Field work – Counting sea urchins on the seashores of Singapore

Together with my supervisor, Dr Serena TEO, we were awarded a grant from the Marine Science R&D Programme, supported by the National Research Foundation to conduct studies and develop tropical model marine organisms for experimental research.

On top of marine science experiments, marine animals are also increasingly being used as model organisms in multi-disciplinary studies such as evolution, developmental biology, biomedical sciences, biomimetics, and biophysical engineering. Current examples of model marine organisms include the tunicate (or ascidians), sea urchins, and marine snails.

In Singapore’s context, with so few habitats and sea space, experimental research is challenging as every field collection becomes a threat to natural populations. Hence, the other motivation of this project is to reduce collection pressures on wild populations by establishing culture protocols and stocks of local species, so that they may be readily available for experimental research. As a start, we are focussing on three groups of marine invertebrates: ascidians, tubeworms, and sea urchins. And I’m taking charge of the sea urchin component! 🙂

So you’re wondering now, how does counting sea urchins on the seashores help us in our project?

How many sea urchins can you spot? Photo credits: Lynette YING.

First, before we get ahead of ourselves and attempt to culture the species, we must first establish a baseline of natural populations. For our work to succeed, we will require a steady supply of parent urchins. Hence, field surveys of target species will help us understanding the following:

  • Population numbers of sea urchins in the wild
  • Sea urchin size and weight classes – from the babies to the adults, what is the size and weight range?
  • Characteristics of the environment where the sea urchins are living
  • Other observations: Natural recruitment (i.e. season of baby urchins!)

Our goal is to eventually reduce (or eliminate) dependence on field collection, and be able to produce a sustainable supply of sea urchins for experimental research! 😀

The following photographs show our work in the field, and how we perform data collection. With this information, we are better informed on which populations can be retrieved for cultures, and when is the best time to collect mature adults for spawning.

Field survey methodology. A) Sediment cores. B) Line intercept transect. C) and D) Counting, measuring and weighing sea urchins.
Field surveys give us a snapshot of how sea urchin populations change over time.
The team works very hard to quickly count, measure and weigh the sea urchins before the tides sweep us away!
Now you see me, and now you don’t! This sea urchin species carries broken shells, seagrass and seaweed on its body, and in the process, camouflaging itself against the background of habitat.
‘Count me! Count me too!’ says Biscuit seastar.
Other interesting marine animals on the seashores. Clockwise from left: Sundial snail, Feather star, and Knobbly seastar.
Fieldwork on remote patch reef, Cyrene Reefs. Spot the rainbow!

Acknowledgements: This new project is supported and funded by the National Research Foundation (Singapore) under the Marine Science R&D Programme. We also thank National Parks Board for granting permission to access the respective study sites.

Stay tune to my page for updates on our new project! 🙂