Implementation Of Management Measures Research Articles

Understanding the fishery dynamics and stock health of mahi-mahi Coryphaena hippurus (Linnaeus, 1758) from Indian coastal waters

This work delves into the mahi-mahi (dolphinfish) fishery along the Indian coast, noting itsdevelopmental stage precluding a full assessment. The analysis of population characteristicshighlights their inherent resilience, driven by early maturity, substantial fecundity and rapidgrowth rates. These traits collectively mitigate susceptibility to fishing pressure, ensuringthe maintenance of sizable spawning stock biomasses and recruitment. Through Kobeanalysis, it is determined that the present fishing mortality and biomass levels remain withinsafe thresholds, indicating absence of overfishing. However, regular monitoring is imperativeto swiftly implement management measures if necessary, safeguarding the sustainability ofthe mahi-mahi fishery in the long term. Keywords:Kobe plot, Population characteristics, Recruitment,Resilience, Spawning stock biomass

Pesticide water variability and prioritization: The first steps towards improving water management strategies in irrigation hydro-agriculture areas

The presence of pesticides in aquatic ecosystems poses significant risks to non-target organisms, necessitating monitoring and environmental risk assessment. This study aimed to evaluate the dynamics and environmental risk of pesticides in a hydro-agricultural area with intensive agricultural practices, in the Mediterranean region (South of Portugal). Seasonality and location influenced pesticide numbers and concentrations, with the highest levels observed during the dry season. Triazines, phenylureas, and organophosphates were the predominant pesticide classes, with terbuthylazine, bentazone, terbutryn, diazinon, and metolachlor exhibiting the highest detection frequencies (68 % to 72 %). Notably, 44 % of the quantified pesticides are no longer authorized in Portugal, with 33 % posing a high environmental risk. Some insecticides, including imidacloprid, methiocarb, and malathion, were occasionally detected at concentrations that posed high risks to the aquatic ecosystem (RQ ≥ 1). Irgarol, an algicide used in irrigation canals, presented a high risk in 91 % of the analysed samples.The study's distribution profile of pesticides revealed a significant transportation of these compounds from reservoirs to irrigation hydrants, establishing them as a secondary source of crop and environmental contamination. Additionally, the assessment of spatial distribution and environmental risk allowed for the identification of specific pollutants in different locations, prioritizing them based on their ecotoxicological risk to aquatic ecosystems. These findings reinforce the importance of implementing management measures at the level of hydro-agricultural areas, helping to stop the cycle of pesticide contamination. Only this type of strategy will make it possible to protect water quality, biodiversity and the health of citizens, contributing to the European Union's objectives of improving the condition of freshwater bodies and promoting the sustainable use of pesticides.

The spatio-temporal distribution of small-scale fisheries along the northern Panay Gulf, Philippines: Implications for management

The small-scale fisheries along the northern region of the Panay Gulf face a distinctive challenge as multiple communities compete for access to the same fishing areas and resources. In response, neighboring coastal municipalities implemented conventional management measures, such as Marine Protected Areas (MPAs) and seasonal closures, aiming to enhance the abundance of fisheries resources. However, these measures only imposed economic hardships on artisanal fishermen. To address this issue, a survey involving 135 informants from coastal barangays was conducted between June to November 2021. The study used semi-structured questionnaires and GPS data loggers to collect essential information on the spatial and temporal distribution of fishing activities and specific target catches. The integration of local knowledge played a crucial role in bridging critical data gaps within the study site, facilitating the identification of more effective management reforms. The findings revealed that traditional harvest locations for various gear types exhibited zonation patterns across the gulf. Fishing activities were strategically conducted in areas with available resources, often disregarding municipal fishing boundaries. Coordinated management strategies are deemed imperative due to the varying timing of seasonal closures among municipalities. On the other hand, the temporal analysis of fishing activities revealed peak seasons of fisheries resources, providing a basis for adjusting the selection of target species and the duration of seasonal closures. Interestingly, the existing management measures failed to reduce the annual fishing activities and were ineffective, contrary to popular claims. This outcome was primarily due to constant shifts in the types of fishing gear used and target catches between seasons, highlighting the displacement of exploitation. In conclusion, this study underscores the importance of aligning fisheries policies with the dynamic nature of small-scale fisheries. Unless these policies adapt to the evolving conditions of the sector, they are likely to remain ineffective in addressing issues faced by artisanal fishermen in the region.

Investigating the Determinants of Malaria Outbreak in Nono Benja Woreda, Jimma Zone, Ethiopia: A Case-Control Study.

Malaria is one of the most widespread infections worldwide, particularly in developing countries. Accordingly, Jimma Zone is one of the widely affected areas by malaria in Ethiopia. In 2020 woreda health offices have reported the possible malaria epidemic that needs further investigation. Accordingly, this study aims to characterize the scope, pinpoint determinants connected to the Nono Benja woreda malaria outbreak, and implement suitable public health management measures. A descriptive cross-sectional study was followed by an unmatched case-control study with a 1:1 ratio of cases to controls. The sample size of 136 individuals (68 cases and 68 controls) was used. The collected data was imported into Epi-data version 3.1 and analyzed using SPSS version 25.0. By doing multivariate logistic regression association was determined at 95% confidence intervals P value of 5%. A total of 687 instances were identified, giving an overall attack incidence of 1%. The assault rate ranged from 51.6 per 1000 people in Benja rural to 1.1 per 1000 people in Dhokonu Kebele. But there were no recorded deaths. Plasmodium falciparum and Plasmodium vivax were the major types of Plasmodium species reported. From independent variables absence of ITNS [AOR 3.98 (CI = 1.11-24.8)], residing in an unsprayed home [AOR = 3.83 (CI = 1.04-14.08], presence of stagnant water in residential area [AOR = 4.25, CI (1.37-12.24113.10)], and lack of awareness on malaria prevention [AOR = 8.28 (CI 2.31-29.73)] were significantly associated with Malaria outbreak. A number of factors, including lack of ITNS, lack of malaria health education, stagnant water, and IRS (indoor residual spray), were significantly linked with the occurrence of malaria outbreaks. The woreda health office should therefore provide ITNS to the community, use indoor residual spray, and disseminate health information regarding efficient and long-lasting malaria preventive and control techniques.

Abundance of Xanthium spinosum L. along the different land types and its impacts on invaded plant communities in North Shewa Zone, Ethiopia

A biological invasion is a form of biological pollution that is most likely more terrible than chemical pollution. Xanthium spinosum is one of the most invasive alien plant species. However, its abundance and impacts on invaded plant communities have not yet thoroughly studied. This study aimed to investigate the abundance and impacts of X. spinosum on invaded plant communities in the North Shewa Zone, Ethiopia. The study applied the quadrat method, sampling 80 main plots within 1 m2. Differences in mean cover-abundances of X. spinosum across various land types were compared using one-way-ANOVA followed by Tukey’s Honestly Significant Difference (HSD) Test. The results showed that roadsides and flooded areas exhibited the maximum mean cover-abundance of X. spinosum compared to farmland and rangeland. The number of plant species recorded was 106 in the control areas, compared to only 73 in the invaded areas. Hence, the number of plant species decreased by 31.13% in the infested area compared to the control. Thus, X. spinosum was among the factors contributing to the reduction of plant diversity, affecting the sustainability of biodiversity in the study areas. Therefore, implementing management measures against the spread of X. spinosum is to address the ongoing threat to biodiversity.

Regional blue and green water-saving potential and regulation paths for crop production: A case study in the Yellow River Basin

A comprehensive assessment of the regional water-saving potential (WSP) for crop production is the foundation for setting targets, formulating strategies, and implementing management measures for agriculture. Water footprint (WF) for crop production is a well-known indicator of blue and green water consumption and an effective tool for evaluating blue and green WSP in crop production. The WSP evaluations based on crop WF primarily rely on crop redistribution (CR) and the crop WF benchmark (WFB). The CR can be completed relatively quickly, but the WSP is limited. In contrast, reaching an area’s maximum WSP is possible with WFB, but it requires long-term and multi-aspect inputs. However, existing evaluations of regional crop WSP are often based on a single methodology, and the results are various, which confuse the policymakers at times. This study estimated both blue and green WSP of wheat and maize based on two approaches—crop redistribution (CR) and crop water footprint benchmark (WFB)—at the county level in the Yellow River basin (YRB) in different hydrological years. The WSP was 7–11% based on CR, whereas 17–24% based on the crop WFB. The green WSPs were larger than blue WSPs. Over half of counties had larger WSP based on the WFB. These values vary with the crop, region, and hydrological year. The analysis emphasises the importance of considering both blue and green water, and quantitatively comparing different water-saving methods when evaluating regional crop WSP.

Quantifying interspecific and intraspecific diversity effects on ecosystem functioning.

Rapid environmental changes result in massive biodiversity loss, with detrimental consequences for the functioning of ecosystems. Recent studies suggest that intraspecific diversity can contribute to ecosystem functioning to an extent comparable to contributions of interspecific diversity. Knowledge on the relative importance of these two sources of biodiversity is essential for predicting ecosystem consequences of biodiversity loss and will aid in the prioritization of conservation targets and implementation of management measures. However, our quantitative insights into how interspecific and intraspecific biodiversity loss affects ecosystem functioning and how the effects of these two sources of biodiversity loss on ecosystem functioning can be compared are still very limited. To facilitate such quantitative insights, we extend the interspecific Price partitioning method originally introduced by J. Fox in 2006, previously used to quantify species loss and gain effects on ecosystem functioning, to also account for the effects of intraspecific diversity loss and gain on ecosystem function. Using this extended version can yield the quantitative information required for answering research questions addressing correlations between interspecific and intraspecific diversity effects on ecosystem functioning, identifying interspecific and intraspecific groups with large effects, and assessing whether intraspecific diversity can compensate for losses in interspecific diversity. Applying this method to carefully designed experiments will provide additional insights into how biodiversity loss at different ecological levels contributes to and changes ecosystem functioning.

A comprehensive operation and maintenance assessment for intelligent highways: A case study in Hong Kong-Zhuhai-Macao bridge

The integration of business flow status updates creates a framework for dynamically evaluating operation and maintenance activities, and that assessment is an essential component of achieving intelligent management and control. Highway managers have relied on the operation and maintenance system to integrate business initiatives that improve performance at the organizational and individual levels recently. There are a few studies considering the actual accident or road infrastructure to improve the quality of the highway, but they ignore the power of operation and maintenance (O&M) management involving multiple parties. Furthermore, there is no comprehensive scale to measure the effect of implementing management measures. Therefore, this paper aims to develop a comprehensive multidimensional evaluation framework that considers the integration of the actual business and the objective environment from four aspects: worker, equipment, environment, and management measures. The proposed framework evaluates the current O&M performance with the improved Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) model, which is used to interpret the comprehensive index results, and highlights the differences and variations of the factors that influence the evaluation results based on the deconstruction analysis. We utilize a mixed dataset of the Hong Kong-Zhuhai-Macao Bridge (HZMB) for two consecutive years to evaluate the performance of each month. The results show that the evaluation framework can effectively measure the O&M performance, and “Worker- Quality of daily inspection work” was identified as the most critical factor affecting the O&M performance. In particular, a comprehensive multiparty operational status assessment helps to review and revise current management strategies for targeted improvements that will enhance the safety and quality of management.

The 5C's of soil security guiding realization of ecosystem services in line with the UN-SDGs

The UN Sustainable Development Goals (SDGs) have a deadline of 2030 so, restricting attention to agriculture, development and implementation of management measures, aimed at reaching the goals, is urgent. Even though the current 159 very broad targets and 234 indicators for the SDGs don't mention soils, soils play a key role when addressing indicators 2.4.1 and 15.3.1 aimed at “sustainable agriculture” and “degraded land”, by introducing operational methods to assess soil health and interdisciplinary ecosystem services in line with the SDGs. Application of the soil security concept, combining biophysical and socioeconomic approaches, is essential for sustainability research where dominant socioeconomic considerations by stakeholders should frame the biophysical analysis. If stakeholders don't embrace SDG-inspired innovative management, nothing will materialize in the real world. Much research is still needed to address inter- and transdisciplinary sustainability issues but a plea is made at this critical point in time to also apply a relatively straightforward and pragmatic research approach, essentially based on available data and methods, to assess ecosystem services, defining indicators and thresholds, in line with five key SDGs. Reference is made to an exploratory Dutch case study in a:”Living Lab”. The National Soil Health Institute in the US has already pioneered such a pragmatic approach by first emphasizing socioeconomic aspects and by incorporating the soil health analysis in regenerative farm management that is recognized by farmers. But the five ecosystem services will still have to be assessed here to maintain the link with the SDGs and the policy arena. The 5C's of soil security apply very well at farm level. The soil science profession will benefit from showing specific examples of “Living Labs” where five thresholds of ecosystem services are met, creating: ”Lighthouses” showing examples of achieved sustainable development in which soil health plays a key role as demonstrated by specific measurements.

A common statement on anthropogenic hybridization of the European wildcat (Felis silvestris)

Preserving natural genetic diversity and ecological function of wild species is a central goal in conservation biology. As such, anthropogenic hybridization is considered a threat to wild populations, as it can lead to changes in the genetic makeup of wild species and even to the extinction of wild genomes. In European wildcats, the genetic and ecological impacts of gene flow from domestic cats are mostly unknown at the species scale. However, in small and isolated populations, it is known to include genetic swamping of wild genomes. In this context, it is crucial to better understand the dynamics of hybridization across the species range, to inform and implement management measures that maintain the genetic diversity and integrity of the European wildcat. In the present paper, we aim to provide an overview of the current scientific understanding of anthropogenic hybridization in European wildcats, to clarify important aspects regarding the evaluation of hybridization given the available methodologies, and to propose guidelines for management and research priorities.

Chloeia rozbaczyloi, a new species of polychaete (Archinominae: Amphinomidae) and first record of the family for the Nazca Ridge, southeastern Pacific Ocean

The amphinomid polychaete Chloeia rozbaczyloi sp. nov., collected from seamounts of the Nazca Ridge (NR), northwest of Desventuradas islands, southeastern Pacific Ocean, is described. The new species was observed on only two of seven seamounts surveyed in the area (25.079°S, 82.006°W, and 25.408°S, 81.769°W, ∼220 m depth), being abundant on one of them.Specimens were observed under optical and scanning electron microscopes, and DNA was sequenced (COI, 16S, 18S, and 28S nucleotide alignment). Chloeia rozbaczyloi sp. nov. belongs to the venusta group of Chloeia and is distinguished mainly by: (i) the chromatic pattern of the dorsum (with a single middorsal dark band) and the caruncle (with 16–20 vertical folds and 12 to 14 black spots posteriorly decreasing in diameter), (ii) by the bi-annulated dorsum of the first ten chaetigers, each with a bean-shaped anterior pseudosegment, (iii) long neuropodial cirri, with a short ceratophore, at chaetiger 2 and reaching chaetiger 6, and (iv) bipinnate branchiae from chaetiger 4, with seven to nine lateral branches arising from the primary axis, each possing five pinnules; branchiae change progressively in size to the posterior end. The ciliated margin of the accessory dorsal cirri suggests a respiratory function that might be relevant considering that both seamounts in which the species was observed could be influenced by low-oxygen waters. DNA results further support that C. rozbaczyloi sp. nov. differs from the other five congeneric taxa (C. bimaculata, C. flava, C. parva, C. pocicola, and C. viridis) for which genetic information is available.This finding constitutes the first report of the genus for Chilean waters, increasing the number of species of Amphinomidae in this area to seven. It also confirms the presence of the family in the NR and increases the number of Chloeia species in the world to 43.The seamounts where the new species have been collected are within the newly created offshore Nazca-Desventuradas Marine Park. Information on potentially unique and endemic species, such as the one discussed here, is of utmost importance to preserve special ecological units, address ecosystem services, and implement management measures in the area.

Comparative Population Dynamics of Schizothorax wangchiachii (Cyprinidae: Schizothoracinae) in the Middle Reaches of the Yalong River and the Upper Reaches of the Jinsha River, China.

To explore the differences in the growth characteristics and population dynamics of Schizothorax wangchiachii populations in the Jinsha River (JSR) and the Yalong River (YLR), samples were collected in the upper reaches of the JSR (n = 230) from 2019 to 2020 and the middle reaches of the YLR (n = 187) from 2017 to 2018. In the JSR and YLR populations, the age range was 11 and 12 years old, respectively, and the best growth equation was the Von Bertalanffy equation. The comparative analysis of the two populations showed that the growth coefficient, initial sexual maturity age and age at first capture of the YLR population were greater than those of the JSR population. Comparing the mortality rates of the two groups, we found that the YLR population had the higher female mortality rate (0.658 years-1) and the lower male mortality rate (0.453 years-1). Our assessment of the three natural mortality rates showed that the Fcur of both male and female populations was greater than F25%, indicating that both populations were in an overexploited state. Therefore, we suggest considering the two groups as separate protection units and implementing management measures such as ecological regulation, restoration of tributary habitat and strengthening of fishing ban monitoring to protect their resources.

Environmental aspects and management preferences: A case study of small pelagic fisheries in the Crucita parish of the Portoviejo canton

The extractive context of artisanal fishing in Ecuador is very broad and diverse considering the different fishing equipment that is used to capture a very varied set of species. As part of this broad sector, there is a small pelagic fishery, which is in the Crucita parish of the Portoviejo canton and is a long-standing and economically very relevant resource for the community. The objective of this article is to analyze the environmental and management aspects of this fishery as aspects relevant to achieving sustainable exploitation. To this end, information was collected from the beneficiaries of the purse-seine fishing fleet with the use of a structured questionnaire. The results revealed that there is widespread ignorance of the environmental aspects that affect the conservation of ecosystems and marine bioresources. On the other hand, the fishermen are aware of a general need to implement management measures that guarantee the sustainability of their fishing. However, they consider that the current regulations are not adapted to the current local context. Finally, from the perspective of those involved, the implementation of minimum capture sizes as a management measure could guarantee the sustainable capture of the species.

MODELING OF THE NITROGEN PARAMETER OF THE PARAÍBA DO SUL RIVER USING THE QUAL-UFMG METHOD

Background: Due to population growth and increased use of water resources, there has been a need to implement management measures to control and monitor river parameters. Aims: This study aims to demonstrate the application of mathematical modeling using the QUAL-UFMG model for studying nitrogen concentration in the Paraíba do Sul River located in Volta Redonda. Methods: Through mathematical modeling, it is possible to identify areas of greater impact, evaluate the effectiveness of control measures, and propose a strategy to improve water quality and preserve the balance of local aquatic ecosystems. Results: The results obtained during the study showed that the nitrogen parameters and their derivatives are within the pre-established limits set by CONAMA. Discussion: During the modeling, it was observed that there is a tendency for nitrate levels to increase along the points, indicating good self-purification of the river. Organic nitrogen values increase along the points, which is due to the contribution of sewage discharge along the course of the river, as organic nitrogen and ammonia have a physiological origin in domestic sewage. Conclusions: Through the QUAL-UFMG model, it was possible to validate the conducted analyses and create future projections of the water quality in the Paraíba do Sul River along the studied points.

Construction of enterprise business management analysis framework based on big data technology

With the development of science and technology, people have added a new concept big data, which is the most concerned topic at present, and has also brought great changes to the business management environment of enterprises. At present, most of the business administration work of enterprises is mainly based on human resources, and the enterprise activities are managed through the professional knowledge of relevant management personnel. However, due to human subjective factors, the management effect is unstable. Therefore, this paper designed an enterprise business management system based on intelligent data technology, and constructs an enterprise business management analysis framework. The system can help managers to make the best plan when implementing management measures, improve the efficiency of production management, sales management, financial management, personnel organization structure management, etc., so as to make business management more scientific. The experimental results showed that the improved C4.5 algorithm in the business management system proposed in this paper reduced the fuel consumption cost of shipping company A by 220.21 yuan at least and 11050.12 yuan at most, which reduced the fuel consumption cost of the company's five voyages by 13349.09 yuan in total. This indicates that the improved C4.5 algorithm has higher accuracy and better time efficiency compared to traditional C4.5 algorithms. At the same time, the optimized ship speed management effectively reduces the fuel consumption cost of flights and improves the company's operating profit. The article proves the feasibility of improved algorithms based on decision trees in enterprise business management systems, and has a good decision support effect.

Forage Supply–Demand Assessment and Influencing Factor Analysis from the Perspective of Socio-Ecological System: A Case Study of Altay Prefecture, China

The provision and utilization of grassland resources connect grassland ecosystems and pastoral society. Revealing the mechanism behind the forage supply–demand relationship and balancing forage supply and demand is essential in pastoral socio-ecological systems. Taking Altay Prefecture as the case study, this study quantified the dynamics of natural forage supply, artificial supplemental forage, and forage demand. The ratio of forage supply to demand was calculated in the traditional grazing scenario and the grazing prohibition and supplemental feeding scenario. The results showed that during 2001–2018, the forage supplied by natural grasslands fluctuated, with the highest and lowest values in 2013 and 2008, respectively. The artificial supplemental forage increased at a higher rate in 2011–2018 than in 2001–2010. The overall trend of forage demand was upward, at approximately 2.98 × 104 t/a. The ratio of forage supply to demand decreased in the traditional scenario with an average value of 0.4717 and increased in the grazing prohibition and supplemental feeding scenario with an average value of 0.8289. The influencing factors were analyzed from the perspective of the interactions between the socio-ecological system elements, and the forage supply–demand relationships were conceptualized based on the social–ecological system framework. This study concludes that natural grasslands cannot entirely meet the increasing forage demand without artificial supplemental forage. The increasing artificial supplemental forage has promoted a balance between forage supply and demand, indicating an optimized grassland utilization pattern. The factors that affect forage supply–demand relationships are interrelated, and a holistic perspective should be adopted when implementing management measures.

Soil quality assessment of different land use systems of peri-urban - rural landscape of Deccan plateau, hot semi-arid agro-ecosystem

ABSTRACT Soil quality assessment is important for arable land, particularly in the vicinity of urban areas. The research was carried out to determine the quality of soil that has been farmed for different land uses. Geo-referenced 200 surface soil samples were collected from agriculture, horticulture, flower and plantation land-uses, and were analyzed for soil texture and nutrients, of which pH, OC, N, P2O5, K2O, Mn, Cu, Ca, and dehydrogenase activity (DHA) were found statistically significant and were chosen for principal component analysis (PCA). Based on the level of significance from PCA only five variables (pH, K2O, Cu, Ca, and DHA) were retained for minimum data set and linear scoring functions were used to provide unit-less scores for the selected data sets, which were then integrated into a soil quality index (SQI). Plantation land use had the lowest (SQI) of 0.51, whereas agriculture land use had the highest SQI (0.55) and was comparable to flower and horticultural land uses (0.53). The SQI of agriculture land was found better than the plantation land use in nearly all of the quality indicators evaluated. As a result, implementing management measures that improve soil quality, such as OC, is critical for sustainable agricultural production.

Determination of new glucocorticoid called clobetasol acetate in cosmetics by ultra performance liquid chromatography-tandem mass spectrometry

At present, new prohibited substances are becoming more common illegal additions in cosmetics. Clobetasol acetate is a new glucocorticoid, which is not covered in the current national standards and is a homologue of clobetasol propionate. A method was established for the determination of clobetasol acetate as a new glucocorticoid (GC) in cosmetics by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Five common cosmetic matrices were suitable for this new method: creams, gels, clay masks, masks and lotions. Four pretreatment methods were compared: direct extraction by acetonitrile, PRiME pass-through column purification, solid-phase extraction (SPE) purification, and QuEChERS purification. Further, the effects of different extraction efficiencies of the target compound, such as extraction solvents and extraction time, were investigated. The MS parameters, such as ion mode, cone voltage and collision energy of ion pairs of the target compound, were optimized. The chromatographic separation conditions and response intensities of the target compound in different mobile phases were compared. Based on the experimental results, the optimal extraction method was determined to be direct extraction, wherein the samples were vortex dispersed with acetonitrile, ultrasonic extraction over 30 min and filtered by a 0.22 μm organic millipore filter, and then the samples were detected by UPLC-MS/MS. The concentrated extracts were separated on a Waters CORTECS C18 column (150 mm×2.1 mm, 2.7 μm), where the water and acetonitrile were used as the mobile phases for gradient elution. The target compound was detected with the multiple reaction monitoring (MRM) mode under electrospray ionization and positive ion scanning (ESI+). Quantitative analysis was performed by matrix matching standard curve. Under the optimum conditions, the target compound had good linear fitting in the range of 0.9-37 μg/L. The linear correlation coefficient (R2) was greater than 0.99, the limit of quantification (LOQ) of the method was 0.09 μg/g and the limit of detection (LOD) was 0.03 μg/g for these five different cosmetic matrices. The recovery test was conducted under three spiked levels: 1, 2 and 10 times of LOQ. The recoveries of the tested substance were between 83.2% and 103.2% in these five cosmetic matrices, and the relative standard deviations (RSDs, n=6) were between 1.4% and 5.6%. This method was used to screen cosmetic samples of different matrix types, and a total of five positive samples were found, in which the content range of clobetasol acetate was from 1.1 to 48.1 μg/g. In conclusion, the method is simple, sensitive and reliable, and is suitable for high-throughput qualitative and quantitative screening, and the analysis of cosmetics with different matrix types. Moreover, the method provides crucial technical support and a theoretical basis for the establishment of feasible detection standards for clobetasol acetate in China, as well as for the control of the compound in cosmetics. This method has important practical significance to implement management measures of illegal additions in cosmetics.

Parameters of the Spondylus limbatus GB Sowerby II, 1847, population in the Central-West Gulf of California, Mexico

ABSTRACT The main Spondylus limbatus population parameters were estimated based on the analysis of individual growth and reproductive aspects of specimens collected monthly (n = 30) from January to December 2009 in the fishing area of Agua Verde, Gulf of California. The size structure determined from shell measurements was 82–167 mm and the direct reading of shell sections indicated ages of 1–14 years. The data were adjusted to the von Bertalanffy, Gompertz, logistic, Richards and Schnute (Type 1) growth models. The von Bertalanffy model provided the best fit to describe individual growth in this species (SH∞ = 142.7 mm, k = 0.47, t0 = −0.20 years). The spawning season was determined through gonadal histology, and the size and age at sexual maturity through a logistic model. Reproductive activity occurred from March to September, with spawning peaks in July and August. The size and age at sexual maturity were 10.8 mm and 2.7 years, respectively. This information provides the necessary knowledge to implement management measures in the area. We recommend independent studies to establish management measures for each fishing area.

Fishing activity in the Atlantic Moroccan Ocean: Mathematical modeling and optimal control

As it spans the Mediterranean sea and the Atlantic Ocean on the north and west respectively, Morocco is characterized by its marine sources’ diversity. Fishing Activity is considered to be the backbone of the country’s economy. the process of structuring the exploited population, and the marine environment are two major fields that the kingdom must understand to implement management measures to sustain the equilibrium of national fisheries and marine sources. Here, we have built a discrete-time model to describe the dynamic of fishing of two small pelagic species on the Atlantic Coast. The equilibrium between marine population and fishing effort, and maximizing profit are what the control parameter proposed have to achieve. We use a discrete version of Pontryagin’s principal maximum to calculate the optimal system. The numerical simulation is carried out using Matlab.