Ease Of Capture Research Articles

Brown bear (Ursus arctos) foraging in a mosaic of spatially discrete and variable habitats over 25 years of shifting Pacific salmon densities

Many foraging models assume “perfect information” and “free movement” when describing predator foraging behavior, although this is rare in nature. Here, we quantified predation by brown bears ( Ursus arctos Linnaeus, 1758) on adult sockeye salmon ( Oncorhynchus nerka (Walbaum, 1792)) in a series of spatially proximate ponds that largely satisfied both assumptions. Salmon abundance varied among years, but pond area and depth were fixed, allowing us to examine interactions between prey abundance and habitat features. We applied versions of two models to 25 years of data on the number and proportion of salmon killed by bears, modifying these models to include habitat features and temporal variability. The functional response model with a year effect fit the data well, indicating bears could take almost all salmon in ponds when salmon were scarce, but bears were sated when salmon were abundant. The proportion of salmon killed by bears was similar across habitats after correcting for pond depth and area. Overall, bears foraged across all habitats but killed higher proportions of salmon in smaller and shallower habitats, consistent with ease of capture.

Development and validation of a real-world model to predict 1-year Level 3 (severe) hypoglycaemia risk in adults with diabetes (the iNPHORM study, United States).

We aimed to develop and internally validate a real-world prognostic model for Level 3 hypoglycaemia risk compatible with outpatient care in the United States. iNPHORM is a 12-month, US-based panel survey. Adults (18-90 years old) with type 1 diabetes mellitus or insulin- and/or secretagogue-treated type 2 diabetes mellitus were recruited from a nationwide, probability-based internet panel. Among participants completing 1 follow-up questionnaire(s), we modelled 1-year Level 3 hypoglycaemia risk using Andersen and Gill's Cox survival and penalized regression with multiple imputation. Candidate variables were selected for their clinical relevance and ease of capture at point-of-care. In total, 986 participants [type 1 diabetes mellitus: 17%; men: 49.6%; mean age: 51 (SD: 14.3) years] were analysed. Across follow-up, 035.1 (95% CI: 32.2-38.1)% reported ≥1 Level 3 event(s), and the rate was 5.0 (95% CI: 4.1-6.0) events per person-year. Our final model showed strong discriminative validity and parsimony (optimism corrected c-statistic: 0.77). Numerous variables were selected: age; sex; body mass index; marital status; level of education; insurance coverage; race; ethnicity; food insecurity; diabetes type; glycated haemoglobin value; glycated haemoglobin variability; number, type and dose of various medications; number of SH events requiring hospital care (past year and over follow-up); type and number of comorbidities and complications; number of diabetes-related health care visits (past year); use of continuous/flash glucose monitoring; and general health status. iNPHORM is the first US-based primary prognostic study on Level 3 hypoglycaemia. Future model implementation could potentiate risk-tailored strategies that reduce real-world event occurrence and overall diabetes burden.

Effect of Animal Stocking Density and Habitat Enrichment on Survival and Vitality of Wild Green Shore Crabs, Carcinus maenas, Maintained in the Laboratory.

The wide geographic distribution, large size and ease of capture has led to decapod crustaceans being used extensively in laboratory experiments. Recently in the United Kingdom decapod crustaceans were listed as sentient beings, resulting in their inclusion in animal care protocols. Ironically, little is known about how captive conditions affect the survival and general condition of wild decapod crustaceans. We used the green shore crab, Carcinus maenas, to investigate the effects of stocking density and shelter on survival and vitality indices during a 6 month period in the laboratory. Neither stocking density nor the presence of shelter affected survival. Stocking density also had no effect on the vitality indices (limb loss, claw strength, BRIX, righting time, leg flare and retraction). The presence of shelter did affect the number of limbs lost and the leg retraction response, but had no effect on the other vitality indices. All vitality indices changed, and mortality increased over time, independent of treatment: this became most apparent after 8 to 11 weeks storage in the laboratory. This decline in condition may have been due to repeated handling of the crabs, rather than the stocking conditions. In support of this, untracked, non-handled (control) individuals sustained a 4% mortality rate compared with 67% mortality in experimental crabs during the 6 month period. Although simple experimental monitoring of crabs with biweekly vitality tests only produced transient short-term stress events, the repeated handling over time apparently led to a cumulative stress and a deterioration in animal health. Bringing wild crustaceans into the laboratory and holding them, even with modest experimental manipulation, may result in high mortality rates. Researchers and animal care committees need to be aware that wild captive invertebrates will respond very differently to laboratory-bred vertebrates, and plan experiments accordingly.

A stakeholder-engaged approach to evaluating spawning aggregation management as a strategy for conserving bonefish (Albula vulpes) in Cuba.

Animals that congregate in large numbers to reproduce in spatially and temporally distinct locations are particularly susceptible to overexploitation. Many fishes form spawning aggregations that are intentionally targeted given ease of capture. Bonefish (Albula spp.) species aggregate to spawn and are culturally and economically important, but generally lack management such as spawning area protections to ensure that fisheries are sustainable. Here, we use Cuba as a case study to inform the development and refinement of management strategies for bonefish. Recommendations for the management of bonefish pre-spawning aggregations were based on international experiences, which have been adapted to the Cuban context from results of surveys and interviews with Cuban fisheries professionals and fishing guides. The achievability and feasibility of recommendations were further reviewed by additional experts in the field of fisheries, management and Cuban policy. The process revealed extensive data-limitations for bonefish fisheries and underscored the importance of including fishing guides, local ecological knowledge and the context of marine protected areas in Cuba for bonefish management. Recommendations include (1) initiating information exchange between Cuban management agencies and third-party institutions related to bonefish management; (2) utilizing local ecological knowledge to gather information, formulate management strategies and enforce regulations; (3) implementing spatial and temporal management measures for bonefish spawning sites; (4) using what is already in place, by protecting spawning sites in the context of existing marine protected areas; (5) collaborating with all stakeholders to manage bonefish spawning sites; and (6) reducing the commercial harvest of the species.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10641-022-01355-0.

Response to exploitation and life history characteristics of two Acanthurus fish species with divergent mating behaviour along the Kenyan coastline

In reef ecosystems, vulnerability to exploitation is species-specific and may vary with natural abundance, life history characteristics, or ease of capture. Therefore, understanding the growth parameters and exploitation rate of individual species is important, because application of a uniform management strategy in species with different responses or vulnerability to exploitation can be inappropriate. In this study, growth parameters (length at first maturity, length at optimum yield, asymptotic length, growth constant, and growth performance index) and mortality from two Acanthurus fish species were compared, to deduce whether differences in species-specific traits (spawning mating behaviour) could lead to differences in exploitation rate. Despite comparable estimates of the von Bertalanffy asymptotic length (L∞) in the two species [A. triostegus (27.9–29.6) and A. leucosternon (26.1–27.4)], the growth coefficient constant (K) estimates for A. triostegus (0.85–1.23) were almost three to fivefold higher than those of A. leucosternon (0.29–0.38), suggesting that A. triostegus attains its maximum length faster than A. leucosternon. Length at first maturity (Lm), length at optimum yield (Lopt), and exploitation rate (E) were also different between the two species, specifically indicating exploitation beyond the sustainable yield in A. triostegus but not in A. leucosternon. The finding of a higher exploitation rate in A. triostegus as compared to A. leucosternon could suggest that regardless of similar body sizes, the former is more susceptible to exploitation.

Modeling opportunistic exploitation: increased extinction risk when targeting more than one species

Extinction rates are increasing globally, and direct exploitation is an important driver. Many pathways have been proposed to explain how exploitation can lead to extinction. One of these proposed but understudied multispecies pathways is opportunistic exploitation, which occurs when a highly valuable but rare species is encountered and targeted during exploitation of a less valuable, but more common, target species. Using individual-based simulations of exploiters in a two-species spatial model, we contribute evidence which supports that opportunistic exploitation increases depletion when compared to single-species exploitation, and is as detrimental to the more valuable, rare species as the anthropogenic Allee effect (where price increases with rarity) and the Allee effect (where population growth declines at low abundance). The most important factors affecting the impact of opportunistic exploitation are gross revenue and abundance of the more common, less valuable species, while ease of capture and growth rate of the more common, less valuable species are less important. Thus, valuable but rare species are most at risk when harvested alongside low-value abundant species; this information is relevant for managers focused on protection of rare species in multispecies systems.

Predicting potential compliance of small-scale fishers in Brazil: The need to increase trust to achieve fisheries management goals

Many global management and conservation initiatives fail to prevent overfishing either because they do not plan for local engagement, surveillance, and enforcement, and/or because they fail to include alternatives for short-term losses. Thus, these initiatives do not gain support among fishers. In this study, we interviewed fishers to investigate their stated behavior toward fisheries regulations. We assessed possible (non)compliant behavior under scenarios where fishers would face a moratorium on some of their target species. Additionally, we investigated the consequences of such a moratorium on the food web if it were to lead to fishing alternative species. Using data from two Brazilian coastal sites, we found that younger fishers and those who demonstrated a trustworthy relationship with stakeholders were inclined to comply with the rules. The level of potential compliance also varied between the studied places, probably due to unidentified local idiosyncrasies. Fishers tended to trust community actors (e.g., the leader or head of the fishing community) more than institutional actors (e.g., environmental agencies). When fishers were asked why they would choose specific replacement species in the event of a moratorium, they most often cited expected profitability and ease of capture as reasons. Fishers also tended to say that they would replace endangered species with species in the same and/or lower trophic categories. We suggest working toward stronger stakeholder engagement, given that an overall sense of trust in a community appears to be an important asset toward successful management. Higher levels of trust could promote more transparency in the decision-making process, which could facilitate information dissemination, awareness, and the need for compliance. The mixed methods approach used here could help predict responses to new and existing management policies and support adaptive fisheries management.

Quality indicator selection for the Canadian Partnership against Cancer rectal cancer project: A modified Delphi study.

It is well established that (i) magnetic resonance imaging, (ii) multidisciplinary cancer conference (MCCs), (iii) preoperative radiotherapy, (iv) total mesorectal excision surgery and (v) pathological assessment as described by Quirke are key processes necessary for high quality, rectal cancer care. The objective was to select a set of multidisciplinary quality indicators to measure the uptake of these clinical processes in clinical practice. A multidisciplinary panel was convened and a modified two-phase Delphi method was used to select a set of quality indicators. Phase 1 included a literature review with written feedback from the panel. Phase 2 included an in-person workshop with anonymous voting. The selection criteria for the indicators were strength of evidence, ease of capture and usability. Indicators for which ≥90% of the panel members voted 'to keep' were selected as the final set of indicators. During phase 1, 68 potential indicators were generated from the literature and an additional four indicators were recommended by the panel. During phase 2, these 72 indicators were discussed; 48 indicators met the 90% inclusion threshold and included eight pathology, five radiology, 11 surgical, six radiation oncology and 18 MCC indicators. A modified Delphi method was used to select 48 multidisciplinary quality indicators to specifically measure the uptake of key processes necessary for high quality care of patients with rectal cancer. These quality indicators will be used in future work to identify and address gaps in care in the uptake of these clinical processes.

Does prey abundance affect prey size selection by the Eagle Owl (Bubo bubo)?

Optimal foraging theory predicts that in situations of high prey abundance, predators will select the largest ones if the cost of capture is similar. This relationship is not clear in species of large owls. We aimed to evaluate the selection by the Eagle Owl (Bubo bubo) of different body sizes of a profitable prey, the European Rabbit (Oryctolagus cuniculus). Evaluations were made in a semi-natural rabbit population with high rabbit availability (Los Melonares), and in two natural populations with different abundances of rabbit (low to high). In Los Melonares, we compared the size distribution of rabbits in the owl diet with the body size distribution of the rabbit population. In the natural populations, we compared the size of the rabbits in the owl diet with the abundance of rabbits. Results from Los Melonares showed that the Eagle Owl positively selected smaller rabbits (< 300 g) regardless of rabbits size distribution within the population throughout the year but such selection was only significant when the abundance of rabbits reached the highest levels. On the contrary, owls avoided rabbits belonging to the largest size class (> 900 g) throughout the year, being not significant in winter with low abundance of rabbits. In natural populations, smaller rabbits were included in the owl diet more frequently when rabbit abundance increased. Thus, Eagle Owl seemed to select the smallest rabbits, probably due to their higher vulnerability, ease of capture, their predictable location in areas surrounding warrens, and the lesser effort required to handle, consume and deliver to nestlings.

Diets of scaup occupying baitfish and sportfish farms in eastern Arkansas

Although not typically associated with eating fish, lesser scaup (Aythya affinis) and greater scaup (Aythya marila) have recently been reported consuming large quantities of bait- and sportfish produced on Arkansas commercial aquaculture facilities. During winters 2016–2017 and 2017–2018, we collected 529 lesser scaup and 19 greater scaup foraging on golden shiner (Notemigonus crysoleucas), fathead minnow (Pimephales promelas), goldfish (Carassius auratus), sunfish (Lepomis spp.), and other sportfish production ponds to investigate the diet composition of scaup. We compared lesser scaup diet between years, among temperature categories (Low, Medium, High), and among pond types using PERMANOVAs to investigate foraging dynamics. Lesser scaup diets differed between winters, and between Low and both Medium and High temperature categories. Only traces of fish were detected in scaup in winter 2016–2017, but fish comprised 18% of birds' overall diet in winter 2017–2018. Chironomidae was the most common prey item in lesser scaup during both winters, occurring in 86% and 68% of diets in winter 2016–2017 and 2017–2018, respectively. Chironomidae comprised 40% of lesser scaup diet by weight in winter 2017–2018, but 71% in winter 2016–2017. Similar to lesser scaup, Chironomidae was the most commonly occurring prey item in greater scaup, which occurred in 88% of the diets, or composed 74% of their overall diet. Fish comprised about 13% of the overall diet of greater scaup. We suspect that scaup increasingly exploited fish in colder winters, perhaps because of the birds' increased energy demands, prey availability, and ease of capture, or some combination of these.

Clothing color mediates lizard responses to humans in a tropical forest

AbstractIdentifying how ecotourism affects wildlife can lower its environmental impact. Human presence is an inherent component of ecotourism, which can impact animal behavior because animals often perceive humans as predators and, consequently, spend more time on human‐directed antipredator behaviors and less on other fitness‐relevant activities. We tested whether human clothing color affects water anole (Anolis aquaticus) behavior at a popular ecotourism destination in Costa Rica, testing the hypothesis that animals are more tolerant of humans wearing their sexually selected signaling color. We examined whether clothing resembling the primary signaling color (orange) of water anoles increases number of anole sightings and ease of capture. Research teams mimicked an ecotourism group by searching for anoles wearing one of three shirt treatments: orange, green, or blue. We conducted surveys at three different sites: a primary forest, secondary forest, and abandoned pasture. Wearing orange clothing resulted in more sightings and greater capture rates compared with blue or green. A higher proportion of males were captured when wearing orange whereas sex ratios of captured anoles were more equally proportional in the surveys when observers wore green or blue. We also found that capture success was greater when more people were present during a capture attempt. We demonstrate that colors “displayed” by perceived predators (i.e., humans) alter antipredator behaviors in water anoles. Clothing choice could have unintended impacts on wildlife, and wearing colors resembling the sexually selected signaling color might enhance tolerance toward humans.Abstract in Spanish is available with online material.

Polyandry and Polygyny in a Social Rodent: An Integrative Perspective Based on Social Organization, Copulations, and Genetics

Animal mating systems have fascinated biologists for thousands of years. Accurate descriptions of mating systems are nonetheless elusive, because social organization can be difficult to quantify, documentation of copulations is often challenging, many copulations do not produce offspring, and genetic assignments of parentage are usually expensive. From a 7-year study of colonial white-tailed prairie dogs (Cynomys leucurus) living under natural conditions in Colorado USA, we estimated the frequencies of polyandry (i.e., copulation with >2 males) and polygyny (i.e., copulation with >2 females) from three independent approaches: (1) determination of the number of males and females living in the same territory (social organization); (2) observations of copulations; and (3) genetic assignments of paternity from seven polymorphic microsatellites. For polyandry, behavioral observations and genetics indicate similar overall percentages (27%), but social organization indicates a much lower percentage (2%). For polygyny, behavioral observations indicate the highest overall percentage (84%), then social organization (59%), then genetics (46%). All three approaches show striking annual variation in the frequencies of polyandry and polygyny. Long-term studies that integrate behavioral and genetic insights provide a detailed view of a mating system, but feasibility will depend on ease of capture, visibility of copulations, length of mating season, research objectives, genetic variation, and finances.

Assessing Vulnerability of Fish in the U.S. Marine Aquarium Trade

The trade in coral reef fishes for aquariums encompasses over 1,800 species from over 40 exporting countries, yet the population status for most traded species is unknown and unevaluated. At the same time, these coral reef fishes face a growing number of threats and often occur in jurisdictions with limited management capacity and data. In response, we assess vulnerability to overfishing for 72 coral reef fishes popular in the aquarium trade for the United States – the top importer – from the top exporting countries (Indonesia and the Philippines). We use a data-limited assessment approach: productivity susceptibility analysis (PSA). PSA estimates relative vulnerability of species by assessing their biological productivity and susceptibility to overfishing. The most and least vulnerable stocks were differentiated by attributes related to the reproductive biology (e.g., breeding strategy, recruitment pattern, and fecundity), appropriateness, ease of capture (e.g., schooling and aggregation), and rates of natural mortality. Our analysis identifies several of the most and least vulnerable species popular in the aquarium fish trade. The species that ranked as least vulnerable to overcollection were Gobiodon okinawae, Nemateleotris magnifica, Gobiodon acicularis, Salarias fasciatus, Ptereleotris zebra, Gobiodon citrinus, Pseudocheilinus hexataenia, Chaetodon lunula, Nemateleotris decora, and Halichoeres chrysus. In contrast, the ten most vulnerable species were Chromileptes altivelis, Plectorhinchus chaetodonoides, Pterapogon kauderni, Premnas biaculeatus, Echidna nebulosa, Centropyge bicolor, Zebrasoma veliferum, Pomacanthus semicirculatus, Zebrasoma scopas, and Thalassoma lunare. In a data-limited context, we suggest how these vulnerability rankings can help guide future efforts for reducing vulnerability risk. In particular, species that are relatively high-vulnerability and high-volume are prime targets for research and aquaculture efforts, increased monitoring of collection and exports, species-specific stock assessments, and voluntary reductions by retailers and consumers to avoid overexploitation.

Prey-specific impact of cold pre-exposure on kill rate and reproduction.

Temperature influences biological processes of ectotherms including ecological interactions, but interaction strengths may depend on species-specific traits. Furthermore, ectotherms acclimate to prevailing thermal conditions by adjusting physiological parameters, which often implies costs to other fitness-related parameters. Both predators and prey may therefore pay thermal acclimation costs following exposure to suboptimal temperatures. However, these costs may be asymmetrical between predator and prey, and between the predator and different species of concurrent prey. We investigated whether thermal pre-exposure affected subsequent kill rate and predator fitness when foraging on prey that differ in ease of capture, and whether changes were primarily caused by predator or by prey pre-exposure effects. Specifically, we were interested in whether there were interactions between predator pre-exposed temperature and specific prey. Using the mesostigmatid mite Gaeolaelaps aculeifer as a generalist predator and the collembolans Folsomia candida and Protaphorura fimata as prey, we measured the impact of present temperature, predator pre-exposure temperature, prey pre-exposure temperature (all 10 or 20°C), prey species, and all interactions on prey numbers killed, predator eggs produced, and exploitation of killed prey in a full factorial design. Mites killed P.fimata in equal numbers independent of the presence of F.candida, but killed F.candida when P.fimata was absent. Mite kill rate and reproduction were significantly affected by mite pre-exposure temperature and test temperature, but not by prey pre-exposure temperature. Significantly more of the slower prey was killed than of the quicker prey. Importantly, we found significant synergistic negative interaction effects between predator cold pre-exposure and hunting prey of higher agility on predator kill rate and reproduction. Our findings show that the negative effects of cold and cold pre-exposure on kill rate and reproduction may be more severe when predators forage on quick prey. The study implies that predator cold exposure has consequences for specific prey survival following cold due to altered predation pressures, which in nature should influence the specific prey population dynamics and apparent competition outcomes. The findings exemplify how not only current but also preceding conditions affect ecological interactions, and that effect strength depends on the species involved.

An exploratory study of energy reserves and biometry as potential tools for assessing the effects of pest management strategies on the earwig, Forficula auricularia L.

Apple orchards are heavily treated crops and some sprayed insecticides are recognized to have toxic effects on non-target arthropods. Earwigs are important natural enemies in pip-fruit orchards and contribute to the biological control of aphids. In addition, due to their ease of capture and identification, they are an interesting potential bioindicator of the possible detrimental effects of different orchard management strategies. In this study, we measured the energy reserves and some morphological traits of Forficula auricularia L. sampled in apple orchards under management strategies (organic versus integrated pest management (IPM)). We observed a significant decrease in mass (22 to 27%), inter-eye width (3%), and prothorax width (2 to 5%) in earwigs from IPM compared to organic orchards. Energy body reserves also confirmed these results with a significant decrease of 48% in glycogen and 25 to 42% in lipid content in earwigs from IPM compared to organic orchards. However, the protein content was approximately 70% higher in earwigs from IPM than in organic orchards. Earwigs sampled in IPM orchards may adapt to minimize the adverse toxic effects of pesticide treatments using a large number of strategies, which are reflected in changes to their energy reserves. These strategies could, in turn, influence the population dynamics of natural enemies and impair their role in the biological control of pests in apple orchards.

Biometric: fingerprints protection

Biometric template gives a reliable solution to the hassle of user authentication in identity control systems. Numerous biometric technologies have been developed and correctly deployed around the world together with fingerprints, face, iris, palm–print, hand geometry and signature. Fingerprints are the most famous because of their ease of capture, uniqueness and remains over the years, as well as the low fee and maturity of sensors and algorithms. A biometric authentication scheme with template safety this is irreversible against almost all types of adversaries. If a biometric template inside the database of the system of someone is compromised that consequently would mean identity robbery of that individual. Maximum biometric systems which are presently in use, generally use a single biometric trait to set up identity, they may be referred to as uni–modal biometric systems which have some obstacles. Assurance of biometric template is basic for acceptability in light of the potential bargain of framework security and client’s protection. Similarly indispensable is examination of the security bestowed by the systems created to ensure the biometric template. A template protection scheme with provable protection and suited popularity overall performance has to this point remained elusive.

Can composite digital monitoring biomarkers come of age? A framework for utilization.

The application of digital monitoring biomarkers in health, wellness and disease management is reviewed. Harnessing the near limitless capacity of these approaches in the managed healthcare continuum will benefit from a systems-based architecture which presents data quality, quantity, and ease of capture within a decision-making dashboard. A framework was developed which stratifies key components and advances the concept of contextualized biomarkers. The framework codifies how direct, indirect, composite, and contextualized composite data can drive innovation for the application of digital biomarkers in healthcare. The de novo framework implies consideration of physiological, behavioral, and environmental factors in the context of biomarker capture and analysis. Application in disease and wellness is highlighted, and incorporation in clinical feedback loops and closed-loop systems is illustrated. The study of contextualized biomarkers has the potential to offer rich and insightful data for clinical decision making. Moreover, advancement of the field will benefit from innovation at the intersection of medicine, engineering, and science. Technological developments in this dynamic field will thus fuel its logical evolution guided by inputs from patients, physicians, healthcare providers, end-payors, actuarists, medical device manufacturers, and drug companies.

Fear no colors? Observer clothing color influences lizard escape behavior.

Animals often view humans as predators, leading to alterations in their behavior. Even nuanced aspects of human activity like clothing color affect animal behavior, but we lack an understanding of when and where such effects will occur. The species confidence hypothesis posits that birds are attracted to colors found on their bodies and repelled by non-body colors. Here, we extend this hypothesis taxonomically and conceptually to test whether this pattern is applicable in a non-avian reptile and to suggest that species should respond less fearfully to their sexually-selected signaling color. Responses to clothing color could also be impacted by habituation to humans, so we examine whether behavior varied between areas with low and high human activity. We quantified the effects of four T-shirt colors on flight initiation distances (FID) and on the ease of capture in western fence lizards (Sceloporus occidentalis), and we accounted for detectability against the background environment. We found no differences in lizard behavior between sites. However, lizards tolerated the closest approaches and were most likely to be captured when approached with the T-shirt that resembled their sexually-selected signaling color. Because changes in individual behavior affect fitness, choice of clothing color by people, including tourists, hikers, and researchers, could impact wildlife populations and research outcomes.

Traditional fisher perceptions on the regional disappearance of the largetooth sawfish Pristis pristis from the central coast of Brazil

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 29:189-200 (2016) - DOI: https://doi.org/10.3354/esr00711 Theme Section: Biology and ecology of sawfishes Traditional fisher perceptions on the regional disappearance of the largetooth sawfish Pristis pristis from the central coast of Brazil José Amorim Reis-Filho1, 2, 3,*, Renato H. A. Freitas4, Miguel Loiola1, 5, Luciana Leite6, Gabriel Soeiro3, Heigon H. Q. Oliveira7, Cláudio L. S. Sampaio8, José de Anchieta C. C. Nunes1, 2, Antoine O. H. C. Leduc1 1Programa de Pós Graduação em Ecologia e Biomonitoramento, Universidade Federal da Bahia, Campi Ondina, Salvador,BA 40.170-000, Brazil 2Laboratório de Ecologia Bentônica, Universidade Federal da Bahia, Campi Ondina, Salvador BA 40.170-115, Brazil 3Instituto de Educação, Ciência e Utilidade Sócio Ambiental (ECUS), Rio Vermelho, Salvador, BA 40.170-115, Brazil 4Laboratório de Biologia de Teleósteos e Elasmobrânquios (LABITEL), Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil 5Laboratório de Recifes de Corais e Mudanças Globais, Universidade Federal da Bahia, Campi Ondina, Salvador BA 40.170-115, Brazil 6Department of Geography, Downing Place, Cambridge CB2 3EN, UK 7Programa de Pós Graduação em Diversidade Animal, Campi Ondina, Salvador BA 40.170-115, Brazil 8Laboratório de Ictiologia e Conservação, Departamento de Engenharia de Pesca, Unidade de Ensino Penedo, Universidade Federal de Alagoas, Penedo, AL 57.200-000, Brazil *Corresponding author: amorim_agua@yahoo.com.br ABSTRACT: Overfishing is considered one of the main threats to the health of global marine fish populations. Elasmobranchs that are characterized by low reproductive outputs may be particularly sensitive to intense fishing pressures. The sawfishes stand out as a highly threatened group, due in part to their life history in shallow coastal waters and their ease of capture. In Brazil, sawfish populations are now virtually extinct and these declines have gone undocumented, leaving their precise causes and timing poorly understood. Here, based on ecological and fisheries knowledge of local fishers, we document the disappearance of largetooth sawfish Pristis pristis from 5 estuaries on the central Brazilian coast. Fisher knowledge, combined with an estuarine morphology perspective, revealed important insights on this species, along with a timeline of its decline. Furthermore, fishers’ accounts of the protracted decline revealed clear inter-estuary differences in the timing of population declines, potentially influenced by local geomorphological features. The onset of sawfish population decline appears to have been earlier in estuaries with a direct connection to the sea than in estuaries connected to an inner bay, occurring in the former case from the 1930s onward. A second wave of intensifying decline began in the 1970s in more structurally complex estuaries. Pressures from artisanal and modern fishery practices appear to have led to an earlier population decline in structurally less complex estuaries, while in larger and more complex ones this decline occurred decades later. The replacement of traditional by more modern fishing practices may have triggered the initial phase of local sawfish extinctions. KEY WORDS: Largetooth sawfish · Population decline · Overfishing · Estuarine morphology · Local ecological knowledge · Brazil Full text in pdf format Supplementary material NextCite this article as: Reis-Filho JA, Freitas RHA, Loiola M, Leite L and others (2016) Traditional fisher perceptions on the regional disappearance of the largetooth sawfish Pristis pristis from the central coast of Brazil. Endang Species Res 29:189-200. https://doi.org/10.3354/esr00711 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 29, No. 3. Online publication date: January 21, 2016 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2016 Inter-Research.

Multimodal biometric-information fusion using the Radon transform

This paper proposes multimodal biometric-based personal identification. Palmprint and fingerprint modalities are utilized in the proposed model due to the availability of more distinctive features and the ease of capture. Principle lines are the main discriminative features in the palmprint, whereas orientations of the ridge and valley structures are the main features by which to identify the fingerprint. To extract these features, the use of the Radon transform is proposed in this work. However, the Radon transform is sensitive to the orientation. In order to make the model rotation invariant and insensitive to noise, a normalization process is generally used. Here, a logarithm-based normalization process has been utilized in the proposed model. A Euclidean-based matching process that is invariant to the rotation has been used. The proposed model is applicable to low resolution images and is invariant to rotation, insensitive to noise, and has less computational complexity as compared to other models.