Rather than posting the following as the intended comment on this article, I'm posting it here as Stan Lhota's reply has too much substance to be hidden away.
—– Original Message —–
Sent: Friday, March 15, 2013 5:20 AM
Subject: Tried to comment this but blocked (probably by my firewall)
I've lived in East Kalimantan for 16 of the last 22 or so years, and I have to say that I've never heard of Irrawaddy dolphins anywhere near Balikpapan, nor dugongs for that matter. I've dived just north of Bontang for eight years also and have yet to see/hear of a dugong up here either. My Dayak wife insists that the pink dolphins exist way up the Mahakam and in the lakes but again I've never seen one. What sort of population of either exists in the Balikpapan Bay?
I've just returned from a short break out of town, so apologies for this tardy reply.
Also, sorry you couldn't post your comment but it was probably blocked by the moderation facility I apply for first-time commentators; I receive way too many spam comments.
Regarding your query, I've copied this to Stan Lhota who is one of the activists trying to preserve the environment of Balikpapan Bay.
Dear Shane and Jay,
There are four species of marine mammals that live permanently in coastal waters of Balikpapan, and few more who can visit it temporarily. The four resident species inhabit two distinct areas around Balikpapan – east coast (Makassar Strait) and west coast (Balikpapan Bay).
The two species found along the eastern coast of Balikpapan (Makassar Strait) are the Indo-Pacific bottle-nosed dolphin (Tursiops aduncus) and the finless porpoise (Neophocaena phocaenoides). They only occasionally visit Balikpapan Bay and their population is continuous with the populations of the same species north and east of Balikpapan, along the Makassar Strait.
Much more attention has been focused on the two species that live along the west coast of Balikpapan – in Balikpapan Bay. They are the Irrawaddy dolphins (Orcaella brevirostris – locally known as pesut) and dugongs (Dugong dugon).
They are restricted to the shallow waters of the bay and only rarely visit the open waters of Makassar Strait. Their populations have been subject of a long-term monitoring by Yayasan RASI (Rare Aquatic Species of Indonesia). Based on their data, there is a stable population of 60-140 Irrwaddy dolphins in Balikpapan Bay. But the number of dugongs has already decreased dramatically – there may be no more than 10 dugongs left in Balikpapan Bay!
In other parts of Kalimantan, the dugong is just as rare as in Balikpapan, or even rarer. There are probably a few left around Derawan Island and possibly also near Bontang but I do not know about any recent sightings. Dugongs are truly on the brink of extinction in Kalimantan.
Irrawaddy dolphins are still, al least locally, common in Kalimantan. Their main population is in Tanah Tidung. The major remaining populations in East Kalimantan are Sangkulirang Bay, Mahakam Delta, Balikpapan Bay and probably also Adang and Apar Bay. And there is indeed a very distinct population of approximately 80-90 Irrawaddy dolphins living in Mahakam Lakes. It is the only freshwater dolphin population in Indonesia, and one of only a few worldwide.
I hope this helps!