Research @ Otago - Josie Crawshaw

Josie Crawshaw is studying the role of coastal lagoons and estuaries in removing nitrate from the water column before it reaches the ocean.

Josie collecting a sediment core from an enclosure at Lake Ellesmere

Our coastal waters are experiencing an increase in nutrient loading, due to increases in agricultural farming. Luckily, coastal ecosystems such as coastal lagoons and estuaries can perform an extremely important ecosystem function, and remove nitrate from the water column, before it reaches our oceans. This process is called denitrification, which is the conversion of nitrate from the water column, into nitrogen gas, and it is carried out in the sediment by denitrifying bacteria. Knowing what factors might influence this process, and how efficiently these systems can carry out this process is an important component that needs to be considered in catchment models of allowable nutrient loading.

The flexible enclosure in place

To study this, Josie has designed and built flexible in situ enclosures, which enclose a section of the water column and sediment. She uses stable isotope tracers to follow the conversion of nitrate to nitrogen gas and nitrous oxide.

Taking water samples from enclosures on windy days requires good balance!

Josie is also a keen diver, and an ambassador for Atlantis Dive. She tries to get out as often as she can, especially on research dives!

You can follow Josie's research and diving journey on the following pages.

https://www.facebook.com/josie.coastal
http://superbcreationjellyfish.tumblr.com/

Marine Science @ Otago - Oarfish

An Oarfish was found washed up in the Otago Harbour on 17th April 2015.  This specimen was 3 metres long.  They are known to grow to more than 11 metres in length!

There are thought to be only two species of Oarfish and this is the southern one, Regalecus glesne.  There are periodic strandings round New Zealand, but mainly in the Cook Strait region between our two islands.  It is an oceanic fish, so that is probably because of the ocean currents that are funnelled between our two main islands and then get caught in shallow bays or sandbanks.  

However, It is pretty rare to find an Oarfish washed up in our area, and especially such a good specimen.  The Otago Museum had about 5 reports of Oarfish found on local beaches from the last 150 years.  Since our story went out, I've had two further reports.  One was stranded in almost the same spot in 1998, and one was reported on a beach further south in 2011.

They are often found after storms or earthquakes, which has given them a bit of a reputation as harbingers of doom!  This specimen was stranded after some very stormy weather.
 
Little is known about the Oarfish.  When this was dissected, its stomach was full of nyctiphanes (krill).  Other specimens have also been found stuffed full of krill.  They are a deep water ocean fish.  They have been some caught on video in recent years and they have been observed swimming vertically with their pectoral fins out to the side, which is how they get their name "Oarfish". 

Tyson Roberts wrote a book on Oarfish in 2012 and he suggested that Oarfish "self-amputate"  their tails.  This is his theory based on finding specimens that have obviously healed up after losing their tails.   It has been suggested by others that this might be caused by injuries or attacks by other creatures.  Perhaps they shed parts of their tails as a defence mechanism - like skinks and lizards - to help them escape.  As long as the injury is not too bad it may heal and grow back.  But who knows what goes on in the deep ocean and the lives of these amazing fish!

Marine Science @ Otago - Sir Peter Blake Ambassadors

Marine Science Students, Zac Penman and Blake Hornblow, were selected by the Sir Peter Blake Trust as NIWA Science Ambassadors and in early 2015 joined a voyage to Antarctica on the NIWA vessel, Tangaroa. 

The Blake NIWA Ambassador programme is a once-in-a-lifetime adventure to work alongside and assist world class scientists in ground breaking research for New Zealand. 

The 2015 expedition on board the NIWA research vessel Tangaroa partnered with Antarctica New Zealand and the Australian Antarctic Division to undertake a six-week research initiative in the Southern Ocean on areas of importance to humpback, blue ‪whales and Antarctic toothfish.

To read about their journey see their voyage blog:

The 2015 expedition is on-board the NIWA research vessel Tangaroa which will be partnering with Antarctica New Zealand and the Australian Antarctic Division and undertaking a six-week research initiative in the Southern Ocean on areas of importance to humpback, blue ‪whales and Antarctic toothfish.
- See more at: http://www.sirpeterblaketrust.org/young-blake-expeditions/niwa-science-ambassador/follow-the-adventure-2015/#sthash.J71db5uI.dpufFor more about their journey:

http://www.sirpeterblaketrust.org/young-blake-expeditions/niwa-science-ambassador/follow-the-adventure-2015/

Marine Chemistry @ Otago

Otago researchers, Rob Middag and Ella Patterson, have been in the Antarctic looking into the role trace metals, notably iron, play in the Antarctic ecosystem. 

Deploying the rosette

Iron is necessary for the growth of phytoplankton which is the base of the food web.  Since phytoplankton takes up CO2 from the atmosphere, iron influences atmospheric CO2 levels and global climate. 

Phytoplankton in the ice

This project will reveal what role trace metals play in the Antarctic ecosystem and give us the ability to predict how its role in global climate will change under future climate scenarios.

Rob in the lab on board ship

To find out more about this research project, check out Rob and Ella's blog: antarcticiron.blogspot.co.nz/

Marine Science @ Otago – Will Rayment

Will Rayment is a lecturer in the Marine Science Department at Otago University.  He was recently interviewed about his work.

What is your job?

I am a lecturer in the Marine Science Department. My job is to do research on marine science and teach our undergraduate and postgraduate students. My field of research is marine mammal biology and conservation - the species I work on most are southern right whales, sperm whales and Hector's dolphins.

  

Do you like being a marine biologist, and why?

I love being a marine biologist. I love being out on the ocean, in boats, diving and snorkelling. I get the opportunity to go to amazing places, see heaps of cool stuff and meet some really interesting and passionate people. I am driven by the desire to try and conserve our marine life so future generations will be able to appreciate it as well.

What is the best place in New Zealand to see marine life?

That depends on what you think is "best". Marine Reserves probably offer the best opportunity to see the marine environment in a natural state, i.e. not influenced by fishing and disturbance by humans. The first marine reserve in NZ was designated at Leigh, just north of Auckland, in 1977. In that time, the populations of seaweed, fish and crayfish have recovered to natural levels. It's a fantastic place to go for a snorkel.

My favourite place to explore is the Auckland Islands in the sub-Antarctic, 450 km south of mainland New Zealand. In the winter it is the breeding area for hundreds of southern right whales. There are so many that you have to drive your boat very slowly to avoid bumping into them. They can be very curious and will sometimes approach very close.

What inspired you to become a marine biologist?

I was inspired to become a marine biologist because I was fascinated by life in the oceans. I grew up near the sea and loved going out in boats and getting under the water. Marine biology seemed like a super exciting career, that would take me to some beautiful places and meet some amazing people.

How much money do you earn?

 How much you earn depends on what kind of job you do. A marine biologist working in practical conservation might earn about $30,000 a year when they start off their career. A professor at a university could eventually earn $150,000 a year. The main thing is that most marine biologists don't do the job because they are interested in earning a big salary. They do it because they love the job, and they want to make some kind of positive difference to the world.

How long did it take you to become a marine biologist?

I started my career path by studying biology at university. Then I did a Masters degree in conservation, and a PhD in marine science. That was 8 years of study for me in total. However, I got my first marine biology job straight after my first degree. There is no set, rigid path to becoming a marine biologist. No matter how old you are, or how much study you have done, if you are learning about biology in the oceans, you can call yourself a marine biologist.

What type of equipment do you use in marine research?

For my research on whales and dolphins, the most important pieces of equipment are a good camera, a GPS and a sturdy boat. Much of what I do involves photographing and identifying unique individual whales and dolphins. That enables me to learn about their populations: how many there are, how long they live and how they move around. These questions are really important in figuring out how to protect endangered species.

  

Where did you study to become a marine biologist?

I was born in England, so I did much of my study there. I went to Oxford University for my Bachelors degree and then did a Masters degree at University College London. I came to New Zealand in 1999 because the opportunites for marine biology are so amazing here. I did my PhD at the University of Otago in Dunedin, which is where I am lucky enough to have a job now. Otago University offers lots of options for starting your studies in Marine Science. There are courses here in marine biology, oceanography and fisheries science. If you want to learn more about studying marine science at the University of Otago, take a look at the website: www.otago.ac.nz/marinescience/

Marine Science @ Otago - Lucy Jack

Sea lions as food web ambassadors

By finding out what sea lions have been eating, Lucy Jack hopes to gain insights into marine food webs and how they have changed over time.

Stable isotope analysis is being used to identify whether these apex predators, at the top of the food chain, are eating food from a kelp-based or coastal food web, or from a phytoplankton-based open ocean food web.  

This research will also reveal the trophic level of the seals and sea lions (how far up the food web they are eating, and therefore how tall the food web is).  This is important because since humans have impacted the world's oceans by fishing, marine food webs have become shorter. By looking at changes in sea lion trophic level, Lucy will be able to see if and when these changes have taken place, since the arrival of humans in NZ.

Lucy gains insights into the diet of present day animals through analysis of fur samples, which should show what the animals have been eating over the last year.  Samples of bones from Maori middens will show what a pre-European diet was like.

She is collecting samples from animals in Otago, Southland, Stewart Island and the Auckland Islands.

Marine Science @ Otago - Spectacled Porpoise

Marine Science @ Otago - Spectacled Porpoise

 
Scientists dissect a rare find

On Wednesday 17th September 2014 a Spectacled Porpoise was stranded on Pipikaretu Beach on the Otago Peninsula.  Very little is known about this marine mammal. There have been infrequent sightings round the southern oceans, and most specimens are from strandings in Tierra del Fuego.  As far as we know, there have been no sightings around New Zealand and only ten of these porpoises have ever been found washed up on our shores.

 
The round mark around the eye is how they got the "spectacled" name.  A key feature is the extraordinarily large dorsal fin, which is much larger in males than females.  These porpoises grow up to about 2.25 metres in length.  This male measured 2.15 metres.

A team of marine mammal scientists from the University, the Otago Museum and Department of Conservation dissected the porpoise at Invermay.  Here, Professor Ewan Fordyce works on dissecting the ribs, freeing them from the overlying tissue.

In the final picture below, the ribcage as been removed, and the massive muscles along the back that flex the tail flukes, to exposed the internal organs.

In addition to getting a rare look at the anatomy of the species, the team discovered this porpoise had  a fractured lower jaw, and broken hyoid bones. The hyoids support the larynx.  It appears the animal  had suffered a blunt trauma of some sort.  The stomach was effectively empty and there was water in the lungs, suggesting the animal probably drowned.