title: Is black swan grazing a threat to seagrass? Indications from an observational study in New Zealand

authors: Dos Santos, Virginie

subjects: waterfowl herbivory

abstract: In New Zealand, the black swan (Cygnus atratus) is the only large grazer of intertidal seagrass (Zostera muelleri). The present study examined spatial and temporal variations in black swan grazing activity in a large temperate estuary to estimate potential site-specific and estuary-wide impacts on seagrass biomass. We monitored diel swan grazing activities, their seasonal abundance, estimated the rate at which swans consumed seagrass and measured changes in the standing stock of seagrass biomass at four sites in Tauranga Harbour. Black swans foraged primarily at high tide (both during the day and night) and were more numerous at sites with larger meadows, particularly during autumn. Grazing created circular devegetated patches (average size ∼0.28 m²) with 92% of shoots, 25% of roots and 99% of rhizomes removed. We measured an average seagrass consumption rate of 394 g dry mass (DM) swan⁻¹ d⁻¹ in line with consumption rates of other Zostera-feeding waterfowl. At sites where grazing was most intense (annual removal of 19–20% of the average seagrass biomass), we observed a substantial decline (43–69%) in plant biomass in the subsequent growing season. These results suggest that black swan grazing could constitute a threat to seagrass under high grazing pressure.

text: Is black swan grazing a threat to seagrass? Indications from an observational study in New Zealand In New Zealand, the black swan (Cygnus atratus) is the only large grazer of intertidal seagrass (Zostera muelleri). The present study examined spatial and temporal variations in black swan grazing activity in a large temperate estuary to estimate potential site-specific and estuary-wide impacts on seagrass biomass. We monitored diel swan grazing activities, their seasonal abundance, estimated the rate at which swans consumed seagrass and measured changes in the standing stock of seagrass biomass at four sites in Tauranga Harbour. Black swans foraged primarily at high tide (both during the day and night) and were more numerous at sites with larger meadows, particularly during autumn. Grazing created circular devegetated patches (average size ∼0.28 m²) with 92% of shoots, 25% of roots and 99% of rhizomes removed. We measured an average seagrass consumption rate of 394 g dry mass (DM) swan⁻¹ d⁻¹ in line with consumption rates of other Zostera-feeding waterfowl. At sites where grazing was most intense (annual removal of 19–20% of the average seagrass biomass), we observed a substantial decline (43–69%) in plant biomass in the subsequent growing season. These results suggest that black swan grazing could constitute a threat to seagrass under high grazing pressure.

year: 2012

title: Telemetric longitudinal measurement of young driver behaviour

authors: Starkey, Nicola J.

subjects: New Zealand

abstract: New Zealand is one of the few countries that currently allows teenagers to become solo drivers at 15 ½ years of age. During their first six months of solo driving, these teenagers are 19 times more likely to crash compared to the period of supervised driving. The behaviour of these adolescent drivers represents the single largest cause of fatalities in that age group and is widely acknowledged as one of the most serious social issues facing New Zealand. This state of affairs, often referred to as ‘the young driver problem,’ with an over representation of young drivers in motor vehicle crashes, is not unique to New Zealand. In fact, a similar situation can be found inmost of the world’s developed nations.

text: Telemetric longitudinal measurement of young driver behaviour New Zealand is one of the few countries that currently allows teenagers to become solo drivers at 15 ½ years of age. During their first six months of solo driving, these teenagers are 19 times more likely to crash compared to the period of supervised driving. The behaviour of these adolescent drivers represents the single largest cause of fatalities in that age group and is widely acknowledged as one of the most serious social issues facing New Zealand. This state of affairs, often referred to as ‘the young driver problem,’ with an over representation of young drivers in motor vehicle crashes, is not unique to New Zealand. In fact, a similar situation can be found inmost of the world’s developed nations.

year: 2008

title: A newly-available resource for historians of early New Zealand: The Marist Missionary Letters (1838-54)

authors: Jennings, William

abstract: The 7000 pages of primary documents of the Lettres reçues d’Océanie constitute a vast new source for the study of the Pacific during the period 1838-54. Published in 2009 after sixteen years of transcription, the Lettres are the collected correspondence of the first French Marist missionaries to New Zealand and other Pacific islands. In the words of Pacific historian Hugh Laracy, they are ‘the single most important foundational contribution to Pacific history in its fullest extent since J. C. Beaglehole’s magisterial editions of James Cook’s Journals. About 2000 of those pages are transcripts of letters written in New Zealand that open up a fresh perspective of life before the wars of the 1860’s. This paper will locate the early French Marist Māori mission within the context of New Zealand public history before exploring how the Lettres reçues d’Océanie can complement existing views of early colonial New Zealand. To better contextualise the correspondence, it would be useful to begin with a brief background of the Marists’ presence in New Zealand.

text: A newly-available resource for historians of early New Zealand: The Marist Missionary Letters (1838-54) The 7000 pages of primary documents of the Lettres reçues d’Océanie constitute a vast new source for the study of the Pacific during the period 1838-54. Published in 2009 after sixteen years of transcription, the Lettres are the collected correspondence of the first French Marist missionaries to New Zealand and other Pacific islands. In the words of Pacific historian Hugh Laracy, they are ‘the single most important foundational contribution to Pacific history in its fullest extent since J. C. Beaglehole’s magisterial editions of James Cook’s Journals. About 2000 of those pages are transcripts of letters written in New Zealand that open up a fresh perspective of life before the wars of the 1860’s. This paper will locate the early French Marist Māori mission within the context of New Zealand public history before exploring how the Lettres reçues d’Océanie can complement existing views of early colonial New Zealand. To better contextualise the correspondence, it would be useful to begin with a brief background of the Marists’ presence in New Zealand.

year: 2012