Category: Geen categorie

It has been a while since I wrote a blogpost. A lot of fun and time-consuming things have happened in the meantime which kept me from writing a blogpost (yeah yeah, it’s a bad excuse). First of all, Paola, my partner came to Sydney to visit me for 7 weeks over February and March. The weather was terrible but we did get to see a lot of great things in and around Sydney. I will write a separate blogpost about that at some point. The other exciting thing that happened was that I got to do the first experiment of my PhD! And that is what I want to dedicate this blogpost to.

As you may know, I was not very lucky in terms of my time of arrival in Sydney at the end of June 2021. I went straight into a COVID lockdown that lasted until November, and I couldn’t go to the university, let alone run an experiment. So when that was finally over, it was time to get away from my desk and over to the Sydney Institute of Marine Science (SIMS). This beautifully located institute in Sydney harbour has a great aquarium facility and that’s where I ran my experiment.

For this experiment, I was interested in the role below-ground microbes play in the performance of seagrasses when under stress from a marine heatwave. Interestingly, not much is known about the importance of below-ground microbes for seagrasses, especially not in the context of environmental change. There are indications that below-ground microbes indeed play an important role, similar to terrestrial plants, but so far there have been no experiments testing this. Coming from a terrestrial background, where the importance of the soil for plant health is now widely recognised, I felt like we should look into this more for seagrasses.

But why bother, you may ask? Seagrass meadows are incredibly important ecosystems that provide numerous benefits for other marine organisms by providing food or shelter, including for those cute seaturtles and dugons. They also protect our coasts from storms, and sequester large amounts of the carbon that we’re all happily emitting. If these microbes indeed play an important role in the health and functioning of seagrasses, and if the interactions between seagrasses and their microbes change under environmental stressors such as marine heatwaves, then this may have cascasing effects throughout the ecosystem which could impact a lot of marine organisms and humans that depend on them. So yeah, seagrasses are kind of a big deal.

Unfortunately, these important seagrasses are, like many other organisms in the world today, not doing very well in a lot of places. Coastal development, water pollution and climate change is causing them to dissappear at a rate of 20,000 soccer fields a year since the 1980’s (I know, that’s a lot…). You don’t hear so much about this compared to the loss of coral reefs or tropical rainforests, but they are in fact on of the most threatened ecosystems in the world. Many ongoing restoration efforts have only had limited success and we need to know more about their ecology to be able to improve and upscale restoration.

So for my experiment I compared the growth of seagrasses under different temperature treatments while also manipulating the presence and absence of belowground microbes in the sediment and on the roots. I have to say that I was feeling pretty nervous before starting. I like to plan everything in detail and prepare everything as much as I can to make sure things run smoothly, but since this was my first seagrass experiment there were a lot of unknowns for me. Deep down I knew I would pull it off, but still. I definitely learned that marine experiments are a lot harder than terrestrial ones. There are so many more things to take into account when it comes to fieldwork such as the weather, visibility under water, safety issues, and damn sediment is a lot heavier than soil! And I’ve lifted lots and lots of kilo’s of soil before. Then when trying to keep the seagrasses alive it’s not just a decent amount of water and light (and good soil of course) that they need like terrestrial plants, no no, you need to keep track of the pH, temperature, and salinity of the water, the right light intensity and flow rate of the water. And then there’s algae that start to grow in places you don’t want them. Oh boy, oh boy, these babies definitely kept me busy! On top of that, there were also machines breaking down, delayed deliveries and me getting COVID right before the start of the experiment. What a ride!

It was a lot of hard work, but luckily all went well, and I’m now analysing the first data that I collected. There are some interesting results already, but for that you’ll have to wait. The next step, is to extract DNA from the samples I collected to see if the microbial community composition changed in response to the different treatments and whether that might explain the health and growth of seagrasses. But first, I’ll be going to Europe for almost 2 months in 1.5 week. I’ll be working from there but also going for a holiday in Italy together with Paola. Very much looking forward to that! And I might even see some beautiful Posidonia while I’m there 😉

Nature in Australia is what I would call extreme. It’s extremely beautiful, but can be really dangerous as well. The animals extremely cute, but there are also some very horrible ones. I was hoping to avoid any experience with animals of the latter category for as long as possible, but unfortunately that hope painfully ended today.

As some of you may know, I started surfing a couple of months ago. Sydney is the place to be for surfing, with some great surf beaches around. I am lucky to live at a 10 min walk from Maroubra beach (aka the bra), which is a world class surfing beach. Not the easiest for beginners I would say, but fun nonetheless. When I started surfing I got warned for the potential dangers in the water. We all know about sharks, but there are some smaller creatures in the water that won’t bite off your arm but can be very painful nonetheless. One of those is the bluebottle jellyfish. They don’t look like a typical jellyfish, but more like a blue, small sandwich bag filled with air that floats on the water. But this air sac is not the thing to worry about, it’s the long tentacles that are attached to that blue sandwich bag. And today I was the lucky person to get within a not very covid-safe distance of one of these assholes…

I was surfing, all nice and fun. The sun was shining, the waves were okay and then Marta, my housemate saw a bluebottle floating around in the water. Everyone here gets stung by them at some point and I was joking whether I shouldn’t just get stung by one, to check that off the list. And then I don’t know what happened, it was quite far when we saw it, but all of a sudden I felt this horrible pain on my legs. I took my leg out of the water and the bluebottle had completely wrapped itself around one of my legs. In my attempt to get rid of it, it somehow managed to also attack my other leg. What a disaster! While in the water, Marta helped me to try and get the tentacles off my leg. Which we managed in the end. Damn this thing hurt!! I stayed in the water for a bit more but then decided to go out because it wasn’t fun anymore. And that’s when the real fun happened…

As soon as I got out of the water, I started to feel strange. My legs were burning like hell and I felt a weird pressure in my chest. I decided to better be safe than sorry and walked up to one of the lifeguards on the beach to explain what happened and what I felt. They immediately sat me down in a beach tent close by and rinsed my legs with water. Than I started to feel worse and worse… I got really bad abdominal and back pain, all the way from my chest down to my groin. I felt like I was about to give birth or something. I would describe the pain like really bad menstrual pain but then much worse and throughout your entire torso. The pressure in the chest also got worse. They put me on oxygen and measured my heart rate and oxygen levels in my blood. They were not how they should be and a bit all over the place. I’ve never felt this terrible in my life. Because of the chest pain, they decided to call an ambulance to check out my heart. Luckily, by the time the ambulance arrived, I already felt a lot better. The pressure in the chest was much less and so was the abdominal pain. My heart was checked anyway, just in case, and luckily all was good. It was quite a scary experience! But I’m happy I now know what it feels like, so in case this happens and there are no lifeguards around, I know that I’m not dying hehe.

Now I’m back home and feel okay. No weird feelings in my chest anymore. The legs though, are still burning as if I decided to step into a campfire. This should get better in the next hours or so. And then I’m just left with some beautiful scars for a few weeks to remind me of this relaxing, Sunday afternoon event. Welcome to the real Australia, Renske!

After months of computer-based work, universities have opened and I can finally work on starting an experiment! It feels almost strange to be working on the design of an experiment and actually doing some practical stuff. I’ve gotten kind of used to lots of reading and writing and I’m enjoying it. Nevertheless, getting some of your own data, analysing that and writing that up is way more exciting. Also somewhat scary. This would be the first experiment for my PhD, and it’s not that I’ve never designed or performed an experiment before, but it somehow feels different. Maybe that’s because it’s a whole new system I’m working on, or because I don’t know many of the research methods, or simply because it’s my first experiment and I want to do a good job. Probably it’s a combination of all of this, plus the general unfamiliarity with the protocols, the university systems that are different from what I’m used to, or the field sites that I don’t know. But today was the day on which I could (partly) take one of these things off the list. It was time to go to the field and stick my head in the water!

For my PhD, I’ll be working on seagrass-sediment interactions and how we can potentially use beneficial belowground microbes to enhance seagrass restoration efforts. I’m particularly interested in the effects of climate change on these interactions, so for my first experiment I want to look at the effects of belowground microbes on seagrass performance during a heatwave. For this, I will be running a mesocosm experiment at the Sydney Institute of Marine Science (SIMS). To do this experiment, I will need to collect seagrass and sediment from the field. So today, my supervisor and I checked out a site close to SIMS that has the species I want to work with (Zostera muelleri).

This was actually the first time I saw this seagrass and it was amazing. I mean, spending your morning snorkelling in a bay in Sydney Harbour, doesn’t sound bad, right? The seagrass looked good and healthy, and they were on average at a depth of 1.5 m, which would make it easy to collect them. I finally got a better feel for how to work with this species, how to collect them and where to find them. Next week, we will go to another field site where I could do some future field experiments. Already looking forward to that!

I love Australian birds: there are so many different and very beautiful birds. The most iconic one probably being the kookaburra; famous for its crazy laughing sound. Here in Sydney there’s a bird that’s particularly well-known, and equally unpopular. Unlike the colourful, elegant birds such as the superb fairy wrens, the rainbow lorikeet or the sulfur-crested cockatoo which can often be found on postcards or t-shirts, this bird can be found all the way down the pecking order. You can see them all over the city, often scavenging for scraps to eat. They are like the pigeons found in big cities in Europe. It’s the Australian white ibis, commonly known as the ‘bin chicken’.

I get where the nickname comes from, but I find it painful to hear and I don’t like to call it this way. Something inside me feels sorry for this bird. It is a strange sight to see them sitting on top of a bin, so I decided to look into the reason behind this behaviour. As it turns out, this bird is another victim of habitat destruction and climate change induced droughts. Apparently, a generation ago these birds were a rare sight in cities, but from the 1980’s they started breeding in Sydney. As a result of these changes to their natural habitat, these water-dependant birds moved from inland wetlands to the coast. Now there are an estimated 10,000 Australian white ibis calling Sydney their home, while the population in their natural ranges has dramatically declined.

The typical features of ibis make them well-adapted to city life. Their large bodies make them too big to be preyed upon by cats. Their beak has a sensory tip, which they normally push into to mud in search of invertebrates such as mussels and crayfish. In the city, it’s a perfect tool to open take-away food containers that are now overflowing in every bin as a result of the covid lockdown.

Not all birds can adapt to city life like this. Humans are fucking up the planet, and it has a negative impact on a lot of plants and animals. Ibis may consider themselves one of the lucky ones, as they have been able to move into new habitat, change their behaviour and thrive in this new environment. So instead of looking at an ibis and seeing it as this filthy, garbage-digging bird, I would like everyone in Sydney to realise what kind of conservation message they actually bring. Ibis are only here because their home is no longer suitable for their needs, all as a result of human actions. In the meantime, I will keep calling them the Australian white ibis.