title: Diet of rainbow trout in Lake Rotoiti: an energetic perspective

authors: Blair, Jennifer Marie

subjects: New Zealand

abstract: We characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout (Oncorhynchus mykiss) in Lake Rotoiti, New Zealand, to better understand the prey requirements of trout in central North Island lakes. Common smelt (Retropinna retropinna) was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by weight), followed by kōura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (Gobiomorphus cotidianus; 5.5%), and kōaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed kōaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (kōaro and kōura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetic modelling of rainbow trout populations in lakes of the central North Island of New Zealand.

text: Diet of rainbow trout in Lake Rotoiti: an energetic perspective We characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout (Oncorhynchus mykiss) in Lake Rotoiti, New Zealand, to better understand the prey requirements of trout in central North Island lakes. Common smelt (Retropinna retropinna) was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by weight), followed by kōura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (Gobiomorphus cotidianus; 5.5%), and kōaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed kōaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (kōaro and kōura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetic modelling of rainbow trout populations in lakes of the central North Island of New Zealand.

year: 2012

title: Heegner cycles and congruences between anticyclotomic p-adic L-functions over CM-extensions

authors: Delbourgo, Daniel

subjects: Science & Technology

abstract: Let E be a CM-field, and suppose that f, g are two primitive Hilbert cusp forms over E⁺ of weight 2 satisfying a congruence modulo λʳ. Under appropriate hypotheses, we show that the complex L-values of f and g twisted by a ring class character over E, and divided by the motivic periods, also satisfy a congruence relation mod λʳ (after removing some Euler factors). We treat both the even and odd cases for the sign in the functional equation – this generalizes classical work of Vatsal [23] on congruences between elliptic modular forms twisted by Dirichlet characters. In the odd case, we also show that the p-adic logarithms of Heegner points attached to f and g satisfy a congruence relation modulo λʳ, thus extending recent work of Kriz and Li [17] concerning elliptic modular forms.

text: Heegner cycles and congruences between anticyclotomic p-adic L-functions over CM-extensions Let E be a CM-field, and suppose that f, g are two primitive Hilbert cusp forms over E⁺ of weight 2 satisfying a congruence modulo λʳ. Under appropriate hypotheses, we show that the complex L-values of f and g twisted by a ring class character over E, and divided by the motivic periods, also satisfy a congruence relation mod λʳ (after removing some Euler factors). We treat both the even and odd cases for the sign in the functional equation – this generalizes classical work of Vatsal [23] on congruences between elliptic modular forms twisted by Dirichlet characters. In the odd case, we also show that the p-adic logarithms of Heegner points attached to f and g satisfy a congruence relation modulo λʳ, thus extending recent work of Kriz and Li [17] concerning elliptic modular forms.

year: 2020

title: Māori Migration: The Social Consequences

authors: Nikora, Linda Waimarie

subjects: Maori

abstract: A team led by Bernard Guerin is looking at the family and community impacts from contemporary forms of migration in a 6-year project Strangers in Town: Enhancing Family and Community in a More Diverse New Zealand Society, funded by the Foundation for Research, Science and Technology. One large part of this research looks at Māori migration, headed by Linda Waimarie Nikora.
Since the research on the 'urban drift' of the 1950s and 1960s, little has been done to research the effects of Māori migration. Our aim is to draw together the researchers and research results and to conduct our own research to fill in the gaps. We also work with others on the 6-year project who are looking at the population statistics of Māori migration, especially Trans-Tasman migrations.

text: Māori Migration: The Social Consequences A team led by Bernard Guerin is looking at the family and community impacts from contemporary forms of migration in a 6-year project Strangers in Town: Enhancing Family and Community in a More Diverse New Zealand Society, funded by the Foundation for Research, Science and Technology. One large part of this research looks at Māori migration, headed by Linda Waimarie Nikora.
Since the research on the 'urban drift' of the 1950s and 1960s, little has been done to research the effects of Māori migration. Our aim is to draw together the researchers and research results and to conduct our own research to fill in the gaps. We also work with others on the 6-year project who are looking at the population statistics of Māori migration, especially Trans-Tasman migrations.

year: 2004-11-01