East Africa’s Lake Victoria provides resources and services to millions of people on the lake’s s... more East Africa’s Lake Victoria provides resources and services to millions of people on the lake’s shores and abroad. In particular, the lake’s fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly understood and currently unpredictable. Furthermore, fishery dynamics are intricately connected to other supporting services of the lake as well as to lakeshore societies and economies. Much research has been carried out piecemeal on different aspects of Lake Victoria’s system; e.g., societies, biodiversity, fisheries, and eutrophication. However, to disentangle drivers and dynamics of change in this complex system, we need to put these pieces together and analyze the system as a whole. We did so by first building a qualitative model of the lake’s social-ecological system. We then investigated the model system through a qualitative loop analysis, and finally examined effects of changes on the system state and structure. The model and its contextual analysis allowed us to investigate system-wide chain reactions resulting from disturbances. Importantly, we built a tool that can be used to analyze the cascading effects of management options and establish the requirements for their success. We found that high connectedness of the system at the exploitation level, through fisheries having multiple target stocks, can increase the stocks’ vulnerability to exploitation but reduce society’s vulnerability to variability in individual stocks. We describe how there are multiple pathways to any change in the system, which makes it difficult to identify the root cause of changes but also broadens the management toolkit. Also, we illustrate how nutrient enrichment is not a self-regulating process, and that explicit management is necessary to halt or reverse eutrophication. This model is simple and usable to assess system-wide effects of management policies, and can serve as a paving stone for future quantitative analyses of system dynamics at local scales.
ABSTRACT: We examined evidence for nonlinear dynamics in fishery-independent survey data for an a... more ABSTRACT: We examined evidence for nonlinear dynamics in fishery-independent survey data for an assemblage of 26 fish species on Georges Bank spanning the period 1963 to 2008.
LeVar is inspired by the book to learn more about the world of coral reefs, so he dons diving gea... more LeVar is inspired by the book to learn more about the world of coral reefs, so he dons diving gear and gives viewers a tour of the National Marine Sanctuary, an underwater park in Florida. Viewers also meet a 'reef doctor'who shows how he restores life to damaged reefs by transplanting living coral.
Abstract: Amphiprion barberi, a new species of anemonefish fish, is described from 46 specimens, ... more Abstract: Amphiprion barberi, a new species of anemonefish fish, is described from 46 specimens, 16.3-85.8 mm SL, collected at depths of 2-10 m from coral reefs of Fiji, Tonga, and Samoa. It is closely allied to A. melanopus, which is widely distributed in the western Pacific. The two species exhibit significant colour-pattern differences, including a mainly reddish orange body in A. barberi and dark brown or blackish body in A. melanopus.
Lake Superior is greater in surface area than Lake Victoria. Lake Baikal is deeper than Lake Tang... more Lake Superior is greater in surface area than Lake Victoria. Lake Baikal is deeper than Lake Tanganyika. Nonetheless, the Great Lakes of East Africa are second to none, when it comes to the wealth of native fishes and the number of people dependent on these lakes. Lake Malawi is thought to host more than 500 species of fishes, nearly all endemic (27).
The annual cycle of the vertical distribution of oxygen concentrations at a deep water station on... more The annual cycle of the vertical distribution of oxygen concentrations at a deep water station on Lake Victoria in 1990-1991 was compared with data collected in 1960-1961. Oxygen concentrations in the mixed layer are higher now, with nearly continuous oxygen supersaturation in surface waters. Oxygen concentrations in hypolimnetic waters are lower now for a longer period, with values< 1 mg liter^-1 occurring in water as shallows s 40 m compared with a shallowest occurrence of> 50 m in 1961.
Abstract Systematic approaches to site selection for marine protected areas (MPAs) are often favo... more Abstract Systematic approaches to site selection for marine protected areas (MPAs) are often favored over opportunistic approaches as a means to meet conservation objectives efficiently. In this study, we compared analytically the conservation value of these two approaches. We locate this study in Danajon Bank, central Philippines, where many MPAs were established opportunistically based on community preference, with few if any contributions from biophysical data.
With respect to vertebrate faunas, there is little doubt that freshwater fishes represent the mos... more With respect to vertebrate faunas, there is little doubt that freshwater fishes represent the most threatened set of vertebrates in the world due to both extensive and intensive human impacts, but also because of the disproportionate richness of inland waters (DUDGEON et al. 2005). Over 10 000 fish species live in freshwater, representing approximately 41% of global fish diversity (LUNDBERG et al. 2000).
Island Press is the only nonprofit organization in the United States whose principal purpose is t... more Island Press is the only nonprofit organization in the United States whose principal purpose is the publication of books on environmental issues and natural resource management. We provide solutions-oriented information to professionals, public officials, business and community leaders, and concerned citizens who are shaping responses to environmental problems. In 1999.
Background The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating int... more Background The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating interactions among corals, algae, and herbivores on Caribbean coral reefs. The preferred microhabitat of S. planifrons is thickets of the branching staghorn coral Acropora cervicornis. Within the past few decades, mass mortality of A. cervicornis from white-band disease and other factors has rendered this coral a minor ecological component throughout most of its range.
The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global... more The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it.
Background The transcription factors of the LSF/Grainyhead (GRH) family are characterized by the ... more Background The transcription factors of the LSF/Grainyhead (GRH) family are characterized by the possession of a distinctive DNA-binding domain that bears no clear relationship to other known DNA-binding domains, with the possible exception of the p53 core domain. In triploblastic animals, the LSF and GRH subfamilies have diverged extensively with respect to their biological roles, general expression patterns, and mechanism of DNA binding.
Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (< 150 m de... more Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (< 150 m depth) subjected to episodic disturbance. Rhodolith beds stand with kelp beds, seagrass meadows, and coralline algal reefs as one of the world's four largest macrophyte-dominated benthic communities. Geographic distribution of rhodolith beds is discontinuous, with large concentrations off Japan, Australia and the Gulf of California, as well as in the Mediterranean, North Atlantic, eastern Caribbean and Brazil.
ABSTRACT.—The largely sedentary behavior of many fishes on coral reefs is well established. Howev... more ABSTRACT.—The largely sedentary behavior of many fishes on coral reefs is well established. However, information on the movement behavior of individual fish, over fine temporal and spatial scales, continues to be limited. While conducting a larger project in the northern Florida Keys in 2002, we surgically-tagged a small number of Scarus coeruleus Bloch 1786 and S. taeniopterus Desmarest in Bory de
Résumé L'introduction de la perche du Nil, Lates niloticus, dans le lac Victoria en Afrique orien... more Résumé L'introduction de la perche du Nil, Lates niloticus, dans le lac Victoria en Afrique orientale a produit une réaction avec l'eutrophication qui a provoqué une réorganisation du réseau alimentaire et l'extirpation de plusieurs poissons endémiques. Le système satellite du lac Kyoga se trouve en aval du lac Victoria. Il englobe des lacs riches en espèces où les perches du Nil sont absentes ou très rares, ainsi que des lacs de pauvre diversité oùL. niloticus est abondante.
Abstract The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of th... more Abstract The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls) were sampled per site with 3–10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003–2005 and 2006–2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period.
We tagged a total of 14 yellowtail snapper (Ocyurus chrysurus Bloch 1790) and black grouper (Myct... more We tagged a total of 14 yellowtail snapper (Ocyurus chrysurus Bloch 1790) and black grouper (Mycteroperca bonaci Poey 1860) inside the Conch Reef Research Only Area (a no-take marine reserve) in the northern Florida Keys National Marine Sanctuary in November 2001. Both species are heavily exploited in the region. Our objective was to characterize site fidelity and movement behavior along the reef tract to the north and south of the release point.
Background Motivated by the precarious state of the world's coral reefs, there is currently a kee... more Background Motivated by the precarious state of the world's coral reefs, there is currently a keen interest in coral transcriptomics. By identifying changes in coral gene expression that are triggered by particular environmental stressors, we can begin to characterize coral stress responses at the molecular level, which should lead to the development of more powerful diagnostic tools for evaluating the health of corals in the field.
East Africa’s Lake Victoria provides resources and services to millions of people on the lake’s s... more East Africa’s Lake Victoria provides resources and services to millions of people on the lake’s shores and abroad. In particular, the lake’s fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly understood and currently unpredictable. Furthermore, fishery dynamics are intricately connected to other supporting services of the lake as well as to lakeshore societies and economies. Much research has been carried out piecemeal on different aspects of Lake Victoria’s system; e.g., societies, biodiversity, fisheries, and eutrophication. However, to disentangle drivers and dynamics of change in this complex system, we need to put these pieces together and analyze the system as a whole. We did so by first building a qualitative model of the lake’s social-ecological system. We then investigated the model system through a qualitative loop analysis, and finally examined effects of changes on the system state and structure. The model and its contextual analysis allowed us to investigate system-wide chain reactions resulting from disturbances. Importantly, we built a tool that can be used to analyze the cascading effects of management options and establish the requirements for their success. We found that high connectedness of the system at the exploitation level, through fisheries having multiple target stocks, can increase the stocks’ vulnerability to exploitation but reduce society’s vulnerability to variability in individual stocks. We describe how there are multiple pathways to any change in the system, which makes it difficult to identify the root cause of changes but also broadens the management toolkit. Also, we illustrate how nutrient enrichment is not a self-regulating process, and that explicit management is necessary to halt or reverse eutrophication. This model is simple and usable to assess system-wide effects of management policies, and can serve as a paving stone for future quantitative analyses of system dynamics at local scales.
ABSTRACT: We examined evidence for nonlinear dynamics in fishery-independent survey data for an a... more ABSTRACT: We examined evidence for nonlinear dynamics in fishery-independent survey data for an assemblage of 26 fish species on Georges Bank spanning the period 1963 to 2008.
LeVar is inspired by the book to learn more about the world of coral reefs, so he dons diving gea... more LeVar is inspired by the book to learn more about the world of coral reefs, so he dons diving gear and gives viewers a tour of the National Marine Sanctuary, an underwater park in Florida. Viewers also meet a 'reef doctor'who shows how he restores life to damaged reefs by transplanting living coral.
Abstract: Amphiprion barberi, a new species of anemonefish fish, is described from 46 specimens, ... more Abstract: Amphiprion barberi, a new species of anemonefish fish, is described from 46 specimens, 16.3-85.8 mm SL, collected at depths of 2-10 m from coral reefs of Fiji, Tonga, and Samoa. It is closely allied to A. melanopus, which is widely distributed in the western Pacific. The two species exhibit significant colour-pattern differences, including a mainly reddish orange body in A. barberi and dark brown or blackish body in A. melanopus.
Lake Superior is greater in surface area than Lake Victoria. Lake Baikal is deeper than Lake Tang... more Lake Superior is greater in surface area than Lake Victoria. Lake Baikal is deeper than Lake Tanganyika. Nonetheless, the Great Lakes of East Africa are second to none, when it comes to the wealth of native fishes and the number of people dependent on these lakes. Lake Malawi is thought to host more than 500 species of fishes, nearly all endemic (27).
The annual cycle of the vertical distribution of oxygen concentrations at a deep water station on... more The annual cycle of the vertical distribution of oxygen concentrations at a deep water station on Lake Victoria in 1990-1991 was compared with data collected in 1960-1961. Oxygen concentrations in the mixed layer are higher now, with nearly continuous oxygen supersaturation in surface waters. Oxygen concentrations in hypolimnetic waters are lower now for a longer period, with values< 1 mg liter^-1 occurring in water as shallows s 40 m compared with a shallowest occurrence of> 50 m in 1961.
Abstract Systematic approaches to site selection for marine protected areas (MPAs) are often favo... more Abstract Systematic approaches to site selection for marine protected areas (MPAs) are often favored over opportunistic approaches as a means to meet conservation objectives efficiently. In this study, we compared analytically the conservation value of these two approaches. We locate this study in Danajon Bank, central Philippines, where many MPAs were established opportunistically based on community preference, with few if any contributions from biophysical data.
With respect to vertebrate faunas, there is little doubt that freshwater fishes represent the mos... more With respect to vertebrate faunas, there is little doubt that freshwater fishes represent the most threatened set of vertebrates in the world due to both extensive and intensive human impacts, but also because of the disproportionate richness of inland waters (DUDGEON et al. 2005). Over 10 000 fish species live in freshwater, representing approximately 41% of global fish diversity (LUNDBERG et al. 2000).
Island Press is the only nonprofit organization in the United States whose principal purpose is t... more Island Press is the only nonprofit organization in the United States whose principal purpose is the publication of books on environmental issues and natural resource management. We provide solutions-oriented information to professionals, public officials, business and community leaders, and concerned citizens who are shaping responses to environmental problems. In 1999.
Background The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating int... more Background The threespot damselfish, Stegastes planifrons (Cuvier), is important in mediating interactions among corals, algae, and herbivores on Caribbean coral reefs. The preferred microhabitat of S. planifrons is thickets of the branching staghorn coral Acropora cervicornis. Within the past few decades, mass mortality of A. cervicornis from white-band disease and other factors has rendered this coral a minor ecological component throughout most of its range.
The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global... more The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it.
Background The transcription factors of the LSF/Grainyhead (GRH) family are characterized by the ... more Background The transcription factors of the LSF/Grainyhead (GRH) family are characterized by the possession of a distinctive DNA-binding domain that bears no clear relationship to other known DNA-binding domains, with the possible exception of the p53 core domain. In triploblastic animals, the LSF and GRH subfamilies have diverged extensively with respect to their biological roles, general expression patterns, and mechanism of DNA binding.
Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (< 150 m de... more Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (< 150 m depth) subjected to episodic disturbance. Rhodolith beds stand with kelp beds, seagrass meadows, and coralline algal reefs as one of the world's four largest macrophyte-dominated benthic communities. Geographic distribution of rhodolith beds is discontinuous, with large concentrations off Japan, Australia and the Gulf of California, as well as in the Mediterranean, North Atlantic, eastern Caribbean and Brazil.
ABSTRACT.—The largely sedentary behavior of many fishes on coral reefs is well established. Howev... more ABSTRACT.—The largely sedentary behavior of many fishes on coral reefs is well established. However, information on the movement behavior of individual fish, over fine temporal and spatial scales, continues to be limited. While conducting a larger project in the northern Florida Keys in 2002, we surgically-tagged a small number of Scarus coeruleus Bloch 1786 and S. taeniopterus Desmarest in Bory de
Résumé L'introduction de la perche du Nil, Lates niloticus, dans le lac Victoria en Afrique orien... more Résumé L'introduction de la perche du Nil, Lates niloticus, dans le lac Victoria en Afrique orientale a produit une réaction avec l'eutrophication qui a provoqué une réorganisation du réseau alimentaire et l'extirpation de plusieurs poissons endémiques. Le système satellite du lac Kyoga se trouve en aval du lac Victoria. Il englobe des lacs riches en espèces où les perches du Nil sont absentes ou très rares, ainsi que des lacs de pauvre diversité oùL. niloticus est abondante.
Abstract The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of th... more Abstract The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls) were sampled per site with 3–10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003–2005 and 2006–2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period.
We tagged a total of 14 yellowtail snapper (Ocyurus chrysurus Bloch 1790) and black grouper (Myct... more We tagged a total of 14 yellowtail snapper (Ocyurus chrysurus Bloch 1790) and black grouper (Mycteroperca bonaci Poey 1860) inside the Conch Reef Research Only Area (a no-take marine reserve) in the northern Florida Keys National Marine Sanctuary in November 2001. Both species are heavily exploited in the region. Our objective was to characterize site fidelity and movement behavior along the reef tract to the north and south of the release point.
Background Motivated by the precarious state of the world's coral reefs, there is currently a kee... more Background Motivated by the precarious state of the world's coral reefs, there is currently a keen interest in coral transcriptomics. By identifying changes in coral gene expression that are triggered by particular environmental stressors, we can begin to characterize coral stress responses at the molecular level, which should lead to the development of more powerful diagnostic tools for evaluating the health of corals in the field.
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Papers by Les Kaufman