Ambon and Halmahera fieldwork: Mini-blog 3 – Surveying Ambon’s reefs

In the previous fieldwork blog I wrote that we were about to leave on the boat to survey coral reefs around Ambon. So let me walk you through how our first week went.

Leaving Ambon took a bit more effort than expected, getting the necessary pre-departure paperwork signed off took 6 hours instead of 10 minutes, but we finally managed to leave late afternoon. We left under a rather gloomy sky, with grey clouds and scattered rain showers seeing us out of the bay instead of the bright sunshine we hoped for. But with an overnight boat trip ahead of us to get to the first sites, we could maybe wake up to blue skies.

That, unfortunately, was not meant to be…

Leaving Ambon

Gloomy Ambon skies

When I mention “dive expedition in Indonesia”, most people tend not to imagine grey skies and unrelenting rain, but the lush tropics wouldn’t be quite as lush without lots and lots of rain! Throughout the week we had plenty of rain, sometimes so much we had to postpone dives because of the limited visibility at the surface: the boat driver needs to be able to see the divers at the surface to pick them up when surveys are done.

 

But we had come to Ambon to study coral reefs, so (mostly) undeterred by the rain, we hopped in and started our work! The first thing we noticed was a conspicuous lack of…coral. We started surveys in an area with a lot of human fishing activity, and it showed, big time. We did not hear any blasts while diving, but there was a lot of evidence of dynamite fishing. Entire reefs were reduced to rubble, some places even had large bomb craters, something I had never seen before. I dread to think about the size of the bomb and the immediate impacts of its blast. A lot of explosive power is required to leave a 40cm deep, 1.5m wide crater underwater!

It wasn’t all bad news though, some places were showing slow signs of recovery, which could mean they hadn’t been bombed for a while. There were still some large fish left, nowhere near as many as there should be, but I did spot a few large groupers and emperors, and even a few adult blacktip reef sharks. We saw encrusting algae and small coral slowly starting to take hold in some places, although they were still a long way from becoming a real coral reef again. I would estimate it could easily take another 50-100 years for these sites to become a fully functional reef, even if they were left in peace and there were no other impacts.

 

After a couple of days of rain and survey dives that made our hearts ache, the team’s morale (or at least mine) had seen better days. Luckily, two things happened: we moved on to sites that had less fishing pressure and the sun started shining!

This part of the trip brought home just how rich coral reefs can be if you just use them in a less destructive way. Sites with very high and diverse coral cover, big schools of fish, lots of invertebrates, funky critters, everything you could want in a dive. This time our only regret was that the tight schedule didn’t give us time to explore each site more thoroughly. Between trying to count and identify large schools of mixed fish species, processing eDNA samples and entering data, little time was left to do anything else than eat and prepare for the next dive. Not that I’m complaining though, being able to work on reefs like this is a privilege that never gets old.

We were also privileged to see some of Ambon’s funky critters. During quite a few dives we came across ghostpipefish (Solenostomus paradoxus and S. cyanopterus), a rare sight on standard coral reef surveys. Our invertebrate expert had his work cut out counting a variety of nudibranchs, shrimp, cowries, and anything in between. Even the algae crew got more fish than they bargained for when a giant frogfish (Antennarius commersoni) decided to swim by and say hello.

 

Despite some adverse weather and a slow start, we finished surveys within the planned time and arrived back in Ambon Bay two days ago. Our two days on land were put to good use, catching up on data entry and admin, meetings, and even catching a movie last night (Joker, pretty good actually). Tomorrow we leave at first light for a longer trip. We are headed to Halmahera, an area where precious little information exists on the health of coral reefs. If all goes according to plan, I should be able to write an update from Ternate in about 6 days!

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Ambon and Halmahera fieldwork: Mini-blog 2 – Logistics

I have made my way to Ambon since the last blog, where I have been preparing the last logistics with my local colleagues from Pattimura University before the actual fieldwork begins. In the last 3 days, the other team members have also started arriving, with the final team member (and master fish counter) landing tomorrow morning. The main things that had to happen before our boat leaves port (besides recovering from jetlag), was organising a detailed plan, training new team members, and preparing all the gear. 

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Cloudy Ambon days

One of the things we will be doing, is collecting environmental DNA (eDNA) to study biodiversity on coral reefs. If you want to know more about eDNA, I have written more about it here or here. In short: eDNA are tiny fragments of DNA in the water column that come from poop, mucus, etc. By filtering and analysing a scoop of water, we can tell what lives in the area we took water from. Because eDNA is such a new method, most people have not used it before. So in a great mutual benefit arrangement, our Pattimura University colleagues took us (my colleague Dom and me) out for a dive and in return we showed them how to collect water 😉

We obviously did more than just collecting seawater, we also went back to the lab to teach them the protocols on how to filter samples while avoiding contamination. Since eDNA analysis is so good at picking up the tiniest fragments of DNA, a careless brush of a fingertip can render the entire sample useless. We are collecting data from a boat instead of a high-tech lab, so being aware of how things can go wrong is absolutely crucial to get reliable data.

Tomorrow morning we set sail (start engine?) for 10 days of research around Ambon. So today we had make sure all the equipment got to the boat, for us to leave at first light in the morning. Between dive gear (including compressors, tanks, etc), survey tools, eDNA equipment, and other random practical bits and pieces, it took multiple returns trips with the pickup to get everything to the boat. Science is of course hungry work and feeding 16 people takes a lot of grocery shopping, which was luckily taken care of by our local team. Gino (our Ambon trip leader) has assured me we have an excellent chef on board, so be aware that there is a decent chance that the rest of these fieldwork blogs will mostly be about tasty Indonesian food!

As we will be on a boat for quite a while in the next weeks, I am not sure yet if I will be able to post blogs until we are back on the mainland. If I can snatch up some 4G signal along the way, you’ll be able to read an update on the fieldwork in a couple of days. Otherwise, the next blog will be online around the 11th of October.

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Sunny Ambon days

Ambon and Halmahera fieldwork: Mini-blog 1 – Departure

It’s that time again! I am on my way to do fieldwork and I will try to post regular, small updates so everyone can follow along with what we’re up to. In the coming month I’m hoping to post at least 4 – 5 mini-blogs (depending on internet speed), so keep an eye out for updates.

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It’s fieldwork time! Photo: Luke Gordon

I am writing this first blog from an airport hotel in Makassar. It took me a train ride and 3 flights (Manchester – Doha – Jakarta – Makassar) to get this far, but I’m not quite where I should be yet. A ridiculously early flight (4:00am) tomorrow will get me to Ambon, where the fieldwork will start. Doing research in remote areas is fun, but it also means 3-day trips to get where you want to be.

The reason our team (more on them later) wants to be in Ambon, is to do research on the biodiversity of Indonesian coral reefs. We are trying to investigate how coral reefs function (or stop to function) when they are affected by human actions like overfishing or pollution.

To do this, we will be working from a boat for most of October, hopefully visiting more than 30 different sites in Ambon and Halmahera. We’ve got a team that is specialised in different topics, people will be counting fish, identifying corals, collecting environmental DNA, mapping reefs, etc. Exciting stuff with hopefully some useful results!

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Survey sites for the upcoming fieldwork

Getting everybody at the right place at the right time can be challenging enough. I flew in from Leeds (UK), but other people are flying in from Germany, Jakarta, and Makassar. Our aim is to leave Ambon harbour on the 1st of October, with most of the team arriving the day before. But sometimes nature can get in the way of even the best planning…

Today two earthquakes have rocked Ambon, causing quite a lot of structural damage. The boat (as far as I am aware) is fine, but unfortunately the damage to the city is quite large. Luckily human casualties seem low at the moment. In any case it is likely that organising the food and other practical matters in the next few days will be more complicated than expected.

In the next post I will go into a bit more detail about the science behind this trip, and ideally I will also have some updates about the situation Ambon.

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Marine science fieldwork and packing lightly don’t go well together

New publication: Flash photography impacts on fish – To flash or not to flash?

The final paper of my PhD thesis has just been published online in the journal Scientific Reports. The paper, titled “Behavioural and pathomorphological impacts of flash photography on benthic fishes” explains the effects of typical diver behaviour while photographing small critters such as seahorses or frogfishes.

The paper itself can be a tad technical, so with the help of two co-authors (Dr. Ben Saunders and Tanika Shalders), I wrote this summary of the research, which was published first at The Conversation (original article here).


We all enjoy watching animals, whether they’re our own pets, birds in the garden, or elephants on a safari during our holidays. People take pictures during many of these wildlife encounters, but not all of these photographic episodes are harmless.

There is no shortage of stories where the quest for the perfect animal picture results in wildlife harassment. Just taking photos is believed to cause harm in some cases – flash photography is banned in many aquariums as a result.

But it’s not always clear how bright camera flashes affect eyes that are so different from our own. Our latest research, published in Nature Scientific Reports, shows that flash photography does not damage the eyes of seahorses, but touching seahorses and other fish can alter their behaviour.

Look but don’t touch

In the ocean it is often easier to get close to your subject than on land. Slow-moving species such as seahorses rely on camouflage rather than flight responses. This makes it very easy for divers to approach within touching distance of the animals.

Previous research has shown that many divers cannot resist touching animals to encourage them to move so as to get a better shot. Additionally, the high-powered strobes used by keen underwater photographers frequently raise questions about the welfare of the animal being photographed. Do they cause eye damage or even blindness?

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Does flash harm fishes? Photo: Luke Gordon

Aquariums all around the world have taken well-meaning precautionary action. Most of us will have seen the signs that prohibit the use of flash photography.

Similarly, a variety of guidelines and laws exist in the scuba-diving community. In the United Kingdom, flash photography is prohibited around seahorses. Dive centres around the world have guidelines that include prohibiting flash or limiting the number of flashes per fish.

While all these guidelines are well-intended, none are based on scientific research. Proof of any damage is lacking. Our research investigated the effects of flash photography on slow-moving fish using three different experiments.

What our research found

During the first experiment we tested how different fish react to the typical behaviour of scuba-diving photographers. The results showed very clearly that touching has a very strong effect on seahorses, frogfishes and ghost pipefishes. The fish moved much more, either by turning away from the diver, or by swimming away to escape the poorly behaving divers. Flash photography, on the other hand, had no more effect than the presence of a diver simply watching the fishes.

For slow-moving fishes, every extra movement they make means a huge expense of energy. In the wild, seahorses need to hunt almost non-stop due to their primitive digestive system, so frequent interruptions by divers could lead to chronic stress or malnutrition.

The goal of the second experiment was to test how seahorses react to flash without humans present. To do this we kept 36 West Australian seahorses (Hippocampus subelongatus) in the aquarium facility at Curtin University. During the experiment we fed the seahorses with artemia (“sea monkeys”) and tested for changes in their behaviour, including how successful seahorses were at catching their prey while being flashed with underwater camera strobes.

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The aquaria were the seahorses were housed during the experiment

An important caveat to this experiment: the underwater strobes we used were much stronger than the flashes of normal cameras or phones. The strobes were used at maximum strength, which is not usually done while photographing small animals at close range. So our results represent a worst-case scenario that is unlikely to happen in the real world.

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West Australian seahorses (Hippocampus subelongatus) in their aquarium at Curtin University

The conclusive, yet somewhat surprising, result of this experiment was that even the highest flash treatment did not affect the feeding success of the seahorses. “Unflashed” seahorses spent just as much time hunting and catching prey as the flashed seahorses. These results are important, as they show that flashing a seahorse is not likely to change the short-term hunting success (or food intake) of seahorses.

We only observed a difference in the highest flash treatment (four flashes per minute, for ten minutes). Seahorses in this group spent less time resting and sometimes showed “startled” reactions. These reactions looked like the start of an escape reaction, but since the seahorses were in an aquarium, escape was impossible. In the ocean or a large aquarium seahorses would simply move away, which would end the disturbance.

Our last experiment tested if seahorses indeed “go blind” by being exposed to strong flashes. In scientific lingo: we tested if flash photography caused any “pathomorphological” impacts. To do this we euthanised (following strict ethical protocols) some of the unflashed and highly flashed seahorses from the previous experiments. The eyes of the seahorses were then investigated to look for any potential damage.

The results? We found no effects in any of the variables we tested. After more than 4,600 flashes, we can confidently say that the seahorses in our experiments suffered no negative consequences to their visual system.

What this means for scuba divers

A potential explanation as to why flash has no negative impact is the ripple effect caused by sunlight focusing through waves or wavelets on a sunny day. These bands of light are of a very short duration, but very high intensity (up to 100 times stronger than without the ripple effect). Fish living in such conditions would have evolved to deal with such rapidly changing light conditions.

This of course raises the question: would our results be the same for deep-water species? That’s a question for another study, perhaps.

So what does this mean for aquariums and scuba diving? We really should focus on not touching animals, rather than worrying about the flash.

Flash photography does not make seahorses blind or stop them from catching their prey. The strobes we used had a higher intensity than those usually used by aquarium visitors or divers, so it is highly unlikely that normal flashes will cause any damage. Touching, on the other hand, has a big effect on the well-being of marine life, so scuba divers should always keep their hands to themselves.

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Look, take pictures, but don’t touch!


NOTE: I realise that this is a controversial topic in underwater photography. If you have relevant questions, comments, or thoughts you want to share, feel free to add them in the comment section below. If you are interested, I would highly advise you to read the original research paper via this link. The paper is open access, so anyone can read and download it. If you have specific questions about the paper, you can always contact me via email here.