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.

Heading Home

Highlights of Gary’s progress on the

Our Far South Expedition

March 7, 2012

Minke Whale

Where next?

As we now steam towards Lyttleton after a brief visit to the Antipodes and Bounty Islands region, it’s time to pause and think about what comes next. What is striking about New Zealand’s subantarctic is that the amount of effort being put into research and understanding of this region is miniscule in proportion to both the size of the region as well as the importance of this region to New Zealand. New Zealand is home to one of the biggest exclusive economic regions in the world, yet what do we know about that portion of New Zealand that is underwater? Or for that matter within the water? 

 The Auckland Islands sit in an ideal place to address the issues – they lie at the northern boundary of the Antarctic Circumpolar Current, they are a biodiversity hotspot, and they are surrounded by fishing grounds. The Islands themselves also house a number of natural environments that have recorded past change – fiord basins, peat swamps, and locations to record present change – natural harbours, channels between the Islands and home to whales, sea lions and other plant, animal and bird species, many that are endemic. The challenge is to improve access and support for scientific and conservation efforts on the Islands and take advantage of their position as the canary in coalmine for the changing oceanic, climatic and biological realms.