High school students investigate Moreton Bay’s declining health

The following research report has been contributed by students Michaela Taylor-Williams, Jess Peart and Caitlin O’Shea, who all recently attended Earthwatch‘s research challenge at Moreton Bay, Queensland.

As part of the Earthwatch Student Challenge, our group was lured to Queensland by the prospect of witnessing the “Snorkel for Queensland’s Marine Mammals,” which happen to feature the charismatic dugong. We were given an opportunity to swim with these splendid creatures on North Stradbroke Island, just outside of Brisbane. But perhaps more importantly, our work was to help pave the way for future environmental management of the area, to help save it for future generations.

The start of our adventures began on the flight to Brisbane. The team consisted of a diverse range of environmentally-conscious secondary students from all over Australia. We met up at Brisbane airport, some of us bleary eyed after flying for over 12 hours and others still perking up after a quick flight from Melbourne. There, we met our team leaders Cass and Kate and eventually set off for North Stradbroke Island in a van, taking the ferry to Dunwich.

On our arrival at Moreton Bay research station (which we would call home for the next week), we received a safety briefing in which we learnt about any and all potential hazards, including dangerous sea creatures such as sharks, blue bottle jelly fish, blue ringed octopuses, razor clams, and more. Thankfully we did not have any bad encounters and did not have to use any of info from the briefing. We then got a chance to walk around and explore the town of Dunwich, quickly finding the ice cream and souvenir shop. After one more presentation on the work we would be doing, and the end of a very long day for some, we decided the best thing would be to get an early night sleep as we would have to be up by 6.15am to begin our research.

On Day Two, the hard work began, our team was led by chief scientist Dr James Udy, along with Dr Paul Maxwell and Dr Tim Stevens. These experts assisted our team in fieldwork activities, and also taught us the importance of the bay, as well as the role each organism plays in its maintenance and protection.

Overview of Methodology

Our main task on the expedition was to survey the density and health of seagrass in the Moreton Bay area, paying particular attention to a common species of seagrass called Zostera marina. Seagrass plays an important role in the maintenance of Moreton Bay and is crucial in the bay’s vast array of biodiversity. It is a vital microenvironment that works to filter nutrients, stabilise sediment, and serves as a feeding and breeding ground for many marine creatures, not least of which is the beloved dugong.

One of the techniques used to observe the health of the bay is with Baited Remote Underwater Video Stations (BRUVS). BRUVS are used to observe and record the relative abundance and diversity in the bay as well as monitor different behaviours displayed by the various sea creatures. The BRUVS were placed in different areas, some in patches of Zostera marina, while others were placed in sandy patches to examine the differences in biodiversity of the different habitats.

To study the Zostera marina, the team took samples of the seagrass – a cylindrical PVC pipe was used to cut out a circular patch from the sea floor. In order to take the core sample, a brave soul holding their breath would furiously try to dig the core into the ground, while another team member helped to hold them down so they would not keep floating back to the surface. These core samples were then used to analyse the amount of seagrass, its health and how it was adapting to the change in water quality.

At times, the water in the bay was too deep to dive to the bottom, so sled cameras were used instead. These cameras were lowered to the sea floor, where live footage was viewed on the boat above. As the sled was pulled along, the team got a chance to see what was happening on the bottom and to identify if there was seagrass and what type. Sediment samples were also taken using a claw that was lowered to the sea floor and then dragged back up with the soil and sand which was then collected for later analysis.

An important aspect of the expedition was the mapping of the extent of coverage of seagrass in the bay. At given GPS locations, a diver from the boat would jump in the water, look around and then report back to the team the type and amount of seagrass, the soil type, and if they saw anything else such as coral or algae. The data was then used to update a map that allowed comparison with past data, so that scientists can chart the rise and decline of the health of the bay.

The Findings in Brief

From the data collected, preliminary analysis showed that the seagrass was declining in many parts of the bay. This is evidence of the decline in the water quality of Moreton Bay, as many areas that were covered in seagrass just a few years back are now sand, while places that were once teeming with coral is now just coral debris.

The data collected will also be used in the future to understand the effects of pollution from Brisbane and the surrounding areas and how Moreton Bay is changing. It will also be used in the Healthy Waterways annual report card, to assess Moreton Bay and inform readers of the impact of pollution on the marine life, and the economic impact due to the change in water quality.

What we accomplished through the expedition was the collection of a huge amount of data that will be used by scientists to understand the impact of humankind on Moreton Bay. But on top of that, all of the expedition members had a special, once-in-a-life-time experience that we will carry with us always.

The expedition gave us a glimpse of how broad research can be. While some scientists work in labs where everything is white and sterile, others work where the outdoors is their laboratory. These scientists do research from boats, while diving into a world most only see in pictures. At the end of the day they are covered in salt and sand, but their mind is filled with images of coral and seagrass, and fleeting but exciting sightings of the animals that live there – sea turtles, manta rays, sharks, and especially the dugongs.

Being part of this Earthwatch experience was an amazing opportunity to literally get our hands dirty and feet wet, doing real science, and seeing what pollution can do to the gorgeous waters of Moreton Bay. We now feel even more inspired to continue to take care of our oceans and seascapes, so that the next generation can share our experiences.