title: Comparative fish abundance in the shallow Waikato lakes Whangape and Hakanoa

authors: Hicks, Brendan J.

abstract: The Waikato-Tainui College for Research and Development contracted the University of Waikato to conduct boat electrofishing estimates of the fish abundance in lakes Whangape and Hakanoa; both are shallow, riverine lakes in the lower Waikato River floodplain and are about 2,000 years old. Lake Whangape (latitude 37.46853°S, longitude 175.05120°W) is a large (1,450 ha), shallow (maximum depth 2.7 m) lake to the west of the Waikato River; Lake Hakanoa (latitude 37.55258°S, longitude 175.16859°W) is a 52-ha lake in suburban Huntly with a maximum depth of 2.5 m.
We fished 10 sites for 10 mins in both lakes Whangape and Lake Hakanoa; sites fished were 253-609 m long (1,012-2,436 m² in area) in Lake Whangape and 125-276 m long (500-1,104 m² in area) in Lake Hakanoa.
No submerged aquatic macrophytes were seen in either lake. Fishing was conducted close to the water's edge in Lake Hakanoa, but the shallow margins in Lake Whangape restricted fishing at most sites to 30-70 m from the shoreline. The shoreline was much more accessible in Lake Hakanoa, and was dominated by raupo (Typha orientalis) with willows (Salix spp.) in places. Submerged tree trunks and logs in Lake Hakanoa made navigation difficult in parts of the lake margins.
We caught a total of 118 fish in Lake Whangape, where shortfin eels (Anguilla australis) were the most abundant fish, and 594 fish in Lake Hakanoa, where gambusia (Gambusia affinis) the most abundant species. In Lake Whangape, shortfin eels comprised the greatest total biomass (12.4 kg), with koi carp (Cyprinus carpio) almost equally abundant (11.4 kg). In Lake Hakanoa, koi carp were most abundant (74.4 kg), followed by shortfin eels (22.1 kg).
Fish were unevenly spread among sites in Lake Whangape and koi carp were relatively sparsely among sites. In Lake Hakanoa, in contrast, fish were more evenly spread among sites, but with higher concentrations of catfish (Ameiurus nebulosus) and goldfish (Carassius auratus) at a few sites. Biomass of fish caught in each of the ten 10-min fishing shots reflected the numerical distributions, with some wide variations between sites. Fish densities were generally lower in Lake Whangape than in Lake Hakanoa; however, common smelt (Retropinna retropinna) and grey mullet (Mugil cephalus) occurred in Whangape but not in Hakanoa. Areal fish biomass was dominated by shortfin eels and koi carp in Lake Whangape, but koi carp dominated the fish biomass in Lake Hakanoa, despite the smaller number of carp than eels. This was because of the large mean weight of koi carp (about 1,000 g) compared to the smaller shortfin eels (mean weight about 200 g in both lakes).

text: Comparative fish abundance in the shallow Waikato lakes Whangape and Hakanoa The Waikato-Tainui College for Research and Development contracted the University of Waikato to conduct boat electrofishing estimates of the fish abundance in lakes Whangape and Hakanoa; both are shallow, riverine lakes in the lower Waikato River floodplain and are about 2,000 years old. Lake Whangape (latitude 37.46853°S, longitude 175.05120°W) is a large (1,450 ha), shallow (maximum depth 2.7 m) lake to the west of the Waikato River; Lake Hakanoa (latitude 37.55258°S, longitude 175.16859°W) is a 52-ha lake in suburban Huntly with a maximum depth of 2.5 m.
We fished 10 sites for 10 mins in both lakes Whangape and Lake Hakanoa; sites fished were 253-609 m long (1,012-2,436 m² in area) in Lake Whangape and 125-276 m long (500-1,104 m² in area) in Lake Hakanoa.
No submerged aquatic macrophytes were seen in either lake. Fishing was conducted close to the water's edge in Lake Hakanoa, but the shallow margins in Lake Whangape restricted fishing at most sites to 30-70 m from the shoreline. The shoreline was much more accessible in Lake Hakanoa, and was dominated by raupo (Typha orientalis) with willows (Salix spp.) in places. Submerged tree trunks and logs in Lake Hakanoa made navigation difficult in parts of the lake margins.
We caught a total of 118 fish in Lake Whangape, where shortfin eels (Anguilla australis) were the most abundant fish, and 594 fish in Lake Hakanoa, where gambusia (Gambusia affinis) the most abundant species. In Lake Whangape, shortfin eels comprised the greatest total biomass (12.4 kg), with koi carp (Cyprinus carpio) almost equally abundant (11.4 kg). In Lake Hakanoa, koi carp were most abundant (74.4 kg), followed by shortfin eels (22.1 kg).
Fish were unevenly spread among sites in Lake Whangape and koi carp were relatively sparsely among sites. In Lake Hakanoa, in contrast, fish were more evenly spread among sites, but with higher concentrations of catfish (Ameiurus nebulosus) and goldfish (Carassius auratus) at a few sites. Biomass of fish caught in each of the ten 10-min fishing shots reflected the numerical distributions, with some wide variations between sites. Fish densities were generally lower in Lake Whangape than in Lake Hakanoa; however, common smelt (Retropinna retropinna) and grey mullet (Mugil cephalus) occurred in Whangape but not in Hakanoa. Areal fish biomass was dominated by shortfin eels and koi carp in Lake Whangape, but koi carp dominated the fish biomass in Lake Hakanoa, despite the smaller number of carp than eels. This was because of the large mean weight of koi carp (about 1,000 g) compared to the smaller shortfin eels (mean weight about 200 g in both lakes).

year: 2016

title: Te taiao: Te titiro a te Māori

authors: Kirby, Dean Robert

subjects: Cosmology

abstract: Ko te kaupapa o tēnei tuhinga ko te titiro a te Māori ki te taiao. He mea tuhi i runga i te aroha, i te whakapono ki ngēnei mea, ki te ātaahua o te taiao me ngā kōrero mōna. E whakatangatatia ana ngā āhuatanga o te taiao, ngā rākau, ngā manu, ngā ika, te kohu, ngā kapua, ngā maunga, otirā ngā mea katoa. Ara noa atu ngā kōrero, he whakapapa ō rātou, he huānga tētehi mea ki tētehi, he mauri tō tēnā mea tō tēnā mea. E ora ana ngā mea katoa o te ao, ka whai tamariki, he mātua he tūpuna anō, te katoa tae atu hoki ki te tangata, he wāhanga ia nō te taiao.
Hei aha tēnei tuhinga? Ko tāna mahi he whakaatu i ngēnei āhuatanga. Ā he whakamātau hoki ki te whakautu i te pātai he aha i whērā ai te titiro a ngā tūpuna ki tō rātou taiao. He kohikohingā tēnei nō ngā kōrero maha e takoto mai naka i roto i ngā pukapuka kua tāia kētia. Ehake i te mea ka kōrerotia ngā mea katoa, otiia ka tirohia noatia ngētehi āhuatanga o tēnei hanga te taiao. Kāhore i tuhia i runga i ngā kōrero ā waha a ngētehi kaikōrero, whēnā i ngētehi atu tuhinga roa. He mahi nui tērā mā tētehi atu hei whai, heoi anō tēnei he huihuinga nō ngētehi kōrero kua tuhia i mua atu.
Ka whakarārangitia ngā kōrero neki i muri ake nei. Ko tōna timatanga kei te Ōrokohanga, ko te timatanga tērā o te taiao. Ko te whenua ka whai mai me ngā kōrero mōna. Muri iho ko te wai me ngōna āhuatanga katoa. Ko te rangi, ngā mea katoa o te rangi ka whai mai i muri i tēnā. Muri iho anō ko ngā manu, ko ngā ngārara me ngā ngāngara, ngā rākau me ngā ika. Ka mutu atu i ngā tupua, i ngā taniwha me ngā patupaiarehe, i ngā kōrero mō ngērā. E iwa wāhanga nui te katoa o tēnei tuhinga. Kei te timatanga tētehi wāhanga hei whakamārama i te tuhinga ā kei te mutunga tētehi atu wāhanga hei whakatōpū, hei whakarāpopoto i ngā kōrero o roto i te puku o te tuhinga nei.
Kei ngā wāhanga o te pukapuka nei he kōrero mō tēnā mea, mō tēnā mea i raro i tōna ūpoko anō, me ngā whakaāhua e rite ana mōna. Ko te tūmanako ka kite te kaipānui i te pūrotutanga o te taiao o te Māori.

text: Te taiao: Te titiro a te Māori Ko te kaupapa o tēnei tuhinga ko te titiro a te Māori ki te taiao. He mea tuhi i runga i te aroha, i te whakapono ki ngēnei mea, ki te ātaahua o te taiao me ngā kōrero mōna. E whakatangatatia ana ngā āhuatanga o te taiao, ngā rākau, ngā manu, ngā ika, te kohu, ngā kapua, ngā maunga, otirā ngā mea katoa. Ara noa atu ngā kōrero, he whakapapa ō rātou, he huānga tētehi mea ki tētehi, he mauri tō tēnā mea tō tēnā mea. E ora ana ngā mea katoa o te ao, ka whai tamariki, he mātua he tūpuna anō, te katoa tae atu hoki ki te tangata, he wāhanga ia nō te taiao.
Hei aha tēnei tuhinga? Ko tāna mahi he whakaatu i ngēnei āhuatanga. Ā he whakamātau hoki ki te whakautu i te pātai he aha i whērā ai te titiro a ngā tūpuna ki tō rātou taiao. He kohikohingā tēnei nō ngā kōrero maha e takoto mai naka i roto i ngā pukapuka kua tāia kētia. Ehake i te mea ka kōrerotia ngā mea katoa, otiia ka tirohia noatia ngētehi āhuatanga o tēnei hanga te taiao. Kāhore i tuhia i runga i ngā kōrero ā waha a ngētehi kaikōrero, whēnā i ngētehi atu tuhinga roa. He mahi nui tērā mā tētehi atu hei whai, heoi anō tēnei he huihuinga nō ngētehi kōrero kua tuhia i mua atu.
Ka whakarārangitia ngā kōrero neki i muri ake nei. Ko tōna timatanga kei te Ōrokohanga, ko te timatanga tērā o te taiao. Ko te whenua ka whai mai me ngā kōrero mōna. Muri iho ko te wai me ngōna āhuatanga katoa. Ko te rangi, ngā mea katoa o te rangi ka whai mai i muri i tēnā. Muri iho anō ko ngā manu, ko ngā ngārara me ngā ngāngara, ngā rākau me ngā ika. Ka mutu atu i ngā tupua, i ngā taniwha me ngā patupaiarehe, i ngā kōrero mō ngērā. E iwa wāhanga nui te katoa o tēnei tuhinga. Kei te timatanga tētehi wāhanga hei whakamārama i te tuhinga ā kei te mutunga tētehi atu wāhanga hei whakatōpū, hei whakarāpopoto i ngā kōrero o roto i te puku o te tuhinga nei.
Kei ngā wāhanga o te pukapuka nei he kōrero mō tēnā mea, mō tēnā mea i raro i tōna ūpoko anō, me ngā whakaāhua e rite ana mōna. Ko te tūmanako ka kite te kaipānui i te pūrotutanga o te taiao o te Māori.

year: 1992

title: Seagrass resilience to waterfowl grazing in a temperate estuary: A multi-site experimental study

authors: Dos Santos, Virginie

subjects: Cygnus atratus

abstract: In New Zealand, black swans have been observed to graze a moderate to large proportion of the biomass of intertidal seagrass (Zostera muelleri) meadows. To evaluate the resilience of seagrass meadows to swan grazing, we performed a grazing simulation experiment at four sites in a large temperate estuary (Tauranga Harbour). In late summer, when swan grazing pressure typically peaks, we established control (0% biomass removed), low grazing intensity (~ 40% biomass removed) and high grazing intensity (~ 100% biomass removed) plots (0.25 m2) to mimic the grazing scars created by black swans. For one year, percentage seagrass above-ground cover of plots and a wider area surrounding the plots (0.75 m2) was monitored monthly. Seagrass biomass and leaf size were measured at the start and end of the experiment. Results showed no significant grazing treatment effect on seagrass leaf size (length and width). The low grazing intensity treatment had no detectable effect on seagrass cover or biomass relative to controls. For the high grazing intensity plots at all sites seagrass cover was restored within 8 months but biomass was not fully restored (only 25–42% of controls) one year later. This suggests that it may take several years (2.4–4.0, assuming a constant recovery rate) for seagrass below-ground biomass and leaf layering to regenerate completely in the grazing scars created by swans.

text: Seagrass resilience to waterfowl grazing in a temperate estuary: A multi-site experimental study In New Zealand, black swans have been observed to graze a moderate to large proportion of the biomass of intertidal seagrass (Zostera muelleri) meadows. To evaluate the resilience of seagrass meadows to swan grazing, we performed a grazing simulation experiment at four sites in a large temperate estuary (Tauranga Harbour). In late summer, when swan grazing pressure typically peaks, we established control (0% biomass removed), low grazing intensity (~ 40% biomass removed) and high grazing intensity (~ 100% biomass removed) plots (0.25 m2) to mimic the grazing scars created by black swans. For one year, percentage seagrass above-ground cover of plots and a wider area surrounding the plots (0.75 m2) was monitored monthly. Seagrass biomass and leaf size were measured at the start and end of the experiment. Results showed no significant grazing treatment effect on seagrass leaf size (length and width). The low grazing intensity treatment had no detectable effect on seagrass cover or biomass relative to controls. For the high grazing intensity plots at all sites seagrass cover was restored within 8 months but biomass was not fully restored (only 25–42% of controls) one year later. This suggests that it may take several years (2.4–4.0, assuming a constant recovery rate) for seagrass below-ground biomass and leaf layering to regenerate completely in the grazing scars created by swans.

year: 2013