The Blue Carbon Lab recently helped run three citizen science workshops at Truganina Wetland, a 175-hectare area of Biodiversity Significance containing critical habitat for threatened and protected flora and fauna. This wetland is however degraded in several areas and faces various threats to its health as an ecosystem.
These workshops focused on identifying such threats, collecting data, and providing options for protection and restoration. The first workshop looked at saltmarsh vegetation and carbon stock, the second on invasive weeds and plastic pollution, while the third was geared towards demonstrating various blue carbon research techniques and putting them into action to survey the current status of this wetland. Citizen scientists from the local area were able to learn about blue carbon and wetland ecosystems, the negative impacts of invasive weeds and plastic pollution, and how wetlands can be restored and protected.
The first workshop included citizen scientists from Intrepid Travel and focused on vegetation surveys and sediment cores. The banks of Laverton Creek as well as areas within the nearby nature reserve were surveyed for saltmarsh and other vegetation, while several sediment cores were taken to examine carbon stock. The data collected by these citizen scientists in this workshop will be used to advise work conducted on this site to ‘shave’ the creek bank to promote expansion of saltmarsh vegetation.
For the second and third workshops we were joined by citizen scientists and student volunteers from Hobsons Bay Wetlands Centre. During the second workshop the group split in two, with one half undertaking weed surveys while the other conducted plastic surveys in a different part of the wetland. The groups then switched over so that everyone had a chance to complete both activities.
The citizen scientists learned about several key environmental weeds at Truganina and how to identify them, such as serrated tussock (Nassella trichotoma), spiny rush (Juncus acutus) and Chilean needlegrass (Nassella neesiana). The presence and status of these and other high threat weeds was recorded within 12 plots split between two sites within the wetland. The sites had a mixture of grassland and saltmarsh species, as well as varying ratios of native versus invasive plants. It is important for the future management of this area to know exactly which invasive weed species are present, how prevalent they are, and how this may change over time. This knowledge is critical to create a weed management plan and should prove valuable to ensuring the gradual formation of a functional ecosystem featuring a large proportion of native plants. As such, it is also important to recognize the native plants present across the site, and citizen scientists learned to identify many of these and estimate their percentage cover across each plot. Native plants can be vital to promoting biodiversity – for example, the Chaffy Saw-sedge (Gahnia filum) present in Truganina Wetland provides the only suitable habitat for the critically endangered Altona Skipper butterfly (Hesperilla flavescens).
Plastic pollution is another important issue for many wetlands, as Dr. Tanveer Adyel described in a talk to the citizen scientists. Each group was unfortunately able to find plastics in the form of bottles, bags and other litter during their surveys. Additionally, several sediment cores were taken and the top 5cm sieved in order to search for microplastics. Both macro and micro plastics can cause problems in a wetland such as Truganina by contaminating the environment and negatively affecting the health of many plants and animals. Because they do not degrade as other materials do, they remain in the ecosystem well into the future, exacerbating the problem over time. Therefore, it is very important to investigate how much plastic pollution is present in a wetland and its composition in order to better protect and restore the ecosystem.
In the third and final workshop, citizen scientists were able to learn about various techniques used by researchers to study and monitor blue carbon ecosystems. Dr. Melissa Wartman gave a talk introducing coastal wetland and restoration research before several field techniques were demonstrated. These included burying tea bags to measure carbon decomposition rates, sampling sediment using PVC cores, vegetation surveys, saltmarsh species identification, and more. Citizen scientists were then able to conduct fieldwork utilizing these techniques themselves in order to survey the current status of this degraded wetland.
The data collected during these workshops in, addition to the knowledge gained by members of the local community, should provide a valuable contribution to future management of this ecosystem. Many thanks to everyone who came along to each event and tried their hand at wetlands research for the day.