Richard J. Hamilton

Designing a resilient network of marine protected areas for Kimbe Bay, Papua New Guinea

The Nature Conservancy takes a strategic and systematic approach to conservation planning. Ecoregional assessments are used to set goals and identify geographical priorities, and Conservation Action Planning is used to develop strategic plans for conservation areas. This study demonstrates how these planning processes were applied at the seascape scale based on a case study of Kimbe Bay, Papua New Guinea. Conservation Action Planning was used to identify key threats and strategies, and systematic conservation planning (similar to that used for ecoregional assessments) was used to design a network of marine protected areas to be resilient to the threat of climate change. The design was based on an assessment of biodiversity and socio-economic values, and identified 14 Areas of Interest that meet specific conservation goals. A detailed community-based planning process is now underway with local communities that own and manage these areas to refine and implement the marine protected area network.

Developing Marine Protected Area Networks in the Coral Triangle: Good Practices for Expanding the Coral Triangle Marine Protected Area System

The Coral Triangle Marine Protected Area System aspires to become a region-wide, comprehensive, ecologically representative and well-managed system of marine protected areas (MPAs) and MPA networks. The development of this system will proceed primarily through the implementation of ecological, social, and governance MPA networks at the sub-national scale. We describe six case studies that exemplify different approaches taken to develop MPA networks in the Coral Triangle region at different scales: Nusa Penida in Indonesia; Tun Mustapha Park in Malaysia; Kimbe Bay in Papua New Guinea; Verde Island Passage in the Philippines; The Lauru Ridges to Reefs Protected Area Network in Choiseul, Solomon Islands; and Nino Konis Santana Park in Timor Leste. Through synthesis of these case studies, we identify five common themes that contributed to successful outcomes: (1) the need for multi-stakeholder and cross-level management institutions; (2) the value of integrating cutting-edge science with local knowledge and community-based management; (3) the importance of building local capacity; (4) using multiple-use zoning to balance competing objectives; and (5) participation in learning and governance networks. These lessons will be invaluable in guiding future efforts to expand the Coral Triangle Marine Protected Area System, and provide important insights for MPA practitioners elsewhere.

Sexual development and reproductive demography of the green humphead parrotfish (Bolbometopon muricatum) in the Solomon Islands

An investigation of the reproductive biology of the green humphead parrotfish (Bolbometopon muricatum) from three areas in the Western Province of the Solomon Islands revealed that B. muricatum exhibits several features that differ from the pattern of reproductive development observed in most parrotfishes. Unlike most parrotfishes, histological evidence suggests that the sexual pattern of B. muricatum is essentially gonochoristic with high incidences of anatomical but non-functional hermaphroditism. B. muricatum also differs from other parrotfishes in that all males pass through an immature female (or bisexual) phase as demonstrated by all adult testis retaining the ex-ovarian lumen and peripheral sperm sinuses in the gonad wall. However, a protogynous diandric reproductive strategy cannot be excluded given that sampling may have missed transitional individuals. Marked variation in the demography of male B. muricatum between the three locations examined is considered to reflect variation in historical fishing effort.

Research partnerships with local communities: two case studies from Papua New Guinea and Australia

Partnerships between scientists and local communities can increase research capacity and data delivery while improving management effectiveness through enhanced community participation. To encourage such collaboration, this study demonstrates how these partnerships can be formed, drawing on two case studies in coral reef ecosystems in very different social settings (Papua New Guinea and Australia). In each case, steps towards successfully engaging communities in research were similar. These included: (1) early engagement by collaborating organizations to build trust, (2) ensuring scientific questions have direct relevance to the community, (3) providing appropriate incentives for participation, and (4) clear and open communication. Community participants engaged in a variety of research activities, including locating and capturing fishes, collecting and recording data (weight, length and sex), applying external tags, and removing otoliths (ear bones) for ageing and elemental analysis. Research partnerships with communities enhanced research capacity, reduced costs and, perhaps more importantly, improved the likelihood of long-term community support for marine protected areas (MPAs).

A cultural landscape approach to community-based conservation in Solomon Islands

International environmental organizations have an increasing commitment to the development of conservation programs in high-diversity regions where indigenous communities maintain customary rights to their lands and seas. A major challenge that these programs face is the alignment of international conservation values with those of the indigenous communities whose cooperation and support are vital. International environmental organizations are focused on biodiversity conservation, but local communities often have a different range of concerns and interests, only some of which relate to biodiversity. One solution to this problem involves adoption of a cultural landscape approach as the ethical and organizational foundation of the conservation program. In our conservation work in coastal Melanesia, we have developed a cultural landscape approach that involves the construction of a conceptual model of environment that reflects the indigenous perceptions of landscape. This model incorporates cultural, ideational, and spiritual values alongside other ecosystem services and underpins the conservation activities, priorities, and organizational structure of our programs. This cultural landscape model was a reaction to a survey of environmental values conducted by our team in which Solomon Islanders reported far greater interest in conserving cultural heritage sites than any other ecosystem resources. This caused a radical rethinking of community-based conservation programs. The methodologies we adopted are derived from the fields of archaeology and historical anthropology, in which there is an established practice of working through research problems within the framework of indigenous concepts of, and relationship to, landscape. In our work in Isabel Province, Solomon Islands, coastal communities have enthusiastically adopted conservation programs that are based on cultural landscape models that recognize indigenous values. A particularly useful tool is the Cultural Heritage Module, which identifies cultural heritage sites that become targets of conservation management and that are used as part of a holistic framework for thinking about broader conservation values.

Refined bomb radiocarbon dating of two iconic fishes of the Great Barrier Reef

Refinements to the methodology of bomb radiocarbon dating made it possible to validate age estimates of the humphead wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum). Age for these species has been estimated from presumed annual growth zones in otoliths at ,30 and ,40 years respectively. The validity of these estimates was tested using bomb radiocarbon dating on the small and fragile otoliths of these species, and provided an opportunity to refine the method using advanced technologies. A regional D 14 C reference record from hermatypic coral cores from the Great Barrier Reef was assembled and D 14 C measurements from extracted otolith cores of adult otoliths were successful. Validated ages supported the accuracy of growth zone derived ages using sectioned sagittal otoliths. Additional keywords: Australia, Bolbometopon muricatum, bumphead parrotfish, carbon-14, Cheilinus undulatus, humphead wrasse, Labridae, micromilling, otolith.

Hyperstability masks declines in bumphead parrotfish (Bolbometopon muricatum) populations

Bolbometopon muricatum, the largest species of parrotfish, is a functionally important species that is characterised by the formation of aggregations for foraging, reproductive, and sleeping behaviours. Aggregations are restricted to shallow reef habitats, the locations of which are often known to local fishers. Bolbometopon muricatum fisheries are therefore vulnerable to overfishing and are likely to exhibit hyperstability, the maintenance of high catch per unit effort (CPUE) while population abundance declines. In this study, we provide a clear demonstration of hyperstable dynamics in a commercial B. muricatum fishery in Isabel Province, Solomon Islands. Initially, we used participatory mapping to demarcate the Kia fishing grounds into nine zones that had experienced different historic levels of fishing pressure. We then conducted comprehensive underwater visual census (UVC) and CPUE surveys across these zones over a 21-month period in 2012–2013. The individual sites for replicate UVC surveys were selected using a generalised random tessellation stratified variable probability design, while CPUE surveys involved trained provincial fisheries officers and local spearfishers. A comparison of fishery-independent abundance data and fishery-dependent CPUE data indicate extreme hyperstability, with CPUE maintained as B. muricatum abundance declines towards zero. Hyperstability may explain the sudden collapses of many B. muricatum spear fisheries across the Pacific and highlights the limitations of using data-poor fisheries assessment methods to evaluate the status of commercially valuable coral reef fishes that form predicable aggregations.

Reproductive biology of squaretail coralgrouper Plectropomus areolatus using age-based techniques

The squaretail coralgrouper Plectropomus areolatus was identified as a fast-growing, early maturing and relatively short-lived aggregation-spawning epinephelid. Examinations of sectioned otoliths found females and males first maturing at 2 and 3 years, respectively, suggesting protogynous hermaphroditism; however, no transitionals were observed in samples. Age distribution for the two sexes was similar and both were represented in the oldest age class; however, significant sex-specific differences in size-at-age were identified. Both sexes fully recruit into the fishery at age 4 years and reach 90% of asymptotic length by age 3 years. Underwater visual assessments, combined with the gonado-somatic indices, revealed a 5 month reproductive season, with interannual variability observed in the month of highest density within the spawning aggregation. Catch restrictions on adults during spawning times and at reproductive sites, combined with gear-based management and enhanced enforcement, are recommended to maintain spawning stocks. Based on the available evidence, the sexual pattern for this species is unresolved.

Solomon Islands largest hawksbill turtle rookery shows signs of recovery after 150 years of excessive exploitation.

The largest rookery for hawksbill turtles in the oceanic South Pacific is the Arnavon Islands, which are located in the Manning Strait between Isabel and Choiseul Province, Solomon Islands. The history of this rookery is one of overexploitation, conflict and violence. Throughout the 1800s Roviana headhunters from New Georgia repeatedly raided the Manning Strait to collect hawksbill shell which they traded with European whalers. By the 1970s the Arnavons hawksbill population was in severe decline and the national government intervened, declaring the Arnavons a sanctuary in 1976. But this government led initiative was short lived, with traditional owners burning down the government infrastructure and resuming intensive harvesting in 1982. In 1991 routine beach monitoring and turtle tagging commenced at the Arnavons along with extensive community consultations regarding the islands’ future, and in 1995 the Arnavon Community Marine Conservation Area (ACMCA) was established. Around the same time national legislation banning the sale of all turtle products was passed. This paper represents the first analysis of data from 4536 beach surveys and 845 individual turtle tagging histories obtained from the Arnavons between 1991-2012. Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter. Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995. The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

Restricted grouper reproductive migrations support community-based management

Conservation commonly requires trade-offs between social and ecological goals. For tropical small-scale fisheries, spatial scales of socially appropriate management are generally small—the median no-take locally managed marine area (LMMA) area throughout the Pacific is less than 1 km2. This is of particular concern for large coral reef fishes, such as many species of grouper, which migrate to aggregations to spawn. Current data suggest that the catchment areas (i.e. total area from which individuals are drawn) of such aggregations are at spatial scales that preclude effective community-based management with no-take LMMAs. We used acoustic telemetry and tag-returns to examine reproductive migrations and catchment areas of the grouper Epinephelus fuscoguttatus at a spawning aggregation in Papua New Guinea. Protection of the resultant catchment area of approximately 16 km2 using a no-take LMMA is socially untenable here and throughout much of the Pacific region. However, we found that spawning migrations were skewed towards shorter distances. Consequently, expanding the current 0.2 km2 no-take LMMA to 1–2 km2 would protect approximately 30–50% of the spawning population throughout the non-spawning season. Contrasting with current knowledge, our results demonstrate that species with moderate reproductive migrations can be managed at scales congruous with spatially restricted management tools.