Marine protected areas are more effective but less reliable in protecting fish biomass than fish diversity

Abstract. Protected areas are an important conservation measure. However, there are controversial findings regarding whether closed areas are beneficial for species and habitat conservation as well as for harvesting. Species dispersal is acknowledged as a key factor for the design and impacts of protected areas. A series of agent-based models using random diffusion to model fish dispersal were run before and after habitat protection. All results were normalized without the protected habitat in each scenario to detect the relative difference after protecting an area, all else being equal. Model outputs were compared with published data regarding the impacts over time of MPAs on fish biomass. In addition, data on species' dispersal potential in terms of kilometres per year are compared with model outputs. Results show that fish landings of species with short dispersal rates will take longer to reach the levels from before the Marine Protected Areas (MPAs) were established than landings of species with long dispersal rates. Further, the establishment of an MPA generates a higher relative population source within the MPA for species with low dispersal abilities than for species with high dispersal abilities. Results derived here show that there exists a feasible win-win scenario that maximizes both fish biomass and fish catches.

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Impact of marine protected areas on economical important coral reef fish communities: An evaluation of the biological monitoring of coral reef fish in Anambas Islands, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d221006 ◽

2021 ◽

Vol 22 (10) ◽

Author(s):

RISANDI DWIRAMA PUTRA ◽

RIKOH MANOGAR SIRINGIRINGO ◽

Ani Suryanti ◽

NI WAYAN PURNAMA SARI ◽

MUIN SINAGA ◽

...

Keyword(s):

Coral Reef ◽

Biological Monitoring ◽

Protected Areas ◽

Reef Fish ◽

Marine Protected Areas ◽

Coral Reef Fish ◽

Coral Cover ◽

Fish Diversity ◽

The Impact ◽

Destructive Fishing

Abstract. Putra RD, Siringiringo RM, Suryanti A, Sari NWP, Sinaga M, Hidayati NV, Hukom FD, Abrar M, Makatipu PC, Sianturi R, Ilham Y. 2021. Impact of marine protected areas on economical important coral reef fish communities: An evaluation of the biological monitoring of coral reef fish in Anambas Islands, Indonesia. Biodiversitas 22: 4169-4181. The use of Marine Protected Areas (MPAs) is the core strategy to reduce the impact of the anthropogenic stressor on marine fisheries, especially in reducing the overexploitation of fisheries resources and destructive fishing in which this plays a significant role in the conservation of marine biodiversity and populations. We conducted a study over 4 years to evaluate and assess the impact of MPAs on economically important reef fish in the Anambas Islands. We compared density, size, biomass, and diversity indices from the seven families of coral reef fish (Acanthuridae, Haemulidae, Lethrinidae, Lutjanidae, Scaridae, Siganidae, and Serranidae) using Underwater Visual Census (UVC) with a total of 12 MPAs stations (70-m transect). Multivariate analysis of variance (MANOVA) was used to evaluate and assess reserve protection on the coral reef fish, and several ecological indices were used to compare the potential change of economically coral reef fish diversity. We also measured the rate of change in coral cover to identify the effectiveness of the MPAs. After 4 years of studies, our result showed that there was an increase of economical reefs. Fish diversity, density, and biomass increased by 244%, 257%, and 179% respectively. There was no significant difference in the rate of coral cover change among MPAs stations. Economical coral reef fish in Anambas Islands were restored in marine reserve overtimes after fisheries restriction protection, but this does not change the rate of coral cover through time. In addition, the government managed and increased community awareness that significantly influenced decreasing destructive fishing practices and overexploited reef fish species in Anambas Islands but no change in coral cover. The MPAs environmental condition and natural disturbance, including thermal stress and high sedimentation, play a key role in coral cover recovery besides fisheries restriction in the MPAs area.

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Ecosystem-Based Management in Fiji: Successes and Challenges after Five Years of Implementation

Journal of Marine Biology ◽

10.1155/2011/940765 ◽

2011 ◽

Vol 2011 ◽

pp. 1-14 ◽

Cited By ~ 46

Author(s):

Stacy D. Jupiter ◽

Daniel P. Egli

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Fish Biomass ◽

Fishing Pressure ◽

Visual Census ◽

Underwater Visual Census ◽

Visual Distance ◽

Future Success ◽

Successes And Challenges

In 2005, a network of 3 large, district-wide marine protected areas (MPAs) and 17 village-managed closures (tabu) was established in Kubulau District, Fiji. Underwater visual census (UVC) data of fish biomass and benthic cover were collected between 2007 and 2009 and analysed with PERMANOVA and ANOSIM to assess differences between closed and open areas. High reef fish biomass (>1000 kg/ha) within closures, significantly elevated over open areas, was consistently observed from: (1) tabu areas on naturally productive reefs within visual distance from villages; and (2) the large, long-term permanent closure located away from fishing pressure. Factors that may have contributed to low fish biomass within closures include small size of closures; noncompliance with management rules; and disclosure of management success to fishers from villages with high reliance on fisheries products. Future success of the network depends on improving awareness of management rules and ensuring implementation within a broader ecosystem framework.

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Measuring the long-term success of small-scale marine protected areas in a Philippine reef fishery

Coral Reefs ◽

10.1007/s00338-020-01987-7 ◽

2020 ◽

Vol 39 (6) ◽

pp. 1591-1604

Author(s):

Daniel T. I. Bayley ◽

Andy Purvis ◽

Angelie C. Nellas ◽

Myrtle Arias ◽

Heather J. Koldewey

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Coral Cover ◽

The Philippines ◽

Anthropogenic Sources ◽

Small Scale ◽

Fish Biomass ◽

Trophic Groups ◽

Study Region

AbstractTropical coral reefs are subject to multiple pressures from both natural and anthropogenic sources. These pressures have caused widespread declines in reef health, resulting in the increased use of spatial management tools such as marine protected areas (MPAs). MPAs have proven generally effective if well designed and enforced, but there are limited long-term studies investigating how the presence of small-scale MPAs affects fish populations and reef communities. Using a 12-year time series, we found that small-scale (10–50 ha) community-managed MPAs along the Danajon Bank of the Philippines preserved average fish biomass within their boundaries over time relative to surrounding fished reefs. Unprotected areas are, however, showing significant long-term biomass decline. MPAs were also found to preserve more key trophic groups and larger-bodied commercially targeted reef fish families. Fish biomass of piscivore, scavenger and invertivore trophic groups inside individual MPAs is, however, still declining at a similar rate as outside. Surprisingly, long-term benthic cover and growth form composition were not significantly affected overall by MPA presence, despite the sporadic use of highly destructive dynamite fishing in this region. Coral cover has remained historically low (21–28%) throughout the study, following widespread bleaching mortality. While management tempered overall abundance declines, we found that irrespective of MPA presence, there was a generalised decline of both large- and small-bodied fish size groups across the study region, most steeply within the 20–30 cm length fish, and a shift towards proportionally higher abundances of small (5–10 cm) fish. This indicates a combination of over-exploitation, inadequate MPA size and coverage for larger fish, and the lingering effects of the 1998 bleaching event. Generalised shifts in body size and trophic structure reported here could lead to future reductions in fishery productivity and stability and will be further exacerbated unless broader fishery regulations and enforcement is instated.

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