load and could be more effective than the commonly used measures of external load e.g. GPS.

text: Characterizing heart rate differences across rugby union competition levels Heart rate (HR) monitoring provides insight into the demands of rugby union and may be able to help discriminate between different levels of competition. There is limited data examining the differences in physiological responses among different levels of rugby union. Rugby union athletes from different levels of competition (n=15 School, n=15 Club, n=15 Professional, and n=15 International) were included in the study. HR was measured via chest straps worn during the game with specific variables compared between levels of competition (e.g. Average (Avg) HR (bpm), and HR during worst-case scenario (WCS) periods of play (1, 2, 3, 4 and 5 minutes). Data was collected from eight matches for International, six matches for Professional and Club, and with School only able to play four due to season constraints. A one-way ANOVA revealed statistically significant differences in Avg HR across the four competition levels (p < 0.05). School players recorded the highest Avg HR (175 ± 10 bpm), while International players had the lowest (159 ± 9 bpm). Club and Professional teams had similar values, with no significant difference between them (p = 0.72). This trend was consistent across both forwards and backs. WCS HRs over rolling 1–5-minute intervals followed the same pattern, with School players consistently recording the highest values and International players the lowest. The largest WCS difference was observed at the 2-minute interval between School (191 ± 9 bpm) and International (179 ± 6 bpm) teams. Tukey post-hoc tests confirmed that School and International were significantly different from all other groups, while Club and Professional teams did not differ significantly. To the authors knowledge, this study is the first to compare heart rate metrics through different levels of competition in rugby union and is timely as the age of professional players is getting lower. Coaches should consider accurately tailor training to prepare athletes for optimal performance across different levels of competition as HR provides an accurate measure of internal load and could be more effective than the commonly used measures of external load e.g. GPS.

year: 2025

title: Assessing New Zealand's spider (Araneae) fauna, using DNA barcoding

authors: Binks, Nigel

subjects: Biodiversity

abstract: The ability to accurately monitor biological diversity is the foundation to most ecological research. However, the morphological identification of spiders, as with many arthropod taxa, is often complicated by phenotypic plasticity and sexual dimorphism. New Zealand’s spider fauna is highly endemic (97% of known species), consisting of an estimated 2,000 species. Given such high diversity, it is critical to seek cost-effective measures of assessing species diversity and distributions, and for the identification of cryptic unidentified taxa. 

The aim of my research was to determine whether the described spider fauna can be effectively delineated from unidentified taxa using DNA barcoding. Overall, I establish a molecular inventory for 100 described species and 71 additional unidentified species of spiders found in New Zealand. Using barcoding I determined there to be 59 native described species and classify 66 of the unidentified species as native, leaving 45 species which were recognised as having international distributions by taxonomic descriptions and/or from comparative DNA sequences from the Barcode of Life Datasystem (www.boldsystems.org). The repository of species presented here represent native species pertaining to 26 families and cosmopolitan species from 17 families of which species from the Araneidae, Linyphiidae and Theridiidae families are the most diversly represented in this study. This foundational inventory was used to assess the presence of spider species around the marginal habitats of 5 Waikato study lakes (Puketi, Rotoiti, Kohahuake, Waiwhakareke and Koraha), in relation to community assemblage variation across lakes, habitat (shoreline vs. pasture) and sampling method. 

The combined morphological and molecular approach to identification used here has demonstrated community composition assessments of spiders are viable. Furthermore, the study of these community assemblages revealed a greater diversity of habitat specialists among shoreline samples from lakes Kohahuake, Koraha and Waiwhakareke where greater vegetative heterogeneity along the shoreline provides a greater range of niches for spiders to occupy. This compiled species inventory indicates that New Zealand’s diverse Araneae fauna has been infiltrated by species with international distributions. Further, not all species are easily recognisable due to dissimilarities in their morphological appearance, or because they remain to be genetically identified, and therefore the extent of non-native species infiltration into New Zealand ecosystems is unclear. This lack of knowledge highlights an important area for future biosurveillance work. Lake ecosystems were selected for this study because a variety of spider species prey upon adult aquatic invertebrates as they emerge from the aquatic realm and into the terrestrial. 

Methods which provide complementary data for ranking lake ecosystems is a priority for biodiversity management in the Waikato region due to habitat fragmentation primarily associated with deforestation and subsequent conversion to pastoral habitat. Land use practices affect the distribution and dispersal of many native species and connected expanses of pasture provide opportunities for exotic species to infiltrate established food-webs associated with ecosystems of significant natural character. In conclusion, this molecular inventory provides a key foundation for a COI barcode library for New Zealand’s most commonly-encountered spiders and validates the ability of this identification method to discern between male, female and juvenile specimen from described and unrecognised species with native or international distributions.

text: Assessing New Zealand's spider (Araneae) fauna, using DNA barcoding The ability to accurately monitor biological diversity is the foundation to most ecological research. However, the morphological identification of spiders, as with many arthropod taxa, is often complicated by phenotypic plasticity and sexual dimorphism. New Zealand’s spider fauna is highly endemic (97% of known species), consisting of an estimated 2,000 species. Given such high diversity, it is critical to seek cost-effective measures of assessing species diversity and distributions, and for the identification of cryptic unidentified taxa. 

The aim of my research was to determine whether the described spider fauna can be effectively delineated from unidentified taxa using DNA barcoding. Overall, I establish a molecular inventory for 100 described species and 71 additional unidentified species of spiders found in New Zealand. Using barcoding I determined there to be 59 native described species and classify 66 of the unidentified species as native, leaving 45 species which were recognised as having international distributions by taxonomic descriptions and/or from comparative DNA sequences from the Barcode of Life Datasystem (www.boldsystems.org). The repository of species presented here represent native species pertaining to 26 families and cosmopolitan species from 17 families of which species from the Araneidae, Linyphiidae and Theridiidae families are the most diversly represented in this study. This foundational inventory was used to assess the presence of spider species around the marginal habitats of 5 Waikato study lakes (Puketi, Rotoiti, Kohahuake, Waiwhakareke and Koraha), in relation to community assemblage variation across lakes, habitat (shoreline vs. pasture) and sampling method. 

The combined morphological and molecular approach to identification used here has demonstrated community composition assessments of spiders are viable. Furthermore, the study of these community assemblages revealed a greater diversity of habitat specialists among shoreline samples from lakes Kohahuake, Koraha and Waiwhakareke where greater vegetative heterogeneity along the shoreline provides a greater range of niches for spiders to occupy. This compiled species inventory indicates that New Zealand’s diverse Araneae fauna has been infiltrated by species with international distributions. Further, not all species are easily recognisable due to dissimilarities in their morphological appearance, or because they remain to be genetically identified, and therefore the extent of non-native species infiltration into New Zealand ecosystems is unclear. This lack of knowledge highlights an important area for future biosurveillance work. Lake ecosystems were selected for this study because a variety of spider species prey upon adult aquatic invertebrates as they emerge from the aquatic realm and into the terrestrial. 

Methods which provide complementary data for ranking lake ecosystems is a priority for biodiversity management in the Waikato region due to habitat fragmentation primarily associated with deforestation and subsequent conversion to pastoral habitat. Land use practices affect the distribution and dispersal of many native species and connected expanses of pasture provide opportunities for exotic species to infiltrate established food-webs associated with ecosystems of significant natural character. In conclusion, this molecular inventory provides a key foundation for a COI barcode library for New Zealand’s most commonly-encountered spiders and validates the ability of this identification method to discern between male, female and juvenile specimen from described and unrecognised species with native or international distributions.

year: 2018

title: Ahumoana tawhito (ancient aquaculture): The translocation of  toheroa (Paphies ventricosa) and other marine species by Māori

authors: Taikato, Vanessa Rona

subjects: Mātauranga

abstract: Throughout time, humans have cultivated and translocated plants and animals. Ancient mariculture (the cultivation of marine species) often leaves little trace of human agency. Consequently, the extent to which mariculture was used in the distant past largely remains a mystery. In Aotearoa (New Zealand), Māori have a long history of translocating and cultivating terrestrial and freshwater species. Increasingly, it is becoming apparent that the translocation of marine species is a resource management tool that has been utilized by Māori for hundreds of years. Research into the population genetic structure of a large surf clam endemic to Aotearoa, the toheroa (Paphies ventricosa), has led to the hypothesis that Māori have undertaken long-distance transport and translocation of this shellfish during the earlier phases of Māori occupation within Aotearoa. Specifically, this “translocation hypothesis” suggests that Māori successfully transported toheroa from the West Coast of Te ika-a-Māui (the North Island) to the South Coast of Te Waipounamu (the South Island) thereby explaining the unique and disjunct distribution pattern of this taonga (treasured) species. This thesis weaves together knowledge from multiple disciplines to test the toheroa translocation hypothesis, explore technologies used by Māori and reclaim traditional knowledge regarding resource management. 

An examination of archaeological databases revealed a record that was not consistent with toheroa being endemic to Murihiku (southern South Island). On the west coast of Te Ika-a-Māui, 968 midden records were identified of which 40% either contained or consisted entirely of toheroa. In contrast, along the South Coast of Murihiku (Southland, Te Waipounamu), 122 midden records were examined, of which only 6.5% contained toheroa. Toheroa were not a major component of any of these middens. Toheroa were also absent from a natural shell deposit within Murihiku that pre-dates human arrival to Aotearoa. The general absences of toheroa in all but a few southern middens lends itself to the notion that toheroa did not occur there naturally, but were introduced by Māori at a later date. 

An examination of anthropological, historical and traditional knowledge was conducted to explore the human elements of toheroa translocation. Specifically, I wanted to better understand the reasons why early-Māori might have wanted to translocate toheroa, as well as the capacity and opportunities they would have had to undertake such long-distance transport of live bivalves. The movement of iwi from the north to the south is a concept steeped in kōrero tuku iho (oral history) and is referred to many times in ethnohistorical and contemporary literature. This included the very first movements of Polynesian explorers north to south, as well as multiple accounts of expeditions and southward migrations by Māori originating from the north. Toheroa were an important resource for the earliest occupants of northern regions in Aotearoa and this is evident in the prominence of toheroa in northern Māori culture. Interestingly, while they are a taonga of southern Māori today, toheroa are conspicuously absent in the narratives, whakataukī (proverbs) and whakapapa (genealogy) of Murihiku (Southland). This could be explained by a later introduction of toheroa to the area, leading to less time and opportunity of the resource to shape southern Māori identity. While toheroa may not have been endemic to the south, there was ample opportunity for them to be relocated, either through trade, or as part of a southward migration. Archaeological records of industrial stone, such as obsidian, provide evidence for trade between northern and southern Māori as early as the 14th century. It is clear that people who had come from or were closely connected to northern Māori have occupied the southern most areas of Aotearoa, in the earliest phases of the prehistoric sequence. 
While it is apparent that the opportunity for shellfish translocation existed, the suitability of toheroa for relocation was unknown. This would depend on their ability to cope with and combat stressors (such as hypoxia, bacterial proliferation, starvation and desiccation) associated with such a journey. Respiration rates, morphometric indices, behavioural responses and physiological responses to these stressors were measured in a series of in situ experiments. Toheroa displayed an overall physiological robustness to lack of oxygen and food and, when held in seawater and treated with antibiotics, toheroa were able to switch to anaerobiosis and survive for extended periods of time (more than two weeks). The primary causes of health deterioration were found to be bacterial proliferation (of particular prevalence when held in anoxic water) and desiccation. These are risks that could easily have been mitigated during a translocation journey.

The pōhā, a natural kelp bag fashioned from the large brown alga Durvillaea spp., is a southern Māori technology said to have been used in the translocation and re-seeding of toheroa and other shellfish species, prehistorically. An important first step in understanding this technology was to review the traditional knowledge associated with pōhā and of rimurapa (southern Bull Kelp) from which pōhā are constructed. The literature contained a variety of information covering prehistoric practices to contemporary management of this natural resource as well as details of its wide and varied uses. Interestingly, contemporary use of pōhā and rimurapa has included translocation and restoration of seagrass in Te Waipounamu. 

While there are many historical references to pōhā being used for translocating shellfish, the details of exactly how they were used are missing, both in the literature and in the memories of traditional practitioners of pōhā with whom I have been lucky enough to speak with. Consequently, the final component of this thesis explored the biochemical and bacterial implications of holding live toheroa in pōhā. I found that the photosynthetic blades of the algae were able to replenish dissolved oxygen consumed by the toheroa during respiration. Furthermore, it was clear that the microbiome associated with pōhā, or the secondary metabolites released by pōhā, influenced the bacterial community to which toheroa were exposed when held within the algal bags. From these experiments, it appears unlikely that pōhā were used in the manner employed in this experiment (filled with seawater and left to stagnate) as this resulted in the rapid deterioration of the pōhā bags. However, the biochemical and bacterial results that were found, have direct implications for the functionality of pōhā and the toheroa held within. While possibly not the main vessel in which toheroa were translocated, kōrero tuku iho about the use of pōhā in shellfish re-seeding, suggest that raw pōhā may have been the last link in the chain of shellfish translocation by providing protection while acclimating to a new area. 

The research I have undertaken for this thesis is novel and it contributes to our growing understanding of indigenous resource management in Aotearoa. While I have not been able to determine definitively whether toheroa in the south are solely a consequence of Māori translocation, the evidence presented here is consistent with that hypothesis. The experiments undertaken here are the first of their kind for toheroa, and they highlight how the complex nature of surf clam physiology and behaviour would play into their cultivation, either in ancient or contemporary contexts. This thesis reclaims traditional knowledge regarding the management of two taonga species (toheroa and rimurapa) and highlights several possible avenues for future research. Furthermore, this research demonstrates how academic knowledge and indigenous knowledge can be interwoven, to attempt to unravel the mysteries of the past and to pave the way for the future.

text: Ahumoana tawhito (ancient aquaculture): The translocation of  toheroa (Paphies ventricosa) and other marine species by Māori Throughout time, humans have cultivated and translocated plants and animals. Ancient mariculture (the cultivation of marine species) often leaves little trace of human agency. Consequently, the extent to which mariculture was used in the distant past largely remains a mystery. In Aotearoa (New Zealand), Māori have a long history of translocating and cultivating terrestrial and freshwater species. Increasingly, it is becoming apparent that the translocation of marine species is a resource management tool that has been utilized by Māori for hundreds of years. Research into the population genetic structure of a large surf clam endemic to Aotearoa, the toheroa (Paphies ventricosa), has led to the hypothesis that Māori have undertaken long-distance transport and translocation of this shellfish during the earlier phases of Māori occupation within Aotearoa. Specifically, this “translocation hypothesis” suggests that Māori successfully transported toheroa from the West Coast of Te ika-a-Māui (the North Island) to the South Coast of Te Waipounamu (the South Island) thereby explaining the unique and disjunct distribution pattern of this taonga (treasured) species. This thesis weaves together knowledge from multiple disciplines to test the toheroa translocation hypothesis, explore technologies used by Māori and reclaim traditional knowledge regarding resource management. 

An examination of archaeological databases revealed a record that was not consistent with toheroa being endemic to Murihiku (southern South Island). On the west coast of Te Ika-a-Māui, 968 midden records were identified of which 40% either contained or consisted entirely of toheroa. In contrast, along the South Coast of Murihiku (Southland, Te Waipounamu), 122 midden records were examined, of which only 6.5% contained toheroa. Toheroa were not a major component of any of these middens. Toheroa were also absent from a natural shell deposit within Murihiku that pre-dates human arrival to Aotearoa. The general absences of toheroa in all but a few southern middens lends itself to the notion that toheroa did not occur there naturally, but were introduced by Māori at a later date. 

An examination of anthropological, historical and traditional knowledge was conducted to explore the human elements of toheroa translocation. Specifically, I wanted to better understand the reasons why early-Māori might have wanted to translocate toheroa, as well as the capacity and opportunities they would have had to undertake such long-distance transport of live bivalves. The movement of iwi from the north to the south is a concept steeped in kōrero tuku iho (oral history) and is referred to many times in ethnohistorical and contemporary literature. This included the very first movements of Polynesian explorers north to south, as well as multiple accounts of expeditions and southward migrations by Māori originating from the north. Toheroa were an important resource for the earliest occupants of northern regions in Aotearoa and this is evident in the prominence of toheroa in northern Māori culture. Interestingly, while they are a taonga of southern Māori today, toheroa are conspicuously absent in the narratives, whakataukī (proverbs) and whakapapa (genealogy) of Murihiku (Southland). This could be explained by a later introduction of toheroa to the area, leading to less time and opportunity of the resource to shape southern Māori identity. While toheroa may not have been endemic to the south, there was ample opportunity for them to be relocated, either through trade, or as part of a southward migration. Archaeological records of industrial stone, such as obsidian, provide evidence for trade between northern and southern Māori as early as the 14th century. It is clear that people who had come from or were closely connected to northern Māori have occupied the southern most areas of Aotearoa, in the earliest phases of the prehistoric sequence. 
While it is apparent that the opportunity for shellfish translocation existed, the suitability of toheroa for relocation was unknown. This would depend on their ability to cope with and combat stressors (such as hypoxia, bacterial proliferation, starvation and desiccation) associated with such a journey. Respiration rates, morphometric indices, behavioural responses and physiological responses to these stressors were measured in a series of in situ experiments. Toheroa displayed an overall physiological robustness to lack of oxygen and food and, when held in seawater and treated with antibiotics, toheroa were able to switch to anaerobiosis and survive for extended periods of time (more than two weeks). The primary causes of health deterioration were found to be bacterial proliferation (of particular prevalence when held in anoxic water) and desiccation. These are risks that could easily have been mitigated during a translocation journey.

The pōhā, a natural kelp bag fashioned from the large brown alga Durvillaea spp., is a southern Māori technology said to have been used in the translocation and re-seeding of toheroa and other shellfish species, prehistorically. An important first step in understanding this technology was to review the traditional knowledge associated with pōhā and of rimurapa (southern Bull Kelp) from which pōhā are constructed. The literature contained a variety of information covering prehistoric practices to contemporary management of this natural resource as well as details of its wide and varied uses. Interestingly, contemporary use of pōhā and rimurapa has included translocation and restoration of seagrass in Te Waipounamu. 

While there are many historical references to pōhā being used for translocating shellfish, the details of exactly how they were used are missing, both in the literature and in the memories of traditional practitioners of pōhā with whom I have been lucky enough to speak with. Consequently, the final component of this thesis explored the biochemical and bacterial implications of holding live toheroa in pōhā. I found that the photosynthetic blades of the algae were able to replenish dissolved oxygen consumed by the toheroa during respiration. Furthermore, it was clear that the microbiome associated with pōhā, or the secondary metabolites released by pōhā, influenced the bacterial community to which toheroa were exposed when held within the algal bags. From these experiments, it appears unlikely that pōhā were used in the manner employed in this experiment (filled with seawater and left to stagnate) as this resulted in the rapid deterioration of the pōhā bags. However, the biochemical and bacterial results that were found, have direct implications for the functionality of pōhā and the toheroa held within. While possibly not the main vessel in which toheroa were translocated, kōrero tuku iho about the use of pōhā in shellfish re-seeding, suggest that raw pōhā may have been the last link in the chain of shellfish translocation by providing protection while acclimating to a new area. 

The research I have undertaken for this thesis is novel and it contributes to our growing understanding of indigenous resource management in Aotearoa. While I have not been able to determine definitively whether toheroa in the south are solely a consequence of Māori translocation, the evidence presented here is consistent with that hypothesis. The experiments undertaken here are the first of their kind for toheroa, and they highlight how the complex nature of surf clam physiology and behaviour would play into their cultivation, either in ancient or contemporary contexts. This thesis reclaims traditional knowledge regarding the management of two taonga species (toheroa and rimurapa) and highlights several possible avenues for future research. Furthermore, this research demonstrates how academic knowledge and indigenous knowledge can be interwoven, to attempt to unravel the mysteries of the past and to pave the way for the future.

year: 2021