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.

Marine Science @ Otago - Fede Baltar

Ocean Sampling Day 2014

I'm posting this on Ocean Sampling Day - 21st June 2014 - whilst the biggest global effort in marine science carried out in a single day is happening! 

Scientists from more than 150 marine research locations around the world are collecting seawater samples on the same day in order to identify all the microbes - and there are millions in just one drop!  Gene sequencing will be used to identify the DNA of the microorganisms.

The Marine Science Department at the University of Otago is one of two places in New Zealand that is carrying out scientific sampling.   Dr Fede Baltar is leading the team of volunteers carrying out the sampling.

Dr Fede Baltar is ideally suited to this role.  His research in biological oceanography integrates marine microbial ecology and biogeochemistry within the framework of physical  oceanography.  His research is based on microbes, trying to arrive at a mechanistic understanding of the regulation of marine carbon cycling to better constrain the potential consequences of climate change on the marine biogeochemical cycles and vice versa.

 

Dr Fede Baltar's sampling team on this historic day includes Marine Science staff and students, and students and staff from local high schools.  As Fede says:

"This is an important occasion as it is the first time scientists from all around the world are joining their efforts to do the sampling on one day and under the same conditions.  This provides us with a snapshot of the current state of the microbes that are the basis of all life in our oceans, and will help us to find out how they may respond to climate change."

All samples collected on Ocean Sampling Day will be sent to the Max Planck Institute for Marine Microbiology in Germany for analysis, and samples will be stored at the Smithsonian Institution's Natural History Museum in the USA at their brand new BioArchiving facility. This will facilitate long-term access to this material, as well as advanced analyses in the future which immensely increases the value of the project.

Marine Science @ Otago - Marta Guerra

How do dolphins react to boats and underwater noise?

 

 In the last two decades there has been a rapid growth in nature tourism, including boat-based whale and dolphin watching. As a consequence, coastal cetaceans have been increasingly exposed to boats and noise. Doubtful Sound (Fiordland, New Zealand) is home to a small resident population of 62 bottlenose dolphins (Tursiops truncatus), and is also a hotspot for tourism, with boat cruises running year round in the fiord. 

As part of her MSc thesis, Marta Guerra spent a year making acoustic recordings and observing the dolphins' behaviour to understand how they are affected by the presence and noise of tour boats.

 The research showed that dolphin groups with mother−calf pairs were less coordinated and more dispersed in the presence of tour boats, while groups without calves were not affected. These groups also became more vocal when boats were close and while moving away, presumably to re-establish group structure. Dolphins also responded to boat noise by altering the pitch and duration of their whistles.

These findings suggest that elevated boat noise affects communication, and that groups with calves are particularly sensitive to boat presence and noise.

 Due to the population being endangered and having a history of low calf survival, these findings have relevant implications for the management of boat tourism in Doubtful Sound.

Marine Science @ Otago - Tiffany Stephens

Does Bladder Kelp store nitrogen? If so, in which tissues?

The coastal environment has seasonal fluxes in seawater nitrogen concentrations, with the lowest concentrations coinciding with summer. Due to increased light during the summer, there is potential for high productivity but algae require nitrogen for growth and tissue maintenance.

Tiffany is investigating how Bladder Kelp grows during the summer and what happens to the nitrogen that Bladder Kelp uptake into their tissues.

Unlike other marine algae, Bladder Kelp has six main tissue types (stipe/stem, juvenile blade, adult blade, mature blade, reproductive blade, and holdfast/root) and it is important to understand how nitrogen moves through an individual plant, how it is stored and how/when it is used. Tiffany analyses the pigment concentration, soluble tissue nitrogen, total tissue nitrogen and amino acids to help answer her questions.

Marine Science @ Otago - Jordan Housiaux

Exploring the murky world of the Sevengill Shark

 Jordan Housiaux uses mark-recapture methods and photo identification to investigate genetic relationships and quantify populations of Sevengill Sharks (Notorynchus cepedianus) in Paterson Inlet, Stewart Island, and Otago Harbour, Dunedin.

Marine Science @ Otago - Matt Desmond

How much light is getting through?

What happens on land has a big effect on subtidal coastal reef ecosystems.  When land is modified by farming, forestry and urban development, sediment from this disruption flows into the sea reducing light penetration. This results in less energy being available for primary producers such as macroalgae, in turn disrupting and altering complex marine food webs. 

Matt Desmond's research comparing modified and unmodified coastal reef ecosystems aims to quantify how light affects such valuable systems with the goal of providing information which can be used to support coastal management initiatives.

The photo shows a light logger at one of Matt's research sites on Stewart Island.

Marine Science @ Otago - Esther Stuck

Is this Antarctic echinoderm going to have a harder time than its tropical relative as Ocean Acidification increases?
 

 

It is known that cold polar waters are becoming less carbon-saturated more quickly than warmer waters, possibly becoming undersaturated by the year 2050. This means animals that build their skeletons from calcium carbonate (starfish and sea urchins) may be at risk of not being able to build a skeleton. Polar species are also more vulnerable than their tropical counterparts due to their extremely slow growth rate and metabolism (the polar sea urchin Sterechinus neumayeri grows 80mm in 80 years!).

Esther Stuck's research, involves comparing how species from different latitudes respond to lowered pH and if polar species react differently to their tropical and temperate species.