PART-IV Discussion:

Papua New Guinea (PNG) is the largest equatorial island and lies adjacent to the northern tip of the Great Barrier Reef. The southern reefs of Papua New Guinea are a continuation of the GBR, whereas the reefs to the north and around the islands have strong affinities with reefs of the Solomon Islands to the east and Indonesia to the west.
Coral reefs in PNG have never been properly surveyed. They are among the most diverse in the world and have a high percentage of coral cover. Although all reef types are represented, most are fringing and barrier reefs. The low latitude of these reefs places them mostly outside the cyclone belt and, as a result, the reef crest and upper reef slope are rarely impacted by extreme high seas. Unlike the Great Barrier Reef, which has seasonal cyclones, there is a conspicuous absence of coral rubble and large boulder tracts.
PNG provides one of the last opportunities for the conservation of significant areas of coral reefs in the western Pacific region of maximum marine biodiversity. Few other locations offer the combination of large areas of high diversity reefs mostly undamaged by human activity; relatively low population size in most coastal areas; a scientific and management community that is committed to sustainable use of marine resources, and a customary land tenure system that can be used to enhance conservation efforts (Munday, 2000).

Coral reefs are an integral part of the subsistence economy in most coastal regions where people rely on them for coastal protection, food, medicines and cultural properties. Subsistence and artisinal (or game) fishing is the predominant human activity on PNG reefs. In general, reef fish harvests are thought to be below sustainable levels. The pressures on reef resources in PNG will almost certainly increase as the population continues to grow, especially in large coastal towns, along with a growing tourism industry. The national economy is poorly developed although the islands are rich in resources and foreign aid plays a major role in this economy.
Milne Bay is the largest maritime province and contains the most abundant coral reefs. There are a few mining and oil palm projects in the area, but most of the people are subsistence farmers and fishers. Repeated use of explosives in some areas has resulted in reefs that contain few living corals and are almost devoid of topographic structure (Halstead et al. 1998), although these effects appear to be localized (Werner and Allen 1998). Otherwise, most reefs surveyed in the past few years have had relatively high coral cover and little evidence of damage from human activity.


Echinopora sp. (Pectiniidae - 185kB)

An ecological assessment of Milne Bay Province noted that the bay is separated from the open sea by a barrier reef with both sunken and exposed portions (Opu and Aruga 1999). The diverse coastal habitat of this bay includes seagrass meadows, mangroves, sandy beaches and coral reefs. Its coral reefs are characterized by high species diversity. For example, 1,039 species of fish and 637 species of molluscs were recorded in a recent survey in Milne Bay Province (Werner, and Allen, 1998) along with 362 species of hard coral (Veron 1997) with a live coral cover of up to 83%. He discovered 14 new species and predicted that the total number of coral species could approach 420 - including the free-living hermatype Heteropsammia. Indeed an average coral coverage over 40% is common, but this varies with location, reef type, depth and other variables. In comparison, the average reef-wide cover of hard coral on GBR was estimated at 23% in 2000,with values ranging from 3-51%. These relatively low values reflect fairly frequent disturbances such as cyclones and Crown of Thorns (CoT = Acanthaster planci) outbreaks during the last few decades. Much of the change in coral cover on the GBR is due to growth and destruction of table Acropora spp. (e.g. A.cytherea and A.hyacinthus). These table corals live in areas of high water movement and grow rapidly to cover a large area, but they become increasingly susceptible to storm damage as they grow. On reefs close to the equator, where cyclones are rare, such corals cover much of the reef and average values for coral cover will be higher (up to 80% or more in places - Maniwavie et al. 2000).
Veron noted that there was a high diversity of coral species and that the reefs were remarkable for the enormous, spectacular growth forms of some species. Lobophyllia, for example, was observed to form heads up to 3m across. Turbinaria, Acropora, and Dendrophyllia also attained immense proportions, especially along the sides of deep channels where strong water currents flowed (Weber 1973). The common coral families were Acroporidae, Alcyoniidae, Dendrophylliidae, Faviidae, Milliporidae, Poritidae, Fungiidae and Pocilloporidae. The morphological forms include branching, tabulate, massive, sub massive and encrusting. The corals on the fringing reefs are distributed in a patchy manner. Branching Acropora were the most common representing 16% to 20% of the live coral cover.
Even though quite rare, certain areas reveal cyclone damage (Boia Boia Waga), and as a result seem to display reduced species diversity, and still, Milne Bay's rich biodiversity is a major attraction. Within the province and among those visited, the highest rated sites based on combination of high species numbers and scenic beauty was Dinah's beach. Observation Point, although not as biologically diverse revealed an interesting aspect regarding coral bleaching and predation by CoTs. In fact, at current knowledge it is considered that the reefs are in pristine condition with little to no evidence of destructive fishing practices and few evidence of recent CoTs. While CoTs outbreaks occurred on reefs in countries neighboring PNG such as Palau and the Great Barrier Reef, PNG has been fortunate in not having any large outbreaks. Only in Milne Bay in the late 1970s were starfish reported in significant numbers in isolated areas (Quinn and Kojis 1987).


Montipora sp. probably M.danae (Acroporidae - 255kB)


Platygyra lamellina (Faviidae - 215kB)


Lobophyllia hemprichii (Mussidae - 210kB)

Threats: Some of the most serious threats to coral reefs in PNG appear to come from terrestrial activities, such as sediment mobilisation as a result of large-scale forestry and agriculture. Extensive tracts of coastal forest have been allocated for logging and there are insufficient mechanisms to prevent widespread sediment damage to reefs as a consequence. Given that most of PNG reefs are nearshore and downstream of steep, forested watersheds, then significant additional inputs of sediments can be expected from large-scale deforestation. Although there are almost no data to substantiate elevated sedimentation as a result of past or current logging operations, there is equally no quantitative monitoring of reefs that might be affected by these logging activities. Increasing stresses on reefs will also come from the growing coastal population and pattern of urbanisation, though increased fishing pressure and pollution, such as inadequately treated sewage. Attempts to assess anthropogenic impacts to coral reefs in PNG are limited by a lack of data on the spatial and temporal patterns on the abundances of reef organisms and a lack of data on the physical and chemical characteristics of the reef environment. The apparent good condition of PNG reefs must, therefore, be considered with this lack of information in mind. Reliable monitoring programs should be encouraged, particularly in areas of increasing population pressure and where anthropogenic impacts are likely to occur in the future.
Coral bleaching: This has been observed in PNG during three main periods over the past 20 years. The most severe and widespread bleaching event in PNG appears to have occurred during 1996-1997. Milne Bay was the most affected area with one study reporting 54% of corals exhibiting bleaching. Most other areas had lower level of bleaching and good recovery has been reported in most areas indicating that this bleaching event was short enough to prevent large scale death in affected colonies. On average, none of the bleaching events in PNG appear to have been as severe as those reported from some other countries. Bleaching has again been observed in several locations during early 2000. With the apparent increase in the frequency of bleaching events in PNG over the past few years, it is important that coral bleaching and associated physical parameters (particularly sea temperature) be monitored in a coordinated manner.


Acropora palifera (Acroporidae - 255kB)


Acropora sp. probably A.cytherea ( Acroporidae - 215kB)

Monitoring Change in Tropical Marine Biota: Healthy coral reefs are one of the most exotic and varied habitats known to us, but they also pose problems for conservationists. In order to predict coastal marine habitats, it is essential to know about its past, to understand the bio-geochemical connectivity, and the dynamics of destabilizing processes. Coral reefs may be temporarily damaged by natural events such as hurricanes (although rare), temperature and salinity changes, sedimentation, and a host of biological factors, but many of the most serious and lasting threats come from man himself. Humans tend to consider the sea both as a convenient dumping site as well as a useful provider. Coral reefs are exploited for food, trophies and building material. They are abused by dynamite and other destructive fishing methods. They are choked by silt washed into the sea from erosion on land, or are disturbed during dredging operations or sand extractions in shallow waters. They are polluted by sewage, oil, pesticides, industrial wastes, and are damaged by warm water outflows. Along the coast of Papua New Guinea, the amount of river water and sediment transported into the ocean - especially during the monsoon season - is very large. Satellite based remote sensing technology can be used to map and monitor shallow water habitats (Quinn et al.1985, 1986).With the help of such data, it is also possible to trace river plumes, and relevant information important to understand marine bio-geochemistry. Rain, especially, in the wet season, washes fertilizers and pesticides into the river, industries may spill part of their waste, increased development replaces dense vegetation with concrete and bare soil, causing increased erosion and ultimately increased sedimentation and eutrophication. Layers of marine sediment, accumulated through time, store data of changing land use through history. Researchers are studying patterns of coral reef growth and linking historical climatic records with current information and creating models of climate change through time. The last 200 years can be tracked by the researchers examining coastal sediments, and signatures of climate change as well as contaminants that are incorporated into growing coral skeletons. Researchers can read the history of land use and climate change over the last several centuries that are recorded in the annual growth bands of massive corals. Such information aids in the understanding of the periodicity of ENSO related drought and flood events, climate change, and to detail the pathways of carbon cycles and ocean water circulation. Such findings allow researchers to link present assessments of ecosystem sensitivity to climate variations with the potential effects of climate changes in the future. In this way oceanography is linked to biology, and also to industry (it helps to assess the risk and dispersal of oil spills, pesticides and other organic wastes in the environment or creates more effective strategies of rescue efforts. In addition, such study enables the classification of an ecosystem's stability and its capability to resist outside disturbances). It also helps to understand the influence of wave and tide-induced flushing currents on larval dispersal (how tidally generated internal waves effect vertical and horizontal movement of phytoplankton, as well as the mixing of phytoplankton and other nutrients which occurs). Thus, facilitating prediction of larval dispersal of crown-of-thorns starfish.
Modern techniques for mapping sea surface salinity using airborne microwave instrumentation and applying this information should aid to map river plumes, besides enabling an estimate of a probable impact of river flooding on coral reefs. In addition, it deepens the understanding of the effects of wave motion and small scale circulation on coral skeletal development, as well as the influence waves and currents might have on the erosion of the coastline and benthic environment.
To gain a clearer picture on a smaller scale, it is also essential to comprehend the sources and fates of organic matter in the coastal zone. This involves the study of formation and degradation rates of dissolved and particulate organic matter in mangrove swamps and coastal seas. Organic particle transport, scavenge contaminants, and abiotic suspended matter transported by rivers to estuaries and into coastal seas.


right: Acropora sp. probably A.eyquisita (Acroporidae); left: Pachyseris speciosa (Agarticiidae - 190kB) (Acroporidae - 255kB)


Echinopora sp. (Faviidae - 165kB)


Goniastrea sp. (Faviidae - 185kB)


Acropora palifera (Acroporidae - 180kB)

PNG Legislation and Regulation: There appears to be adequate laws and legislation for the conservation and management of coral reefs. However, most legislation does not specifically refer to marine systems and this has caused uncertainty about how it should be applied to coral reefs. Also, the laws relevant to different sectors (e.g. fisheries, mining, environmental protection) are not fully integrated which has lead to confusion over which laws have priority, who is responsible for management, and the rights of the various interest groups. There is little government capacity for enforcement of laws, quota and regulations. A national surveillance strategy has been suggested which would involve participation from all levels of government, NGOs and local communities. Local communities have to play a greater role in enforcement of fisheries regulations and marine protected area through the expansion of community based management programs.


Montipora sp. (Acroporidae - 190kB)

Management Concepts: The unrivaled cultural and natural attractions of the province's marine environment does have huge tourism potentials, and are already a popular dive destination. Due to ancestral ownership by fishing villagers of Milne Bay Province, financial compensation by visiting dive boats should be given to the locals. They also should be offered the chance to participate in management projects, in order to avoid missuse in form of cyanide and dynamite fishing and the illegal exploitation of giant clams. Any license issued for the purpose of reef fishing should specifically ban the use of such degrading methods, with any commercial fishing activity accurately monitored by a provincial officer that should monitor ongoing activities aboard. Excess harvesting and removal of protected species should result in a fine, seizure of the vessel, and immediate withdrawal of the license.
With respect to locas and visitors alike, skippers of dive boats should ensure that corals are not damaged by anchoring boats, whilst attractive dive sites should be equipped with mooring buoys. In addition, dumping of any sort (cans, bottles, and other non-biodegradable products) should not be allowed at all.
The provincial government should provide the legal framework by declaring most coastal and inland areas as national parkland, while allowing locals access and usage to maintain their traditional lifestyle.
Such initiatives on one side should encourage the people of Milne Bay Province to strengthen their traditional values while creating lucrative cash incentives resulting from eco-tourism. Environmental awareness programs should be offered to the people of the province in order to guarantee that its unique cultural and natural heritage are well preserved for future generations. In addition, periodic surveys by (marine) biologists should monitor the reefs status' and ensure that its diversity is maintained.


Acanthastrea sp. probably A.ishigakiensis or A.hillae (Mussidae - 235kB)


Mycedium sp. or Echinophyllia aspera (Pectiniidae - 205kB)

Marine Park Authorities: PNG has a number of legally designated protected areas that contain coastal and marine habitats within their boundaries. However, insufficient resources for management and enforcement of regulations means the effectiveness of these areas is usually questionable. There are, however, demonstrated successes in the small-scale, community-based protected areas in a number of locations. Currently the most effective marine protected areas in the country are in Kimbe Bay, Madang, and Aroma coast. They provide a model of how other protected areas can be established and managed. Milne Bay province is a priority region for new protected areas, given that it contains much of PNG reef area, the highest overall diversity of fishes and other marine organisms, and most of the endemic species of fish. It appears that the ingredients for success in these areas include:

  1. continuing community consultation and needs assessment;
  2. community education in conjunction with the marine conservation project;
  3. small protected areas, facilitating ease of surveillance and promoted as "seed" areas for adjacent open reefs;
  4. areas with no dispute over resource ownership;
  5. dive tourism and support; as well as
  6. a regular monitoring program with community involvement. Such community based protected areas and conservation initiatives that link social and economic development may be most appropriate to the needs and land tenure realities of PNG.


top: Favites sp. (Faviidae); bottom: Euphyllia sp. probably E.cristata (Euphyllidae - 180kB)


Porites sp. (Poritidae) with Octopus (211kB)

Recommendations: A number of recommendations are made for ways to support efforts to protect and conserve coral reefs in PNG, some of which are already being developed or instigated (Suggestions based on the management concepts of P.L.Munday's The Status of Coral Reefs in PNG, 2000)

Building Scientific Capacity for both the long-term assessment and management programs: Effective management of urban development, watershed degradation and large-scale commercial activities requires much greater capacity in provincial and national government agencies.

  • Extra support for the training of students in marine science.
  • Scholarship system for postgraduate studies in marine science.
  • Support diver and technical skills training to scientists, students and technicians.

Improving knowledge: Monitoring initiatives need to be supported and developed to provide an effective and ongoing assessment of reef health - especially in areas likely to come under stress from coastal development and other terrestrial activities. Support is needed for diver and technical skills training, routine monitoring trips, quality control, data assessment and dissemination; High quality mapping of PNG reefs is important for conservation initiatives and appropriate management of fisheries and biodiversity assessments for the long-term sustainability of PNG’s coral reef resources.

  • High quality mapping of PNG reefs.
  • Integrated monitoring program involving the University of PNG (UPNG), PNG Divers Association (PNGDA), Office of Environment and Conservation (OEC).
  • Establishing a national and international research award system.
  • More support for basic biological and ecological research.

Implementation of Marine Protected Areas: Community-based programs could be established within a network of marine protected areas. Addressing the needs of local communities and integrating them in the development, management and enforcement of protected areas is likely to yield success. Continued community support is important for the success of marine protected areas.

  • Establishing a representative system of community-based marine protected areas.
  • Continued funding for successful marine protected areas.
  • High priority for protected areas in Milne Bay.
  • Support new protected areas in the southern region.
  • Continued monitoring and community support in conjunction with marine protected areas.

Threats to Reefs: Effective methods of enforcing fisheries regulations are urgently needed. This is particularly important for any re-introduction of the live reef-fish trade.

  • Investigate the likely effects of the live reef-fish trade and ensure effective methods for enforcing regulations.
  • Develop community education and alternative income programs to reduce destructive fishing practices and help enforce fisheries regulations.
  • Investigate mechanisms to limit the impacts that terrestrial activities have on coral reefs.

Awareness and Education: Community education and alternative income programs can help reduce destructive fishing practices. Increased commitment is also needed at provincial and national levels.

  • Support community awareness programs to: 1) reduction of unsustainable and destructive fishing practices; 2) providing the incentive for marine protected areas; and 3) increasing enforcement capacity.
  • Support education at three levels: 1) communities; 2) schools; 3) teacher education.

Many of these recommendations focus on specific issues or are community based. A number of other issues such as urban development - here especially the provincial capital of Alotau, watershed degradation and large-scale commercial activities require a more integrated approach that will depend on improved capacity in both provincial and national government agencies. Finding ways to increase the importance of environmental issues at higher policy levels will clearly bring substantial rewards to conservation efforts.


left overview: Platygyra sinensis on top with Echinopora mammiformis (right) and probably Millepora sp. (left); detail right: Platygyra sinensis with Porites sp. (Faviidae / Poritidae - 155kB)


overview: Diploastrea heliopora (Faviidae) with Porites sp. (Poritidae) below; detail: D.heliopora (185kB)


overview: members of the family Acroporidae; detail: Acropora willisae on top and A.sp. (hyacinthus group) below (235kB)


top: Protopalythoa sp. (Zoanthidae) surrounded by an encrusting sponge; bottom: either Scolymia sp. or Lobophyllia pachysepta (Mussidae - 265kB)
Literature: Colin, P.L; Arneson C.; 1995; Tropical Pacific Invertebrates; Coral Reef Press; California - USA.
Gosliner, T.M., Behrens, D.W., Williams, G.C.; 1996; Coral Reef Animals of the Indo-Pacific;
     Sea Challengers; California - USA.
Halstead B., 1997; The Dive Sites of PNG; Passport Books - NTC Publishing Company; Chicago, IL - USA.
March L., Slack-Smith S. 1986; Sea Stingers; Western Australian Museum, Perth - AUS
Pears V.&J.; Buchsbaum M. & R.; 1986; Living Invertebrates; Boxwood Publishers,
     Los Angeles , CA - USA.
Schumacher H.; 1976, Korallenriffe; BLV-Verlagsgesellschaft München - FRG
Tomascik T., Mah A.J., Nontji A., Moosa M.K.; 1997; The Ecology of Indonesian Seas - Part I;
     Oxford University Press - Singapore.
Veron, J.E.N; 1997; Corals of Australia and the Indo-Pacific; University of Hawaii Press, Honolulu, USA.
Veron, J.E.N. 2000; Corals of the World; Australian Institute of Marine Science; Townsville - AUS.
Werner T.B., Allen G.R. eds. 1998; A rapid biodiversity assessment of the coral reefs of
     Milne Bay Province, PNG
; Rapid Assessment Program, RAP Working Papers 11;
     Conservation International; Washington DC - USA
Wood E.M. 1983; Corals of the World; TFH Publications Inc Ltd - USA
Wood R.; 1999; Reef Evolution; Oxford University Press; New York - USA
Further References: Australian Institute of Marine Science in Townsville - AUS:
Recent AIMS Report sheets:
     Human Impacts on Coastal Marine Ecology;
     Marine Biogeochemistry of Contaminants;
     Marine Bioproducts;
     Monitoring Change in Tropical Marine Biota;
     Predicting the Coastal Marine Environment;
     Supporting Tropical Fisheries;
     Sustaining Coral Reefs;
Sport Diving Australia Magazine #77, Nov-Dec 1999-2000
Coral Reef Research Center:
Great Barrier Reef Marine Park authority:
Reef Teach Center (Paddy Colwell); Cairns - AUS:
ReefBase - A Global Information System On Coral Reefs: