Research

Research is a vital part of the protection and conservation of the NZ Sea Lions. Research undertaken by the New Zealand Sea Lion Trust began in 1995 as part of  former Trustee Shaun McConkey’s  MSc thesis and today we work closely with Department of Conservation and University Researchers on a wide range of research projects.

Links to some recent research:

2017

Slooten, L. et al. : Evidence of bias in assessment of fisheries management impacts

Meyer, S. et al. :  Marine mammal population decline linked to obscured by-catch

2016

Assoc. Prof. Bruce Robertson: Submission on the Operational Plan to Manage the Incidental Capture of New Zealand Sea lions in the Southern Squid Fishery (SQU 6T) 2016-17

Assoc. Prof. Bruce Robertson : Submission on the Draft New Zealand sea lion Threat Management Plan (Aug 2016)

Assoc. Prof. Bruce Robertson : Appendices to Submission on the Draft New Zealand sea lion Threat Management Plan (Aug 2016)

Debski, I & Walker ,N (2016): A Summary of the Risk Assessment of Threats to New Zealand Sea lions MPI Information Paper No: 2016/03

Meyer,S. et al 2016 Reply to Comment on “Population dynamics reveal conservation priorities of the threatened New Zealand sea lion Phocarctos hookeri” by Middleton and Breen (2016)

Stefan Meyer et al. Mar Biol (2016) 163:113

Rawlence et al 2016: Human-mediated extirpation of the unique Chatham Islands sea lion and implications for the conservation management of remaining New Zealand sea lion populations.

Nicolas J Rawlence et al. in Molecular Ecology (2016)

MacMillan, H. et al. 2016 GIS-based multi-criteria analysis of breeding habitats for recolonising species: New Zealand sea lions Hamish MacMillan et al. Ocean & Coastal Management 130 (2016)

2015

Meyer et al. Population dynamics reveal conservation priorities of the threatened New Zealand sea lion Phocarctos hookeri

Robertson.  Management limiting recovery of NZSL

Osborne et al NZSL susceptibility to disease. Examining the Role of Components of Slc11a1 (Nramp1) in the Susceptibility of New Zealand Sea Lions (Phocarctos hookeri) to Disease.

Hamilton & Baker –Review of research and assessments on the efficacy of sea lion exclusion devices in reducing the incidental mortality of New Zealand sea lions Phocarctos hookeri in the Auckland Islands squid trawl fishery.

Desmond, J et al – Outlook on a Species. Evaluation of Public Outreach and Educational Strategies Regarding Conservation Efforts of the New Zealand Sea Lion. DoC  Report March 2015. Contact : DOC  Coastal Otago

2014

Auge et al. Site fidelity NZSL – Importance of studying foraging site fidelity for spatial conservation measures in a mobile predator

Lalas and Webster Sea Lion Diet – Contrast in the importance of arrow squid as prey of male New Zealand sea lions and New Zealand fur seals at The Snares, subantarctic New Zealand

Leung et al Diving behaviour of juvenile NZSL – Size and experience matter: diving behaviour of juvenile New Zealand sea lions (Phocarctos hookeri)

Meynier et al Foraging diversity in lactating NZSL – Foraging diversity in lactating New Zealand sea lions: insights from qualitative and quantitative fatty acid analysis

Collins et al. Extinction and recolonization of coastal megafauna following human arrival in New Zealand.

Robertson. Comment on “Review of research and assessments on the efficacy of sea lion exclusion devices in reducing the incidental mortality of New Zealand sea lions Phocarctos hookeri in the Auckland Islands squid trawl fishery”.

2013

Leung et al Juvenile female foraging – Foraging Behaviour of Juvenile Female New Zealand Sea Lions (Phocarctos hookeri) in Contrasting Environments

2012

Roe et al. Pinniped necropsy – Freezing and thawing of pinniped carcasses results in artefacts that resemble traumatic lesions

Maloney et al Campbell Island pup production -Increasing pup production of New Zealand sea lions at Campbell Island/Motu Ihupuku: can it continue?

Leung et al. Sexual segregation in NZSL foraging –Sexual Segregation in Juvenile New Zealand Sea Lion Foraging Ranges: Implications for Intraspecific Competition, Population Dynamics and Conservation

Kahui Bioeconomic model for NZSL bycatch A bioeconomic model for Hooker’s sea lion bycatch in New Zealand

Federico et al Milk composition in NZSL –  Interannual and individual variation in milk composition of New Zealand sea lions (Phocarctos hookeri)

Chilvers Causes of NZSL decline – Using life-history traits of New Zealand sea lions, Auckland Islands to clarify potential causes of decline.

Auge et al. Predicting interactions between recolonising marine mammals and fisheries: defining precautionary management.

2011

Auge et al female foraging behaviour  –Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations

Auge et al female habitat preferences    On-land habitat preferences of female New Zealand sealions at Sandy Bay, Auckland Islands

Auge et al Otago female diet  – Autumn diet of recolonising female New Zealand sea lions based at Otago Peninsula, South Island, New Zealand

2011 Chilvers PopulationViabilityAnalysis – Population viability analysis of New Zealand sea lions, Auckland Islands, New Zealand’s sub-Antarctics: assessing relative impacts and uncertainty. Review

Robertson & Chilvers Population decline – The population decline of the New Zealand sea lion Phocarctos hookeri: a review of possible causes.

2010

Childerhouse et al Age distribution –  Age distribution of lactating New Zealand sea lions: Interannual and intersite variation.

Childerhouse et al Growth and reproduction of females – Growth and reproduction of female New Zealand sea lions.

Chilvers & MacKenzie survival estimates – Age- and sex-specific survival estimates incorporating tag loss for New Zealand sea lions, Phocarctos hookeri

2007

McConkey –Summary of NZ Sea Lion research undertaken on mainland New Zealand, including updated publication list    (63 page pdf document)

2004

Zaino & Ory –  Impact of tourists  – Student projects conducted at the end of 2004 found sea lions to be very tolerant of people.  The greatest effect came not surprisingly from the  more extreme  actions such as clapping or throwing things at the sea lions to make them move.  This caused them to wake up and aggressively roar at people. Sea lion behaviours were also found to change with time of day, weather conditions and the presence of other sea lions. Sea lions were found to be least active during the middle of the day which is unfortunately when most people go to see them. It is therefore most important to prevent people deliberately disturbing sea lions in order to get photos, when they are resting.

Bleaching sea lions (Shannon Williams) The main focus of this study was to document the annual breeding migration of adult male sea lions, resident in Otago, to the Auckland Island breeding colonies – a distance of approximately 600 km. This involved bleach marking letters and numbers into the hair of adult male sea lions which allowed a DoC team led by Dr Louise Chilvers to record the presence and breeding behaviour of these males in the Auckland Island colonies. Of the 34 adult males bleached, 21 were positively identified in the Auckland Islands and 5 of these were observed holding breeding territories. The quickest recorded migration was just four days! Many of the migratory males showed  evidence of  dramatic weight loss, and often multiple scars from fighting,. My study has revealed a high rate of migration by adult males from Otago to the Auckland Islands in the breeding season. These sea lions are involved in breeding and thus provide genetic input to the population as a whole. The study has also reinforced how easily disease could be spread throughout the entire population.

2003-2005

Breeding behaviour  on Otago Peninsula (Jojo Jackson) This study focused on the breeding behaviour of New Zealand sea lions at Otago Peninsula. Timing and location of births were recorded as accurately as possible for the 2003/04 and 2004/05 breeding seasons. Birth dates at Otago were similar to peak pupping dates at the main breeding colonies. Foraging cycles and attendance patterns of mothers were determined through 10 consecutive days of observation each month from March-June. Otago females were found to have, on average, shorter duration cycles than females at the Auckland Island breeding colonies. This may suggest a better foraging environment at Otago. In an effort to understand the dynamics involved in the formation of breeding colonies, interactions between females ashore were recorded to investigate the gregarious behaviour of New Zealand sea lions. At the Auckland Islands females gather for pupping and then disperse, compared with Otago where they disperse prior to pupping and converge later.