Fish Biomass

The TimeFISH database provides the first public time‐series dataset on reef fish assemblages in the southwestern Atlantic (SWA), comprising 15 years of data (2007–2022) based on standardized Underwater Visual Censuses (UVCs). The rocky reefs covered by our dataset are influenced by pronounced seasonal cycles of ocean temperatures with warm tropical waters from the Brazil Current in the summer (~27°C) and colder waters from the La Plata River Plume discharge and upwelling from the South Atlantic Central Water in the winter (~18°C). These oceanographic conditions characterize this area as the southernmost tropical–subtropical climatic transition zone in the Atlantic Ocean. As a result, reef fish assemblages are comprised of both tropical and subtropical species. All records included in TimeFISH were collected using UVCs, a nondestructive method that allows the estimation of fish species richness, abundance, and body size distributions. UVCs were performed through 40 m2 belt transects ...

Habitat heterogeneity is known to promote species diversity and other effects in communities by increasing structural complexity, access to food resources and to refuge spaces. However, the influence of environmental heterogeneity at small spatial scale settings is challenging to detect and to measure. In tropical intertidal rocky shores, the low tidal zones are sometimes encrusted by reef-building organisms forming complex biogenic flat reefs below rocky outcrops that appear at mid-to-upper intertidal level. Here, we investigated a tidepool community situated on an intertidal shore with marked variation in structure and texture within metres to test whether tidepool fauna would differ between biogenic and rocky reefs in regard to their composition, diversity and trophic structure. Our findings revealed that tidepool fish assemblages differed significantly between reef types. Trophic structure exhibited variations in resource use, food web hierarchy and trophic roles of species occurring in both biogenic and rocky tidepools. Our results imply that tropical intertidal reefs show pronounced taxonomic and trophic distinctiveness at small spatial scales.

Tulisan ini mengangkat praktik bank ikan sebagai bentuk pengelolaan sumber daya pesisir berbasis masyarakat yang berkembang di Desa Tangkop. Inisiatif ini berangkat dari kesadaran lokal bahwa penurunan hasil tangkapan bukan semata karena faktor alam, melainkan akibat tekanan penangkapan berlebih dan praktik yang merusak. Melalui kesepakatan bersama, sebagian wilayah laut dijaga sebagai “lumbung ikan” yang hanya dimanfaatkan pada waktu dan kebutuhan tertentu, terutama untuk kepentingan sosial dan adat.

Pengalaman lapangan menunjukkan bahwa area yang dijaga mampu menyimpan biomassa ikan dan menyediakan tangkapan dalam jumlah relatif besar dalam waktu singkat ketika dibutuhkan. Temuan ini diperkuat oleh kondisi ekologi setempat, di mana wilayah dengan tutupan terumbu karang yang lebih baik menunjukkan potensi pemulihan stok yang lebih cepat dibanding perairan yang mengalami degradasi. Praktik bank ikan dengan demikian berfungsi tidak hanya sebagai mekanisme konservasi, tetapi juga sebagai strategi ketahanan pangan komunitas pesisir.

Secara sosial, penerapan sistem ini pada awalnya memunculkan perdebatan karena kuatnya persepsi bahwa laut merupakan ruang milik bersama tanpa batas. Namun, setelah manfaatnya dirasakan secara langsung, penerimaan masyarakat meningkat dan memperkuat dukungan kolektif terhadap perlindungan kawasan. Dalam kerangka pengelolaan perikanan modern, praktik ini sejalan dengan konsep community reserve yang menjaga indukan, menyediakan ruang pemijahan, dan mendorong efek limpahan stok ke wilayah tangkap.

Tulisan ini menunjukkan bahwa keberhasilan konservasi skala lokal sangat ditentukan oleh pertemuan antara pengetahuan ekologis, nilai budaya, dan refleksi etika-spiritual masyarakat. Ketika sebagian ruang laut dibiarkan pulih, ekosistem kembali produktif dan mampu menopang kebutuhan pangan komunitas. Dengan demikian, praktik bank ikan merepresentasikan bentuk stewardship ekologis—sebuah cara menjaga alam yang sekaligus menjaga keberlanjutan kehidupan masyarakat pesisir.

Monitoring of coral reefs has become a major tool for understanding how they are changing, and for managing them in a context of increasing degradation of coastal ecosystems. The Global Coral Reef Monitoring Network (GCRMN) has near-global coverage, but there are few remote sites free of direct human impact that can serve as reference sites. This study provides baseline data for the French Iles Eparses in the Mozambique Channel, Western Indian Ocean (WIO), whose coral reefs are little known owing to their limited accessibility, and have been free from fishing pressure for over 20 years. Surveys of coral reef health and fish community structure were undertaken at four of the islands (Europa, Bassas da India, Juan de Nova and Glorieuses) in 2011e2013. Monitoring was conducted using standardized GCRMN methods for benthos and fish communities, at the highest taxonomic level. Benthic cover showed a latitudinal gradient, with higher coral cover and conversely lower algae cover (60% and 14% respectively) in the south of the Mozambique Channel. This could be due to the geomorphology of the islands, the latitudinal temperature gradient, and/or the history of chronic stress and bleaching events during the last decades. Fish also showed a latitudinal gradient with higher diversity in the north, in a center of diversity for the western Indian Ocean already recognized for corals. An exceptional biomass fish was recorded (approximately 3500 kg/ha excluding sharks, compared to a maximum of 1400 kg/ha elsewhere in the WIO). The presence of large predators and sharks in all the islands as well as the absence of fleshy benthic algae were indicators of the good health of the reef systems. Nevertheless, these islands are beginning to experience illegal fishing, particularly in the north of the Mozambique Channel, demonstrating their vulnerability to exploitation and the need to protect them as reference sites for coral reef studies, including of climate change impacts, for the region and globally.

Promotion of successful examples of biomanipulation and long-term monitoring is important for encouragement of similar activities, which are still relatively scarce. A project to improve water quality in the Velky Bolevecky pond (Plzeň, Czech Republic) began in 2006. The main activities in this project were: large scale fish reduction; stocking of predatory fish; usage of phosphorus binding coagulants; and reintroduction of macrophytes. During five years the impact of a eutrophic system with massive cyanobacterial blooms with low water transparency transformed into a clear water system with high water transparency and well developed macrophyte cover. All aspects relating to the ecological status of the water body such as total phosphorus concentration, chlorophyll-a concentration and cyanobacterial and other phytoplankton density improved significantly during or immediately after the project realization. For example, water transparency increased three fold. Zooplankton density also increased, however the difference was not significant. Oligotrophication of the system became evident also in the species composition of zooplankton and phytoplankton. Species adapted to nutrient reduction and macrophyte cover developed. Seven years after the project was over, the fish stock remained on the low densities naturally. A good ecological stage was achieved with low nutrient levels, high water transparency, very low densities of cyanobacteria and other phytoplankton together with a well-developed macrophyte cover. All of which has been maintained without any expensive impact. The highest expenditure is, paradoxically, due to macrophyte harvesting because their massive explosion in the pond is not in accordance with recreational and sporting utilization. It seems, that reduction of nutrient loading and switching of a formerly eutrophic system to an oligotrophic one is possible and sustainable over a relatively long time period in a shallow temperate pond. Subsequent good management of the system will, of course, be necessary.

Promotion of successful examples of biomanipulation and long-term monitoring is important for encouragement of similar activities, which are still relatively scarce. A project to improve water quality in the Velky Bolevecky pond (Plzeň, Czech Republic) began in 2006. The main activities in this project were: large scale fish reduction; stocking of predatory fish; usage of phosphorus binding coagulants; and reintroduction of macrophytes. During five years the impact of a eutrophic system with massive cyanobacterial blooms with low water transparency transformed into a clear water system with high water transparency and well developed macrophyte cover. All aspects relating to the ecological status of the water body such as total phosphorus concentration, chlorophyll-a concentration and cyanobacterial and other phytoplankton density improved significantly during or immediately after the project realization. For example, water transparency increased three fold. Zooplankton density also increased, however the difference was not significant. Oligotrophication of the system became evident also in the species composition of zooplankton and phytoplankton. Species adapted to nutrient reduction and macrophyte cover developed. Seven years after the project was over, the fish stock remained on the low densities naturally. A good ecological stage was achieved with low nutrient levels, high water transparency, very low densities of cyanobacteria and other phytoplankton together with a well-developed macrophyte cover. All of which has been maintained without any expensive impact. The highest expenditure is, paradoxically, due to macrophyte harvesting because their massive explosion in the pond is not in accordance with recreational and sporting utilization. It seems, that reduction of nutrient loading and switching of a formerly eutrophic system to an oligotrophic one is possible and sustainable over a relatively long time period in a shallow temperate pond. Subsequent good management of the system will, of course, be necessary.

When oil and gas platforms become obsolete they go through a decommissioning process. This may include partial removal (from the surface to 26 m depth) or complete removal of the platform structure. While complete removal would likely eliminate most of the existing fish biomass and associated secondary production, we find that the potential impacts of partial removal would likely be limited on all but one platform off the coast of California. On average 80% of fish biomass and 86% of secondary fish production would be retained after partial removal, with above 90% retention expected for both metrics on many platforms. Partial removal would likely result in the loss of fish biomass and production for species typically found residing in the shallow portions of the platform structure. However, these fishes generally represent a small proportion of the fishes associated with these platforms. More characteristic of platform fauna are the primarily deeper-dwelling rockfishes (genus Sebastes). "Shell mounds" are biogenic reefs that surround some of these platforms resulting from an accumulation of mollusk shells that have fallen from the shallow areas of the platforms mostly above the depth of partial removal. We found that shell mounds are moderately productive fish habitats, similar to or greater than natural rocky reefs in the region at comparable depths. The complexity and areal extent of these biogenic habitats, and the associated fish biomass and production, will likely be reduced after either partial or complete platform removal. Habitat augmentation by placing the partially removed platform superstructure or some other additional habitat enrichment material (e.g., rock boulders) on the seafloor adjacent to the base of partially removed platforms provides additional options to enhance fish production, potentially mitigating reductions in shell mound habitat.

The ecological management effectiveness (EME) of Marine Protected Areas (MPAs) is the degree to which MPAs reach their ecological goals. The significant variability of EME among MPAs has been partly explained by MPA design, management and implementation features (e.g. surface area, enforcement, age of protection). We investigated EME variability by employing, for the first time, Organization Science. Eight Mediterranean MPAs were taken into account as case studies to explore the relationships between EME and MPA features, such as: 1) organizational size (i.e. the ratio between the number of full-time employees and the total MPA surface area), 2) management performance (i.e. the level of effort exerted to enhance and sustain the MPA management, including enforcement), 3) total surface area, and 4) MPA age. The log-response ratios of fish biomass and density in protected vs unprotected (control) areas were used as a proxy of EME. Management performance, organizational size and, to a lesser extent, MPA age were positively correlated with the log-response ratio of fish biomass, whereas total surface area did not display a significant role. None of the four features considered was significantly correlated with the log-response ratio of fish density. Based on our findings, we argue that the employment of Organization Science in the management effectiveness assessment can assist MPA managers to reach MPAs goals more effectively, with a more efficient use of available resources.

The MacArthur & Wilson theory of island biogeography predicts that the balance between immigration and extinction rates results from the size and degree of isolation of the island. Here, we test this assumption using data from the marine gastropods of Brazilian oceanic islands. Species lists were compiled for Rocas Atoll, the Fernando de Noronha Archipelago, the Sa˜o Pedro and Sa˜o Paulo Archipelago and Trindade Island. These were compared with the predictions of the theory based on the shallow platform area and distance from the mainland (Model 1) and the nearest reef habitat (Model 2). Results corroborated at least in part the assumptions proposed by MacArthur & Wilson. Sa˜o Pedro and Sa˜o Paulo and Fernando de Noronha fitted the equilibrium model of extinction and immigration rates, while Trindade and Rocas Atoll stood out as an exception to Model 1 and to Models 1 and 2, respectively. The relevance of the age of the island and presence of seamount chains is discussed to explain this discrepancy.

Monitoring of coral reefs has become a major tool for understanding how they are changing, and for managing them in a context of increasing degradation of coastal ecosystems. The Global Coral Reef Monitoring Network (GCRMN) has near-global coverage, but there are few remote sites free of direct human impact that can serve as reference sites. This study provides baseline data for the French Iles Eparses in the Mozambique Channel, Western Indian Ocean (WIO), whose coral reefs are little known owing to their limited accessibility, and have been free from fishing pressure for over 20 years. Surveys of coral reef health and fish community structure were undertaken at four of the islands (Europa, Bassas da India, Juan de Nova and Glorieuses) in 2011e2013. Monitoring was conducted using standardized GCRMN methods for benthos and fish communities, at the highest taxonomic level. Benthic cover showed a latitudinal gradient, with higher coral cover and conversely lower algae cover (60% and 14% respectively) in the south of the Mozambique Channel. This could be due to the geomorphology of the islands, the latitudinal temperature gradient, and/or the history of chronic stress and bleaching events during the last decades. Fish also showed a latitudinal gradient with higher diversity in the north, in a center of diversity for the western Indian Ocean already recognized for corals. An exceptional biomass fish was recorded (approximately 3500 kg/ha excluding sharks, compared to a maximum of 1400 kg/ha elsewhere in the WIO). The presence of large predators and sharks in all the islands as well as the absence of fleshy benthic algae were indicators of the good health of the reef systems. Nevertheless, these islands are beginning to experience illegal fishing, particularly in the north of the Mozambique Channel, demonstrating their vulnerability to exploitation and the need to protect them as reference sites for coral reef studies, including of climate change impacts, for the region and globally.

Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government-and community-managed MPAs on the density, size and biomass of seagrassand coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km 2 in size, 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby fisheries.

Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government-and community-managed MPAs on the density, size and biomass of seagrassand coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km 2 in size, 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby fisheries.

The increasing need to introduce and highlight the analysis of deep water temperature (both horizontal and vertical) profile for up welling process and its relationship to fish biomass spatial distribution was inevitable. Especially to avoid the misleading interpretation of using only surface water temperature data for deep water fish biomass analysis. The paper analyze and revealed the fate / occurrence of up welling zone in adjacent of Halmahera islands through the analysis of both multi-layer horizontal and vertical temperature data. Further analysis on the temperature and fish biomass data revealed the close relationship of horizontal temperature pattern especially at depth of 80m with spatial distribution of total fish biomass (acoustic numeric data : in dB unit) and fish biomass (ton/mile square) with fish total-length above 30cm.

Background There is growing evidence of the potential negative consequences of altered flow regimes, in terms of magnitude, frequency, timing, duration or season pattern, on fluvial ecosystems and the fisheries they support. The scientific and policy communities have acknowledged the need for a better understanding of the effects of flow alteration on fish productivity. We conducted a systematic map to provide an overview of the existing literature base on the effects of flow-regime changes on direct outcomes of freshwater or estuarine fish productivity in temperate regions to inform stakeholders and policy makers. Methods To identify relevant articles for inclusion in this systematic map, we searched six bibliographic databases, 29 organizational websites, one search engine, and 297 reviews, and solicited grey literature through relevant sources. We screened articles at title and abstract, then by full-text using predefined inclusion criteria. Included studies were coded for key va...

Monitoring of coral reefs has become a major tool for understanding how they are changing, and for managing them in a context of increasing degradation of coastal ecosystems. The Global Coral Reef Monitoring Network (GCRMN) has near-global coverage, but there are few remote sites free of direct human impact that can serve as reference sites. This study provides baseline data for the French Iles Eparses in the Mozambique Channel, Western Indian Ocean (WIO), whose coral reefs are little known owing to their limited accessibility, and have been free from fishing pressure for over 20 years. Surveys of coral reef health and fish community structure were undertaken at four of the islands (Europa, Bassas da India, Juan de Nova and Glorieuses) in 2011e2013. Monitoring was conducted using standardized GCRMN methods for benthos and fish communities, at the highest taxonomic level. Benthic cover showed a latitudinal gradient, with higher coral cover and conversely lower algae cover (60% and 14% respectively) in the south of the Mozambique Channel. This could be due to the geomorphology of the islands, the latitudinal temperature gradient, and/or the history of chronic stress and bleaching events during the last decades. Fish also showed a latitudinal gradient with higher diversity in the north, in a center of diversity for the western Indian Ocean already recognized for corals. An exceptional biomass fish was recorded (approximately 3500 kg/ha excluding sharks, compared to a maximum of 1400 kg/ha elsewhere in the WIO). The presence of large predators and sharks in all the islands as well as the absence of fleshy benthic algae were indicators of the good health of the reef systems. Nevertheless, these islands are beginning to experience illegal fishing, particularly in the north of the Mozambique Channel, demonstrating their vulnerability to exploitation and the need to protect them as reference sites for coral reef studies, including of climate change impacts, for the region and globally.

We present a checklist of 278 species of reef fishes recorded along the coastline of Santa Catarina state, the southernmost limit of distribution of tropical ichthyofauna on the coast of Brazil. Twelve new species records for this state are presented: Acanthurus coeruleus, Acanthurus monroviae, Apogon americanus, Cantherhines macrocerus, Chaetodon sedentarius, Chromis flavicauda, Clepticus brasiliensis, Decapterus punctatus, Gymnothorax vicinus, Herpetoichthys regius, Muraena retifera and Stegastes partitus. Stegastes partitus and H. regius are reported for the first time, respectively, from the Southwestern Atlantic and for the coastal part of this region, while Acanthurus monroviae is reported for the second time for the Southwestern Atlantic. We present habitat distribution, trophic structure and comment on biogeographic affinities of this transitional region, discussing both remarkable species presences and absences.

The ecological management effectiveness (EME) of Marine Protected Areas (MPAs) is the degree to which MPAs reach their ecological goals. The significant variability of EME among MPAs has been partly explained by MPA design, management and implementation features (e.g. surface area, enforcement, age of protection). We investigated EME variability by employing, for the first time, Organization Science. Eight Mediterranean MPAs were taken into account as case studies to explore the relationships between EME and MPA features, such as: 1) organizational size (i.e. the ratio between the number of full-time employees and the total MPA surface area), 2) management performance (i.e. the level of effort exerted to enhance and sustain the MPA management, including enforcement), 3) total surface area, and 4) MPA age. The log-response ratios of fish biomass and density in protected vs unprotected (control) areas were used as a proxy of EME. Management performance, organizational size and, to a lesser extent, MPA age were positively correlated with the log-response ratio of fish biomass, whereas total surface area did not display a significant role. None of the four features considered was significantly correlated with the log-response ratio of fish density. Based on our findings, we argue that the employment of Organization Science in the management effectiveness assessment can assist MPA managers to reach MPAs goals more effectively, with a more efficient use of available resources.

We present a checklist of 278 species of reef fishes recorded along the coastline of Santa Catarina state, the southernmost limit of distribution of tropical ichthyofauna on the coast of Brazil. Twelve new species records for this state are presented: Acanthurus coeruleus, Acanthurus monroviae, Apogon americanus, Cantherhines macrocerus, Chaetodon sedentarius, Chromis flavicauda, Clepticus brasiliensis, Decapterus punctatus, Gymnothorax vicinus, Herpetoichthys regius, Muraena retifera and Stegastes partitus. Stegastes partitus and H. regius are reported for the first time, respectively, from the Southwestern Atlantic and for the coastal part of this region, while Acanthurus monroviae is reported for the second time for the Southwestern Atlantic. We present habitat distribution, trophic structure and comment on biogeographic affinities of this transitional region, discussing both remarkable species presences and absences.

The European Union Water Framework Directive requires monitoring of biological quality elements to assess the ecological status of aquatic ecosystems and assure their good quality. Hydroacoustics could provide an effective tool for monitoring certain aspects of fish populations in fresh waters, but to ensure the comparability of datasets between lakes and reservoirs across Europe standardisation is required for equipment, survey design, data acquisition, data analysis, and data reporting. In the present paper we investigate the repeatability and precision of hydroacoustic fish surveys in a deep lake comprising two basins (mesotrophic and eutrophic) conducted in accordance with a provisional CEN standard. Results are presented from an international hydroacoustic intercalibration that included six systems comprising hardware from three manufacturers using four sound frequencies (70, 120, 200 and 400 kHz), together with analysis software from three manufacturers. The findings are very encouraging and demonstrate a considerable degree of similarity in the measures of fish biomass and fish abundance produced by these six diverse hydroacoustic systems operated under the mesotrophic and eutrophic conditions of this deep lake.

The ecological management effectiveness (EME) of Marine Protected Areas (MPAs) is the degree to which MPAs reach their ecological goals. The significant variability of EME among MPAs has been partly explained by MPA design, management and implementation features (e.g. surface area, enforcement, age of protection). We investigated EME variability by employing, for the first time, Organization Science. Eight Mediterranean MPAs were taken into account as case studies to explore the relationships between EME and MPA features, such as: 1) organizational size (i.e. the ratio between the number of full-time employees and the total MPA surface area), 2) management performance (i.e. the level of effort exerted to enhance and sustain the MPA management, including enforcement), 3) total surface area, and 4) MPA age. The log-response ratios of fish biomass and density in protected vs unprotected (control) areas were used as a proxy of EME. Management performance, organizational size and, to a lesser extent, MPA age were positively correlated with the log-response ratio of fish biomass, whereas total surface area did not display a significant role. None of the four features considered was significantly correlated with the log-response ratio of fish density. Based on our findings, we argue that the employment of Organization Science in the management effectiveness assessment can assist MPA managers to reach MPAs goals more effectively, with a more efficient use of available resources.

Fish anatomical vertical dimensions are extracted from a time-of-flight analysis of fish echo shape using narrow-bandwidth echosounding of swimming individuals. These vertical dimensions fit a Gumbel distribution model and are successfully correlated with fish weight. The proposed method can be used to estimate the mean weight of fish in aquaculture cages as an alternative to target strength measurements. Full-waveform acquisition and signal correlation techniques permitted to increase the signal-to-noise ratio and to improve the performance against traditional envelope-based echosounding.

We present a checklist of 278 species of reef fishes recorded along the coastline of Santa Catarina state, the southernmost limit of distribution of tropical ichthyofauna on the coast of Brazil. Twelve new species records for this state are presented: Acanthurus coeruleus, Acanthurus monroviae, Apogon americanus, Cantherhines macrocerus, Chaetodon sedentarius, Chromis flavicauda, Clepticus brasiliensis, Decapterus punctatus, Gymnothorax vicinus, Herpetoichthys regius, Muraena retifera and Stegastes partitus. Stegastes partitus and H. regius are reported for the first time, respectively, from the Southwestern Atlantic and for the coastal part of this region, while Acanthurus monroviae is reported for the second time for the Southwestern Atlantic. We present habitat distribution, trophic structure and comment on biogeographic affinities of this transitional region, discussing both remarkable species presences and absences.

The natural, prehuman abundance of most large predators is unknown because of the lack of historical data and a limited understanding of the natural factors that control their populations. Determining the supportable predator biomass at a given location (that is, the predator carrying capacity) would help managers to optimize protection and would provide site-specific recovery goals. We assess the relationship between predatory reef fish biomass and several anthropogenic and environmental variables at 39 reefs across the Caribbean to (i) estimate their roles determining local predator biomass and (ii) determine site-specific recovery potential if fishing was eliminated. We show that predatory reef fish biomass tends to be higher in marine reserves but is strongly negatively related to human activities, especially coastal development. However, human activities and natural factors, including reef complexity and prey abundance, explain more than 50% of the spatial variation in predator...

The ecological management effectiveness (EME) of Marine Protected Areas (MPAs) is the degree to which MPAs reach their ecological goals. The significant variability of EME among MPAs has been partly explained by MPA design, management and implementation features (e.g. surface area, enforcement, age of protection). We investigated EME variability by employing, for the first time, Organization Science. Eight Mediterranean MPAs were taken into account as case studies to explore the relationships between EME and MPA features, such as: 1) organizational size (i.e. the ratio between the number of full-time employees and the total MPA surface area), 2) management performance (i.e. the level of effort exerted to enhance and sustain the MPA management, including enforcement), 3) total surface area, and 4) MPA age. The log-response ratios of fish biomass and density in protected vs unprotected (control) areas were used as a proxy of EME. Management performance, organizational size and, to a lesser extent, MPA age were positively correlated with the log-response ratio of fish biomass, whereas total surface area did not display a significant role. None of the four features considered was significantly correlated with the log-response ratio of fish density. Based on our findings, we argue that the employment of Organization Science in the management effectiveness assessment can assist MPA managers to reach MPAs goals more effectively, with a more efficient use of available resources.

Day and night acoustic surveys were used to compare fish stock estimates at eight European reservoirs and one flooded mining pit. During both photoperiods of summer, higher fish biomass was observed in the uppermost 4 m of the water column by horizontal beaming than in deeper water by vertical beaming. Comparisons of volume backscattering coefficient (s v), fish biomass (kg ha −1), abundance (ind. ha −1) and average fish weight (g) did not show a common pattern among the reservoirs but were found to vary significantly across photoperiods. At most reservoirs, the night surveys had higher estimates than day surveys. However, at several reservoirs the opposite pattern was observed. These patterns could not be explained by the species composition of the fish stocks. Fish size distributions were found to be different between day and night. A higher proportion of 1+ and older fish were found during the night at two of three studied waterbodies. In general, it was not possible to decide whether day or night acoustic surveys gave more reliable fish stock assessments. We advise performing both day and night transects on a given water body before deciding when to conduct the full survey. For a complete fish assessment it is very desirable to combine acoustic mobile surveys with active sampling gear.

The European Union Water Framework Directive requires monitoring of biological quality elements to assess the ecological status of aquatic ecosystems and assure their good quality. Hydroacoustics could provide an effective tool for monitoring certain aspects of fish populations in fresh waters, but to ensure the comparability of datasets between lakes and reservoirs across Europe standardisation is required for equipment, survey design, data acquisition, data analysis, and data reporting. In the present paper we investigate the repeatability and precision of hydroacoustic fish surveys in a deep lake comprising two basins (mesotrophic and eutrophic) conducted in accordance with a provisional CEN standard. Results are presented from an international hydroacoustic intercalibration that included six systems comprising hardware from three manufacturers using four sound frequencies (70, 120, 200 and 400 kHz), together with analysis software from three manufacturers. The findings are very encouraging and demonstrate a considerable degree of similarity in the measures of fish biomass and fish abundance produced by these six diverse hydroacoustic systems operated under the mesotrophic and eutrophic conditions of this deep lake.

The European Union Water Framework Directive requires monitoring of biological quality elements to assess the ecological status of aquatic ecosystems and assure their good quality. Hydroacoustics could provide an effective tool for monitoring certain aspects of fish populations in fresh waters, but to ensure the comparability of datasets between lakes and reservoirs across Europe standardisation is required for equipment, survey design, data acquisition, data analysis, and data reporting. In the present paper we investigate the repeatability and precision of hydroacoustic fish surveys in a deep lake comprising two basins (mesotrophic and eutrophic) conducted in accordance with a provisional CEN standard. Results are presented from an international hydroacoustic intercalibration that included six systems comprising hardware from three manufacturers using four sound frequencies (70, 120, 200 and 400 kHz), together with analysis software from three manufacturers. The findings are very encouraging and demonstrate a considerable degree of similarity in the measures of fish biomass and fish abundance produced by these six diverse hydroacoustic systems operated under the mesotrophic and eutrophic conditions of this deep lake.

This study examined how riverine inputs, in particular sediment, influenced the community structure and trophic composition of reef fishes within Rio Bueno, north Jamaica. Due to river discharge a distinct gradient of riverine inputs existed across the study sites. Results suggested that riverine inputs (or a factor associated with them) had a structuring effect on fish community structure. Whilst fish communities at all sites were dominated by small individuals (<20 cm), diversity and total biomass were reduced with increased proximity to the river mouth. The abundance of all fishes, but particularly small-bodied, juvenile and herbivorous fishes was reduced in turbid water when compared to clear-water sites. Results strongly suggest that fluvial sediment inputs may play an important role in structuring fish assemblages even under intense fishing pressure.

The Article deseribes the eoneept jor development oj a dynamie ship positioning system based on the information provided by hydroacoustic systems. It is the first presentation jor the wide audienee oj a modern method jor determination oj position using modern measuring and proeessing teehnology where the hydroaeoustie wave is the carrier oj information.

Coral reef communities of the Greater Antilles in the Caribbean have a long history of anthropogenic disturbance, driven by the exploitation for food of both vertebrate and invertebrate species. Exploitation, coupled with region wide declines of coral environments has resulted in local and regional vertebrate extinctions. The impact of those extinctions on reef communities, however, remains largely unexplored. Here we show, using a highly resolved model coral reef-seagrass food web, that at least 40 of 188 expected vertebrate species are absent from Jamaican coral reefs. Twenty one of the absent species are of high trophic level and are exploited by humans. The remainder of the absent species are unexploited, and comprises a significantly high proportion of specialized reef foragers. Many of those species are also more trophically specialized than their closest trophic competitors. We conclude that the absence of unexploited species from Jamaica is caused by the overexploitation of ...

The increasing need to introduce and highlight the analysis of deep water temperature (both horizontal and vertical) profile for up welling process and its relationship to fish biomass spatial distribution was inevitable. Especially to avoid the misleading interpretation of using only surface water temperature data for deep water fish biomass analysis. The paper analyze and revealed the fate / occurrence of up welling zone in adjacent of Halmahera islands through the analysis of both multi-layer horizontal and vertical temperature data. Further analysis on the temperature and fish biomass data revealed the close relationship of horizontal temperature pattern especially at depth of 80m with spatial distribution of total fish biomass (acoustic numeric data: in dB unit) and fish biomass (ton/mile square) with fish total-length above 30cm.

The increasing need to introduce and highlight the analysis of deep water temperature (both horizontal and vertical) profile for up welling process and its relationship to fish biomass spatial distribution was inevitable. Especially to avoid the misleading interpretation of using only surface water temperature data for deep water fish biomass analysis. The paper analyze and revealed the fate / occurrence of up welling zone in adjacent of Halmahera islands through the analysis of both multi-layer horizontal and vertical temperature data. Further analysis on the temperature and fish biomass data revealed the close relationship of horizontal temperature pattern especially at depth of 80m with spatial distribution of total fish biomass (acoustic numeric data : in dB unit) and fish biomass (ton/mile square) with fish total-length above 30cm.

The study was the first ever attempt in fisheries oceanography sciences to explore the empiric correlation between the spatial distribution of tuna (Thunnus.sp) and sub-surface in-situ temperature data. By means of optimalization and use of an in-situ data of both vertical and horizontal which will be processed into a multilayer subsurface seawater temperature of ARGO Float in Indian ocean. So far only sea surface temperature (with temperature around 29 °C) data were used to look for the correlation for tuna spatial distribution, while the Thunnus.sp swimming layer as widely known is in about 80 -250m depth with seawater temperature between 15 -23 °C. The noble character of ARGO Float data is as in-situ data recorded directly by the sensors, transmitted to the satellite, transmitted to the ground station and ready to be used by researcher all over the world.In the study, about 216 seawater temperature coordinates of ARGO Float and actual tuna catch data in the same day were used to represent the dry season (April -November 2007) analysis, and about 90 data were used for the rainy season (December -March 2007). The actual tuna catch and its coordinates data were collected with permission from PT. Perikanan Samudra Besar, (PT.PSB) Benoa -Bali Indonesia. Then both seawater temperature and tuna data were processed using a Krigging method or spatial interpolation method.Based on a monthly actual tuna production by fishing fleet of PT.PSB operated in Indian Ocean indicates that there were two cycles of low catch in March and July and high catch in May and December 2007. In general, seawater temperature in depth of 80m, 100m, 150m and 200m of the dry season was 2 °C warmer than those of the rainy season. Range of seawater temperature will decrease due to the water depth, range of seawater temperature at depth of 150m was between 14 -22 °C and at depth of 200m between 12 -20 °C. Based on the regression and correlation between tuna catch and seawater temperature revealed that seawater temperature at depth 150m has the highest coefficient of correlation than to the seawater temperature at depth 100m and 200m.

The increasing need to introduce and emphasis the analysis of SST and its sub-surface layers of deep water temperature (both horizontal and vertical) profile to analyze some oceanographic phenomena such as up-welling process and its relationship to its seasonal variability and spatial distribution was inevitable. Especially to avoid the misleading interpretation of using only sea surface temperature data for deep water fish biomass distribution analysis, etc.

Biogeographical transition zones are important areas to investigate evolutionary ecological questions, but long-term population monitoring is needed to better understand ecological processes that govern population variations in such edge environments. The southernmost Brazilian rocky reefs are the southern limit of distribution for 96% of the tropical ichthyofauna of the western Atlantic. The Arvoredo Marine Biological Reserve is the only nearshore no-take marine-protected area (MPA) located in this transition zone. The main aim was to investigate how the populations of rocky reef fish species vary in density and biomass in space and over time, inside and outside the Arvoredo MPA. This study presents results based on a 9 year (2008-2017) underwater visual census monitoring study to evaluate the density and biomass of key fish species. Variations in density and biomass were detected for most species. Factors and mechanisms that may have influenced spatial variation are habitat structural complexity and protection from fisheries. Temporal variations, otherwise, may have been influenced by species proximity to their distributional limit, in synergy with density-dependent mechanisms and stochastic winter temperature oscillations. The MPAs harbour higher density and biomass for most species. Nonetheless, a prominent temporal decline in the recruitment of Epinephelus marginatus calls into question the continuous effectiveness of the MPA.

Intertidal reef environments are facing a global crisis as climate changes are causing sea-level rise. Synergistically, other human-induced impacts (e.g., sewage, habitat loss) caused by concentration of human populations near the coast increase the natural vulnerability of intertidal ecosystems. However, the effect of these threats have long been neglected due, in part, to a limited knowledge of some aspects of intertidal fish ecology. We tested what are the main differences and drivers in fish assemblages structure between tidepools in three oceanic and three continental shelf (coastal) sites of the tropical southwestern Atlantic (Brazilian Province) using standardized sampling methods. Oceanic and coastal fish assemblages were distinctly structured at the trophic and composition levels. The noteworthy endemism species rate (38-44%) and high densities in oceanic sites are supported by resident species restricted to mid and high-shore tidepools where herbivores were the major trophic group. The coastal sites, on the other hand, were dominated by widely distributed and carnivore species. Physical (substrate type, pool height, subtidal distance and rock coverage), biological (sessile animal coverage) and chemical (salinity) parameters act as the driving forces influencing fish spatial occupancy. Here, clear evidences of high fish endemism and importance of endemics structuring oceanic communities may act as the last straw in favor of the conservation of oceanic intertidal reefs.

In September 1996, the crew of a three-day marine seismic refraction experiment detonated 141 explosions off the coast of Northern Honshu, Japan. The energy released by the explosion sources was eventually recorded by hydrophoness at Wake Island (WAKE) and Point Sur, California (PSUR), some 28 and 71 degrees distant, respectively. We compared the travel-times, amplitudes, and signal-to-noise ratios of the explosion phases with several sets of synthetic detection attributes generated from one-dimensional or two-dimensional hydroacoustic travel time and transmission loss tables. The two-dimensional tables tended to provide more accurate results. For example, the travel time differences at PSUR were -2.8 +- 6.8 sec. using the two-dimensional model whereas the one-dimensional model exhibited differences of -35.5 +- 4.0 sec. All detected phases were classified as either noise, T-phases, or explosion phases. In spite of varying noise backgrounds, 72% of the explosion phases were correctly identified.
The hydroacoustic data set helped us evaluate the accuracy of the automatic processing performed at the CMR and validate our modeling of these signals. This modeling should prove useful in preparation of the full deployment of the hydroacoustic International Monitoring System.

Macrourids are among the most abundant and diverse demersal fishes in all deep oceans, including the Southwestern Brazilian continental slope. Although not targeted by Brazilian fisheries, they suffer impact similar than the target species, being among the most discarded fishes by deep bottom trawling.
Trophic Ecology: Data from research surveys and commercial fishing were used to analyze the trophic ecology of four species inhabiting the upper slope of southern Brazil: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis and Lucigadus ori. For the two abundant ones, ontogenetic changes, seasonal variations, intra- and interspecific dietary overlap, parasite fauna and aspects of functional morphology are also described. C.marinii had an extremely diverse diet, preying infauna, epifauna, plankton, necton and carcasses.
M.occidentalis fed on larger and nektonic prey, but also included crabs and carcasses in the diet. Both species showed ontogenetic shifts and seasonal variations in diet composition, both leading to changes in intra- and interspecific diet overlap patterns. Species showed quite distinct feeding anatomy and proportions of body with mouth size, reflecting on feeding strategies. There was little interspecific food overlap. In most cases when the diet was more similar there was a spatial segregation. The coexistence of these species appears to be facilitated by the development of different functional morphologies and feeding strategies. A considerable portion of the diet of these species is due to the consumption of carcasses of pelagic and mesopelagic organisms, and even insects, bypassing the benthic trophic web. Conservative (minimum) estimates of the mean weight
of carcasses in diet ranged from 3 to 20%, increasing with the size of the predators and towards deeper waters. C.marinii showed a lower consumption of carcasses and a high proportion of mesopelagic fishes and cephalopods, however, the analysis of the feeding morphology and prey size leads to believe that most of these two groups of prey were consumed as carcasses. This source of food bypass the detritus food chains and connect the concentrations of macrourids to fluctuations in the abundance of epi and mesopelagic organisms and to oceanographic processes that increase their concentration and mortality (e.g. mesoscale anticyclonic eddies).

Distribution, Biomass and Oceanography: Data from two seasonal bottom trawl surveys were used to provide information on distribution, abundances, densities, sizecomposition and biomass estimates for seven species: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis, Lucigadus ori, Hymenocephalus billsam, Ventrifossa macropogon and V. mucocephalus. The total biomass was estimated in 5.5 and 8.3 kt respectively in winter-spring and summer-autumn. C.marinii and M.occidentalis comprised 98% of the biomass. For these two abundant species, surface maps were made with spawning areas, feeding index, sex and immature/mature ratios, and were related to
oceanographic processes, providing insights on strategies and important processes regulating distribution and abundance patterns. Both species showed a marked seasonal variation in the extent and location of spawning areas. Most C.marinii females were mature (90%), suggesting an early maturation during pelagic phase and acquiring demersal habit just prior the onset of maturation, while M.occidentalis showed few matures females and settle to bottom well before maturity. Temperature rather than depth seems to be the main factor regulating the batimetric distribution of both species. We describe three processes responsible for distribution and abundance patterns found in these species. Different patterns of spatial segregation were found in both species, related with depth, sex and maturity. It is suggested that areas with high biomass Macrouridae (scavengers) are induced by zones of occurrence semi-permanent mesoscale processes (e.g. eddies). These processes increase productivity and enable large biomass of short-lived organisms found in the upper layers, and also increase the concentration, mortality and availability of carcasses, favoring scavenger predators. These processes may be responsible for inconsistencies in biomass of megafauna and macrofauna found in some studies, where biomass of megafauna was of the same order of magnitude or larger than macrofauna, contradicting the Eltonian principle. It is suggested that future studies attempt to relate mesoscale processes with the biomass of potential short-lived prey in surface waters and higher biomass of scavengers. This work highlights the importance of the study of ocean dynamics, combining biological and oceanographic observations, trying to understand the role of mesoscale physical processes on the distribution and abundance patterns of species.

This study examined how riverine inputs, in particular sediment, influenced the community structure and trophic composition of reef fishes within Rio Bueno, north Jamaica. Due to river discharge a distinct gradient of riverine inputs existed across the study sites. Results suggested that riverine inputs (or a factor associated with them) had a structuring effect on fish community structure. Whilst fish communities at all sites were dominated by small individuals (<20 cm), diversity and total biomass were reduced with increased proximity to the river mouth. The abundance of all fishes, but particularly small-bodied, juvenile and herbivorous fishes was reduced in turbid water when compared to clear-water sites. Results strongly suggest that fluvial sediment inputs may play an important role in structuring fish assemblages even under intense fishing pressure.