The wonders of Ghent, Belgian precious and nematodes connoisseur

Author: Marta Maria Cecchetto

Yes, you read it correctly. Nematodes. But what is a nematode?

They are roundworms inhabiting a broad range of environments. We could say that Earth is the Planet of the Nematodes; In the 1914 edition of the Yearbook of the United State Department of Agriculture, N.A Cobb wrote on their abundance:

“If all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes and oceans represented by a thin film of nematodes. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites.”

Marine nematode
Generally, this is what a marine nematode looks like under a microscope (Photo Ashleigh Smythe).

Second question, why going to Ghent to study them? The university of Ghent, founded in 1817 by King William I of the Netherlands, is one of the biggest Flemish universities. It is considered a pluralist university which means that is not connected to any particular religion or political ideology to the point where also its motto, Inter Utrumque(in between both extremes) and its coat of arms suggest that the acquisition of wisdom and science are only possible in an atmosphere of peace and support by the monarchy and the fatherland.

And in this university, you will find worldwide experts on the study of nematodes, found from the deepest part of the ocean to the highest mountain on land.

During my week there, from the 9thto the 16thof December 2018, the university of Ghent ran a course on marine nematodes and I applied to it so I could have an idea on how to identify them. During my time there, I had the chance to explore the city and surrounding areas. We went on a field trip to collect samples to practice on.

First day of the course. We went to Paulina polder, an intertidal zone at the border with the Netherlands to collect nematodes. Sunny but very windy day.

Nematodes are really fascinating organisms. They have adapted to live in the most various and extreme environments, however, identifying them is a big challenge.

Was the tide was out we approached the waters. The closer we got to the sea, the muddier we were. Walking became a very big challenge. At the end of the day we were all covered in mud.

When looking down a microscope and looking for the different characteristics that will help you to identify the genus or the family they belong to, you wonder if what you are looking at is really the feature or if it is your imagination having fun with you.

nematode head
This is the head of a nematode. You can clearly see the mouth and the ciliae. The shape of the mouth is one of the characteristics that allows to identify the different species (Photo Ashleigh Smythe).

Nematodes are usually measured in micrometres, which is the same of saying one millionth of a metre, 1×10-6, or one thousandth of a millimetre, 0.001 mm (about 0.000039).

Yes, they are very small!

If during the day I spent my time looking at nematodes, during the evenings I was walking around to enjoy the beautiful sights of the city. Christmas market, hot chocolates, beers and a lot of food. Ghent is very famous for its fries or “fritures” as they call them.

All you can eat ribs
One night we dined in one of the most well recommended restaurant of Ghent: Amadeus. Here you can enjoy a very unhealthy but delicious dinner, all you can eat pork ribs!

The city is divided by different canals which contribute to the romantic Flemish atmosphere. The reflection of street lights playing with the image of churches and old guild houses on the canals create a beautiful and magical feeling which will accompany you during your evening walks.

Evening walk along the canal.

Could you guess how many nematodes you can find in their waters?

Something to think about next time you visit the city!


The importance of science for improving conservation strategies of Scottish maerl beds

Author: Cornelia Simon Nutbrown

My PhD is a NERC iCASE funded project which brings together three institutions: The Lyell Centre for Earth and Marine Science and Technology (Heriot-Watt University), The Royal Botanic Gardens Edinburgh and Scottish Natural Heritage, with the goal of developing more informed and targeted conservation strategies for the maerl beds in Scottish seas. I only started in October so I’m pretty new but already I’ve been able to get out into the field and collect some pilot samples!

Maerl is a type of free-living, coralline red algae that clumps together to form large, structurally complex reef-like ecosystems (called maerl beds). These beds support high levels of biodiversity by creating a habitat for rare, endemic or commercially important species like cod, hake or scallops.


Photo 1
A Scottish maerl bed with lots of brittle stars (photo credit: Nick Kamenos)


Maerl isn’t just important in Scotland, it’s found around the world, from polar to tropical waters and in a huge range of depths from the intertidal zone to 300+ m deep! Along the west coast of Scotland, maerl is particularly abundant.

Maerl beds are threatened by a number of human activities including dredging, aquaculture, rising sea temperatures and ocean acidification. Because maerl beds are so important for supporting biodiversity in Scottish waters around Scotland, lots of maerl beds are protected in Marine Protected Areas, but the placement of these are based on limited data we don’t know the full extent of maerl occurrence around Scotland!

My project aims to increase our understanding of how ‘connected’ maerl beds are around Scotland. This information will help to better design the maerl bed management plan for Scotland. First, I will combine environmental data (e.g. temperature) and current knowledge about maerl bed locations to design a computer model to estimate the true extent of Scottish maerl beds. Then I will test the outputs of the model in the field. I will also collect samples to analyse DNA of maerl from many locations to determine how closely related different beds are. This information is useful for conservation because it will tell us if some beds are reliant on others for reproductive genetic material and so protecting these ‘source’ beds would mean other beds may fare better too. Looking at the genetics of different beds also allows us to evaluate their relative health, informing us about the impacts of different local activities. The genetic analyses will be complemented with laboratory experiments to assess the capacity for different species to capture carbon via photosynthesis. My hope is that the results from my project will be taken on board by Scottish conservation organisations to ensure maerl bed management is sustainable and effective.

Photo 2
Sofie on the hunt for some maerl (photo credit: Sofie Voerman)
Photo 3.jpg
The snorkeling site at Loch Sween (photo credit: Sofie Voerman)

Last month we (my supervisor Heidi Burdett, Sofie Voerman, Beau Marsh and myself, accompanied by a team from the university of Glasgow lead by Nick Kamenos) braved the Scottish winter and went out to Loch Sween to collect some preliminary samples for DNA work and some sediment cores needed by the Glasgow team. We split into two groups, one who snorkeled at the shallower site and one who scuba dove at a deeper site. I was on the snorkeling team and managed a few dives down to the maerl beds to collect some samples before the cold drove me back to shore! Meanwhile the other group scuba dove to a deeper site further up the Loch system to collect some samples there too. Despite the cold it was a great and successful day out and I’m excited to get started extracting DNA so watch this space!

Photo 3
The scuba dive site at Loch Sween (photo credit: Sofie Voerman)

Chasing Rhodoliths

Author: Sofie Voerman

Our team (Heidi Burdett, Beau Marsh, Sofie Voerman) has been chasing rhodoliths across the Atlantic Ocean, to a small island 350 km off the coast of Brazil. Here, rhodoliths occur up to an incredible 100m depth.  Albeit only small amounts, light still reaches those depths in the mid oceanic waters. Our divers were also enjoying the crystal clear conditions. Check out some of the amazing photos below.  This research trip was supported by a Leverhulme Trust Research Project Grant awarded to Dr Heidi Burdett in collaboration with the University of St Andrews.

The full team at  40m at a large rhodolith bed. Photo credit: @All_Angle underwater photography
Sand tilefish Malacanthus plumieri collect to build their home. Photo credit: @All_Angle underwater photography
Me and a ray at the shallow site (about 15m). Photo credit: @All_Angle underwater photography



Back To Reality

Authour: Annabell Moser

On the 16th of June we arrived back to shore and started early in the morning to unload the vessel. Andrew, Marta and I had a bet. Andrew said we could unload the vessel, dismantle our landers and pack everything back in the container in one day. Marta and I bet against it. Despite the bet, we gave our best to pack as fast as possible and after one and a half day everything was packed back in the container so we could enjoy a bit more of Hawai’i and the feeling of having actual solid ground under our feet. After being surrounded by the ocean for a whole month but never being able to go for swim, it was the first thing we did after finishing work.

Unloading the Kilo Moana

It is now a week since we started our journey back to Europe.

For me personally the cruise was an important experience. I learned about all the possibilities that can go all wrong being in the middle of the Pacific but also how to overcome these problems by working together as a team. Thank you Marta and Andrew for taking me with you on the cruise!

Cruise picture of all scientists, crew and the ROV team

For this summer, all the exciting cruises to the Pacific came to an end and I hope you enjoyed reading our blog. However, we try to keep this blog alive because there is so much more our group does from deep-sea algae to master projects all over the world.


P.s.: On this blog ( you can read even more about the adventures and the different researchers on board of the RV Kilo Moana.

Answering Questions

Author: Annabell Moser

I shared my last blog post ‘First data’ on social media like Facebook and Twitter and asked our readers what they like to know about our research cruise. Here I would like to answer the questions. I shared my last blog post ‘The first data’ on social media like Facebook and Twitter and asked our readers what they like to know about our research cruise. Here I would like to answer the questions.

Is anyone experiencing seasickness? If so, how do they deal with it?

Fortunately, I never got seriously seasick. Normally, it takes me the first days to get used to the rocking and rolling. My strategy is to eat some ginger sweets and drink ginger ale. During this cruise, it seems that nobody got severe seasickness. Worst comes to worst the only solution is to take anti-seasickness medication and rest.

Can you tell us what a ‘normal day’ on your research vessel is like?

That is a good but also a hard to answer question. Honestly, there is no such thing as a ‘normal day’. Everyday differs and the mealtimes are the only constants. For our group days divide in ‘Deployment Day’, ‘Recovery Day’ and the days in between like ‘Transit Days’ or ‘Waiting for the Lander Days’.

On a ‘Deployment Day’, we would wake up at any time of the day or night to get some breakfast. Afterwards we would start preparing for a deployment.

Respirometer Lander (Malihini):

  • Put weights on
  • Cleaning syringes
  • Attach syringes to the lander
  • Fill injectors with labelled algae
  • Turn on strobe and beacon
  • Connect and tight all plugs
  • Program the computer

Microprofiler Lander (Yellow tang):

  • Calibrate oxygen electrodes
  • Prepare and attach weights
  • Connect electrodes to lander and field computer
  • Remove protection from electrodes
  • Connect and tight all plugs
  • Program the computer
Respirometer ready to deploy!
Everyone has a last check on it before it goes down.


‘Recovery Days’ are the most nerve wracking days. When we try to communicate with our lander and tell it to come up everybody is anxious if it will work. After recovering, we process the samples and data from the deep sea. (Handling tag lines for the first time, blog post about a recovery)

Respirometer Lander (Malihini):

  • Take water samples
  • Take sediment samples
  • Sieve sediment for fauna

Microprofiler Lander (Yellow tang):

  • Take off the electrodes
  • Download the oxygen data from the field data logger (clever word for computer)

‘Transit Days’ or ‘Waiting for the Lander Days’

On these days we clean up the lab space, prepare whatever we can prepare for the deployments as labeling tubes and bottles for our samples. Marta is always writing something, from her literature review to her major report to the cruise report. Nevertheless, we also try to relax a bit by sleeping in mornings and stay up ‘late’ watching movies. (Life aboard the RV Kilo Moana, more aboutour everyday life)

Thank you for reading our blog and for the questions we received. Never hesitate to ask questions on our blog and feel free to drop a comment!

Let’s get sciency, poking and grabbing deep-sea sediments

Author: Marta Maria Cecchetto

It’s been almost a month since we have left Honolulu harbour. An exciting month collecting sediments and data from the deep blue Pacific Ocean. You will be wondering why poking and grabbing.

Well, let’s see if I can explain it.

In this case it has a literal meaning. In the past month, Andrew, Annabell and I have been poking the deep seafloor with really fine and fragile glass sensors to collect oxygen data. We sent our lander, Yellow Tang, down to 5 km deep into the ocean to observe the changes in oxygen concentrations within deep-sea sediments. Yellow Tang is what we call a micro-profiler lander as its functions is to obtain profiles of different chemicals by using different type of micro-sensors. The data from this lander can be observed immediately as we don’t have to process any samples in the lab once we are ashore.

Annabell showed and explained our data in a previous blog entry (The First Data).

 In addition to mistreating the deep sea by sticking needles into its sediments, our group has been busy measuring sediments oxygen consumption (how much the organisms in the sediments breath) and grabbing sediments samples. This was done by our second lander, Malihini, in Hawaiian means “new comer” as it has been our newest addition.

Malihini consists of three chambers of ~20 cm3 connected to three different deep-sea computers, which have the task to transmit information regarding samples collection. Once the lander reaches the seafloor (it takes 3 hours!), the chambers are programmed to start entering the sediment and different data are collected, from water to sediment samples. In addition the chambers are connected to oxygen optodes (=sensors) and algal injectors, which have the job to inject previously grown isotopically labelled algae into the chambers. Oxygen sensors are measuring the concentration of oxygen over time so we can calculate how much the organisms in the sediments are breathing over time. While at the seafloor, syringes have the job to collect water samples over time just above the sediemnts for Dissolved Inorganic Carbon (DIC) and Nutrient analyses. Once Malihini is safe on deck we start collecting sediment samples at different sediment heights, usually 0-2 cm and 2-5 cm. Sediments samples will be processed again once in the lab at The Lyell Centre, in Edinburgh, to analyse Total Organic Carbon (TOC) and sort between the different faunal assemblages present in the sediments.

Chamber 3 example_small
Malihini Chamber 3 

Isotopically labeled algae Isotopes are forms of the same element that differ in the number of neutrons in the nucleus. Usually, there is a heavy and a light isotope of carbon. 13Carbon or 15Nitrogen have one more neutron than 12Carbon or 14Nitrogen in their nucleus. Six month ago, I have grown diatoms (a type of algae) in seawater with a higher content of heavier carbon and nitrogen isotopes to obtain a substrate (the algae) standing out from normal background conditions.

As we fed the organisms present in the sediments with algae with a heavier carbon isotope ratio than normal conditions we can trace the heavier carbon isotopes and see the resulting feeding pathways among the different organisms and assess benthic (=at the seafloor) ecosystem functioning, determining how an ecosystem works based on carbon flows and turnover.

Our adventure is almost at the end, as sad as this can be it’s been a month rich in new experiences, from manning and tagging lines to see and touch animals from 5000 m depth, now, I look forward to get even more sciency and start a new chapter on the discovery of this remote and unexplored environment; lab work here we come!

The first data

Author: Annabell Moser
The countdown has started, only 8 days left of the cruise and we have accomplished 2 APEIs in the CCZ including 3 microprofiler and 4 respirometer deployments. Some were more successful than others but all together Marta gets a lot of data for her PhD thesis.
We already mentioned in a previous blog post that the microprofiler measures dissolved oxygen in the sediment. To be more precise in the pore-water which is the area between the sediment particles.

OPD_Deep Sea
Fig. 2: Oxygen sediment profile of the first APEI in CCZ. The oxygen is reaching 15 cm deep into the sediment.

Here is an example how the microprofiler data look like (Fig. 1). On the y-axis, the sediment depth (brown) and the height of the water column above (blue) is plotted (Fig. 1). The oxygen concentration in µmol is shown on the x-axis. The maximum of dissolved oxygen (also called oxygen saturation) in water depends on the temperature and the salinity. For this deep-sea site (4893 m deep), the temperature is ~2°C and the salinity is ~35, which results in an oxygen saturation of 340.4 µmol l-1. Here the oxygen concentration is half of the saturation. However, it penetrates deep into the sediment (brown coloured area) where animals and bacteria even in 10 cm depth can use it.
In shallower regions of the ocean, oxygen only penetrates a few mm into the sediment. In the below example (Fig. 2 and 3), oxygen was measured in a sediment core from the Baltic Sea (~30 m deep). The oxygen only penetrates 5 mm into the sediment, and is available only here to be used.


Fig. 2: In comparison an oxygen sediment profile from an eutrophic and shallow (30 m) area in the Baltic Sea. The depth scale is the same as in Fig. 1 
OPD_Shallow_diff scale
An oxygen sediment profile from an eutrophic and shallow (30 m) area in the Baltic Sea. Notice the different depth scale. Oxygen only reachs mm into the sediment.

Why does the oxygen penetration depth vary in different sediments?

Many different reasons determine the oxygen penetration depth of sediments such as sediment structure/size/composition, concentration of organic matter (all particles that fall from the surface layer of the ocean into the deep and function as food), organism activity such as bioturbation, oxygen concentration in the overlying water and physical parameter such as currents.
For example, high concentrations of organic matter lead to a high turnover (organic matter is used/eaten/consumed by organism) and therefore to a high oxygen consumption. The high oxygen consumption is a result of higher activity such as food/nutrient uptake by the organisms. The more active the organism are, the more oxygen they need. To create a better and more understandable picture just imagine us. The more active we are, for example while we are running, the more oxygen (we breathe faster), we need to maintain that activity. In the ocean, a high oxygen consumption leads to low concentrations of oxygen which result into a low oxygen penetration depth in the sediment. Usually, high organic matter can be found in shallower and/or eutrophic (high nutrients -> many algae -> high organic matter) areas like the example from the Baltic Sea.
In contrast, deep-sea sediments, especially here in the CCZ are highly oligotrophic (low in nutrients) since there are not enough nutrients at the surface to develop a significant amount algae that can reach all the way down to 4893 m in the form of organic matter. Therefore, the organic content is low and less oxygen is utilized (the organisms down there are more the lazy kind) resulting in a higher oxygen penetration depth into the sediments.
Actually, it is nice to experience all the theory I have learnt during my Marine Biology Master right in front of me in the middle of the Pacific. The next and last set of deployments just started. So stay tuned to hear more from our adventures.