Guest post – Emily Rowlands

On March 21, 2019March 21, 2019 By ClaireIn Discovery DY098, Guest post, Ocean plastics, Science1 Comment

The night the krill eggs hatched…

Setting sail from the Falklands and heading into the open water, I was slightly apprehensive, with little knowledge of what to expect of the upcoming 40 days at sea on my first research cruise. A barrage of thoughts hit me in sync as I boarded the ship. How rough would the sea be? Would it make me ill? What would the people on board be like? Questions I’d perhaps put to the back of my mind beforehand as I was so focused on preparing for the scientific tasks ahead. Amongst the chaos of preparing the ship for leaving port, I paused to reflect on the first Antarctic expeditions aboard the Discovery, with Captain Scott. The apprehensions of the living conditions and weather worries were immediately put into perspective… I was as ready as I’d ever be!

With so many helping hands, the ship was transformed much faster than I had anticipated. The laboratories, previously blank canvases with nothing but wooden desktops had entirely transformed and were fully functioning with microscopes, light sources, weighing scales and everything else one might imagine needing for conducting zooplankton surveys, all screwed or tied in place to prevent them moving or falling with the rolling and pitching of the ship in rough seas. Finally, with the ship prepped and ready to, I could focus on my purpose for being on board.

The deck lab prior to unpacking. Photographic credit: Sophie Fielding

So what is ‘nanoplastic’? It’s a term much less heard than ‘microplastic’, crowned word of the year in 2018. Microplastics are categorised as small plastic particles under 5mm. Nanoplastic, unseen by the human eye, is even smaller! It describes tiny pieces of plastic less than 0.001 mm in size, that’s at least 2000 times smaller than a grain of sand! Because of their extremely small size, nanoplastics interact differently with the water particles in the sea and within the bodies of animals that eat them, compared to how bigger plastics behave.

We don’t yet know how much nanoplastic there is in Antarctic waters and we know little of how they impact zooplankton such as Krill. Krill are tiny animals that are hugely important for the Antarctic marine food web as they are eaten by larger animals such as penguins, sea birds and even whales. These are the things I hoped to address with my research on board.

The first hurdle for my research was catching pregnant female krill, so that I could look at how nanoplastics would impact the eggs that they produce. This was no easy task. Every day, midwater fishing nets were deployed and hurled by four people back onto the ship.

Recovery of the RMT fishing net. Photographic credit: Alejandro Ariza

The nets, especially with a big catch, are pretty heavy – and when the contents come aboard they were emptied into buckets. Everybody crowded around the buckets with each scientist searching for their focus species whilst trying not to block the little artificial light we had, since fishing often took place throughout the night when the ship was surrounded by darkness.

Sorting the catch from an RMT net. Photographic credit: Alyasa Hulbert

When the day came in which pregnant females were found, we quickly moved them to holding tanks and the waiting game began. Now it was just a case of waiting for the females to release their eggs. The jars in which they were kept were checked day and night, looking for eggs sunken below the protective mesh which was added to prevent the mother eating them. I waited with bated breath and finally….there were eggs! After checking under the microscope we knew they were fertilised eggs that given the right care, would develop into adult krill. I was ready to set-up my experiment.

All set-up, my next job was to document how the eggs developed by taking photographs every 12 hours. In the early stages krill eggs develop very quickly, and it was exciting to see the cells dividing each time I checked from early stages of two cells or four cells to later stages of 32 cells or more. Soon the development of krill eggs slows and my observations at 2am, in a temperature controlled laboratory set at 2 degrees Celsius (we called it the cold lab) with tired eyes became more tedious. At this time the developmental rate is so little between observations it’s difficult to tell whether the eggs are still alive!

On day four of my experiment, at 2am in the morning, when everybody had gone to bed, I put on my salopettes and thermal coat and headed into the cold lab, expecting to do my usual assessment. With tired eyes, I attempted to focus the microscope and noticed a blurry blob moving amongst the eggs. Coming into focus, there it was, a tiny baby krill had hatched and investigating further, there were many more too! Never seeing this in real life before and with little expectation of the krill eggs developing to this stage beforehand (as the eggs from the last year’s cruise had failed to develop to this stage), I was incredibly excited.

Krill babies! (C) Emily Rowland

After finishing my observations (with lots of extra time spent taking video footage of the baby krill), I left the cold lab and went into the main lab, a busy environment during working hours in which everybody is typing away on their computers waiting for instructions to put on their thermal clothing and head on deck for the next round of fishing. Now it was eerily quiet. I took out my laptop and sent some emails to friends back home, to share what to me was an extremely exciting day, though amused by the fact that they may not find it quite so exciting.

The next morning, I showed the video footage of the baby krill to the other scientists on board who were just as excited as I had been the night before. We celebrated the hatching of the krill, and that’s when I realised that one of the greatest things about being on a biology research cruise in the Southern Ocean was being with others just as passionate about the Antarctic marine ecosystem as I am.

Emily Rowlands is a PhD student at Exeter University, studying the effects of nanoplastic on Antarctic Zooplankton. To find out more about her research – give her a follow on twitter: @EmilyRowlands89

MinION sequencing on the RRS Discovery

On February 20, 2019February 20, 2019 By ClaireIn Discovery DY098, Guest post, ScienceLeave a comment

Guest post by Emma Langan

I’m on the RRS Discovery in the Southern Ocean, doing DNA sequencing of Antarctic algae or phytoplankton. To do this I’m using a tiny portable DNA sequencing machine called a MinION (shown next to the other kind of minion in the top photo).

Phytoplankton are microscopic algae which live in the oceans and make their energy from the sun, just like plants on land. They are important for making oxygen and also carbon from the atmosphere – excellent news as too much carbon in the atmosphere is one of the causes of climate change. They are also the bottom of the food web, so without them, there wouldn’t be penguins and whales and seals. My research is focused on investigating which species of phytoplankton are present and what tricks they use to survive somewhere as cold as Antarctica. To investigate this, I use DNA sequencing.

DNA is the basis of all life on earth. Like the code in a computer program telling a computer how to work, DNA tells your body how to work. DNA is made up of 4 bases, called A, T, G, and C which appear in different combinations making genes. Genes tell the body which proteins to produce, and proteins make muscle, or hair, or eyes in the right places. Different genes are what makes plants different to animals, penguins different to elephants, and you different to me. Looking at an organism’s DNA gives us a lot of information; we can use it to see which species are present in a sample and also to see what special genes they have which allow them to live in ice and snow, and in the dark.

The CTD is used to collect water samples from different depths

To look at Antarctic phytoplankton DNA, first we take water samples from the ocean and filter it to catch the phytoplankton. Next, I remove the DNA from all of the proteins and other sticky stuff in the cells. This process is called DNA extraction (if you’re interested and have an adult to help you, you can quite easily extract DNA from fruit or vegetables using things you can buy from a supermarket https://www.sciencefocus.com/science/how-to-extract-dna-in-your-kitchen/.)

Once I have extracted the DNA, I put it into the MinION which runs for 2 days, and you can start to see which species are present almost straight away. The MinION makes a list of all the bases that are in the DNA and compares it to DNA from species that we’ve already sequenced. This way that we can tell which species are in a sample, and what genes they have.

It’s really exciting to be able to do DNA sequencing on a ship, because usually we have to send samples home which takes months, and we don’t know if anything has changed since we collected them. Most DNA sequencing machines are the size of an oven so you can’t take them with you. The MinION is so small that we can take it anywhere – someone even did DNA sequencing in space. I’m going to use the information I get from it to look at whether the phytoplankton species change as the oceans get warmer due to climate change, and to investigate what genes they have which let them live in the Antarctic in the first place.

Emma Langan is a PhD student at UEA and Earlham Institute. You can find out more about her work by following her on Twitter @EmmaGLangan

The Discovery Investigations

On February 9, 2019February 9, 2019 By ClaireIn Cetacean, Discovery DY098, ScienceLeave a comment

Whale and krill surveys are something of a recurring theme on RRS Discovery… in fact, she’s something of a pioneer in this field – or at least her predecessors are.

Known as the “Discovery Investigations”, a series of scientific cruises and shore-based investigations into the biology of whales was initiated in 1923. The ship used for these research cruises in the Southern Ocean was a proven Antarctic stalwart – the first RRS Discovery, more famously used by Captain Scott in his 1901 expedition to Antarctica.

The original RRS Discovery, at her permanent home in Dundee, Scotland.

The research cruises collected data on oceanography, krill and whales; much as we have been doing on our trip. Once they reached South Georgia in February 1926, the team on board worked alongside the then-thriving whaling industry of Grytviken. Working with the whalers, they were able to collect biological data from the remains, as well as at-sea data on the distribution and numbers of whales.

Reprint of a photo of the crew of the original RRS Discovery at anchor in Cumberland Bay, South Georgia. Photographed on the wall of the current RRS Discovery

The history of whaling is still very much in evidence at Grytviken today. The skeletons of both whales and whaling ships lie on the beaches, and the remnants of the processing machinery rust slowly against the hillside, long out of use.

Whale vertebrae lie along the shore, alongside rusting whaling ships

Whale jaw-bones lie outside the South Georgia museum, in what was once the whaling-station managers house

I am very pleased to report that (for the UK at least) current whale biology is carried out in a non-lethal and much less invasive manner; the sheer scale of the infrastructure here and the debris left behind goes some way to providing an idea of what this destructive industry must have been like at it’s peak.

But anyway, back to the Investigations…

RRS Discovery II became involved in the project in 1929, and her Maiden Voyage was a hydrographic survey of the South Sandwich Islands. She remained involved to the end, her last survey was in 1951.

Reprint of a photo of the crew of the Discovery II, photographed on the wall of the current RRS Discovery

The Discovery Investigations continued for many years, with the final survey in 1951 and the final report only being published in 1980. There are more than 37 volumes of reports documenting everything from the biology of elephant seals and fin whales to that of nematode worms; geology and hydrology; mapping and bathymetry.

There can be little doubt that the work of the Discovery Investigations made an enormous contribution to our knowledge and understanding of the whales, seals, penguins, pelagic seabirds and krill that make up this fascinating ecosystem, as well as the geology and oceanography of this previously unstudied area. It’s fascinating to be part of a cruise continuing this line of investigation on the fourth RRS Discovery, and to see the little nods to her heritage – like the photos on the wall and the whale logo on the gate on the way up to the Navigation bridge which takes the form of the old Discovery Investigations logo.

That having been said, I’m very pleased the days of lethal whale research are largely behind us. See other blog posts for further information on what we are up to on this survey, but rest assured, our current whale work is completely non-invasive – merely counting animals and taking photographs.

The current RRS Discovery at anchor in Cumberland Bay, South Georgia

Further info:

I must confess this is something I knew nothing about prior to this cruise – so the bulk of the information has come courtesy of wikipedia. If you’d like to find out some more – I recommend having a look at the following:

https://en.wikipedia.org/wiki/RRS_Discovery

https://en.wikipedia.org/wiki/Discovery_Investigations

https://en.wikipedia.org/wiki/RRS_Discovery_II

The South Georgia Museum: http://sgmuseum.gs/index.php?title=South_Georgia_Museum

For those of you who aren’t currently on a ship with limited internet access, I expect there are lots of other sources too!

The South Sandwich Islands…

On February 9, 2019 By ClaireIn Discovery DY098, ScienceLeave a comment

“So, where are the South Sandwich Islands anyway….?”

This chain of 11 volcanic islands lies deep in the Southern Ocean, 530 km to the south-east of South Georgia. They range in size from 12 km in Diameter (Montagu Island) to 2.4 km in circumference (Leskov Island). All but three of the islands have seen volcanic activity within the last 100 years. Some are completely ice-covered, some are ice free. They are uninhabited by people, but home to large breeding colonies of penguins, seals and pelagic seabirds.

Weather isn’t kind for survey work here. We’ve been in the are for more than two weeks and some of the islands we’ve not even caught a glimpse of due to fog. A shame – as those we have caught sight of have been both varied and striking. It’s a kingdom of swirling cloud, snow showers and strong winds, interspersed with occasional days of flat calm and sunshine – although even then the temperature barely creeps above freezing.

Saunders Island, issuing a reminder of it’s volcanic status

So what are we doing here? The Government of South Georgia and the South Sandwich Islands is looking to extend the existing Marine Protected Area (MPA). The work conducted on this cruise estimating both both krill and whale abundance in the area will be used to inform the decisions regarding the extension of this MPA.

Bristol Island

A day on the RRS Discovery…

On January 22, 2019January 22, 2019 By ClaireIn Discovery DY098, Guest post, Science1 Comment

Guest post by Megan Sørensen

It’s 5am and for the scientists on the early shift it’s time for their day to begin. This includes the scientists who are recording the whales and dolphins they see. They spend the day standing outside on the top deck with their binoculars, cameras and warm layers. Also up at this time are the scientists who have to keep an eye on the overall survey measurements, this means checking a screen that displays everything that the ship passes over and reads all the way to the sea floor, which is over 3km down!

A couple of hours later it’s breakfast, and the scientists on ‘normal’ days are also up and about. These scientists might be running their own experiments in the labs using samples that we’ve already collected. Someone might be on the microscope identifying some of the tiny organisms that live in the sea, and there are probably some people studying krill in the cold lab (set to 2°c so you need all your layers on if you’re working in here).

Then it’s lunch time and the ship starts to get busy as the people from yesterday’s night shift are now awake too. Meal times are important and sometimes they are the only time when everyone comes together. It’s also nice because the crew, scientists, and engineers all sit together. The ship crew keep the entire ship running – from steering the ship, looking after the engines and cooking – and nothing could be done without them.

In the late afternoon we see the change over from the day to night shift in the main lab. The people who started early are now finishing, while the night shift has only just got started. For the engineers and scientists on the night shift their main job is using the different types of nets to take samples from the ocean. We do this to monitor how the different species change year to year, and whether this is impacted by variation in the environment or changes in fishing laws. The samples we take are only small and can only take small creatures – mostly krill, jellyfish, and some small fish. The night shift can last till 3 or 4 am and requires a lot of coffee to see it through.

After that the ship is quiet for an hour or two before the early morning shift starts and it all begins all over again.

Megan Sørensen is a PhD student at the University of Sheffield, studying as part of the BBSRC White Rose DTP Program. For more information on her work, please contact @MESSorensen on twitter

Adventures in whale counting

Category: Science