Kavieng Island S02°33.9' E150°46.9' Reef Report
Health of the Nusa North Reef, Kavieng, New Ireland, Papua New Guinea
Dates of Study:

Apr 15th - Apr 24th, 2002

This reef was also studied intensively by the crew of the RV Heraclitus in August 2000.

Observations of change are at the end of this page. 

Water Temperature range

28.0° - 30.5°C


less than 1% of area studies

Coral diseases:

none observed


usually around 20m, always clearer in morning than afternoon

Crown of Thorns:

none (one seen on nearby reef patches)

Topography and condition:

This reef lies on the north side of Nusa Island, and to the north the open Pacific so is prone to impact from high swells breaking on it.

When we arrived at the beginning of April, the reef was taking a bashing, especially on its north east tip, from swells brought in by a typhoon in Japan a week before. These died down a little, thankfully, allowing us to carry out our study, but they never completely disappeared making explorations in the shallows impossible. This north east corner of the reef is one of the most topographically interesting areas. It bears the scars of repeated wave action, with trenches formed by the backwash. Between the trenches there are small patches of hardy live corals growing but only the encrusting Acropora colonies or massive growth-forms of other genus are able to grow beyond a 20cm diameter.

The reef is at first sight confusing. It appears a little devastated with areas of rubble, sometimes overgrown by calciferous macroalgae. But on closer inspection combined with observations of the conditions under which it survives, the reef is actually very healthy. There are several areas that could be described as pristine, separated by rubble valleys - the effects of wave weathering. Towards the western corner of the reef, there are on average throughout the year more gentle conditions allowing more elaborate coral growth-forms and larger colonies to survive. It's a common site all along the reef to find overturned table Acropora, even massive corals such as Symphillia but these become substrate for new colonies to settle.

The shallower areas that we could study were less diverse in coral genus than the deeper zones, again less corals are hardy enough to withstand the conditions where the waves break and the backwash drags.

Other observations:

Fish: There are no obvious changes in the fish life on the reef in the last two years. The visibility was reduced compared to the last study so it was not possible to observe the passage of pelagic fish unless they came onto the reef itself. The diversity is still high and the numbers of small reef fish appear undisturbed. The dominant families between 3 and 10m are still the surgeon, parrot, damsel, butterfly and wrasse. An encouraging number of groupers were seen (including one barramundi cod) and some handsome emperors, plus two sightings of black tip reef sharks.

Coral: There are no major changes in coral conditions since our last study.  The most prevalent Vitareef conditions were overgrowth by coralline algae especially Halimeda and some Turbinaria and by the ascidian, Lissoclinum patella. There are few large colonies of soft coral or sponge formations.

Invertebrates: One of the most exciting aspects of this reef is the invertebrate life. There are many octopi, some cuttlefish, the delicious spiny lobster Panulirus versicolor, and an array of beautiful crabs and shrimps cowering in the corals. One very interesting sighting was the psychedelic flatworm Pseudobiceros bedfordi.


The beach to the south of the reef is reasonably steep and becomes very narrow (less than 5m) at low tide.

Other diving action:

We encountered one live-aboard operation on the study site - the Febina. They had been diving at Echuca Patch (a submerged offshore reef, less than a mile away) earlier that day and then dropped some divers on the study reef while we were laying our transect lines.

In conclusion:

The reef north of Nusa Island is in roughly the same condition as it was two years ago. There have been no bleaching events, no explosions of algae smothering and no destructive fishing practices on the reef itself.

There is one major change in the Kavieng area which could ultimately have an impact on the reef at Nusa and other reefs in the area. During our visit in April 2002, in the course of the month we were anchored there, we witnessed the arrival and departure of ten large-scale fishing boats - very long nets on board, massive scope for refrigeration etc. It appears that the government in Port Moresby has granted them the rights to fish these waters but without necessarily consulting with the people of Kavieng. The landowner system of New Ireland extends to the reef and miles beyond it and we heard some strong objections from local communities to the activities of these foreign ships. We also heard reports of them having $1m worth of tuna in their holds. These boats are coming mainly from the Philippines, other parts of South East Asia and Korea - countries where waters have been overfished already. If they continue to plunder the reefs of New Ireland, and other reefs in PNG, then the long-term effects could be disastrous. One of the true delights of visiting Papua New Guinea is the underwater wealth and riches that it offers the diver. As scientists, we are enthralled on each dive here but if non-sustainable fishing practices begin to engulf these waters, there will be changes both in the open seas and on the reefs which provide the spawning grounds for much of their catch.

We also heard reports of the dumping of old stocks of cyanide, left over from the gold mining industry in Lihir (an island off the east coast of New Ireland). Cyanide is used by fishermen of many countries in South East Asia and the Pacific but the devastation caused by this poison on the reef itself is fatal. Large catches can be obtained by squirting the cyanide underwater to stun the fish but the overall effect is the death of large areas of coral reef, without which the fish cannot survive in the long term. The Philippines and Indonesia have already lost a great deal of their reefs by fishermen using cyanide. If cyanide is dumped in the ocean around the island of Lihir, there is a chance that currents and tides may circulate it to reefs and have the same effect as if they had been directly targeted with the chemical. There is a potential here for widespread disaster.

What is clear to PCRF is that there are changes happening fast in New Ireland and Papua New Guinea in general. Traditional systems of safe-guarding the land and sea are being disturbed by other influences and actions, mainly driven by economic gain for the few and frequently for those who do not even live here. But these actions bear huge consequences for those peoples who have relied on the reefs for their livelihood for centuries. This is a critical time for ensuring the future health of the spectacular coral reefs of Papua New Guinea. False moves now will cause irreversible changes. One has only to look north to the mistakes made by so many countries of South East Asia to understand the basic concepts that reefs are not indestructible, that the wealth of life in the oceans is so heavily dependent on the existence of the reefs and that human impacts have far-reaching effects.

Reef Report
Vitareef Data
Coral& Fish ID
Video Transect
GPS Data