Changing times: back to Australia and more eDNA

February 8, 2021 / Maarten De Brauwer / 2 Comments

It’s been quiet here for a while, which I fully intend to change in the coming weeks. To get people up to speed, I’ll start by giving an update on what’s happened in the last months.

As you might remember, last time I wrote, I was doing research for the University of Leeds into the biodiversity of central Indonesia’s marine environment. We had some very interesting fieldwork trips and were using environmental DNA to describe the health of coral reefs. Unfortunately, COVID happened and the world got turned upside down. Fieldwork got cancelled, Europe went into lockdown, life slowed down.

Just before that happened though, my partner started her PhD in Australia. What was supposed to be a few months of separation turned into an indeterminate period of uncertainty when Australia decided to close its borders for anyone besides citizens and their immediate family. I made the decision to try to move back to Australia asap under the immediate family rule, just before the government introduced flight caps. This massively limited how many people could fly into the country and resulted in my booked flights being cancelled (and rebooked) 4 times.

*It’s great to be back in Australia – “Look at me now” headland*

Eventually I got lucky and landed in Sydney in mid August 2020. Two delightful weeks of quarantine later, I was declared COVID-free and released out into the wide Australian east coast. More specifically, Tanika and me are now living near Coffs Harbour, a lovely place midway between Sydney and Brisbane. While it’s not a lively city like Leeds or Perth, it more than makes up for that in nature. Its great to be living close to the ocean again, with ancient Gondwana rainforests nearby for hikes, and even a nice creek next door ideal for morning (or evening) kayaks.

*Early morning kayak on the creek next door*

Moving back to Australia did create logistical issues for my job in Leeds. Working from home might be the norm in many countries at the moment, the situation was not viable long-term. As soon as I arrived in Australia, I started applying for jobs and I am very glad to share that I got offered a position working for CSIRO, Australia’s national science organisation. CSIRO does a lot of exciting research, but might be best known (and celebrated) for inventing WiFi, Australia’s ocean-proof plastic bank notes, and coining the term petrichor: the smell of rain in the air.

I won’t be inventing new words at CSIRO (I think), but I am doing very exciting work at the intersection of hardcore scientific research and management. For the next 3 years I will be preparing a roadmap on how environmental DNA (eDNA) can be used to monitor Australia’s marine parks. If you have been following the blog, you’ll know that eDNA is an amazing new method to study the marine environment, but so far the use of eDNA is still mostly restricted to fundamental research. Together with members of Oceans and Atmosphere and the Environomics Future Science Platform, I’ll be turning the many findings and recommendations of eDNA researchers into a realistic pathway for managers of marine parks who want to start using eDNA. A big challenge, but an exciting one which will be research focused on direct, real world applications.

In the coming months I’ll try to get back to regular blogging, hopefully including updates on my new research, explainers of exciting new upcoming papers, and plenty of critters news!

New place, new critters! A juvenile pineapple fish (*Cleidopus gloriamaris*)

Closing one chapter and opening another

April 1, 2019April 1, 2019 / Maarten De Brauwer / 3 Comments

It is time to share some very big news. My time in Australia has officially come to an end and I am starting a new and exciting chapter on the other side of the world. From April onward I will officially become a “Research Fellow in Quantitative Tropical Marine Ecology” at the University of Leeds in the UK. In other words, for the next two years I will work as a postdoctoral researcher on a very exciting new project.

I will write about the new project in more detail soon, but right now I am feeling a bit nostalgic about the past 6 years of living and becoming a scientist in Australia .

Celebrating the end of an experiment on the Great Barrier Reef

I arrived in Australia as a dive instructor, thinking I’d be there for a few months to help out a good friend with a research project on cleaner wrasses in the Great Barrier Reef. Working and living on Lizard Island Research Station gave me the chance to meet some amazing marine scientists passionate about their research. More than anything else, the people I met there are what pushed me in the direction of becoming a marine scientist.

A series of fortunate events lead me to Perth and I somehow managed to convince Professor Euan Harvey that taking on a semi-nomadic beach bum for a student would be a great idea. To this day I still do not know if Euan was being very wise or very stupid, but once I got my foot in the door of the Fish Ecology Lab it took them about 6 years to get me out again.

The amazing team of the Fish Ecology Lab, all of you will be missed!

Happy sunset drinks by the beach

While I never planned on spending a long time in Australia, it didn’t take me long to appreciate the beauty of the place. Western Australia in particular is basically a Europe-sized playground for people who love the outdoors. I can’t count how many camping trips, dives, surf sessions, ocean swims, hikes, … I’ve done in recent years and I still haven’t seen half of what I’d want to see. Some of the highlights that come to mind include camping on remote beaches, diving with seadragons, snorkeling with sea lions, and sunrise surf sessions with friends. I won’t even begin to write about the many wine tasting sessions down south 🙂

I was lucky enough to meet some amazing people along my journey. Almost without noticing it, I built up a group of colleagues and friends. I love the typical Australian easy-going, honest (sometimes in-your-face) style of communication. Even if it could not be more different from what I was used to in Indonesia (or even Belgium). The people more than anything is what make or break a place, and I will miss the ones I left behind in Perth dearly.

Exploring the coastline in southern Western Australia

When I arrived in Australia I never expected that it would become a second home, but that is exactly what happened. The people, the wildlife, the landscapes, all of it have found a spot in my heart, and I am grateful for my time there. I am very much looking forward to starting a new chapter, if it’s even half as good as the last one it is going to be fantastic.

See you next time Australia!

Leafy seadragons: Australia’s favourite fish

November 20, 2018November 20, 2018 / Maarten De Brauwer / 4 Comments

In a recent poll organised by the Australian Society for Fish Biology and Lateral Magazine, the Leafy Seadragon (Phycodurus eques) was voted as Australia’s favourite fish. This exquisite critter definitely deserves its place at the top, to celebrate it amazingness I wrote a blog about it. This blog appeared originally as an article in Lateral Magazine, you can find the original version here.

According to the popular stereotype, marine biologists spend their careers diving on colourful coral reefs, cuddling dolphins, and wrestling sharks. Unfortunately, the truth is a lot more mundane; we are more likely to spend our days diving into data analyses, cuddling too many cups of coffee, and wrestling grant proposals.

But sometimes we get lucky enough to work with animals that exceed the wildest stereotypes. Studying marine life is always exciting, but some animals are so unique they just stop you in your tracks; they make you thank your lucky stars for not listening to your mother when she said ‘marine biologist’ was not a real job.

Two leafy seadragons. Photo credit: David Harasti

For me, the ultimate awe-inspiring fish is the leafy seadragon (Phycodurus eques). “Leafies” only occur in temperate waters off southern Australia, and they are, to say the very least, unique animals — the kind that makes you wonder whether evolution had a stroke of brilliance or just a stroke. Seadragons belong to the Syngnathidae family, which also includes seahorses and pipefishes. Even in a family that is known for their oddly-shaped members, leafies stand out big-time.

These beautiful fish have the head of a seahorse and the body of a seaweed, with flamboyant leaf-like protrusions that wouldn’t look out of place at the Carnival in Rio de Janeiro. Leafy seadragons defy the idea of what a fish should look like.

Maybe that is why they are so popular with fish enthusiasts all over the world. Scuba divers fly halfway across the globe to dive in the cold waters off southern Australia, hoping to catch a glimpse of them. In the few public aquaria that display them, including Melbourne Aquarium, leafies are one of the absolute crowd-pleasers. For fish-lovers, this Australian endemic fish is at least as iconic as kangaroos or koalas.

Leafy seadragon. Photo credit: Tony Brown

Despite their popularity, we know surprisingly little about leafy seadragons. Adult leafies are one of the largest members of the Syngnathidae family, with adults measuring up to 35cm. Like seahorses, male seadragons carry their mating partner’s fertilised eggs; unlike seahorses, they do not have a pouch. Instead, females lay their eggs on the underside of the male’s tail, where they remain until hatching.

Leafy seadragons depend on kelp and seagrass beds as their habitat, where they blend in supremely well to avoid predators. Unfortunately, these habitats are in decline all over the world, including in Australia, caused by coastal development and potentially climate change. As a result, seadragon population numbers are decreasing, although the species is currently not considered to be endangered.

Admiring a Weedy seadragon, a close cousin of the Leafy seadragon. Photo credit: Greg Lecoeur

One would assume that the decreasing population numbers of a unique Australian emblem would inspire multitudes of researchers to study it. Strangely, this is not the case. A search of the scientific literature suggests that nobody has studied them in the wild for almost a decade. This lack of research on evolutionary distinct marine critters is unfortunately not unique to seadragons. It extends to many other species that do not fit in the ‘food’, ‘danger’, or ‘Pixar-famous’ categories in which landlubbers like to divide marine life. If so little attention is paid to the struggles of Australia’s most recognisable and charismatic fish, then what hope do other species have?

Time will tell what the future holds for the leafy seadragon. I, for one, am doing what I can to ensure generations after ours will continue to have their minds boggled by this incredible animal. If you care about seadragons, one way to help is to join citizen science projects such as iNaturalist or Seagrass Spotter. These projects collect observations from divers and snorkellers, directly helping scientists better understand and protect these animals and their habitats.

A short note about this blog: Two weeks after the poll I was awarded a research grant by the Sea World Research and Rescue Foundation to study the seadragons using eDNA. Hopefully the results that will come out of this research will help to better understand and protect these beautiful fishes.

Does climate change create damsels in distress? – Guestblog by Tanika Shalders

October 23, 2018October 23, 2018 / Maarten De Brauwer / Leave a comment

Tanika The latest guestblog on Critter Research is by Tanika Shalders. Tanika is a Technical Officer for the Marine Science Program at the Department of Biodiversity, Conservation, and Attractions in Australia. Her current work entails diving on some of the most amazing reefs in Australia and video analyses of surveys in Australian marine parks. In this guestblog she describes her recently published research on the effects of climate change on damselfishes.

It is currently spring in Australia, a lovely time to be outdoors. Nice temperatures (average maximum of 22), plants in full bloom, perfect picnic weather… just find a nice patch of grass, a cold beverage and some snacks.

Heatwave dog Summer is just around the corner and here in Perth it can get very warm, with an average maximum of 31 degrees (although temperatures up to 40 degrees are not unheard of). Unfortunately, picnics are not as pleasant this time of year. It’s hard to find shade, you’ll likely get sunburnt and your drinks will get warm.

What do you do when the temperatures become unbearable? Head to the coast to cool off in the ocean? Hide in the air-conditioning? Increase your ice-cream consumption? We try to make ourselves as comfortable as possible, moving to a cooler environment where we have everything we need – food, water and shelter.

With this in mind, it is no surprise to learn that other animals are doing exactly the same thing when ocean temperatures rise. Over the past 5 decades ocean temperatures have been increasing due to climate change. There has also been an increase in heat waves.

Heat waves are becoming increasingly common across the world

Many people connect these events to coral reefs, so it may come to some surprise that the ocean in temperate (southern/cool-water) Australia is warming at least twice as fast than the global average.

In 2011, the south-west of Australia experienced a heat wave. The heat wave lasted more than 10 weeks and temperatures increased up to 5 degrees above normal. This event caused massive changes to the marine environment of south-west Australia. One of the most significant documented impacts was the loss of kelp along the south-west coast. In the warmest area (north) kelp disappeared completely. Changes have also been seen in other organisms such as fish and crustaceans.

Ecklonia radiata, the kelp species which was greatly affected by the 2011 heatwave. Source: foragersyear.wordpress.com

After the heat wave, we decided to investigate if fish had also been impacted by the extreme temperatures. We chose to look at territorial damselfish since they are ‘site attached’. Much like the Hobbits of Middle Earth, they don’t like to leave home. These damselfish farm and protect algae which they use for food and reproduction. This trait makes them a good species to indicate of change as it is unlikely individual fish will move from their home to a new location. However, juvenile fish (recruits) may set up camp in new locations.

Using diver operated stereo-video (DOV), we investigated where these damselfish lived before and after the 2011 heat wave, and how many there were.

The damselfishes in this study. A) Parma occidentalis; B) Pomacentrus milleri; C) Parma mccullochi; D) Parma victoriae. Sources: Fishbase and Reef Life Survey

The main result was that the two (northern) warm-water damselfish became more common in the (southern) cooler waters. The two cooler-water damselfish showed less change.

We also saw a change in algae habitat. The kelp that dominated in 2006 had often been replaced by smaller forms of algae by 2015. This included the turfing algae such as those farmed by the damselfish.

So what does this mean?

These results show that both fish and their habitat are changing due to climate change. When warm water fish move to cooler water, they might push out the local cool water fish on their way south.

This process of warm water fish moving into cooler environments is known to the science world as tropicalisation – previously explained in a guest blog by the wonderful Dr Joseph DiBattista so I won’t go into detail here. Instead I will delve into one of the flow-on effects of tropicalisation: increased competition.

Tanika collecting Diver Operated stereo-Video (DOV) footage. Photo: Will Robbins, DBCA

Competition happens everywhere in the natural world. Plants compete for sunlight, lions compete for antelopes, and high school boys compete for the same girl. Usually competition occurs over food, water, shelter, or booty. Any additional players entering such a highly competitive environment can have devastating effects.

The movement of warm water fish into cooler waters could increase competition for the local fish populations. Since these damsels eat the same food and are very territorial, this means they not only have to compete with each other, but also with new damsel species. It’s hard enough to compete with your siblings for the last helping of dinner – imagine having to compete with your whole street!

Often this means that the local species will have retreat from an area once the invading species starts competing with them for food. Fortunately in this case, it looks like the change in habitat meant there was more food for the damselfish. It is likely that this helped to support a larger number of damselfish by reducing competition.

Most people are starting to become aware that climate change is an issue, sadly it’s a much bigger problem than most believe. Scientists are just being to scratch the surface of understanding the full reach of its impacts. If you would like to learn more about climate change and what you can do to help, please visit this site to find out more.

Tanika Shalders

Technical Officer, Marine Science Program

Department of Biodiversity, Conservation and Attractions

Twitter: @TanikaCShalders

Instagram: tanikacs

Research Gate: Tanika Shalders