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| The female Sousa chinensis by-caught in Paloh, pic by Taufik |
17 February 2014
Februanty Purnomo and I were packing our stuff for one night
overnight at Temajuk by the border of Sarawak when Dwi Suprapti, DVM rushed in,
declaring that a fisher just caught a dolphin in a village nearby. We dropped
our overnight stuff, grabbed our GPS, camera and note book, and drove out to
Guntung, about 20 min drive south from the WWF Paloh basecamp where we had been
staying since last Saturday.
We arrived about an hour too late, apparently, for when we
arrived there, the dolphin had been cleanly dissected by the locals for
personal consumption, leaving only about 30x30x30 chunk of meat in whitish skin
on the ground. Thanks to technology tho, even fishers nowadays have
smartphones. One of them produced his Blackberry and showed us the picture of
the dolphin. As I suspected from the white skin, it was a Sousa chinensis
(Indo Pacific humpback dolphin).
We asked permission to collect samples, it was granted. We
collected a piece of blubber for toxicology, a piece of skin for genetic
analyses and a piece of meat for good measure. Then we walked to the beach to
check the boat and gillnet specs. We found that approximately 4 sqm of the 2.5”
gillnet was gone as the result of the entanglement. The fisher, 40 years old
Miraldi, said it was the first time he caught this species, tho he often saw it
milling around the shallow waters of his village. From the dolphin’s position
on the boat, we concluded that the Sousa was about 2.5 m long. After examining
the boat, we walked back to the village, passing by a small river on our left
side. Agri Aditya of WWF saw it first: a weird floating object, which turned
out to be the object of desire of any vets and marine biologists dabbling in
stranding and bycatch cases. An almost complete set of the Sousa’s internal organs.
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| The internal organs of the Sousa chinensis |
Agri fished the organs out of the water; we immediately
realised it lacked the heart and liver. It had the lungs, stomachs and
intestines tho (and later we found out: also the kidneys and spleen). Then we
found another item: the floating fetus, still wrapped in its amniotic sac.
The case is clear now: we had to abandon the Temajuk bycatch
survey and stayed at Paloh to conduct necropsy on the Sousa mum internal organs
and her fetus.
After shopping for necropsy tools (stationery cutter
replacing the scalpels, etc), we started the necropsy at around 8pm last night.
We started with the gross examination of the lungs, including measurement. We
then proceeded to the trachea and the three stomachs. We skipped the intestines
because it was already green and it surely would smell bloody awful. We found
fish thorns in the pyloric and fore stomachs; that dolphin had been eating before it was by-caught,
but not sure the time interval between her finished eating and being caught. I’d
say she had finished digesting the meal before being caught. We also found froth/foam
inside the airway and lungs. However, because
we found the internal organs already floating on the river, we’re not certain
that the froth was post-mortem or ante-mortem.
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| The fish thorns and otolite inside the fore stomach |
After finishing with the kidneys (looked healthy with pronounced
granules), we proceed to the fetus. We felt the fetus before Dwi cut the amniotic
sac. Seemed like it had developed into a complete individual. After Dwi cut the
amniotic sac, we found that the fetus was indeed ready to be born in a few days
(I’d say). Everything was complete, externally. The total length from snout to
fluke is 75 cm, about ¾ of the usual newborn length of a Sousa chinensis
(approx. 1m). The teeth have not developed yet. It was a boy. It might have passed
its third semester when the mum died…
We secured the baby inside the small WWF freezer in Paloh.
We are going to bring the baby to Pontianak today, which is about 10 hours away.
We hope that the baby will still be frozen by the time we found a larger
freezer in Pontianak.
From the mother, we have secured the blubber, skin sample,
and also samples of lungs, kidneys, spleen, trachea, and stomach (the pyloric,
I think). We will ship the samples to IBRC Bali. We will also divide the
genetic sample for the LIPI Lab in Jakarta. We don’t have a scale, so we didn’t
weigh the baby. We also didn’t weigh any of the organs. We couldn’t secure the skeleton,
it was already chopped along with the meat.
What are the lessons learned from this event?
Well, first and foremost: bycatch is bad for the cetaceans
and the communities. The animals are dead, the fishers got the nets destroyed. Even the fisher himself felt sorry when he realized a baby
was inside the mother, and the baby was dead because of the bycatch.
Second: we must find bycatch mitigation techniques for Paloh
and surroundings asap.
Third: for necropsy, we need to have good tools ready to use
in major bycatch areas. Dwi and I (and our team) had to improvise with
stationery cutters as scalpels, and those are not the best tools, particularly
if we have the complete specimens.
Fourth: a standby freezer at major bycatch areas would be
grand to store specimens, particularly for later necropsy usage.
Fifth: bycatch is baaaaaad…
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