scholarly journals Marathon penguins – reasons and consequences of long-range dispersal in Fiordland penguins / Tawaki during the pre-moult period

2018 ◽  
Author(s):  
Thomas Mattern ◽  
Klemens Pütz ◽  
Pablo Garcia-Borboroglu ◽  
Ursula Ellenberg ◽  
David M Houston ◽  
...  
Keyword(s):  
New Zealand ◽  
Long Range ◽  
Anthropogenic Activities ◽  
Surface Current ◽  
Annual Life Cycle ◽  
Subtropical Front ◽  
Sea Level Anomalies ◽  
Breeding Distribution ◽  
Penguin Species ◽  
Subantarctic Front

Migratory species often roam vast distances bringing them into contact with diverse conditions and threats that could play significant roles in their population dynamics. This is especially true if long-range travels occur within crucial stages of a species’ annual life-cycle. Crested penguins, for example, usually disperse over several hundreds of kilometres after completing of the energetically demanding breeding season and in preparation for the costly annual moult. A basic understanding of crested penguins’ pre-moult dispersal is therefore paramount in order to be able to assess factors affecting individual survival. The Fiordland penguin / tawaki, the only crested penguin species breeding on the New Zealand mainland, is currently one of the least studied and rarest penguin species in the world. We successfully satellite tracked the pre-moult dispersal of 17 adult Tawaki from a single colony located in the species’ northern breeding distribution. Over the course of 8-10 weeks the penguins travelled up to 2,500 km away from their breeding colony, covering total swimming distances of up to 6,800 km. During outbound travels all penguins headed south-west within a well-defined corridor before branching out towards two general trip destinations. Birds leaving in late November travelled towards the Subtropical Front some 800 km south of Tasmania, whereas penguins that left in December headed further towards the subantarctic front. Using K-select analysis we examined the influence of oceanographic factors on the penguins’ dispersal. Water depth, surface current velocity and sea level anomalies had the greatest influence on penguin movements at the subantarctic Front, while sea surface temperature, chlorophyll a concentration were key for birds travelling to the subtropical front. We discuss our findings in the light of anthropogenic activities (or lack thereof) in the regions visited by the penguins as well as the potential consequences of Tawaki pre-moult dispersal for the species’ breeding distribution on the New Zealand mainland.

scholarly journals Marathon penguins – reasons and consequences of long-range dispersal in Fiordland penguins / Tawaki during the pre-moult period

2018 ◽  
Author(s):  
Thomas Mattern ◽  
Klemens Pütz ◽  
Pablo Garcia-Borboroglu ◽  
Ursula Ellenberg ◽  
David M Houston ◽  
...  
Keyword(s):  
New Zealand ◽  
Long Range ◽  
Anthropogenic Activities ◽  
Surface Current ◽  
Annual Life Cycle ◽  
Subtropical Front ◽  
Sea Level Anomalies ◽  
Breeding Distribution ◽  
Penguin Species ◽  
Subantarctic Front

Migratory species often roam vast distances bringing them into contact with diverse conditions and threats that could play significant roles in their population dynamics. This is especially true if long-range travels occur within crucial stages of a species’ annual life-cycle. Crested penguins, for example, usually disperse over several hundreds of kilometres after completing of the energetically demanding breeding season and in preparation for the costly annual moult. A basic understanding of crested penguins’ pre-moult dispersal is therefore paramount in order to be able to assess factors affecting individual survival. The Fiordland penguin / tawaki, the only crested penguin species breeding on the New Zealand mainland, is currently one of the least studied and rarest penguin species in the world. We successfully satellite tracked the pre-moult dispersal of 17 adult Tawaki from a single colony located in the species’ northern breeding distribution. Over the course of 8-10 weeks the penguins travelled up to 2,500 km away from their breeding colony, covering total swimming distances of up to 6,800 km. During outbound travels all penguins headed south-west within a well-defined corridor before branching out towards two general trip destinations. Birds leaving in late November travelled towards the Subtropical Front some 800 km south of Tasmania, whereas penguins that left in December headed further towards the subantarctic front. Using K-select analysis we examined the influence of oceanographic factors on the penguins’ dispersal. Water depth, surface current velocity and sea level anomalies had the greatest influence on penguin movements at the subantarctic Front, while sea surface temperature, chlorophyll a concentration were key for birds travelling to the subtropical front. We discuss our findings in the light of anthropogenic activities (or lack thereof) in the regions visited by the penguins as well as the potential consequences of Tawaki pre-moult dispersal for the species’ breeding distribution on the New Zealand mainland.

scholarly journals Distribution and abundance of Chubut Steamerducks: an endemic species to Central Patagonia, Argentina

2011 ◽  
Vol 22 (3) ◽  
pp. 307-315 ◽  
Author(s):  
MARÍA LAURA AGÜERO ◽  
PABLO GARCÍA BORBOROGLU ◽  
DANIEL ESLER
Keyword(s):  
Invasive Species ◽  
Population Size ◽  
Endemic Species ◽  
Oil Pollution ◽  
Anthropogenic Activities ◽  
Breeding Population ◽  
Habitat Destruction ◽  
Small Section ◽  
Marine Park ◽  
Breeding Distribution

SummaryWe documented the breeding distribution and estimated abundance of Chubut SteamerducksTachyres leucocephalus,a flightless waterbird endemic to a relatively small section of coastline in Patagonia, Argentina. The distribution of Chubut Steamerducks is restricted to approximately 700 km of coast. We counted 1,703 adult steamerducks at a subset of shorelines within their range and estimated 1,841 adults after correcting for visibility for shore-based surveys. To estimate adult densities in unsurveyed areas, we used two different methods of extrapolation, resulting in estimates of 1,587 and 1,832 adults. Combined with numbers from surveyed shorelines, the total breeding population size is estimated to be between 3,428 and 3,673 adults. In addition, we counted 1,899 juvenile steamerducks, which occur in irregular aggregations. The Interjurisdictional Marine Park in San Jorge Gulf contains about 46% of the entire population, which may provide some protection from disturbance and habitat destruction. However, oil pollution, other anthropogenic activities, and invasive species still pose potential threats to the population.

scholarly journals Sediment impacts on sponges and a deep-sea coral in New Zealand

2021 ◽  
Author(s):  
◽  
Valeria Mobilia
Keyword(s):  
New Zealand ◽  
Suspended Sediment ◽  
Deep Sea ◽  
Anthropogenic Disturbance ◽  
Habitat Structure ◽  
Anthropogenic Activities ◽  
Benthic Communities ◽  
Bottom Contact ◽  
Suspended Sediment Concentrations ◽  
Offshore Activities

<p><b>Increased levels of suspended sediment in the water column are important factors contributing to the degradation of marine ecosystems worldwide. In coastal waters, temporal variation in suspended sediment concentrations (SSCs) occurs naturally due to seasonal and oceanographic processes. However, there is evidence that anthropogenic activities are increasing sediment concentrations. The volume of sediment moving from land-based sources into coastal ecosystems and human activities in the ocean disturbing the seafloor, such as dredging and bottom-contact fisheries, have been increasing over the last century. In addition, offshore activities, particularly bottom-contact fishing and potential deep-sea mining, can create sediment plumes in the deep-sea that may extend over long distances. Elevated suspended sediment concentrations have detrimental effects on benthic communities, particularly for suspension feeders like sponges and corals.</b></p> <p>The aim of this thesis was to investigate the effects of increased SSCs that might arise from heavy anthropogenic disturbance on common shallow water and deep-sea sponges and a deep-sea coral in New Zealand, as these groups contribute to habitat structure in some benthic environments, including the deep sea.</p>

The influence of submarine currents associated with the Subtropical Front upon seafloor depression morphologies on the eastern passive margin of South Island, New Zealand

2018 ◽  
Vol 61 (1) ◽  
pp. 112-125 ◽  
Author(s):  
Jess I. T. Hillman ◽  
Ingo Klaucke ◽  
Ingo A. Pecher ◽  
Andrew R. Gorman ◽  
Jens Schneider von Deimling ◽  
...  
Keyword(s):  
New Zealand ◽  
Passive Margin ◽  
Subtropical Front
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