Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fi... more Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fish daily (*500 MT year-1) from 152 km 2 of surrounding reef. More than 153 species were represented during surveys , with 25 species very common or common within combined-gear catch. Acanthurids contributed the greatest to catch volume, with bluespine unicornfish, Naso uni-cornis, and orangespine unicornfish, Naso lituratus, among the most frequently observed herbivores. Nighttime spearfishing was the dominant fishing method and inner lagoon areas were primarily targeted. A seasonal sales ban (March–April), intended to reduce pressure on reproductively active serranids, significantly increased the capture volume of other families. Catch was significantly greater during periods of low lunar illumination, suggesting higher fishing success or greater effort, or both. The marketed catch was dominated by juveniles and small adults, based on fishes of known size at sexual maturity. Artificially depressed market prices appear to be catalyzing (potential or realized) overfishing by increasing the volume of fish needed to offset rising fuel prices. These results support the need for comprehensive fisheries management that produces sustainable fishing and marketing practices and promotes shared management and enforced responsibilities between communities and the state. To be effective, management should prohibit nighttime spearfishing.
Biological reviews of the Cambridge Philosophical Society, Jan 25, 2014
Well-designed and effectively managed networks of marine reserves can be effective tools for both... more Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, ...
The aims of this investigation were to document the temporal and spatial dynamics of aggregated c... more The aims of this investigation were to document the temporal and spatial dynamics of aggregated camouflage grouper, Epinephelus polyphekadion in Pohnpei, Micronesia, and to assess seasonal and daily patterns of spawning and reproductive behavior. Camouflage grouper aggregated and spawned adjacent to the Kehpara Marine Sanctuary (KMS), Pohnpei, Micronesia, during two consecutive months in 1998 and 1999. A combination of gonadosomatic indices, oocyte diameter analysis, and histological evidence confirmed that camouflage grouper spawned 1-2 days prior to full moon over an 8-9 h period after dusk in each of the four study months. Males entered the site approximately 7 days prior to females and color variations were frequently observed. Significant differences were detected in mean size between the sexes. A series of management initiatives was initiated by the government in the 1980s to reduce fishing during aggregation periods, such as a March-April grouper sales ban, but these were largely ineffective. Following the 1998-1999 survey, several recommendations were made to halt aggregation fishing, including a commercial and subsistence catch and sales ban during spawning months, and the extension of the KMS to incorporate two additional grouper aggregations directly adjacent to it.
The objective of the present study was to investigate the population genetic structure of the com... more The objective of the present study was to investigate the population genetic structure of the commercially important camouflage grouper, Epinephelus polyphekadion (Bleeker, 1849), in the western and central Pacific Ocean to improve existing management. Camouflage grouper are widely distributed in the Indo-Pacific and form brief, seasonal, spawning aggregations that are often heavily fished. The present study examined populations sampled in
Biological reviews of the Cambridge Philosophical Society, Jan 25, 2014
Well-designed and effectively managed networks of marine reserves can be effective tools for both... more Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, ...
Serranids are important components of artisanal and commercial catch worldwide, but are highly su... more Serranids are important components of artisanal and commercial catch worldwide, but are highly susceptible to overfishing. In Pohnpei (Micronesia), a recent coral reef fish market survey revealed a reliance on night-time spearfishing and a serranid catch composed primarily of juveniles and small adults of practically all epinepheline species. Fishing effort was concentrated in one of five municipalities and was disproportionate
The occurrence of hypolithic cyanobacteria colonizing translucent stones was quantified along the... more The occurrence of hypolithic cyanobacteria colonizing translucent stones was quantified along the aridity gradient in the Atacama Desert in Chile, from less arid areas to the hyperarid core where photosynthetic life and thus primary production reach their limits. As mean rainfall declines from 21 to e 2 mm year _ 1 , the abundance of hypolithic cyanobacteria drops from 28 to G 0.1%, molecular diversity declines threefold, and organic carbon residence times increase by three orders of magnitude. Communities contained a single Chroococcidiopsis morphospecies with heterotrophic associates, yet molecular analysis revealed that each stone supported a number of unique 16S rRNA gene-defined genotypes. A fivefold increase in steady-state residence times for organic carbon within communities in the hyperarid core (3200 years turnover time) indicates a significant decline in biological carbon cycling. Six years of microclimate data suggest that the dry limit corresponds to e 5 mm year _ 1 rainfall and/or decadal periods of no rain, with
1] This paper analyzes linkages between lithic (lithobiontic, lithophytic) cyanobacterial communi... more 1] This paper analyzes linkages between lithic (lithobiontic, lithophytic) cyanobacterial community (LCC) abundance and climate across a wide range of environmental conditions and geographical distance in China's northwest region, an area containing some of the world's oldest, driest and most isolated deserts. In situ monitoring and long-term climate data show that extreme heterogeneity in liquid water availability characterizes the LCC environment across multiple spatial and temporal scales, with rainfall and snowmelt being the main moisture sources. Mean annual precipitation (MAP) primarily dictates LCC ecology across sites, but the interacting effects of temperature, moisture and light create a gradient of soil liquid water (ALW, 505-1839 hr yr À1 ) and conditions suitable for metabolic activity (200-922 hr yr À1 ) that also correlate with LCC abundance (0.99 ± 0.2% to 12.6 ± 1.8%). In situ soil temperatures indicate a minimum range of thermal tolerance for LCC in China's deserts of À23.8°C to 53.8°C. Through a comparison of similar available climate data for other deserts, we conclude that from a microbial physiological standpoint, although the hyperarid core of the Atacama Desert represents the driest nanoclimate environment recorded and the Dry Valleys in Antarctica represent the coldest desert conditions, it is the high-altitude deserts in the Qinghai-Tibetan Plateau that offer the coldest and driest recorded extremes for LCC on Earth.
Lithic photoautotrophic communities function as principal primary producers in the world's driest... more Lithic photoautotrophic communities function as principal primary producers in the world's driest deserts, yet many aspects of their ecology remain unknown. This is particularly true for Asia, where some of the Earth's oldest and driest deserts occur. Using methods derived from plant landscape ecology, we measured the abundance and spatial distribution of cyanobacterial colonization on quartz stony pavement across environmental gradients of rainfall and temperature in the isolated Taklimakan and Qaidam Basin deserts of western China. Colonization within available habitat ranged from 0.37 AE 0.16% to 12.6 AE 1.8%, with cold dry desert sites exhibiting the lowest abundance. Variation between sites was most strongly correlated with moisture-related variables and was independent of substrate availability. Cyanobacterial communities were spatially aggregated at multiple scales in patterns distinct from the underlying rock pattern. Site-level differences in cyanobacterial spatial pattern (e.g. mean inter-patch distance) were linked with rainfall, whereas patchiness within sites was correlated with local geology (greater colonization frequency of large rocks) and biology (dispersal during rainfall). We suggest that cyanobacterial patchiness may also in part be selforganized -that is, an outcome of soil water-biological feedbacks. We propose that landscape ecology concepts and models linking desert vegetation, biological feedbacks and ecohydrological processes are applicable to microbial communities.
Hypolithic cyanobacterial communities occur in hot and cold hyperarid environments but the physic... more Hypolithic cyanobacterial communities occur in hot and cold hyperarid environments but the physical factors determining their diversity are not well understood. Here we report hypolithic diversity and colonization of a common quartz substrate at several hyperarid locations in the ancient deserts of northwestern China, that experience varying mean annual temperature, rainfall and concomitant availability of liquid water in soil. Microscopy and enrichment culture resulted only in Chroococcidiopsis morphotypes which were ubiquitous, but community phylogenetic analysis revealed considerable cyanobacterial and heterotrophic bacterial diversity. Species Richness and Shannon's Diversity Index displayed a significant positive linear correlation with availability of liquid water but not temperature or rainfall alone. Several taxonomic groups occurred only in specific climatically defined locations, while for Chroococcidiopsis, Deinococcus and Phormidium location specific lineages within these genera were also evident. Multivariate analysis was used to illustrate pronounced community shifts due to liquid water availability, although these did not significantly affect the predicted functional relationships within any given assemblage in either hot or cold, wet or dry hyperarid deserts. This study clearly demonstrates that availability of liquid water, rather than temperature or rainfall per se is the key determinant of hypolithic diversity in hyperarid locations, and furthermore that functionally similar yet taxonomically distinct communities occur, characterized by the presence of taxa that are specific to defined levels of aridity.
The goliath grouper Epinephelus itajara (Lichtenstein, 1822) is an integral part of traditional c... more The goliath grouper Epinephelus itajara (Lichtenstein, 1822) is an integral part of traditional coastal fisheries in Belize; however, recent anecdotal reports suggest declining catches, mean size and abundance, particularly of large adults. Quantifying goliath grouper abundance in the waters of Belize is an important first step in developing management plans that can protect stocks of the species as well as local fishing communities. To characterize the status of the goliath grouper in southern Belize, we used a 2 yr market survey, fishery-dependent collections and passive tagging. Market surveys revealed that the vast majority (98% or 1412) of 1441 goliath groupers examined at a fish market comprised juveniles. Eight of the 64 interviewed fishers were responsible for most of the catches (67.2%). Size distributions of goliath grouper collected from coastal to outer reef areas using setlines, longlines and drumlines confirmed the overall paucity of adults in local populations. Specifically, a 90-fold difference in catch rates was observed between adults (n = 1425) and juveniles (n = 16). Of 209, 45 (21.5%) tagged individuals were recaptured during assessments, observed in marketed catch or reported, with 39.3% taken from the Port Honduras Marine Reserve. Fishing mortality was estimated at 0.27, while the specific growth rate was 0.29% d -1 . These results, together with documented loss of known spawning aggregations, suggest that goliath grouper in southern Belize are overfished. To allow population recovery, strict management and enforcement measures are required. Such a plan would have minimal impact on fishing communities, since no fishers are solely reliant on the species. KEY WORDS: Goliath grouper fishery · Marine protected area · Tag-recapture
Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fi... more Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fish daily (*500 MT year -1 ) from 152 km 2 of surrounding reef. More than 153 species were represented during surveys, with 25 species very common or common within combined-gear catch. Acanthurids contributed the greatest to catch volume, with bluespine unicornfish, Naso unicornis, and orangespine unicornfish, Naso lituratus, among the most frequently observed herbivores. Nighttime spearfishing was the dominant fishing method and inner lagoon areas were primarily targeted. A seasonal sales ban (March-April), intended to reduce pressure on reproductively active serranids, significantly increased the capture volume of other families. Catch was significantly greater during periods of low lunar illumination, suggesting higher fishing success or greater effort, or both. The marketed catch was dominated by juveniles and small adults, based on fishes of known size at sexual maturity. Artificially depressed market prices appear to be catalyzing (potential or realized) overfishing by increasing the volume of fish needed to offset rising fuel prices. These results support the need for comprehensive fisheries management that produces sustainable fishing and marketing practices and promotes shared management and enforced responsibilities between communities and the state. To be effective, management should prohibit nighttime spearfishing.
ScientiWc information on reef Wsh spawning aggregation Wsheries is sparse in light of numerous re... more ScientiWc information on reef Wsh spawning aggregation Wsheries is sparse in light of numerous regional declines and extirpations from overexploitation. Fisher interviews of the small-scale commercial mutton snapper (Lutjanus analis) spawning aggregation Wshery at Gladden Spit, Belize, suggests a historic decadal decline. The reported trend is supported by analysis of inter-seasonal catch and eVort and yield (2000)(2001)(2002) that reveals a 59% decline in catch per unit eVort (CPUE) and a 22% decrease in mean landings per boat. Declining population-level trends are also supported by a signiWcant decrease in interannual median lengths of mutton snappers (2000)(2001)(2002)(2003)(2004)(2005)(2006). These Wndings demonstrate the need for additional life history information that includes length-associated age and details on growth to provide clearer support of the eVects on, and responses by, populations following Wshing. In view of the historical changes to mutton snapper CPUE and landings at Gladden Spit and the Wshery-associated declines in Wsh spawning aggregations observed globally, a precautionary approach to spawning aggregation management is warranted that provides full protection from Wshing to enhance population persistence. The Wndings also highlight the need for substantially greater enforcement and longterm Wsheries monitoring under a comprehensive regional management strategy.
The aims of this investigation were to document the temporal and spatial dynamics of aggregated c... more The aims of this investigation were to document the temporal and spatial dynamics of aggregated camouflage grouper, Epinephelus polyphekadion in Pohnpei, Micronesia, and to assess seasonal and daily patterns of spawning and reproductive behavior. Camouflage grouper aggregated and spawned adjacent to the Kehpara Marine Sanctuary (KMS), Pohnpei, Micronesia, during two consecutive months in 1998 and 1999. A combination of gonadosomatic indices, oocyte diameter analysis, and histological evidence confirmed that camouflage grouper spawned 1-2 days prior to full moon over an 8-9 h period after dusk in each of the four study months. Males entered the site approximately 7 days prior to females and color variations were frequently observed. Significant differences were detected in mean size between the sexes. A series of management initiatives was initiated by the government in the 1980s to reduce fishing during aggregation periods, such as a March-April grouper sales ban, but these were largely ineffective. Following the 1998-1999 survey, several recommendations were made to halt aggregation fishing, including a commercial and subsistence catch and sales ban during spawning months, and the extension of the KMS to incorporate two additional grouper aggregations directly adjacent to it.
Groupers are a valuable fishery resource of reef ecosystems and are among those species most vuln... more Groupers are a valuable fishery resource of reef ecosystems and are among those species most vulnerable to fishing pressure because of life history characteristics including longevity, late sexual maturation and aggregation spawning. Despite their economic importance, few grouper fisheries are regularly monitored or managed at the species level, and many are reported to be undergoing declines. To identify major threats to groupers, the International Union for Conservation of Nature (IUCN) Red List criteria were applied to all 163 species. Red List assessments show that 20 species (12%) risk extinction if current trends continue, and an additional 22 species (13%) are considered to be Near Threatened. The Caribbean Sea, coastal Brazil and Southeast Asia contain a disproportionate number of Threatened species, while numerous poorly documented and Near Threatened species occur in many regions. In all, 30% of all species are considered to be Data Deficient. Given that the major threat is overfishing, accompanied by a general absence and/or poor application of fishery management, the prognosis for restoration and successful conservation of Threatened species is poor. We believe that few refuges remain for recovery and that key biological processes (e.g. spawning aggregations) continue to be compromised by uncontrolled fishing. Mariculture, through hatchery-rearing, increases production of a few species and contributes to satisfying high market demand, but many such operations depend heavily on wild-caught juveniles with resultant growth and recruitment overfishing. Better management of fishing and other conservation efforts are urgently needed, and we provide examples of possible actions and constraints.
Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fi... more Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fish daily (*500 MT year-1) from 152 km 2 of surrounding reef. More than 153 species were represented during surveys , with 25 species very common or common within combined-gear catch. Acanthurids contributed the greatest to catch volume, with bluespine unicornfish, Naso uni-cornis, and orangespine unicornfish, Naso lituratus, among the most frequently observed herbivores. Nighttime spearfishing was the dominant fishing method and inner lagoon areas were primarily targeted. A seasonal sales ban (March–April), intended to reduce pressure on reproductively active serranids, significantly increased the capture volume of other families. Catch was significantly greater during periods of low lunar illumination, suggesting higher fishing success or greater effort, or both. The marketed catch was dominated by juveniles and small adults, based on fishes of known size at sexual maturity. Artificially depressed market prices appear to be catalyzing (potential or realized) overfishing by increasing the volume of fish needed to offset rising fuel prices. These results support the need for comprehensive fisheries management that produces sustainable fishing and marketing practices and promotes shared management and enforced responsibilities between communities and the state. To be effective, management should prohibit nighttime spearfishing.
Biological reviews of the Cambridge Philosophical Society, Jan 25, 2014
Well-designed and effectively managed networks of marine reserves can be effective tools for both... more Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, ...
The aims of this investigation were to document the temporal and spatial dynamics of aggregated c... more The aims of this investigation were to document the temporal and spatial dynamics of aggregated camouflage grouper, Epinephelus polyphekadion in Pohnpei, Micronesia, and to assess seasonal and daily patterns of spawning and reproductive behavior. Camouflage grouper aggregated and spawned adjacent to the Kehpara Marine Sanctuary (KMS), Pohnpei, Micronesia, during two consecutive months in 1998 and 1999. A combination of gonadosomatic indices, oocyte diameter analysis, and histological evidence confirmed that camouflage grouper spawned 1-2 days prior to full moon over an 8-9 h period after dusk in each of the four study months. Males entered the site approximately 7 days prior to females and color variations were frequently observed. Significant differences were detected in mean size between the sexes. A series of management initiatives was initiated by the government in the 1980s to reduce fishing during aggregation periods, such as a March-April grouper sales ban, but these were largely ineffective. Following the 1998-1999 survey, several recommendations were made to halt aggregation fishing, including a commercial and subsistence catch and sales ban during spawning months, and the extension of the KMS to incorporate two additional grouper aggregations directly adjacent to it.
The objective of the present study was to investigate the population genetic structure of the com... more The objective of the present study was to investigate the population genetic structure of the commercially important camouflage grouper, Epinephelus polyphekadion (Bleeker, 1849), in the western and central Pacific Ocean to improve existing management. Camouflage grouper are widely distributed in the Indo-Pacific and form brief, seasonal, spawning aggregations that are often heavily fished. The present study examined populations sampled in
Biological reviews of the Cambridge Philosophical Society, Jan 25, 2014
Well-designed and effectively managed networks of marine reserves can be effective tools for both... more Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, ...
Serranids are important components of artisanal and commercial catch worldwide, but are highly su... more Serranids are important components of artisanal and commercial catch worldwide, but are highly susceptible to overfishing. In Pohnpei (Micronesia), a recent coral reef fish market survey revealed a reliance on night-time spearfishing and a serranid catch composed primarily of juveniles and small adults of practically all epinepheline species. Fishing effort was concentrated in one of five municipalities and was disproportionate
The occurrence of hypolithic cyanobacteria colonizing translucent stones was quantified along the... more The occurrence of hypolithic cyanobacteria colonizing translucent stones was quantified along the aridity gradient in the Atacama Desert in Chile, from less arid areas to the hyperarid core where photosynthetic life and thus primary production reach their limits. As mean rainfall declines from 21 to e 2 mm year _ 1 , the abundance of hypolithic cyanobacteria drops from 28 to G 0.1%, molecular diversity declines threefold, and organic carbon residence times increase by three orders of magnitude. Communities contained a single Chroococcidiopsis morphospecies with heterotrophic associates, yet molecular analysis revealed that each stone supported a number of unique 16S rRNA gene-defined genotypes. A fivefold increase in steady-state residence times for organic carbon within communities in the hyperarid core (3200 years turnover time) indicates a significant decline in biological carbon cycling. Six years of microclimate data suggest that the dry limit corresponds to e 5 mm year _ 1 rainfall and/or decadal periods of no rain, with
1] This paper analyzes linkages between lithic (lithobiontic, lithophytic) cyanobacterial communi... more 1] This paper analyzes linkages between lithic (lithobiontic, lithophytic) cyanobacterial community (LCC) abundance and climate across a wide range of environmental conditions and geographical distance in China's northwest region, an area containing some of the world's oldest, driest and most isolated deserts. In situ monitoring and long-term climate data show that extreme heterogeneity in liquid water availability characterizes the LCC environment across multiple spatial and temporal scales, with rainfall and snowmelt being the main moisture sources. Mean annual precipitation (MAP) primarily dictates LCC ecology across sites, but the interacting effects of temperature, moisture and light create a gradient of soil liquid water (ALW, 505-1839 hr yr À1 ) and conditions suitable for metabolic activity (200-922 hr yr À1 ) that also correlate with LCC abundance (0.99 ± 0.2% to 12.6 ± 1.8%). In situ soil temperatures indicate a minimum range of thermal tolerance for LCC in China's deserts of À23.8°C to 53.8°C. Through a comparison of similar available climate data for other deserts, we conclude that from a microbial physiological standpoint, although the hyperarid core of the Atacama Desert represents the driest nanoclimate environment recorded and the Dry Valleys in Antarctica represent the coldest desert conditions, it is the high-altitude deserts in the Qinghai-Tibetan Plateau that offer the coldest and driest recorded extremes for LCC on Earth.
Lithic photoautotrophic communities function as principal primary producers in the world's driest... more Lithic photoautotrophic communities function as principal primary producers in the world's driest deserts, yet many aspects of their ecology remain unknown. This is particularly true for Asia, where some of the Earth's oldest and driest deserts occur. Using methods derived from plant landscape ecology, we measured the abundance and spatial distribution of cyanobacterial colonization on quartz stony pavement across environmental gradients of rainfall and temperature in the isolated Taklimakan and Qaidam Basin deserts of western China. Colonization within available habitat ranged from 0.37 AE 0.16% to 12.6 AE 1.8%, with cold dry desert sites exhibiting the lowest abundance. Variation between sites was most strongly correlated with moisture-related variables and was independent of substrate availability. Cyanobacterial communities were spatially aggregated at multiple scales in patterns distinct from the underlying rock pattern. Site-level differences in cyanobacterial spatial pattern (e.g. mean inter-patch distance) were linked with rainfall, whereas patchiness within sites was correlated with local geology (greater colonization frequency of large rocks) and biology (dispersal during rainfall). We suggest that cyanobacterial patchiness may also in part be selforganized -that is, an outcome of soil water-biological feedbacks. We propose that landscape ecology concepts and models linking desert vegetation, biological feedbacks and ecohydrological processes are applicable to microbial communities.
Hypolithic cyanobacterial communities occur in hot and cold hyperarid environments but the physic... more Hypolithic cyanobacterial communities occur in hot and cold hyperarid environments but the physical factors determining their diversity are not well understood. Here we report hypolithic diversity and colonization of a common quartz substrate at several hyperarid locations in the ancient deserts of northwestern China, that experience varying mean annual temperature, rainfall and concomitant availability of liquid water in soil. Microscopy and enrichment culture resulted only in Chroococcidiopsis morphotypes which were ubiquitous, but community phylogenetic analysis revealed considerable cyanobacterial and heterotrophic bacterial diversity. Species Richness and Shannon's Diversity Index displayed a significant positive linear correlation with availability of liquid water but not temperature or rainfall alone. Several taxonomic groups occurred only in specific climatically defined locations, while for Chroococcidiopsis, Deinococcus and Phormidium location specific lineages within these genera were also evident. Multivariate analysis was used to illustrate pronounced community shifts due to liquid water availability, although these did not significantly affect the predicted functional relationships within any given assemblage in either hot or cold, wet or dry hyperarid deserts. This study clearly demonstrates that availability of liquid water, rather than temperature or rainfall per se is the key determinant of hypolithic diversity in hyperarid locations, and furthermore that functionally similar yet taxonomically distinct communities occur, characterized by the presence of taxa that are specific to defined levels of aridity.
The goliath grouper Epinephelus itajara (Lichtenstein, 1822) is an integral part of traditional c... more The goliath grouper Epinephelus itajara (Lichtenstein, 1822) is an integral part of traditional coastal fisheries in Belize; however, recent anecdotal reports suggest declining catches, mean size and abundance, particularly of large adults. Quantifying goliath grouper abundance in the waters of Belize is an important first step in developing management plans that can protect stocks of the species as well as local fishing communities. To characterize the status of the goliath grouper in southern Belize, we used a 2 yr market survey, fishery-dependent collections and passive tagging. Market surveys revealed that the vast majority (98% or 1412) of 1441 goliath groupers examined at a fish market comprised juveniles. Eight of the 64 interviewed fishers were responsible for most of the catches (67.2%). Size distributions of goliath grouper collected from coastal to outer reef areas using setlines, longlines and drumlines confirmed the overall paucity of adults in local populations. Specifically, a 90-fold difference in catch rates was observed between adults (n = 1425) and juveniles (n = 16). Of 209, 45 (21.5%) tagged individuals were recaptured during assessments, observed in marketed catch or reported, with 39.3% taken from the Port Honduras Marine Reserve. Fishing mortality was estimated at 0.27, while the specific growth rate was 0.29% d -1 . These results, together with documented loss of known spawning aggregations, suggest that goliath grouper in southern Belize are overfished. To allow population recovery, strict management and enforcement measures are required. Such a plan would have minimal impact on fishing communities, since no fishers are solely reliant on the species. KEY WORDS: Goliath grouper fishery · Marine protected area · Tag-recapture
Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fi... more Commercial coral reef fisheries in Pohnpei (Micronesia) extract approximately 1,521 kg of reef fish daily (*500 MT year -1 ) from 152 km 2 of surrounding reef. More than 153 species were represented during surveys, with 25 species very common or common within combined-gear catch. Acanthurids contributed the greatest to catch volume, with bluespine unicornfish, Naso unicornis, and orangespine unicornfish, Naso lituratus, among the most frequently observed herbivores. Nighttime spearfishing was the dominant fishing method and inner lagoon areas were primarily targeted. A seasonal sales ban (March-April), intended to reduce pressure on reproductively active serranids, significantly increased the capture volume of other families. Catch was significantly greater during periods of low lunar illumination, suggesting higher fishing success or greater effort, or both. The marketed catch was dominated by juveniles and small adults, based on fishes of known size at sexual maturity. Artificially depressed market prices appear to be catalyzing (potential or realized) overfishing by increasing the volume of fish needed to offset rising fuel prices. These results support the need for comprehensive fisheries management that produces sustainable fishing and marketing practices and promotes shared management and enforced responsibilities between communities and the state. To be effective, management should prohibit nighttime spearfishing.
ScientiWc information on reef Wsh spawning aggregation Wsheries is sparse in light of numerous re... more ScientiWc information on reef Wsh spawning aggregation Wsheries is sparse in light of numerous regional declines and extirpations from overexploitation. Fisher interviews of the small-scale commercial mutton snapper (Lutjanus analis) spawning aggregation Wshery at Gladden Spit, Belize, suggests a historic decadal decline. The reported trend is supported by analysis of inter-seasonal catch and eVort and yield (2000)(2001)(2002) that reveals a 59% decline in catch per unit eVort (CPUE) and a 22% decrease in mean landings per boat. Declining population-level trends are also supported by a signiWcant decrease in interannual median lengths of mutton snappers (2000)(2001)(2002)(2003)(2004)(2005)(2006). These Wndings demonstrate the need for additional life history information that includes length-associated age and details on growth to provide clearer support of the eVects on, and responses by, populations following Wshing. In view of the historical changes to mutton snapper CPUE and landings at Gladden Spit and the Wshery-associated declines in Wsh spawning aggregations observed globally, a precautionary approach to spawning aggregation management is warranted that provides full protection from Wshing to enhance population persistence. The Wndings also highlight the need for substantially greater enforcement and longterm Wsheries monitoring under a comprehensive regional management strategy.
The aims of this investigation were to document the temporal and spatial dynamics of aggregated c... more The aims of this investigation were to document the temporal and spatial dynamics of aggregated camouflage grouper, Epinephelus polyphekadion in Pohnpei, Micronesia, and to assess seasonal and daily patterns of spawning and reproductive behavior. Camouflage grouper aggregated and spawned adjacent to the Kehpara Marine Sanctuary (KMS), Pohnpei, Micronesia, during two consecutive months in 1998 and 1999. A combination of gonadosomatic indices, oocyte diameter analysis, and histological evidence confirmed that camouflage grouper spawned 1-2 days prior to full moon over an 8-9 h period after dusk in each of the four study months. Males entered the site approximately 7 days prior to females and color variations were frequently observed. Significant differences were detected in mean size between the sexes. A series of management initiatives was initiated by the government in the 1980s to reduce fishing during aggregation periods, such as a March-April grouper sales ban, but these were largely ineffective. Following the 1998-1999 survey, several recommendations were made to halt aggregation fishing, including a commercial and subsistence catch and sales ban during spawning months, and the extension of the KMS to incorporate two additional grouper aggregations directly adjacent to it.
Groupers are a valuable fishery resource of reef ecosystems and are among those species most vuln... more Groupers are a valuable fishery resource of reef ecosystems and are among those species most vulnerable to fishing pressure because of life history characteristics including longevity, late sexual maturation and aggregation spawning. Despite their economic importance, few grouper fisheries are regularly monitored or managed at the species level, and many are reported to be undergoing declines. To identify major threats to groupers, the International Union for Conservation of Nature (IUCN) Red List criteria were applied to all 163 species. Red List assessments show that 20 species (12%) risk extinction if current trends continue, and an additional 22 species (13%) are considered to be Near Threatened. The Caribbean Sea, coastal Brazil and Southeast Asia contain a disproportionate number of Threatened species, while numerous poorly documented and Near Threatened species occur in many regions. In all, 30% of all species are considered to be Data Deficient. Given that the major threat is overfishing, accompanied by a general absence and/or poor application of fishery management, the prognosis for restoration and successful conservation of Threatened species is poor. We believe that few refuges remain for recovery and that key biological processes (e.g. spawning aggregations) continue to be compromised by uncontrolled fishing. Mariculture, through hatchery-rearing, increases production of a few species and contributes to satisfying high market demand, but many such operations depend heavily on wild-caught juveniles with resultant growth and recruitment overfishing. Better management of fishing and other conservation efforts are urgently needed, and we provide examples of possible actions and constraints.
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