Purple Grant Research Fellow Spotlight: Understanding Seagrass Meadows and Green Turtle Foraging in Bira

Completing fieldwork is a major milestone for any early-career researcher, particularly when that work takes place in under-studied and under-protected marine ecosystems. Through the Purple Grant, Indo Ocean Project supports students conducting meaningful, field-based research that contributes directly to marine science, conservation, and management in Indonesia. This grant is made possible through the support of Purple Dive Penida and Daughters of the Deep, whose shared commitment to empowering the next generation of ocean professionals helps turn research ideas into real-world impact.

In this interview, Purple Grant Research Fellow Anggi reflects on her recently completed fieldwork in Bira, South Sulawesi. Her research focuses on the relationship between seagrass meadows and green turtle foraging activity, an ecological interaction that remains poorly understood in many parts of Indonesia. Below, Anggi shares her motivations, methods, challenges, and reflections in her own words.

Research Focus and Motivation

Understanding why a researcher chooses a particular topic often provides important context for the work itself. We asked Anggi to explain the core focus of her thesis and what drew her to study seagrass ecosystems and green turtles in Indonesia.

Why did you choose this research topic, and what drew you to study it in Indonesia?

I love seagrass!

Seagrass is one of the most important marine ecosystems and plays crucial ecological roles, just like coral reefs and mangroves. But the way we often see and treat seagrass is different, it’s underrated and least protected. I tend to hear warnings like “don’t touch coral” or “don’t cut mangroves,” but I barely hear “don’t step on seagrass,” at least during my fieldwork. Scientifically, United Nations Environment Programme (UNEP) reports that only 26% of recorded seagrass meadows fall within marine protected areas, which is much lower compared with 40% of coral reefs and 43% of mangroves.

One of the roles of seagrass is as a food source for herbivores, such as green turtles. Seagrass can perform photosynthesis and absorb carbon, which is then converted into biomass through growth. This biomass is subsequently consumed by green turtles.

Indonesia is historically recorded to have approximately 17 seagrass species (although not all of these species are currently confirmed to persist) and is also a key habitat for green turtles. However, the ecological interactions between seagrass and green turtles remain poorly understood in Indonesia, particularly regarding how seagrass availability influences turtle presence and how grazing by green turtles affects seagrass distribution and biomass, especially in under-protected areas. That’s the reason why I chose this research topic and decided to conduct it in Indonesia.

What gap in existing knowledge does your research aim to address?

In Indonesia, many studies have focused on seagrass density, and some recent studies have also examined biomass and carbon stock, while research on sea turtles, particularly on nesting habitats, is also fairly well documented. However, studies examining the relationship between seagrass biomass and green turtle foraging activity are still limited, especially in Bira, a marine unprotected area, where no such research has been conducted.

Similar studies were conducted in West Wawonii (Muhtar et al., 2019), but they only looked at seagrass density and did not include biomass, even though biomass better reflects the amount of organic matter available and is crucial for assessing the ecosystem’s capacity to support herbivores like green turtles. Other studies linking seagrass biomass with turtle foraging were conducted in Derawan Island (Christianen et al., 2014; Roem, 2012), but none focused on Bira. In this study, we aim to investigate the relationship between seagrass biomass and its use by turtles (foraging activity) in Bira. Additionally, we also consider seagrass density. This allows us to demonstrate that seagrass density and biomass are not always linearly correlated, highlighting why biomass is a more appropriate parameter for understanding how green turtles utilize seagrass meadows.

Fieldwork and Methodology

Field research rarely unfolds exactly as planned. In this section, Anggi outlines the methods used during her fieldwork and reflects on the realities of collecting data in dynamic coastal environments.

What field methods or data collection techniques will you be using during your research?

In this study, I collected data on seagrass density, coverage, distribution, occurrence frequency, and biomass, as well as on green turtle sightings and foraging activity. Seagrass density was measured using the transect-quadrat method, by counting the number of shoots within each quadrat to calculate density per square meter. This method also allowed us to determine seagrass distribution and calculate its occurrence frequency. Seagrass coverage was estimated using the canopy cover method, which visually measures the percentage of area covered by seagrass, while seagrass biomass was determined using the harvesting method, where samples were collected, dried, and weighed to obtain dry weight biomass.

Green turtle sightings were primarily observed using a drone, with flights conducted at each station in the morning, noon, and afternoon, depending on tidal conditions. When drone flights were not possible due to weather, a monocular was used as an alternative. The method adapted principles from BRUV to record the maximum number of turtles observed in a single frame at a specific time and location. In addition, drone observations were used to identify foraging behavior, focusing on the dive duration and activity of individual turtles. When possible, follow-up underwater observations using a camera were conducted to record detailed feeding behavior, such as the number of bites or feeding strokes per dive.

What has been the most challenging part of planning or conducting your fieldwork so far?

Tides!

They proved to be the most challenging part of the fieldwork, especially during seagrass surveys. When the tide rose too high, it limited our movement, so each time we conducted surveys, we could only complete two transect lines in a day. Nevertheless, it turned out to be one of the most valuable experiences. By racing against the tides, my only teammate and I had an unbeatable level of support for each other to complete the surveys, and we also became better at predicting the best times to enter the water for data collection.

Has working in the field changed the way you think about your research question? If so, how?

Basically, working in the field made me realize that collecting data on green turtles, especially using my chosen method, was not as simple as I initially expected. The actual field conditions required me to adapt frequently, which changed how I understood and approached my research question.

The Role of the Purple Grant

The Purple Grant is designed to remove practical barriers to research and allow students to focus on data collection, learning, and growth. Here, Anggi reflects on what this support made possible.

How has receiving the Purple Grant supported your research in practical terms?

Receiving the Purple Grant has enabled me to access equipment not provided by my faculty, such as a drone, underwater camera, and monocular. With this grant, I could have speed boat transportation, making it easier to reach my research sites quickly, making the fieldwork more efficient. Also, a cozy place to rest after the day, surrounded by people who were always excited to hear my daily updates from the field (Blue Planet, I’m into you!). Overall, thanks to this grant, my research was able to be conducted, and as a bonus, I was able to unlock a new technical skill, operating a drone!

What would not have been possible without this funding?

Without this grant, I would not have had access to drone surveys, underwater cameras, or monocular as alternative equipment, making it impossible to collect data on green turtle activity and link it with seagrass biomass, which is a central component of this research.

Reflections and Learning

Beyond the data collected, this project also shaped how Anggi approaches research, problem-solving, and her own development as a scientist.

What has been your biggest learning moment or turning point during this research project so far?

I initially believed that my methodology was well prepared, as I had conducted preliminary surveys and considered an alternative method. However, completing the fieldwork revealed that this alternative was not well aligned with the actual field conditions. This became a turning point for me, highlighting the need to engage more deeply with the literature, compare methods across different contexts, and seek input beyond a limited number of sources. I learned that while multiple perspectives may feel overwhelming, they lead to more informed choices than relying on only one or two options.

How has this experience influenced your confidence as an early-career researcher?

I have conducted fieldwork quite often before, so when I encountered challenges during my research, I was able to handle them relatively quickly. However, there was one change that I clearly noticed in myself. I tend to be an introverted and nervous person, but when I was in Bira, I had the opportunity to present my preliminary results and I did it!, even though I didn’t know I could. During the writing process, I sometimes felt stupid and lost, but this pushed me to read more scientific papers and stay curious. The confidence and curiosity that I gained from this experience made me realize that I have grown, and as a beginner, this growth will be valuable as I continue my career as a researcher.

Looking Ahead

Research does not end with a thesis submission. In this final section, Anggi shares how she hopes this work will continue beyond her degree.

What are your next steps after completing your thesis?

After completing my thesis, I hope to share my research by presenting it at symposiums and publishing it, so it can reach more people and open space for discussion and feedback. Through this process, I also want to build connections with others in this field. Moving forward, I aim to work in marine conservation as a form of dedication to protecting marine ecosystems, while gaining hands-on experience and gradually shaping the direction of my future studies.

Do you see this research continuing beyond your degree, either through publications, conferences, conservation work, or further study?

Yes, I do! It can continue beyond my degree because the data collected are relevant not only for academic purposes but also for conservation and management either for seagrass or green turtle. The findings can be shared through publications or conferences and may be useful for future conservation work or further studies on seagrass and green turtle foraging habitats.

How do you hope your findings will contribute to marine science, conservation, or management in the region?

Bira is known as a tourism area with high levels of tourism activity, such as snorkeling, diving, and other water-based recreation. If not well managed, these activities can place pressure on marine ecosystems in Bira, like seagrass meadows. Through this research, I hope to highlight the close relationship between seagrass and green turtles in the area, showing that both depend on and influence each other. Therefore, these findings are expected to support more sustainable regional management in Bira through education and the implementation of a clear code of conduct for tourism activities, so that seagrass habitat protection receives greater attention.

What advice would you give to students or early-career researchers who are considering applying for the Purple Grant in the future?

Start with reading, as it will help you clearly define your research objectives and methods, making the research process more effective and enabling you to respond quickly when unexpected challenges arise.

Mistakes may happen, especially when you are a beginner. Realising that you have made a mistake does not mean failure, but rather a sign that you are learning.

At the end, always return to reading, and let curiosity lead the way.