Impacts of Ecotourism on Short-Beaked Common Dolphins (Delphinus delphis) in Mercury Bay, New Zealand

2006 ◽  
Vol 32 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Dirk R. Neumann ◽  
Mark B. Orams
Keyword(s):  
New Zealand ◽  
Delphinus Delphis ◽  
Common Dolphins

scholarly journals Fourier transform infrared (FTIR) analysis identifies microplastics in stranded common dolphins (Delphinus delphis) from New Zealand waters

2021 ◽  
Vol 173 ◽  
pp. 113084
Author(s):  
Karen A. Stockin ◽  
Olga Pantos ◽  
Emma L. Betty ◽  
Matthew D.M. Pawley ◽  
Fraser Doake ◽  
...  
Keyword(s):  
Fourier Transform ◽  
New Zealand ◽  
Fourier Transform Infrared ◽  
Ftir Analysis ◽  
Delphinus Delphis ◽  
Common Dolphins

Feeding behaviours of short-beaked common dolphins, Delphinus delphis, in New Zealand

2003 ◽  
Vol 29 (1) ◽  
pp. 137-149 ◽  
Author(s):  
Dirk R. Neumann ◽  
Mark B. Orams
Keyword(s):  
New Zealand ◽  
Delphinus Delphis ◽  
Common Dolphins ◽  
Feeding Behaviours

scholarly journals Deposition of growth layer groups in dentine tissue of captive common dolphins Delphinus delphis

2014 ◽  
Vol 8 ◽  
Author(s):  
Sinéad Murphy ◽  
Matthew Perrott ◽  
Jill McVee ◽  
Fiona L Read ◽  
Karin A Stockin
Keyword(s):  
Population Dynamics ◽  
New Zealand ◽  
Age Structure ◽  
Older Individuals ◽  
Growth Layer ◽  
Delphinus Delphis ◽  
Pulp Cavity ◽  
In Captivity ◽  
Layer Groups ◽  
Common Dolphins

Knowledge of age structure and longevity (maximum age) are essential for modelling marine mammal population dynamics. Estimation of age in common dolphins (Delphinus spp.) is primarily based on counting Growth Layer Groups (GLGs) in the dentine of thin, decalcified and stained sections of teeth. An annual incremental deposition rate was validated for Delphinus spp. 30-years ago through the use of tetracycline. However, it is not known if the pulp cavity becomes occluded in older individuals or GLGs continue to be deposited in dentine tissue. To investigate the deposition of GLGs in dentine tissue, teeth samples were obtained during the necropsies of two short-beaked common dolphins (Delphinus delphis) that were held in captivity for 31 and 33 years in New Zealand. Individuals were captured together in Hawkes Bay, North Island, New Zealand and classified as juveniles based on physical appearance. Teeth were processed in two ageing laboratories, using four different bone decalcifiers, two sectioning techniques incorporating the use of both a freezing microtome (-20°C) and paraffin microtome, and two different stains. An age was estimated for one of the dolphins, in line with that proposed based on estimated age at capture and period in captivity. However, a hypomineralised area was observed in the dentine tissue close to the pulp cavity of the second individual, preventing estimation of maximum age. The presence and structure of this anomaly is explored further within the study. 

Foraging ecology of the common dolphin Delphinus delphis revealed by stable isotope analysis

2020 ◽  
Vol 652 ◽  
pp. 173-186
Author(s):  
KJ Peters ◽  
SJ Bury ◽  
EL Betty ◽  
GJ Parra ◽  
G Tezanos-Pinto ◽  
...  
Keyword(s):  
New Zealand ◽  
Stable Isotope ◽  
Body Length ◽  
Stable Isotope Analysis ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Minor Effect ◽  
Common Dolphin ◽  
Delphinus Delphis ◽  
Common Dolphins

Dolphins are among the largest and most diverse predators in marine ecosystems, but our understanding of their foraging ecology, which is crucial for ecosystem management, is poor. Delphinus delphis (common dolphins) are found in tropical and temperate waters globally. Stomach content studies indicate they are opportunistic predators that feed locally on abundant small pelagic schooling fish, but information is lacking on how their diet may vary seasonally and with ontogeny. We investigated effects of body length, sex, season, and year on D. delphis diet in the Hauraki Gulf, New Zealand, using carbon (δ13C) and nitrogen (δ15N) stable isotope analysis of 56 skin samples collected during 13 years (2004-2016). Dolphin δ15N values changed with body length, suggesting ontogenetic dietary variation. Nitrogen isotope values were higher in austral autumn/winter compared to spring/summer, whilst δ13C values decreased throughout the study period, suggesting temporal changes in primary productivity likely affecting the dolphins’ diet. Sex had a minor effect on dolphin δ13C values, with male and female isotopic niches overlapping by 62.6% and 45.2% (respectively). Our results provide a baseline for detecting future changes in the trophic ecology of D. delphis in a key habitat in New Zealand and highlight their role as a sentinel species in this coastal ecosystem.

Anomalously Pigmented Common Dolphins (Delphinus sp.) off Northern New Zealand

2005 ◽  
Vol 31 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Karen A. Stockin ◽  
Ingrid N. Visser
Keyword(s):  
New Zealand ◽  
Common Dolphins

scholarly journals Long-term dietary segregation of common dolphins Delphinus delphis in the Bay of Biscay, determined using cadmium as an ecological tracer

2005 ◽  
Vol 305 ◽  
pp. 275-285 ◽  
Author(s):  
V Lahaye ◽  
P Bustamante ◽  
J Spitz ◽  
W Dabin ◽  
K Das ◽  
...  
Keyword(s):  
Bay Of Biscay ◽  
Delphinus Delphis ◽  
Common Dolphins

Injuries, healing and management of common dolphins (Delphinus delphis) in human-impacted waters in the south Iberian Peninsula

2020 ◽  
Vol 100 (2) ◽  
pp. 315-325
Author(s):  
Liliana Olaya-Ponzone ◽  
Rocío Espada ◽  
Estefanía Martín Moreno ◽  
Isabel Cárdenas Marcial ◽  
José C. García-Gómez
Keyword(s):  
Iberian Peninsula ◽  
Healing Process ◽  
Local Population ◽  
Survival Rates ◽  
Whale Watching ◽  
The South ◽  
Delphinus Delphis ◽  
Photo Identification ◽  
Type Of Injury ◽  
Common Dolphins

AbstractThis study focuses on the dolphins populating the water between Gibraltar and Algeciras in the south Iberian Peninsula, an area subjected to pressure due to high human activity. The area is considered an important feeding and breeding ground for common dolphins (Delphinus delphis). Due to the degree of residence of some specimens, and the large gap in knowledge about the evolution of wounds in D. delphis specimens with lacerations, this work sought to perform the following analyses: identify lacerated individuals; characterize sequences of ‘before – during – after’ with respect to the occurrence of lacerations; and associate the type of injury with its severity. This work will inform future studies by expanding a database on injured individuals and contribute to periodical monitoring of specimens that frequent these geographic areas. Between 2013 and 2017, we were able to track the healing process of five injured individuals of common dolphins from a whale-watching platform thanks to photo identification. The animals exhibited fresh external wounds from different sources. In the majority of individuals, the wound-healing processes lasted 3–21 weeks. The frequency with which sightings are made and knowledge about the local population will help track injured animals, follow their wound evolution, and document their survival rates. The documented injuries inflicted by human interactions described in this paper may include fishing interactions and propeller strikes, probably as a consequence of the high intensity of recreational fishing and whale-watching activities in the area.

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