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Papua New Guinea – Fisheries Management


Shared Benefits of Protecting Fish Spawning Aggregations Lead to Cooperative Management

Location
Manus Province, Papua New Guinea

Healthy Hard Coral Reef with Anthias and Coral Grouper at Killibob's Knob dive site in Kimbe Bay of Papua New Guinea. The Coral Triangle contains 75 percent of all known coral species, shelters 40 percent of the world’s reef fish species and provides for 126 million people. © Jeff Yonover

Healthy Hard Coral Reef with Anthias and Coral Grouper at Killibob’s Knob dive site in Kimbe Bay of Papua New Guinea. The Coral Triangle contains 75 percent of all known coral species, shelters 40 percent of the world’s reef fish species and provides for 126 million people. © Jeff Yonover

The Challenge
The coral reefs of Papua New Guinea (PNG) are among the most species-diverse in the world and an important source of food and income for communities. The 40,000 km2 of coral reefs form an extensive resource that is exploited almost exclusively by small-scale artisanal and subsistence fishers. On a national level, harvests are thought to be well below the maximum sustainable yield. Despite the overall health of the PNG fishery, local over-exploitation has been noted, particularly in fisheries with access to cash markets. Fish spawning aggregations are particularly vulnerable even to light fishing pressure, which can have a profound impact on the reproductive population over a brief period and substantially reduce reproductive output.

As in many other tropical nations, fishery management in Papua New Guinea requires a community-based approach because small customary marine tenure (CMT) areas define the spatial scale of management. However, the fate of larvae originating from a fish spawning aggregation in a community’s CMT area is unknown, and thus the degree to which a community can expect their management actions to replenish the fisheries within their CMT is unclear. Therefore, information on larval dispersion is important: if larvae disperse in large numbers across tenure areas, this can provide a strong impetus for cooperative management between adjacent communities.

Conservancy marine scientist, Alison Green surveying coral during a rapid ecological assessment (REA) in the area of Manus Province, North Bismarck Sea, Papua New Guinea. The coral reefs of Papua New Guinea (PNG) are among the most species-diverse in the world and an important source of food and income for communities. © Louise Goggin

Conservancy marine scientist, Alison Green surveying coral during a rapid ecological assessment (REA) in the area of Manus Province, North Bismarck Sea, Papua New Guinea. The coral reefs of Papua New Guinea (PNG) are among the most species-diverse in the world and an important source of food and income for communities. © Louise Goggin

Actions Taken
To better understand the dispersal dynamics of fish larvae, The Australian Research Council (ARC) and The Nature Conservancy (TNC) conducted a genetic analysis to measure larval dispersal from a single fish spawning aggregation (FSA) of squaretail coralgrouper (Plectropomus areolatus) at Manus, Papua New Guinea. In 2004, to replenish local fish stocks, fishers within a single CMT area established a marine protected area (MPA) protecting 13% of their fishing grounds, including the studied FSA. Researchers and local fishers sampled this FSA over 2 weeks in May 2010 and collected tissue samples from, and externally tagged, 416 adult coralgroupers, which represented an estimated 43% of the FSA population.

Over 6 weeks (November–December 2010), 782 juvenile coralgroupers from 66 reefs were collected from within the CMT area and four other surrounding CMT areas up to 33 km from the sampled FSA. The analysis identified 76 juveniles from 25 reefs that were the offspring of adults sampled at the FSA.

Researchers quantified how larvae dispersing from the coralgrouper FSA contribute to recruitment in the surrounding CMT area and four adjacent CMT areas. They found that 17–25% of recruitment to the CMT area that contains the sampled FSA came from that same FSA and that in each of the four adjacent CMT areas, 6–17% of recruitment was also from the sampled FSA. Finally, the dispersal models based on these data predict that 50% of larvae will settle within 13 km and 95% within 33 km of the FSA.

Location and abundance of sampled and assigned juveniles: spatial patterns of coral grouper (A) juvenile sample collection and (B) juvenile parentage assignments. Green (A) and yellow (B) circles are scaled to the number of juveniles. Adults were sampled from a single fish spawning aggregation (red cross), and juveniles were collected from 66 individual reefs (green circles in A). White dashed lines show the customary marine tenure boundaries of the five communities, with the name of each community in white (A). Land is black, coral reefs are gray, and water is blue (Almany et al. 2013).

Location and abundance of sampled and assigned juveniles: spatial patterns of coral grouper (A) juvenile sample collection and (B) juvenile parentage assignments. Green (A) and yellow (B) circles are scaled to the number of juveniles. Adults were sampled from a single fish spawning aggregation (red cross), and juveniles were collected from 66 individual reefs (green circles in A). White dashed lines show the customary marine tenure boundaries of the five communities, with the name of each community in white (A). Land is black, coral reefs are gray, and water is blue (Almany et al. 2013).

How Successful Has It Been?
The final results and recommendations of this study were presented in November 2011 to all five communities that participated in the research as well as in Mbuke, the largest community among the offshore islands to the south of the study area. The three main conclusions from this work are:

  • Small, managed areas that protect FSAs can help rebuild and sustain a community’s coralgrouper fishery because many larvae stay close to the FSA.
  • The coralgrouper fishery represents one large stock that would be better managed collectively because some larvae and fish travel across CMT boundaries.
  • The results of the coralgrouper study are similar to results from other studies on both fishery and non-fishery species, all of which suggest that some larvae only travel short distances from their parents.

These results suggest that community-based management can definitely provide local benefits for some fishery species, and possibly for a wide range of fishery species.

At the time of the study, there was no formal framework in place to support collective management. Communities had traditionally made independent decisions about the fisheries within their CMT area. However, many community members immediately saw the value in collective community-based fisheries management after the results of this study were presented. Those communities in support of collective management, which consisted of eight Titan tribal areas including the five CMT areas that participated in the coralgrouper study, sent 70 leaders to a gathering in June 2013 to officially establish the Manus Endras Asi Resource Development Network.

Island fishing boats and children in the area of Manus Province, North Bismarck Sea, Papua New Guinea. © Louise Goggin

Island fishing boats and children in the area of Manus Province, North Bismarck Sea, Papua New Guinea. © Louise Goggin

The eight tribal areas of the network contain more than 10,000 people spread across approximately a third of Manus province (~73,000 km2 of ocean). The network was established around existing sociocultural boundaries, with all members sharing a common language (Titan), common religion (Wind Nation), and a maritime culture. Some strategies the network used for achieving its mission include: advocating for and supporting equitable and sustainable development to improve livelihoods; preservation of cultural heritage; developing a learning forum to share experiences among network members to build local capacity; improving communities’ resilience to climate change through community-based projects; supporting research partnerships between communities and scientists that benefit communities; and establishing a network of managed and protected areas.

Since its inception in June 2013, the network has crafted and signed an official charter establishing itself as a registered business, developed and agreed on a strategic plan, and established a formal relationship with the Papua New Guinea National Fisheries Authority (NFA) to coordinate fisheries management activities. A recent outcome of this link with NFA has been a pledge from NFA to provide shallow water fish aggregating devices (FADs) to each community in the network to reduce fishing pressure on reefs.

At the September 2014 network meeting, the Tribal Council of Chiefs, acting as representatives of their tribal areas, approved the establishment of a comprehensive system of managed and protected areas across the entire area under the network’s jurisdiction. The two main goals of this system of managed and protected areas are to ensure the sustainability of a range of fishery resources and to protect cultural heritage sites. Next steps include a participatory planning workshop to integrate community priorities and conservation targets, local knowledge, and scientific data into a comprehensive spatial management plan for the area.

Lessons Learned and Recommendations

  • Increased cooperation between communities in managing their fisheries benefits both fish populations and communities.
  • Actions taken by one community will influence its neighbors, and cooperation among communities in managing a fishery is likely to enhance both fisheries sustainability and the long-term persistence of fish meta-populations.
  • The strength of connectivity between coral reefs will decline as the distance between them increases, and localized larvae dispersal is common in coral reef fishes.
  • Resolving larval dispersal patterns and their relationship to recruitment may provide a compelling argument for cooperative management.
  • Fisheries management decisions on the size and spacing of marine protected areas may provide benefits to a range of species simultaneously.

Funding Summary
Australian Research Council Centre of Excellence for Coral Reef Studies
The David and Lucile Packard Foundation
The Nature Conservancy’s Rodney Johnson/Katherine Ordway Stewardship Endowment
National Fish and Wildlife Foundation

Lead Organizations
Australian Research Council Centre of Excellence for Coral Reef Studies
The Nature Conservancy

Partners
James Cook University
King Abdullah University of Science and Technology
The University of Hawaii at Hilo
Woods Hole Oceanographic Institution

Resources
Video: Larval dispersal and its influence on fisheries management

Local Benefits of Community-based Management: Using Small Managed Areas to Rebuild and Sustain Some Coastal Fisheries (pdf)

Dispersal of Grouper Larvae Drives Local Resource Sharing in a Coral Reef Fishery (pdf)

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Sewage Pollution: Mitigation Is Key For Coral Reef Stewardship

In this new paper, the authors highlight the importance of addressing sewage, a global stressor affecting coral reefs. The authors note that of 112 coral reef geographies, 104 have documented sewage contamination problems, with the majority documenting direct ocean discharge. Despite this threat, the authors find that scientists and conservationists have paid less attention to understanding and abating sewage impacts on coral reefs, as compared to other stressors like overfishing. They suggest that reasons for this include the challenges of dealing with a large-scale diffuse threat, the diversity of pollutants involved, the high cost of water-treatment facilities, and bureaucracy. The authors explore how sewage discharge is often mischaracterized as a single stressor in coral reef management and suggest that it is important to recognize that sewage is a conglomerate of many potentially toxic and distinct stressors, including freshwater, inorganic nutrients, pathogens, endocrine disrupters, suspended solids, sediments, heavy metals, and other toxins. The authors state that mitigating the threat of sewage pollution will require: 1) understanding tolerance thresholds that corals have to sewage exposure, evaluating individual contaminants, additive, and synergistic combinations of contaminants; 2) quantifying the spatial extent and magnitude of the sewage discharge problems; and, most importantly, (3) testing both proactive and reactive strategies that can be employed to reduce the adverse impacts of human sewage in tropical coastal waters.

Author: Wear, S.L. and R. Vega-Thurber
Year: 2015
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Annuals of the New York Academy of Sciences: 1–16. doi: 10.1111/nyas.12785

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The Intrinsic Vulnerability To Fishing Of Coral Reef Fishes And Their Differential Recovery In Fishery Closures

Coral reef fisheries play a role in livelihoods and local economies around the world, but the impacts of fishing on targeted species of reef fish is poorly understood. The authors of this study examined the vulnerability of different species of coral reef fish to fisheries and evaluated the effectiveness of no-take reserves and periodically-harvested closures. Using life history traits to characterize the vulnerability of fish species to fishing, they found that larger-bodied carnivorous fish have a higher vulnerability compared to smaller-bodied herbivores and detritivores. In no-take areas, moderately to highly vulnerable species take a significantly longer time (decades) to recover than less vulnerable species. Based on these findings, they make the following recommendations for managers:

    • Expand studies of reef fish to improve estimates of vulnerability; Maintain long-term (20-40 year) no-take areas for full population recovery
    • Enforce compliance of no-take areas
    • Control timing and intensity of periodic closures for long-term fishery benefits
    • Use periodic and closures and no-take areas together as fishery management tools

    Author: Abesamis, R.A., A.L. Green, G.R. Russ, and C.R.L. Jadloc
    Year: 2014
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    Email for the full article: resilience@tnc.org

    Reviews in Fish Biology and Fisheries. doi: 10.1007/s11160-014-9362-x

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Recovery Potential Of The World’s Coral Reef Fishes

Fishing is the primary source of reduced reef function globally. Marine reserves are a critical tool to help fish populations recover, however, there are no benchmarks to determine if the protection is effective, or whether a reserve has recovered enough to be fished again. By studying remote and marine protected areas, they estimate how many fish would be on a coral reef without fishing, and how long it should take newly protected areas to recover. This helps to assess the impact of reef fisheries, and make informed management decisions that include timeframes for recovery.

Specifically, this paper presents the first empirical estimate of coral reef fisheries recovery potential, compiling data from 832 coral reefs across 64 localities (countries and territories. The authors estimate the expected density of reef fish on unfished reefs; quantify the rate of reef fish biomass recovery in well-enforced marine reserves; characterize the state of reef fish communities within fished and managed areas; predict the time required to recover biomass and ecosystem functions; and explore the potential returns in biomass and function using off-reserve management throughout the broader reefscape. The research team studied the fish biomass on coral reefs around the world and discovered that near-pristine reefs contain 1,000 kg of fish per hectare. Using this figure as a benchmark, they found that 83% of fished reefs have lost more than half of their fish biomass (volume of fish).

The authors discuss how reef fish populations were better off when fishing activities were restricted (e.g., including limitations on the species that could be caught, the gears that could be used, and controlled access rights). The authors determined that once protected, fished reefs take about 35 years to recover, while heavily depleted reefs take almost 60 years. Although the influence of marine reserves can be detected within several years, this global analysis demonstrated that full recovery of reef fish biomass takes decades to achieve. Importantly, this suggests that most marine reserves implemented in the past 10–20 years, will require many more years to achieve their recovery potential. This has important implications for managing expectations of MPAs and also reinforces the need for continued, effective protection and consideration of other viable management options. The authors also found that in reef areas where MPAs cannot be implemented, a range of fisheries can have substantial effects on fish functional groups that support important reef processes.

Author: MacNeil, M.A., N.A.J. Graham, J.E. Cinner, S.K. Wilson, I.D. Williams, J. Maina, S. Newman, A.M. Friedlander, S. Jupiter, N.V.C. Polunin, and T.R. McClanahan
Year: 2015
View Abstract
Email for the full article: resilience@tnc.org

Nature 520: 341-344. doi:10.1038/nature14358

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Using Wastewater Treatment Technologies to Reduce Nutrient Pollution Impacts on Coral Reefs

Watch on YouTube

March 11, 2015

Jim Bays, Technology Fellow at CH2M HILL discusses wastewater treatment technologies ranging from low-tech onsite treatment to large system level upgrades that improve public health and mitigate nutrient pollution impact to coral reefs and sensitive marine ecosystems. Case histories from small communities, resorts and large cities in coral reef areas are shared. Click here for resources from the presentation.

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Persistence and Change in Community Composition of Reef Corals through Present, Past and Future Climates

This study looked at long-term data from fossil and modern coral reefs to test for variation among coral genera over time, both in rates and directions of change in abundance. Data was synthesized from seven extant reefs, creating 78 trajectories of changing coral cover by genus in the Caribbean and 153 trajectories in the Indo-Pacific. Fossil records from 70 localities from late Miocene to late Pleistocene were used to understand the temporal nature of changes affecting current coral reef communities. A model was developed to evaluate potential coral reef composition of the future under increased thermal stress predicted by climate change. The model suggested that coral mortality and adult coral growth were the most important ecological indicators of coral persistence; thermal tolerance became increasingly important when looking at severe climate change. Overall, corals most likely to persist in future climate scenarios are characterized by rapid growth and moderate mortality but changes in the genera of coral composition in the future are likely to occur.

Author: Edmunds, P.J., M. Adjeroud, M.L. Baskett, I.B. Baums, A.F. Budd, et al.
Year: 2014
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PLoS ONE 9(10): e107525. doi: 10.1371/journal.pone.0107525

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New and improved Network Forum

The Reef Resilience Network has launched a new and improved online discussion forum!

Now part of the Reef Resilience website, this interactive online community is a place where coral reef managers and practitioners from around the world can connect and share with others to better manage marine resources.

If you work to protect, manage, or promote coral reefs please join the conversation: www.reefresilience.org/network

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New Reef Resilience Online Course Launched

The new online course Advanced Studies in Coral Reef Resilience is designed to provide coral reef managers and practitioners in-depth guidance on managing for resilience. This free course incorporates new science, case studies, and management practices described in the Reef Resilience Toolkit.

The course includes six modules that discuss local and global stressors affecting coral reefs, guidance for identifying coral reef resilience indicators, design principles for resilient MPA networks, methods for implementing resilience assessments, and important communication tools for managers. Course participants can choose to complete any or all lessons within course modules. Read more.

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Meta-Analysis Indicates Habitat-Specific Alterations to Primary Producer and Herbivore Communities in Marine Protected Areas

A recent global quantitative review and meta-analysis was conducted on the effects of MPAs on coral reef herbivores and primary producers to support management decisions. Based on criteria for the meta-analysis, which included only well-enforced no-take MPAs, 41 individual publications representing 57 MPAs worldwide were included in the study. The authors found that within MPAs, macroalgal cover and sea urchin density were significantly lower as compared to fished areas. The relationship between macroalgae cover and herbivores was also explored. MPAs with higher populations of herbivorous fishes had significantly lower macroalgal cover. The authors conclude that the community response to MPAs is highly variable. Management implications include protecting key echinoid predators which appear crucial to the recovery of reefs. Also, actively managing grazers and predators should be an integral component of MPA design.

Author: Gilby, B.L. and T. Stevens
Year: 2014
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Global Ecology and Conservation 2: 289-299. doi: 0.1016/j.gecco.2014.10.005

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