Showing papers by "James Cook University published in 2003"

Climate Change, Human Impacts, and the Resilience of Coral Reefs

Abstract: The diversity, frequency, and scale of human impacts on coral reefs are increasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past half-million years. However, reefs will change rather than disappear entirely, with some species already showing far greater tolerance to climate change and coral bleaching than others. International integration of management strategies that support reef resilience need to be vigorously implemented, and complemented by strong policy decisions to reduce the rate of global warming.

Global Trajectories of the Long-Term Decline of Coral Reef Ecosystems

Abstract: Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.

Ways of knowing, being and doing: A theoretical framework and methods for indigenous and indigenist re‐search

Abstract: [Extract] The myth of terra nullius implied that this country was uninhabited and terra nullius social policy supported by research enabled for the dispossession of knowledges of Indigenous peoples. It must be remembered that university curriculum, teaching methodologies and research endeavours have a history of development that contributed to this dispossession. Has the time come for change?

Climate change in Australian tropical rainforests: an impending environmental catastrophe

Abstract: It is now widely accepted that global climate change is affecting many ecosystems around the globe and that its impact is increasing rapidly. Many studies predict that impacts will consist largely of shifts in latitudinal and altitudinal distributions. However, we demonstrate that the impacts of global climate change in the tropical rainforests of northeastern Australia have the potential to result in many extinctions. We develop bioclimatic models of spatial distribution for the regionally endemic rainforest vertebrates and use these models to predict the effects of climate warming on species distributions. Increasing temperature is predicted to result in significant reduction or complete loss of the core environment of all regionally endemic vertebrates. Extinction rates caused by the complete loss of core environments are likely to be severe, nonlinear, with losses increasing rapidly beyond an increase of 2 degrees C, and compounded by other climate-related impacts. Mountain ecosystems around the world, such as the Australian Wet Tropics bioregion, are very diverse, often with high levels of restricted endemism, and are therefore important areas of biodiversity. The results presented here suggest that these systems are severely threatened by climate change.

Limited functional redundancy in high diversity systems: resilience and ecosystem function on coral reefs

Abstract: Biodiversity is frequently associated with functional redundancy. Indo-Pacific coral reefs incorporate some of the most diverse ecosystems on the globe with over 3000 species of fishes recorded from the region. Despite this diversity, we document changes in ecosystem function on coral reefs at regional biogeographical scales as a result of overfishing of just one species, the giant humphead parrotfish (Bolbometopon muricatum). Each parrotfish ingests over 5 tonnes of structural reef carbonates per year, almost half being living corals. On relatively unexploited oceanic reefs, total ingestion rates per m2 balance estimated rates of reef growth. However, human activity and ecosystem disruption are strongly correlated, regardless of local fish biodiversity. The results emphasize the need to consider the functional role of species when formulating management strategies and the potential weakness of the link between biodiversity and ecosystem resilience.

Emerging disease of amphibians cured by elevated body temperature

Abstract: The emerging infectious disease chytridiomycosis is thought to have contributed to many of the recent alarming declines in amphibian populations Mortalities associated with these declines have often occurred during cooler seasons and at high elevations, suggesting that environmental temperature may be an important factor in disease emergence We found that thermal environment affects the progress of the disease, and that housing frogs Litoria chloris at an environmental temperature of 37°C for less than 16 h can clear them of the chytrid pathogen Batrachochytrium dendrobatidis Our experiment demonstrated that elevated body temperatures similar to those experienced in behavioral fever and during normal thermoregulation can clear frogs of chytrid infection; therefore, variation in thermoregulatory opportunities and behaviors are likely to contribute to the differences in disease incidence observed among host species, populations, and regions Although further refinement of the technique is needed to encompass various host species, appropriately applied thermal manipulations of amphibians and their enclosures may prove to be a safe and effective way of eliminating the fungal pathogen from captive amphibian populations and preventing accidental spread of the pathogen when animals are translocated or released from captivity

The Palm Island mystery disease 20 years on: a review of research on the cyanotoxin cylindrospermopsin.

Abstract: Poisoning of humans resulting from consumption of water affected by the toxic cyanobacterium Cylindrospermopsis raciborskii was first reported almost 20 years ago from Palm Island, northern Queensland, Australia. Since that time a great deal has been learned about this organism and cylindrospermopsin (CYN), the toxin it produces. This article reviews the information now available to us. It summarizes aspects of the chemistry of the toxin-now known to be produced by some cyanobacterial species other than C. raciborskii-and its biosynthesis and chemical synthesis in vitro, as well as its detection and measurement by chemical and biological assay. Some of the factors affecting toxin production by cultured isolates of C. raciborskii are reviewed and the conditions that cause its release from the cells described. The occurrence of CYN in water bodies and the management strategies used to minimize the harmful effects of the toxin are outlined. These include a range of water-treatment practices now in place to remove CYN-producing organisms and/or to neutralize the toxin together with some management procedures that have been tried, with varying degrees of success, to prevent buildup of blooms of the offending organisms. Some of the public-health considerations arising from exposure to water supplies affected by CYN are summarized along with the risk factors and guidance values as they are currently applied. Among the more recent developments described are those that come from the application of molecular techniques for characterizing toxic and nontoxic strains and for exploring the genetic aspects of CYN production.

Low back pain in Australian adults: The economic burden

Abstract: This paper reports the results of a "cost-of-illness" study of low back pain (LBP) in Australian adults. It estimates the direct cost of LBP in 2001 to be AU$1.02 billion. Approximately 71% of this amount is for treatment by chiropractors, general practitioners, massage therapists, physiotherapists and acupuncturists. However, the direct costs are minor compared to the indirect costs of AU$8.15 billion giving a total cost of AU$9.17 billion. LBP in Australian adults represents a massive health problem with a significant economic burden. This burden is so great that it has compelling and urgent ramifications for health policy, planning and research. This study identifies that research should concentrate on both direct but particularly the indirect costs including cost-effective management regimes that encourage an early return to duties.

Multilocus sequence typing suggests the chytrid pathogen of amphibians is a recently emerged clone

Abstract: Chytridiomycosis is a recently identified fungal disease associated with global population declines of frogs. Although the fungus, Batrachochytrium dendrobatidis , is considered an emerging pathogen, little is known about its population genetics, including the origin of the current epidemic and how this relates to the dispersal ability of the fungus. In this study, we use multilocus sequence typing to examine genetic diversity and relationships among 35 fungal strains from North America, Africa and Australia. Only five variable nucleotide positions were detected among 10 loci (5918 bp). This low level of genetic variation is consistent with the description of B. dendrobatidis as a recently emerged disease agent. Fixed (i.e. 100%) or nearly fixed frequencies of heterozygous genotypes at two loci suggested that B. dendrobatidis is diploid and primarily reproduces clonally. In contrast to the lack of nucleotide polymorphism, electrophoretic karyotyping of multiple strains demonstrated a number of chromosome length polymorphisms.

Fungicidal effects of chemical disinfectants, UV light, desiccation and heat on the amphibian chytrid, Batrachochytrium dendrobatidis

Abstract: The efficacy of a number of disinfection treatments was tested on in vitro cultures of the fungus Batrachochytrium dendrobatidis, the causative agent of chytridiomycosis in amphibians The aim was to evaluate the fungicidal effects of chemical disinfectants, sterilising ultraviolet (UV) light, heat and desiccation, using methods that were feasible for either disinfection in the field, in amphibian husbandry or in the laboratory The chemical disinfectants tested were: sodium chloride, household bleach (active ingredient: sodium hypochlorite), potassium permanganate, formaldehyde solution, Path-XTM agricultural disinfectant (active ingredient: didecyl dimethyl ammonium chloride, DDAC), quaternary ammonium compound 128 (DDAC), Dithane, Virkon, ethanol and benzalkonium chloride In 2 series of experiments using separate isolates of B dendrobatidis, the fungicidal effect was evaluated for various time periods and at a range of chemical concentrations The end point measured was death of 100% of zoospores and zoosporangia Nearly all chemical disinfectants resulted in 100% mortality for at least one of the concentrations tested However, concentration and time of exposure was critical for most chemicals Exposure to 70% ethanol, 1 mg Virkon ml–1 or 1 mg benzalkonium chloride ml–1 resulted in death of all zoosporangia after 20 s The most effective products for field use were Path-XTM and the quaternary ammonium compound 128, which can be used at dilutions containing low levels (eg 0012 or 0008%, respectively) of the active compound didecyl dimethyl ammonium chloride Bleach, containing the active ingredient sodium hypochlorite, was effective at concentrations of 1% sodium hypochlorite and above Cultures did not survive complete drying, which occurred after <3 h at room temperature B dendrobatidis was sensitive to heating, and within 4 h at 37°C, 30 min at 47°C and 5 min at 60°C, 100% mortality occurred UV light (at 1000 mW m–2 with a wavelength of 254 nm) was ineffective at killing B dendrobatidis in culture

Detritus in the epilithic algal matrix and its use by coral reef fishes

Abstract: The epilithic algal matrix (EAM) is a ubiquitous component of coral reefs and is the primary grazing surface for many reef fishes. Detritus accounts for at least 10% to 78% of all the organic matter present in the EAM, variation being attributed to hydrodynamic forces such as wave energy and biological elements such as algal morphology. When compared with filamentous algae, the other major source of organic matter in the EAM, protein:energy ratios, C:N ratios and total hydrolysable amino acids all suggest that detritus is of higher nutritional value than the algae. Lipid biomarkers indicate that more than 70% of the detritus is derived from the filamentous algae but the addition of bacteria and microalgae add essential nutrients and improve the nutritional value of the detritus. The detritus is typically of an amorphic form with protein:energy ratios which indicate that it is capable of sustaining fish growth. Detritus within the EAM may be derived from dissolved organic matter, which reduces refractory material, enhancing the palatability and digestibility of detritus relative to filamentous algae. Detritus in the EAM may also come from settling material and fish faeces. Studies that quantified the amount of detritus ingested by fishes have identified at least 24 species from five families that predominantly ingest detritus. These species represent some of the most widespread and abundant EAM feeding fishes on coral reefs. It is estimated that detritivorous fishes account for at least 20% of individuals and 40% of the biomass of an EAM-feeding fish assemblage on the Great Barrier Reef. Comparisons of ingested material with the EAM indicate that many of these species selectively feed on detritus, particularly the small, organic rich particles <125 μm. Furthermore, analysis of lipids in body tissues of blennies and assimilation of nutrients from the alimentary canal of scarids and acanthurids provide strong evidence that detritus is assimilated by coral reef fishes. Consequently, a large percentage of EAM-feeding fishes on coral reefs can unequivocally be classified as detritivores. The ingestion and assimilation of detritus by these fishes represents a significant pathway for transferring energy from within the EAM to secondary consumers, making detritivorous fishes a critically important component of coral reef trophodynamics.

Survival of Batrachochytrium dendrobatidis in water: quarantine and disease control implications.

Abstract: Amphibian chytridiomycosis is an emerging infectious disease of amphibians thought to be moved between countries by trade in infected amphibians. The causative fungus, Batrachochytrium dendrobatidis, produces aquatic, motile zoospores; infections have been achieved in experiments by exposing amphibians to water containing zoospores. However, the ability of this fungus to survive in the environment in the absence of an amphibian host is unknown. We show that B. dendrobatidis will survive in tap water and in deionized water for 3 and 4 weeks, respectively. In lake water, infectivity was observed for 7 weeks after introduction. The knowledge that water can remain infective for up to 7 weeks is important for the formulation of disease control and quarantine strategies for the management of water that has been in contact with amphibians.

Death to Critique and Dissent? the Policies and Practices of New Managerialism and of ‘evidence-based Practice’

Abstract: In this article, the author develops a critique of new managerialism and of its implications for the professional work of scholars and teachers. She then critiques 'evidence-based practice' as it is being developed for schools. She argues that it is only possible to make sense of the policies and practices of the evidence-based practice movement within the framework of new managerialism. She also explores some of the tensions and contradictions between managerialism and gender reform in educational contexts. She ends with a challenge to begin the work of generating the collective story through which we can dismantle the hegemony of new managerialism and engage in the transformative work that will afford us a different future.

Pit membrane porosity and water stress-induced cavitation in four co-existing dry rainforest tree species.

Abstract: Aspects of xylem anatomy and vulnerability to water stress-induced embolism were examined in stems of two drought-deciduous species, Brachychiton australis (Schott and Endl.) A. Terracc. and Cochlospermum gillivraei Benth., and two evergreen species, Alphitonia excelsa (Fenzal) Benth. and Austromyrtus bidwillii (Benth.) Burret., growing in a seasonally dry rainforest. The deciduous species were more vulnerable to water stress-induced xylem embolism. B. australis and C. gillivraei reached a 50% loss of hydraulic conductivity at −3.17 MPa and −1.44 MPa, respectively; a 50% loss of hydraulic conductivity occurred at −5.56 MPa in A. excelsa and −5.12 MPa in A. bidwillii . To determine whether pit membrane porosity was responsible for greater vulnerability to embolism (air seeding hypothesis), pit membrane structure was examined. Expected pore sizes were calculated from vulnerability curves; however, the predicted inter-specific variation in pore sizes was not detected using scanning electron microscopy (pores were not visible to a resolution of 20 nm). Suspensions of colloidal gold particles were then perfused through branch sections. These experiments indicated that pit membrane pores were between 5 and 20 nm in diameter in all four species. The results may be explained by three possibilities: (a) the pores of the expected size range were not present, (b) larger pores, within the size range to cause air seeding, were present but were rare enough to avoid detection, or (c) pore sizes in the expected range only develop while the membrane is under mechanical stress (during air seeding) due to stretching/flexing.

Geographic and habitat partitioning of genetically distinct zooxanthellae (Symbiodinium) in Acropora corals on the Great Barrier Reef.

Abstract: Intra- and intercolony diversity and distribution of zooxanthellae in acroporid corals is largely uncharted. In this study, two molecular methods were applied to determine the distribution of zooxanthellae in the branching corals Acropora tenuis and A. valida at several reef locations in the central section of the Great Barrier Reef. Sun-exposed and shaded parts of all colonies were examined. Single-stranded conformational polymorphism analysis showed that individual colonies of A. tenuis at two locations harbour two strains of Symbiodinium belonging to clade C (C1 and C2), whereas conspecific colonies at two other reefs harboured a single zooxanthella strain. A. valida was found to simultaneously harbour strains belonging to two distinct phylogenetic clades (C and D) at all locations sampled. A novel method with improved sensitivity (quantitative polymerase chain reaction using Taqman™ fluorogenic probes) was used to map the relative abundance distribution of the two zooxanthella clades. At two of the five sampling locations both coral species were collected. At these two locations, composition of the zooxanthella communities showed the same pattern in both coral species, i.e. correlation with ambient light in Pioneer Bay and an absence thereof in Nelly Bay. The results show that the distribution of genetically distinct zooxanthellae is correlated with light regime and possibly temperature in some (but not all) colonies of A. tenuis and A. valida and at some reef locations, which we interpret as acclimation to local environmental conditions.

The effects of marine reserve protection on the trophic relationships of reef fishes on the Great Barrier Reef

Abstract: What are the effects of no-take marine reserves on trophic relationships of coral reef fish? Previous studies often have lacked detailed dietary information on major predators, and have often been confounded by differences in habitat complexity between reserve and fished sites. This study investigates the effects of marine reserve protection on predator-prey interactions of coral reef fish on the inshore islands of the Great Barrier Reef (GBR). The abundance of species of prey fish of Plectropomus leopardus (Serranidae), a piscivore and the major target of the hook and line fisheries on the GBR, were estimated in protected and fished zones. These prey species were identified from previous detailed studies of the diet of P. leopardus. Fish populations and habitat characteristics were surveyed by underwater visual census. Previous studies had determined that the biomass of P. leopardus was 3–4 times higher in protected than fished zones in the Whitsunday and Palm Islands, central GBR, after 14 years of protection. Eight of the nine prey species had a higher density within fished zones than protected zones, six significantly so. The density of all prey fish was twice that in the fished than the protected zone (p < 0.001). There were no significant differences in availability of different sized refuge holes, structural complexity or live coral cover between zones. Thus, important attributes of habitat complexity did not confound the comparisons between reserve and fished zones. Finally, a significant negative correlation (r = 0.46) between coral trout biomass and summed prey fish biomass suggested that predation may be an important structuring process in this system. The results have implications for the conservation of fishery targets and their prey. The study highlights the potential ecosystem implications of the use of no-take marine reserves as conservation and fisheries management tools.

Variation in coral photosynthesis, respiration and growth characteristics in contrasting light microhabitats: an analogue to plants in forest gaps and understoreys?

Abstract: 1.The often complex architecture of coral reefs forms a diversity of light microhabitats. Analogous to patterns in forest plants, light variation may drive strategies for efficient light utilization and metabolism in corals. 2.We investigated the spatial distribution of light regimes in a spur-and-groove reef environment and examine the photophysiology of the coral Montipora monasteriata (Forskal 1775), a species with a wide habitat distribution. Specifically, we examined the variation in tissue and skeletal thickness, and photosynthetic and metabolic responses among contrasting light microhabitats. 3.Daily irradiances reaching corals in caves and under overhangs were 1–5 and 30–40% of those in open habitats at similar depth (3–5 m), respectively. Daily rates of net photosynthesis of corals in cave habitats approximated zero, suggesting more than two orders of magnitude variation in scope for growth across habitats. 4.Three mechanisms of photoadaptation or acclimation were observed in cave and overhang habitats: (1) a 20–50% thinner tissue layer and 40–60% thinner skeletal plates, maximizing light interception per unit mass; (2) a two- to threefold higher photosynthetic efficiency per unit biomass; and (3) low rates of dark respiration. 5.Specimens from open and cave habitats displayed a high capacity to acclimate to downshifts or upshifts in irradiance, respectively. However, specimens in caves displayed limited acclimation to further irradiance reduction, indicating that these live near their irradiance limit. 6.Analogous to patterns for some plant species in forest gaps, the morphological plasticity and physiological flexibility of M. monasteriata enable it to occupy light habitats that vary by more than two orders of magnitude.

Heart rate variability and endogenous sex hormones during the menstrual cycle in young women.

Abstract: To our knowledge, the relationship between all four endogenous female sex hormones and resting cardiac autonomic function has not been studied. The aim of the current study was to examine the association between the normal endogenous levels of oestrogen (17beta-oestradiol), progesterone, luteinising hormone and follicle-stimulating hormone and heart rate variability (HRV) during the menstrual cycle in young eumenorrheic women. Ten healthy, young, female subjects volunteered for this study. HRV and endogenous hormone levels were recorded at three phases of the menstrual cycle: menses (day 3.8 +/- 0.5), ovulation (day 15.8 +/- 0.7) and luteal (day 22.1 +/- 0.4) to ensure HRV recordings at times of low (menses) and high (ovulation and luteal) hormonal influence. Heart rate recordings were obtained from supine resting subjects and analysed on a Holter analysis system. Total power (TP, 0-1.0 Hz), low frequency (LF, 0.041-0.15 Hz), high frequency (HF, 0.15-0.80 Hz) and LF/HF components of HRV were examined. Despite a significantly greater HR at ovulation and normal cyclic variations in all endogenous sex hormone levels, no measure of HRV was significantly different between menstrual cycle phases. Significant correlations between oestrogen levels and absolute measures of HRV at ovulation were identified. The results of the current study demonstrated that the normal cyclic variations in endogenous sex hormone levels during the menstrual cycle were not significantly associated with changes in cardiac autonomic control as measured by HRV. Significant correlation between peak oestrogen levels and HRV measures at ovulation provided further support for the reported cardioprotective effects of oestrogen in healthy females.

Indo-pacific biodiversity of coral reefs: deviations from a mid-domain model

Abstract: Understanding the nature and causes of global gradients in species richness is a perennial ecological problem, and recent work has highlighted the need to assess these gradients relative to an appropriate statistical expectation. This paper examines latitudinal and longitudinal gradients in species richnesses of corals and reef fishes in the Indo-Pacific domain and compares them with gradients predicted by a mid-domain model in which geographic domains are located at random between the latitudinal and longitudinal boundaries of this region. We test for significant differences between observed and predicted species-richness patterns, and we identify regions that are enriched or depauperate in species, relative to expectation. In addition, we move beyond previous mid-domain analyses by directly comparing observed spatial distributions of geographic ranges with those predicted by a mid-domain model. This comparison indicates precisely how species-richness anomalies are produced by nonrandomness in the distribution of species ranges. For both corals and fishes, large and statistically significant differences exist between observed latitudinal and longitudinal species-richness gradients and those predicted by mid-domain models. Longitudinally, species richness is markedly higher than predicted along the African coast and, to a lesser extent, within the Indo-Australian Archipelago (IAA), and it is markedly lower than expected in the eastern Pacific. Latitudinally, species richness becomes increasingly higher than predicted as one moves from the equator to the tropical margins; then it becomes sharply lower than predicted beyond the tropics. Unexpectedly, differences between observed and predicted spatial distributions of range endpoints and midpoints reveal a pattern of nonrandomness that is highly congruent with the hypothesis that gyres in the Indian and Pacific Oceans, with the IAA forming a porous boundary between them, have a major influence on Indo-Pacific species-richness patterns. Our analyses indicate that the perspective offered by a focus on explaining nonrandomness in the location of geographic ranges (rather than explaining why species numbers vary in space) is likely to dramatically alter our assessments of alternative explanations for global species-richness gradients.

Grazer biomass correlates more strongly with production than with biomass of algal turfs on a coral reef

Abstract: The biomass of large herbivorous grazing fish on the shallow reef crest of Myrmidon Reef, Great Barrier Reef, is 7.0 times that on the reef slope (15 m depth), and 2.3 times that on the reef flat. Biomass of algal turfs on the crest was only 1.4 and 1.0 times that on the slope and flat, respectively. In contrast, rate of production of algal turfs on the crest was 5.3 and 2.8 times that on the slope and flat, respectively. A multiple correlation between large grazer biomass, algal turf biomass, and algal turf production across the three zones showed that only rate of algal production correlated significantly with large grazer biomass (algal production p=0.007, algal biomass p=0.418). This result suggests that large grazers may aggregate in zones of highest algal turf production. The mechanisms by which fish respond to habitat-specific differences in food production remain unclear.

Microtopography and antifouling properties of the shell surface of the bivalve molluscs mytilus galloprovincialis and pinctada imbricata

Abstract: Biofouling rapidly covers most submerged surfaces in the marine environment. However, some marine organisms remain clean despite strong fouling pressure. Potential physical inhibitors of fouling were investigated by comparing the thickness, cover, and microtopographic structure of the periostracum of two bivalve molluscs, the blue mussel, Mytilus galloprovincialis , and the pearl oyster, Pinctada imbricata . The cover and thickness of the periostracum were measured on four size classes of each species using histological and microscopic techniques. The periostracum of M. galloprovincialis was significantly thicker than that of P. imbricata and did not differ significantly between size classes. In contrast, the periostracum of P. imbricata decreased significantly with increasing size in both thickness and cover. The microtopography of the shell surface of both species was measured using atomic force microscopy (AFM) and scanning electron microscopy (SEM), which revealed a homogeneous ridged surface for M. g...

Spillover from marine reserves: the case of Naso vlamingii at Apo Island, the Philippines

Abstract: The use of no-take marine reserves as fisheries management tools is controversial. A major expectation of marine reserves is that they will become net exporters of adult biomass (the 'spillover effect'). Herein, we show that the biomass of the surgeonfish Naso vlamingii tripled over 18 yr (1983 to 2001) in a reserve at Apo Island, Philippines. Over time, the biomass of N. vlamingii increased by a factor of 40 outside but close to the reserve boundaries (200 to 250 m) but not at greater distances (250 to 500 m). In 2000/2001 hook-and-line catch per unit effort (CPUE) for N. vlamingii was 45 times higher within 200 m of the reserve boundary than for all other fishing grounds combined, with 62.5% of the hook-and-line catch records being recorded within 200 m either side of the reserve, in just 11% of the reef fishing area. This comprises some of the best evidence that reserves can benefit fisheries by spillover.

Marine reserves: rates and patterns of recovery and decline of predatory fish, 1983–2000

Abstract: The application of no-take marine-reserve status to an area is expected to increase spawning-stock biomass of species targeted by fisheries, and to help sustain fisheries external to the reserve. However, empirical evidence on rates and patterns of increase of density and biomass of target species following closures to fishing, and of decrease when reserve status is removed, remains rare. We have monitored density and biomass of large predatory coral-reef fish (Serranidae [Epinephelinae], Lutjanidae, Lethrinidae, and Carangidae, as a group) visually in two small no-take marine reserves and at two control (open to fishing) sites in the Philippines from 1983 to 2000. At Sumilon reserve a complex history of management allowed 13 measurements of density and biomass at durations of reserve protection of −3 yr (i.e., fished for 3 years after reserve status removed) to 9 yr. At Apo reserve 13 measurements were taken at durations of protection of 1–18 yr. We recorded 11 significant (P < 0.05) changes in density at the four sites over the 17 years, three declines and eight increases. All three significant declines occurred when reserve protection was removed. Four of the eight significant increases occurred when reserve status was applied. This represents some of the best evidence currently available that application of marine-reserve status causes increases in abundance of target species. Three of the four significant increases in density required 4–6 yr of protection. Significant positive linear correlations of mean density of large predators against years of reserve protection were observed at both reserves. The pattern of increase of mean biomass against years of reserve protection was exponential, with biomass initially increasing more slowly than density. Density and biomass increased by factors of 12.2 and 17.3, respectively, during 18 yr of continuous protection in Apo reserve. At Sumilon Island three bouts of unregulated fishing of 1.5–3 yr duration eliminated density and biomass gains accumulated over 5–9 yr of marine reserve protection.