Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


Sea lion teeth provide window on past

Sea lion teeth provide window on past


A NIWA scientist is drilling the teeth of New Zealand sea lions to learn more about why the species is struggling to survive.

Dr Brittany Graham explains her unique work in the latest edition of NIWA’s flagship publication Water & Atmosphere.

She says sea lion teeth have bands that grow annually, similar to rings in tree trunks.

By taking tiny samples within these bands and then preparing them for stable isotope analysis, Dr Graham aims to find out what the sea lion ate, where it foraged and whether ocean conditions changed over its lifetime.

The New Zealand sea lion was extensively hunted in the 18th and 19th centuries and only about 10,000 remain. In 1997 it was officially declared a threatened species. There are just two main breeding colonies, one at the Auckland Islands and the other at Campbell Island.

However, while the Campbell Island population is faring well, the Auckland Islands’ colony has been declining for a number of years. Several research programmes are under way to find out what factors could be involved in the decline.

Dr Graham’s work enables her to go back through time and use the teeth as an historical library to reveal new layers of information.

“These teeth will provide information not only on whether ocean conditions have changed through time, but also whether there have been changes to the structure of the marine food web.

“In other words, this is a new tool that provides a glimpse at the past 20 years from a sea lion’s perspective.”

The Water & Atmosphere article also explores the work of NIWA’s Dr Jim Roberts, who is developing ways to identify the causes of sea lion decline at the Auckland Islands.

He uses “mark and recapture’ data observed by field teams who record which sea lions have returned to the rookeries. The data also enables scientists to estimate changes in reproductive rates and shifts in age at first pupping.
Also in this issue of Water & Atmosphere, we look at the battle against foreign weeds taking over our lakes and showcase life under the ice at Antarctica in a series of photographs taken when NIWA scientists and specialist divers were conducting experiments in McMurdo Sound over summer.

Ends


© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Drones: First Certificate Issued Under New UAV Rules

Transport Minister Simon Bridges and Associate Transport Minister Craig Foss say the first certified flight of an unmanned helicopter under new aviation rules is a great example of how they can enable commercial use. More>>

ALSO:

GE Swedes And Cow Deaths: Plant Analysis Backs Up Earlier Advice

The industry body is recommending that farmers do not feed Herbicide Tolerant (HT) swedes to cows in spring when the animals are in late pregnancy or early lactation. DairyNZ is also advising caution if farmers are considering other leafy varieties. More>>

ALSO:

Statistics: Dairy And Travel Still Our Largest Export Earners

New Zealand earned $2.3 billion more from exports than we spent on imports during the year ended June 2015... total exports of goods and services were $67.5 billion, while total imports were $65.1 billion. More>>

ALSO:

Approval: Air New Zealand And Air China Launch New Alliance Route

Air New Zealand and Air China have today launched joint sales for a new daily direct service between Auckland and Beijing after receiving approval from New Zealand Minister of Transport Hon Simon Bridges to form a strategic alliance. More>>

ALSO:

Money Trading: FX Trader Jin Yuan Finance Warned Over Lack Of Monitoring

Jin Yuan Finance, an Auckland-based foreign exchange trader, has been warned over its lack of anti-money laundering processes in place in the first public notification by the Department of Internal Affairs. More>>

ALSO:

Auckland Surge, Possible Peak: House Values Accelerate At Fastest Annual Pace In 8 Years

New Zealand residential property values rose at their fastest annual pace in eight years in August, pushed higher by overflowing demand in Auckland, which is showing signs speculators think it has reached its peak, according to Quotable Value. More>>

ALSO:

Cash Money: Reserve Bank Launches New $5 And $10 Banknotes

The $5 and $10 final banknotes were revealed at an event at the Bank in Wellington, and will start to be released from mid-October 2015. More>>

ALSO:

Truck Sales Booted: Commerce Commission Files Charges Against Mobile Trader

The Commerce Commission has filed charges against a mobile trader, or truck shop operator, claiming he obtained money from customers by deception and never intended to supply them with the goods they paid for. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news