I have just returned to Sorong, after another fantastic trip aboard the beautiful Dewi Nusantara around northern Raja Ampat, West Papua, Indonesia. This was the first of Paul Humann, Ned and Anna DeLoach’s two charters,
so, as you might expect, we have been excitedly looking for all manner of weird and wonderful sea creatures – I’ve been in my element!
My highlights for this trip included snorkelling with an inquisitive dugong (Dugong dugon) in northern Batanta Island, observing and photographing my first baby Pewter angelfish (Chaetodontoplus dimidiatus) in Aljui Bay in northern Waigeo and seeing a tiny newborn tasselled wobbegong shark (Eucrossorhinus dasypogon) back in Batanata.
It struck me that the words ‘wobbegong’ and ‘dugong’ must have a similar derivation, so I contacted my dear friend, and wobbe-botherer, Jo Stead to clear up the origin of the shark’s name. Apparently, ‘Wobbegong’ means ‘bearded fish’ in an aboriginal Australian language. I need to do more research, but I imagine ‘dugong’ must also mean ‘something-fish’. In any case, the dugong was my first ever in-water experience with these elusive mammals. I went snorkelling with one of the trip’s guests, Holmes. Something caught my eye, I looked into the distance and the dugong came towards us. It circled several meters below us before swimming off after what seemed like hours, but was more likely tens of seconds to a minute.
No less exciting, was the baby wobbegong shark. It was so small it would have fit in the palm of my hand. Wobbegongs are live-born, and resemble miniature versions of their parents on birth. It sat motionless in the centre of a vase sponge, waiting for some prey to happen past it. The baby pewter angel was also a great sighting. These fish are found only at scattered locations of northeast Indonesia, and it seems that relatively few images exist of the adults, let alone the juveniles too.
Whilst you may have heard about the impending global coral bleaching event that is being tracked by NOAA scientists, I am happy to report that I have made no observations, as yet, of coral bleaching from Raja Ampat. Coral bleaching events, such as the massive one in 1998 that killed 16% of the world’s hard corals, are a result of the El Niño phenomenon and are a very real threat to the coral reefs of the world. Although fine at the moment, the warming waters that cause bleaching are forecast to spread over the coming months, so we will have to wait and see how the world’s reefs fare with this onslaught. Check out this link to read more about the present global bleaching event forecast – it’s a sobering read.
Funnily enough, Raja Ampat has been facing the opposite effect recently. We have experienced relentless and unseasonal south winds with unexpectedly cool waters for this time of year. Usually 28-29˚C, we have had at least 2-3˚C degrees less than this at several of the sites we’ve dived. Luckily, we planned to stay north for this trip and have enjoyed stunning visibility in the Dampier Strait and been able to dive in some areas of north Waigeo, which are usually inaccessible. We’re already very excited about the next trip, which promises some exciting diving as ever!
If you’d like to see some more of my images from the trip, please check out my gallery HERE.
Originally written for BirdsHeadSeascape.com, and based on this trip, I wrote about my recent rekindled interest in damselfishes for their blog ‘Bird’s Head Natural History Notes: In Appreciation of Damsels‘. You can read this on the fantastic BHS website by following this link (coming soon) or read below. The BHS is an online collective, funded in part by Conservation International (one of the beneficiaries from our own ‘Our Beloved Seas’ trip donations – OceanRealmImages.com/Expeditions). They aim to spread the word about the amazing area that is Raja Ampat and inspire the important region’s conservation. Check out their website for a mine of information about West Papua and the Bird’s Head Seascape.
BIRD’S HEAD SEASCAPE – SCIENCE/CONSERVATION BLOG
Bird’s Head Natural History Notes: In Appreciation of Damsels
By Dr Richard Smith – www.OceanRealmImages.com
Damselfishes are a ubiquitous, but often overlooked, member of the Indo-Pacific reef fish community. Around two hundred and fifty species, three quarters of the world’s damsels, are known to live in the Indo-West Pacific. With the world’s highest marine biodiversity, where better to enjoy these fishes first hand than Raja Ampat?
Damselfishes are egg layers, most often laying their clutch on a pre-prepared nest site somewhere on the reef. When their eggs hatch, the majority of species’ fry will immediately be swept off in the currents to disperse around the ocean. Whilst the parents of these young fishes will never see the fruits of their reproductive endeavours, others raise young that never seem to leave home: the ‘Gen Y’ of the fish world. Over the past eleven days, I have been exploring the northern islands of Raja Ampat aboard Dewi Nusantara observing this unassuming group of fishes and their array of reproductive strategies.
Ecosystem Engineers
Many of us have had personal experience of a damselfish protecting its eggs. Sergeant Majors, anemonefishes and golden damsels are amongst a few of the common damsels that will not hesitate to take on us bubble blowers, seemingly unperturbed by our comparatively massive size. These demersal spawners, lay their eggs directly onto the substrate. Sergeant Majors nest en masse, with dozens of individuals making a wasteland of a few square metres of the reef, laying their purplish spawn that they enthusiastically protect from marauders. As such they are a kind of ecosystem engineer, altering the habitat for their own benefit but changing it for others too.
Swimming along a reef in northern Batanta Island, I came across a honeyhead damsel that had also strikingly altered its local environment. Rather than denuding it to lay its eggs, it had encouraged verdant algal growth within the square metre or so of its territory that it enthusiastically warded me away from. Like a disgruntled farmer it chased off any other creatures that tried to enter the confines of its little farmyard. Within the allotment honeyheads farm filamentous algae, which act as their primary food source. Their agricultural proclivities, and the exclusion of other herbivores and corallivores, alter the composition of species within these plots. By changing patches of the reef, these damsels are altering it for other species too. Their influences having a disproportionately large reach given their size.
Golden damsels on the other hand, usually lay their clutch of bright pink eggs on a whip coral or some other such protuberance coming off the reef. You’ll often see the diligent parent tending to their clutch. By aerating and removing infertile or spoiled eggs, they remove a reservoir of infection for others in the clutch. Like the eggs of many fishes, the initially vivid fresh eggs soon become grey in colour as they mature and the fry develop within. Just prior to hatching you can even see the reflective eyes of the tiny fish within.
Doting Parents
One of the more extreme parental investments of a damselfish is found in spiny chromis. These inconspicuous damsels lay few large eggs, which both parents tend for an extended period until the relatively large fry hatch. They are rare amongst reef fishes, in that the fry lack a pelagic larval stage and remain close to where they were born their entire life. Although adults aren’t as protective of their fry as some other damsels, they keep an ever-watchful eye over the brood from hatching until they are quite large in size. When small the fry are almost transparent, but take on a faint yellow stripe as they grow. Adult spiny chromis have quite pointed fins and although variable in colour geographically, they are more often than not dark in colour, especially in the West Papua region. Finally the youngsters darken to become miniature versions of their parents, and even at this late stage remain in a loose school casually overseen by their parents.
Changing Colours
A final quirk of damselfish reproduction, which for me makes them one of the most beautiful reef fish groups, is the diversity of their juvenile forms. Adult black damsels, for instance, are midnight black in colour whereas their juveniles are almost indistinguishable as the same species. They are unexpectedly white and bright yellow, with bluey black ventral and anal fins. The leading theory for the dramatic change in colour or pattern from juvenile to adult in reef fishes is to reduce territorial aggression from adults. If juveniles appear completely different, the adults are less likely to hound them out of their territory and the two can coexist amicably.
Damselfishes are a group that many divers seem to overlook. I hope that I’ve convinced you to spare these unassuming fishes a thought on your next visit to the Bird’s Head. The more you learn about these abundant fishes the more fascinating they become, adding both to the diversity of the region and your diving experience.
BIOGRAPHY: Richard Smith, a British underwater photographer and writer, aspires to promote an appreciation for the ocean’s inhabitants and raise awareness of marine conservation issues through his images. A marine biologist by training, Richard’s pioneering research on the biology and conservation of pygmy seahorses, led to the first PhD on these enigmatic fishes. Over the past decade, Richard’s photographs and marine life focused features have appeared in a wide variety of publications around the world. Richard leads expeditions where the aim is for participants to get more from their diving and photography by learning about the marine environment through marine biology lectures: www.OceanRealmImages.com