title: Connectivity and complexity of floodplain habitats govern zooplankton dynamics in a large temperate river system

authors: Górski, Konrad

subjects: flood pulse

abstract: 1.	Large river–floodplain systems are characterised by seasonal flow variability. High flows lead to hydrological connection between the main channel and inundated off-channel lakes, wetlands and floodplains, which provide essential habitats for riverine biota. We tested the following hypotheses: (i) that crustacean zooplankton are more abundant in connected lentic habitats such as riverine lakes and wetlands and have a different community composition compared with the main channel and (ii) that vegetation structure will moderate abundances of crustacean zooplankton in the lower reaches of the Waikato River, New Zealand.
2.	Zooplankton densities in main channel inflows and inundated floodplains showed clear seasonal changes, with cladoceran and copepod abundance peaks occurring in the majority of sites 2–3 weeks following the peak spring discharges (coinciding with the retreat of water from floodplains into the main channel).
3.	Mean densities of zooplankton were highest in the inflows originating from riverine lakes (10–20 ind. Lˉ¹) where rotifers were dominant. We recorded significantly higher abundances of copepods in peat bog and swamp wetland inflows (c. 5 ind. Lˉ¹) relative to the main river channel and riverine lake inflows (0.1–1 ind. Lˉ¹). Some lake inflows also had high numbers of cladocerans (5–10 ind. Lˉ¹). 
4.	Inundated floodplains displayed heterogeneity in zooplankton community composition in relation to their structural complexity. Flooded forest accommodated higher numbers of copepods (c. 8 ind. Lˉ¹) and cladocerans (c. 17 ind. Lˉ¹) than flooded grassland, where zooplankton assemblages resembled those in the main river channel and were characterised by dominance of rotifers and low overall zooplankton densities (1–2 ind. Lˉ¹).
5.	Our results suggest that seasonal flow and flood pulses, which determine the degree of connectivity of the main channel with the floodplain and off-channel habitats, govern zooplankton densities and community structure in this large temperate river. Furthermore, the structural complexity of floodplain habitats may play an important role in enhancing riverine zooplankton diversity. We postulate that the post-flood peak of large-bodied cladocerans and copepods might have historically played an important role in the provision of food for juvenile fish such as migrating Galaxiidae.

text: Connectivity and complexity of floodplain habitats govern zooplankton dynamics in a large temperate river system 1.	Large river–floodplain systems are characterised by seasonal flow variability. High flows lead to hydrological connection between the main channel and inundated off-channel lakes, wetlands and floodplains, which provide essential habitats for riverine biota. We tested the following hypotheses: (i) that crustacean zooplankton are more abundant in connected lentic habitats such as riverine lakes and wetlands and have a different community composition compared with the main channel and (ii) that vegetation structure will moderate abundances of crustacean zooplankton in the lower reaches of the Waikato River, New Zealand.
2.	Zooplankton densities in main channel inflows and inundated floodplains showed clear seasonal changes, with cladoceran and copepod abundance peaks occurring in the majority of sites 2–3 weeks following the peak spring discharges (coinciding with the retreat of water from floodplains into the main channel).
3.	Mean densities of zooplankton were highest in the inflows originating from riverine lakes (10–20 ind. Lˉ¹) where rotifers were dominant. We recorded significantly higher abundances of copepods in peat bog and swamp wetland inflows (c. 5 ind. Lˉ¹) relative to the main river channel and riverine lake inflows (0.1–1 ind. Lˉ¹). Some lake inflows also had high numbers of cladocerans (5–10 ind. Lˉ¹). 
4.	Inundated floodplains displayed heterogeneity in zooplankton community composition in relation to their structural complexity. Flooded forest accommodated higher numbers of copepods (c. 8 ind. Lˉ¹) and cladocerans (c. 17 ind. Lˉ¹) than flooded grassland, where zooplankton assemblages resembled those in the main river channel and were characterised by dominance of rotifers and low overall zooplankton densities (1–2 ind. Lˉ¹).
5.	Our results suggest that seasonal flow and flood pulses, which determine the degree of connectivity of the main channel with the floodplain and off-channel habitats, govern zooplankton densities and community structure in this large temperate river. Furthermore, the structural complexity of floodplain habitats may play an important role in enhancing riverine zooplankton diversity. We postulate that the post-flood peak of large-bodied cladocerans and copepods might have historically played an important role in the provision of food for juvenile fish such as migrating Galaxiidae.

year: 2013

title: Evolution and comparative haemoglobin oxygen binding in new zealand mudfishes

authors: Brijs, Jeroen

subjects: mudfish

abstract: New Zealand's five endemic mudfish (Neochanna spp.) species have distributions that differ both geographically and by habitat type. Differences in habitat preferences between species have led to the proposal of an evolutionary series within the group. A morphological cline can be observed from the galaxiform Chatham Island and Canterbury species inhabiting lakes and streams, respectively, to the anguilliform Northland and brown mudfishes of ephemeral wetlands. Morphological specializations proposed for wetland dwelling include loss of pelvic fins, reduced eyes, enlarged nostrils, development of caudal flanges, and elongation of dorsal and anal fin bases to become almost confluent with the caudal fin.  Another expectation of adaptation to wetland dwelling is specializations in respiratory physiology to obtain oxygen from highly hypoxic or acidic waters, and the ability to cope with seasonal exposure to air during the drought season.  Expected respiratory specializations to wetland dwelling include high oxygen affinity haemoglobins, high levels of cooperative oxygen binding, the presence of multiple haemoglobins and the ability to aestivate and survive long periods of emersion. 

The four mainland Neochanna species were examined to determine if differences in haemoglobin expression as well as differences in haemoglobin oxygen binding correlated with differing habitats and treatments.  Whole blood oxygen affinity was determined at several pH levels (6.5, 7.0, 7.5 and 8.0) and temperatures (10'C, 15'C and 20'C), as well as different treatments (aestivating, fasting and control) using a Hemox analyzer.  The presence of multiple haemoglobins was determined by isoelectric focusing.  All four species displayed high oxygen affinities (p50 = 6.5 to 9.5 mm Hg at pH 7.5  15'C), moderate levels of cooperativity (Hill coefficients = 1.75 to 2.00 at pH 7.5  15'C), pH sensitivity (Bohr coefficients = -0.62 to -0.94 between pH 7.5 and 7.0 at 15'C), temperature sensitivity (ΔH = -2.20 to -15.78 k cal mol-1 between 10'C and 15'C) and the presence of multiple haemoglobins.  Black, brown and Northland mudfish were able to survive aestivation for six weeks but there were no changes between air-breathing and water-breathing individuals with respect to oxygen binding characteristics.  Although there is evidence of habitat specialization in haemoglobin physiology between mudfish species, differences between species did not correlate with the evolutionary series proposed for specialization to dwelling in ephemeral wetlands and latitudinal distributions of mudfish species appear to strongly dictate oxygen binding properties of mudfish whole blood.

text: Evolution and comparative haemoglobin oxygen binding in new zealand mudfishes New Zealand's five endemic mudfish (Neochanna spp.) species have distributions that differ both geographically and by habitat type. Differences in habitat preferences between species have led to the proposal of an evolutionary series within the group. A morphological cline can be observed from the galaxiform Chatham Island and Canterbury species inhabiting lakes and streams, respectively, to the anguilliform Northland and brown mudfishes of ephemeral wetlands. Morphological specializations proposed for wetland dwelling include loss of pelvic fins, reduced eyes, enlarged nostrils, development of caudal flanges, and elongation of dorsal and anal fin bases to become almost confluent with the caudal fin.  Another expectation of adaptation to wetland dwelling is specializations in respiratory physiology to obtain oxygen from highly hypoxic or acidic waters, and the ability to cope with seasonal exposure to air during the drought season.  Expected respiratory specializations to wetland dwelling include high oxygen affinity haemoglobins, high levels of cooperative oxygen binding, the presence of multiple haemoglobins and the ability to aestivate and survive long periods of emersion. 

The four mainland Neochanna species were examined to determine if differences in haemoglobin expression as well as differences in haemoglobin oxygen binding correlated with differing habitats and treatments.  Whole blood oxygen affinity was determined at several pH levels (6.5, 7.0, 7.5 and 8.0) and temperatures (10'C, 15'C and 20'C), as well as different treatments (aestivating, fasting and control) using a Hemox analyzer.  The presence of multiple haemoglobins was determined by isoelectric focusing.  All four species displayed high oxygen affinities (p50 = 6.5 to 9.5 mm Hg at pH 7.5  15'C), moderate levels of cooperativity (Hill coefficients = 1.75 to 2.00 at pH 7.5  15'C), pH sensitivity (Bohr coefficients = -0.62 to -0.94 between pH 7.5 and 7.0 at 15'C), temperature sensitivity (ΔH = -2.20 to -15.78 k cal mol-1 between 10'C and 15'C) and the presence of multiple haemoglobins.  Black, brown and Northland mudfish were able to survive aestivation for six weeks but there were no changes between air-breathing and water-breathing individuals with respect to oxygen binding characteristics.  Although there is evidence of habitat specialization in haemoglobin physiology between mudfish species, differences between species did not correlate with the evolutionary series proposed for specialization to dwelling in ephemeral wetlands and latitudinal distributions of mudfish species appear to strongly dictate oxygen binding properties of mudfish whole blood.

year: 2007

title: He maimoa i ngā whakatupuranga anamata: Ko te mātauranga taketake o ngā tūpuna me te whakarea tamariki

authors: Greensill, Hineitimoana

subjects: Poipoi tamariki

abstract: Kua āraua ki roto i te reo me ngā pūnaha mātauranga o ngā iwi taketake, ko ngā uara, ko ngā whakapono me ngā rapunga whakaaro e toko ake nei i tērā iwi. Kia whakahoropakitia tēnei ki roto o Aotearoa me Hawai‘i, i te whakaekenga o ō tātou kāinga tupu e ngā taua a te Pākehā me ngā tāmi o ngā tikanga whakawhenumi a te Kāwanantanga o muri, i tauwhatia ai te tuku o te reo Māori me te ‘ōlelo (reo) o Hawai‘i i waenga i ngā whakatupuranga, waihoki ko ngā māramatanga pūmau o roto i ngā reo i tauwhatia ai (Walker, 2004; Blaisdell & Mokuau, 1991). Ahakoa ēnei tauwhatinga, ka pupuri tonu tātou ki ngā karere i mau rā i te reo i roto i ngā ngā pātaka mātauranga a te Māori me nā kānaka (ngā tāngata) o Hawai‘i. Ko te mātauranga taketake, ngā kōrero o nehe me ngā ariā e āraua nei ki ngā tuhituhinga-ā-waha huhua, tae atu ki ngā whakataukī, ngā ‘ōlelo no‘eau, me ngā kīanga rongonui i tāngia hoki ki te pepa (Pukui, 1983). Ko te ia o ēnei momo kōrero tuku-iho taketake nei kei te kōrerotia i roto i ngā whakataukī me ngā ‘ōlelo no‘eau, he mea whakaara anō tēnei mātauranga ki ngā kaupapa whakaora reo ki Aotearoa me Hawai‘i. He momo mātauranga ēnei hei whakaara i a tātou kia mārama rawa ki ngā kano tirohanga o ō tātou tūpuna ki tō rātou ao, waihoki ko ngā hononga maha e paihere nei i a tātou ki ō tātou whanaunga.

Hei whāinga matua e āta arohaehae ana tēnei pepa i ngā momo tuhituhinga-ā-waha nei, arā ko te ‘ōlelo no‘eau me te whakataukī, kia tīroua ake ngā karere e hāngai ana ki ngā tamariki a te Māori rātou ko ngā kānaka o Hawai‘i me ngā pānga ki ngā mahi whakatupu tamariki o mua. Ka toro tēnei tuhinga ki te whakataukī me te ‘ōlelo no‘eau ki te whakapuaki i te mātauranga i mahue mai i ngā tūpuna hei rei arataki mā tātou ngā iwi taketake me ō tātou wheako tonu o nāianei.

text: He maimoa i ngā whakatupuranga anamata: Ko te mātauranga taketake o ngā tūpuna me te whakarea tamariki Kua āraua ki roto i te reo me ngā pūnaha mātauranga o ngā iwi taketake, ko ngā uara, ko ngā whakapono me ngā rapunga whakaaro e toko ake nei i tērā iwi. Kia whakahoropakitia tēnei ki roto o Aotearoa me Hawai‘i, i te whakaekenga o ō tātou kāinga tupu e ngā taua a te Pākehā me ngā tāmi o ngā tikanga whakawhenumi a te Kāwanantanga o muri, i tauwhatia ai te tuku o te reo Māori me te ‘ōlelo (reo) o Hawai‘i i waenga i ngā whakatupuranga, waihoki ko ngā māramatanga pūmau o roto i ngā reo i tauwhatia ai (Walker, 2004; Blaisdell & Mokuau, 1991). Ahakoa ēnei tauwhatinga, ka pupuri tonu tātou ki ngā karere i mau rā i te reo i roto i ngā ngā pātaka mātauranga a te Māori me nā kānaka (ngā tāngata) o Hawai‘i. Ko te mātauranga taketake, ngā kōrero o nehe me ngā ariā e āraua nei ki ngā tuhituhinga-ā-waha huhua, tae atu ki ngā whakataukī, ngā ‘ōlelo no‘eau, me ngā kīanga rongonui i tāngia hoki ki te pepa (Pukui, 1983). Ko te ia o ēnei momo kōrero tuku-iho taketake nei kei te kōrerotia i roto i ngā whakataukī me ngā ‘ōlelo no‘eau, he mea whakaara anō tēnei mātauranga ki ngā kaupapa whakaora reo ki Aotearoa me Hawai‘i. He momo mātauranga ēnei hei whakaara i a tātou kia mārama rawa ki ngā kano tirohanga o ō tātou tūpuna ki tō rātou ao, waihoki ko ngā hononga maha e paihere nei i a tātou ki ō tātou whanaunga.

Hei whāinga matua e āta arohaehae ana tēnei pepa i ngā momo tuhituhinga-ā-waha nei, arā ko te ‘ōlelo no‘eau me te whakataukī, kia tīroua ake ngā karere e hāngai ana ki ngā tamariki a te Māori rātou ko ngā kānaka o Hawai‘i me ngā pānga ki ngā mahi whakatupu tamariki o mua. Ka toro tēnei tuhinga ki te whakataukī me te ‘ōlelo no‘eau ki te whakapuaki i te mātauranga i mahue mai i ngā tūpuna hei rei arataki mā tātou ngā iwi taketake me ō tātou wheako tonu o nāianei.

year: 2017