Celebrating World Oceans Day in the Indian Ocean – One Ten East log

One Ten East Logs from the IIOE-2 voyage aboard RV Investigator will be posted on the WAMSI website during the month long voyage.

Log from One Ten East

The RV Investigator is currently undertaking oceanographic research along the 110°E meridian off Western Australia as part of the second International Indian Ocean Expedition. The voyage is led by Professor Lynnath Beckley of Murdoch University and the research is supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility.

Celebrating World Oceans Day in the Indian Ocean

By Dr Jessica Benthuysen and Micheline Jenner AM

June 8th is World Oceans Day. First celebrated in 1992, World Oceans Day was officially recognized by the United Nations in 2008. Globally it is important to celebrate the vital role the oceans play, particularly in the light of current threats. Without oceans, life would not exist on our blue planet.

On RV Investigator, an international team of marine scientists comprising equal numbers of male and females is working day and night to understand the dynamics of the south-east Indian Ocean. This voyage is Australia’s contribution to the second International Indian Ocean Expedition (IIOE-2). The expedition is co-sponsored by the UNESCO Intergovernmental Oceanographic Commission (IOC), Scientific Committee on Oceanic Research (SCOR) and the Indian Ocean regional alliance of the Global Ocean Observing System (IOGOOS).

Over the past 26 days we have been at sea repeating a line of oceanographic stations along the 110° East meridian across 30 degrees of latitude, that was last examined by HMAS Diamantina in 1963 during the first IIOE. We have measured chemical and physical properties and collected water samples down to 5,800m depth, which we will compare to data collected during the first expedition. Across every data stream, we have used the latest technologies to investigate organisms from microbes to mesopelagic fishes and megafauna, such as pygmy blue and humpback whales. In addition, we have also focused on bio-optics to ground-truth satellite observations of ocean colour in this oligotrophic part of the blue planet.

We are now en route towards North West Cape adjacent to Ningaloo Reef, a UNESCO World Heritage Site. We are towing a Triaxus, which is an undulating platform with an array of instrumentation to investigate the Eastern Gyral Current, which feeds into the Leeuwin Current.

We celebrated World Oceans Day in anticipation of our team’s dedicated efforts over the last month making a lasting contribution to the understanding of the dynamics of this relatively small, but vitally important ocean, upon which more than a billion people depend.

One Ten East Logs from the IIOE-2 voyage aboard RV Investigator will be posted on the WAMSI website during the month long voyage.

We have beautiful weather again today, but sadly we are seeing rubbish in the beautiful deep blue sea…

– Captain Micheline Jenner 

Log from One Ten East

The RV Investigator is currently undertaking oceanographic research along the 110°E meridian off Western Australia as part of the second International Indian Ocean Expedition. The voyage is led by Professor Lynnath Beckley of Murdoch University and the research is supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility.

IMOS Continuous Plankton Recorder Survey

By Claire Davies

The Continuous Plankton Recorder (CPR) is unusual in the context of a modern day science voyage, as the technology has remained virtually unchanged since 1927. There are no electronics associated with it and it doesn’t even require internet connectivity! It is heavy and awkward, so why are we still using it? Simply, because it remains one of the best ways of simultaneously monitoring the phyto- and zooplankton in our oceans over large spatial scales.

The CPR has been towed at about 10 m depth behind the RV Investigator along the 110°East line, collecting the plankton through an opening about the size of a thumbnail. The plankton is trapped between two silks, which are rotating at a pre-determined speed. This means we can determine the location at which the plankton is caught allowing us to map their distributions and abundances across Australia’s Oceans.

Plankton are excellent indicators of ocean health as they are very sensitive to change and respond quickly. The IMOS-funded AusCPR survey has been regularly towing CPRs around Australia for the last ten years. Analysing this data is allowing us to describe the condition of Australia’s oceans in more detail than has previously been known and to develop an understanding of the environmental factors that are driving changes.

The Continuous Plankton Recorder (CPR) is an “oldie but a goodie” instrument for collecting plankton (phyto- and zooplankton) while underway. As RV Investigator has steamed the 90 nautical miles between each station on the 110°East meridian, the CPR has continuously collected plankton. Photo: Micheline Jenner AM.

Claire Davies (IMOS/CSIRO) winds along the two silks, between which the plankton material has been collected. Photo: Micheline Jenner AM.

With the two silks wound on for fresh plankton collection, Claire Davies (IMOS/CSIRO) replaces the cartridge in the CPR prior to deployment. Photo: Micheline Jenner AM.

Be sure to follow the daily posts of our Log from One Ten East at https://iioe-2.incois.gov.in and www.wamsi.org.au

One Ten East Logs from the IIOE-2 voyage aboard RV Investigator will be posted on the WAMSI website during the month long voyage.

We have had some gorgeous distinctively tropical birds recently, a juvenile red-tailed tropicbird and two Golden Bosun birds!

– Captain Micheline Jenner 

Log from One Ten East

The RV Investigator is currently undertaking oceanographic research along the 110°E meridian off Western Australia as part of the second International Indian Ocean Expedition. The voyage is led by Professor Lynnath Beckley of Murdoch University and the research is supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility.

Particles and the UVP

By David Antoine

A key descriptor of marine ecosystems is a particle size distribution, which is expressed as the number of particles or volume of particles in the water column. The particle size distribution is one of the parameters that determines bulk optical properties of a water mass. Various techniques exist to determine the particle size distribution and for large particles greater than100 microns, we are using the “Under Water Video Profiler” (UVP) on board the RV Investigator.

This instrument captures images of the particles so that one can identify what is present. The technique also allows derivation of the export flux of particles to the deep ocean. 

In the CTD room, Prof David Antoine (Curtin University) checks the UVP (two red cylinders) at the base of the CTD. Photo: Micheline Jenner AM.

Prof David Antoine (Curtin University) processes data from the UVP. Photo: Micheline Jenner AM.

Be sure to follow the daily posts of our Log from One Ten East at https://iioe-2.incois.gov.in and www.wamsi.org.au

One Ten East Logs from the IIOE-2 voyage aboard RV Investigator will be posted on the WAMSI website during the month long voyage.

We have had more beautiful deep blue water and amazing cumulus clouds today. The clouds literally forming vertically before our eyes, just gorgeous!
– Captain Micheline Jenner 

Log from One Ten East

The RV Investigator is currently undertaking oceanographic research along the 110°E meridian off Western Australia as part of the second International Indian Ocean Expedition. The voyage is led by Professor Lynnath Beckley of Murdoch University and the research is supported by a grant of sea time on RV Investigator from the CSIRO Marine National Facility.

Notes: We have seen a white-tailed tropicbird, a frigate and two golden bosun birds! We are really in the tropics!

Blue on Blue

By Micheline Jenner AM and Curt Jenner AM

Despite their huge size, blue whales are remarkably elusive. Criss-crossing the world’s oceans as part of their life cycle, these days, they are hard to find. Being so large–in fact, the largest animals on earth, blue whales were once the most desired target species for 19^th and 20^th century whalers. The effort outlaid to chase and capture a whale, known as the catch-per-unit effort was categorized by the whalers as a “1” for a blue whale. The smaller humpback whale was classed as a “4”, indicating that it took four humpback whales to provide the same amount of oil as one prized blue. Alarmingly, in their efforts to provide for lighting of motherland lamps, produce lipstick, wear fine corsets, consume margarine and shade with umbrellas, whalers killed 202,000 to 311,000 Antarctic blue whales and 13,000 pygmy blue whales.

The first blow as a pygmy blue whale surfaces can be up to 9m high. Subsequent exhalations throughout a surfacing sequence, sometimes diffuse in light winds causing a “rainblow” effect. Photo: Micheline Jenner AM.

Now in the 21st century, cetacean scientists are still trying to determine how many blue whales are left in the world’s oceans. The IUCN recognises a global estimate of between 10-25,000 blue whales. Just what proportion of that estimate consists of Antarctic blue whales or pygmy blue whales, is anyone’s guess.

By listening to the sea with sonobuoys from RV Investigator, we are documenting the migration of pygmy blue whales while they migrate from their austral summer/spring feeding areas in the Bonney Upwelling off Victoria and the Perth Canyon, Western Australia to warmer Indonesian waters for the austral autumn/winter. Blue whales make very low frequency calls ranging between 20-70 Hertz (Hz). These rumbles are so low, that without speeding up the sound, they are, in fact, not audible to humans. However, with custom software, we can see the sound and these rumbles appear as big green lines on our computer screen!

Distinctively, the green vertical lines are a pygmy blue whale call, in the low frequency range of 20-70Hz. Underwater sounds collected by the hydrophones in the sonobuoys which are then computer-processed, allow us to see the sound on board RV Investigator, while the whale is calling. This is live from the Indian Ocean! Photo: Micheline Jenner AM.

Pygmy blue whales depend on krill for their very survival and lots of it–they consume up to 2 tonnes of krill per day! On their migration north the whales are actively stopping to feed. During the day when the ship is stationary and all the scientists are collecting various water and biological samples at the twenty stations on the 110° East meridian, we have been monitoring the sonobuoys. We have plotted the direction of the migration of pygmy blue whales hoping to photograph some of them migrating and feeding. However, maybe those scientists studying zooplankton on board RV Investigator are hoping that we are not joined by a pygmy blue whale as, there could go, all their samples, down the greedy gullet of a 22m long pygmy blue whale!

The tell tale shorter and stockier caudal peduncle (from the tail flukes to the dorsal fin) of the so-called pygmy blue whale, as compared with the longer caudal peduncle of the Antarctic blue whale, is shown as this pygmy blue whale raises it’s 7m across flukes to dive down to 500m in the Perth Canyon. Photo: Micheline Jenner AM.

We can hear the whales calling and their unique feeding calls and we know they are migrating north. Just one glimpse of a pygmy blue whale on this IN2019_V03 voyage and we are sure you will hear our joy from wherever you are! Perhaps, as we travel south past the Ningaloo region we might just see one! Hearing is awesome, but seeing them is pretty good too–here’s to hoping!

Be sure to follow the daily posts of our Log from One Ten East at https://iioe-2.incois.gov.in