Diving on Silba Island, Croatia

Hi! My name is Aidan and I have just completed a 4 week long internship with Operation Wallacea in Croatia on the island of Silba. There’s been so much to see, so much to do so I’ll try and keep it as concise as possible!

So, I arrived on Silba island on the 1^st of August and from the very first day was given an opportunity to get myself underwater. And let me tell you, there may be better places to dive than Silba, but they are very few and far between! The waters are so crystal clear, there are fish almost everywhere and its not cold, not even a little bit! Our first dive was just to make sure weights were correct, to see if we could correctly prepare the dive kit and we all passed with flying colours.

Photo by Hrvoje Cizmek

After the first dive, we got into the weekly schedule going forward. This mainly consisted of receiving lectures from the on site marine lecturer, Esmee or our Ngo contact, Barbara. These covered introduction to the native biodiversity around Silba which was typical Adriatic, mostly consisting of small grey fish, but also contained some small hermit crabs, sea cucumbers and sea urchins. Speaking of sea cucumbers and urchins, we also received lectures on how to survey sea urchin and cucumber populations, how to take measurements and to speciate between different urchin species. We also received lectures on how to survey seagrass beds by using Line Impact Transects (LIT) and measure rhizome numbers with quadrats, alongside learning how to measure Adriatic teleost biodiversity using FAST fish surveys, a form of underwater visual census (UVC) surveying incorporating body sizes and repeats.

My primary duty on Silba was to assist another intern with collecting data on Adriatic benthic biodiversity, with my role being focused on photographing the underwater quadrats and measuring the target fauna species that was proposed. It was great and it allowed me to use my underwater camera and develop my skills as an underwater photographer, including framing and macrophotography. I also became far more accustomed to identifying Adriatic species and used this experience to help train up other research assistants on the method.

Photo by Emilia Murcott

At the start of week 3 of my expedition, I was offered a unique project: the local NGO partners wanted to update their biodiversity index and asked if I could take photographs whilst diving and identify species captured. This gave me a wonderful opportunity to take ownership of some research that truly was mine, which is a skill I was longing to improve. By the time my internship was finished, I had identified ~ 90 species of fauna and flora, including some species which hadn’t been previously recorded in local waters, such as the European lobster H. gamarus (Fig. 1) and the invasive Giant monkdragon M. viridis (Fig. 2).

As you can see, a lot of my work focused on the use of underwater photography. And whilst for many it is a hobby, photography either terrestrial or marine, is paramount for conservation efforts. This is because that photography provides tangible evidence of species presence, which can be further refined to date and locate when a species was seen as most cameras record location and date of when photographs were taken. This is naturally very important for conservation management because alternatively relying on anecdotal evidence runs several risks – the first and most obvious being misidentification of a species, whereas photographs allows for direct comparisons to ID books. Photography also comprises an important aspect of invasive species management as when an invasive species is detected, information like date and location can provide a baseplate to model the future spread and where population management will be needed, in addition to understanding how the invasion potentially occurred.

Photo by Frances Budd

So in conclusion, the 4 weeks I spent in Silba were spent faster than I could have imagined! I took part in several research projects and collated data for several large datasets alongside improving skills of interest such as leadership, ownership and species ID. I can’t wait to go back to Silba and even though it hasn’t been long since I left, I still miss the site dearly. I hope anyone who reads this will quash the doubts about going on expedition and once more: it is SO worth it!!!

Best Fishes,

Aidan (@Ac._.tkd)

Title photo by Shearer Shez Viljoan