Port Samples Research Articles

Phytoplankton Saprobity as Pollution Bioindicator: A Study of Genera Chaetoceros in Port of Tanjung Emas Waters, Semarang

Water fertility is an assessment of the condition of organism diversity in relation to aquatic ecosystems. PTES (Port of Tanjung Emas, Semarang) is a major port in Java Sea waters and a domestic port for commercial vessels. Its water condition is influenced by the activities of both commercial and fishing vessels. This research applied a descriptive method with cluster sampling, including a group of samples in the port pool and samples from outside the port pool as a control station (comparator). The research aimed to analyze pla nkton fertility through the analysis of plankton abundance (N) and analyze factors that support the fertility of the waters, such as physicochemical parameters. In this research, diatoms ( Bacillariophyceae ) were found as a class that dominated in the waters with a dominance rate of 95%, meaning that the waters were in β-mesosaprobic condition (moderately polluted). The novelty of this research was the finding of toxic Chaetoceros , which dominated in the waters, resulting in the disappearance of other genera and lower organism abundance and diversity at a higher level. This abundance was a bioindicator that triggered heavy pollution (α-mesosaprobic). Regression analysis showed that phytoplankton abundance was determined by brightness, nitrate, turbidity, and zooplankton abundance. Using factor analysis, there were five factors that affected the total saprobic index (TSI); the largest factor was influenced by the first components (41.49%), including salinity, brightness, temperature, pH, DO, nitrate, and SI. Keywords: Port of Tanjung Emas, water fertility, total saprobic index, factor analysis, physicochemical parameters. https://doi.org/10.55463/issn.1674-2974.50.4.11

Plankton diversity in Anthropocene: Shipping vs. aquaculture along the eastern Adriatic coast assessed through DNA metabarcoding

Coastal ecosystems globally are exposed to the most pervasive anthropogenic activities, caused by a suite of human infrastructure and enterprises such as shipping ports, aquaculture facilities, fishing, and tourism. These anthropogenic activities may lead to changes in ecosystem biodiversity, followed by loss of ecosystem functioning and services. Shipping industry and aquaculture have also been recognized as the main vectors for introduction of marine non-indigenous species (NIS) worldwide. In this study, we used DNA metabarcoding-based methods to investigate plankton biodiversity under varying anthropogenic pressures (shipping and bivalve aquaculture) along the eastern Adriatic coast (the northernmost part of the Mediterranean Sea). Our comparative assessment revealed similar community structures among investigated coastal locations (Northern, Central and Southern Adriatic). When the whole plankton communities were considered, they did not differ significantly between port and aquaculture sites. However, the proportion of the unique zOTUs in the port samples was remarkably higher than that in aquaculture sites (40.5% vs 8.2%), indicating that port areas may receive higher abundance and species richness of NIS than aquaculture sites. Further important difference between the two types of anthropogenically impacted habitats was a high abundance of three notorious invaders – M. leidyi, M. gigas, and H. elegans in late summer at the aquaculture site in Northern Adriatic. Therefore, the plankton community of the area is under pressure not only from aquaculture activities, but also establishment of NIS. Port areas are probably under greater introduction pressure from NIS, but aquaculture sites may experience greater community changes due to their establishment.

Remediation of mining soils by combining Brassica napus growth and amendment with chars from manure waste

Mining activities lead to important physical, chemical and biological effects on soil properties, generating severe impacts in the establishment and maintenance of vegetation. Assisted phytoremediation can be considered an environmentally friendly approach for soil remediation. In this study, two mining soils (PORT and GAM) were treated with 10%, by mass, of the following amendments: manure biochars prepared at 450 °C (BMW450) and 600 °C (BMW600), hydrochars prepared by hydrothermal carbonization (HTC) of manure at 190 °C (HWM190) and 240 °C (HMW240) and manure waste (MW). Brassica napus was used as a phytoextraction species. After 45 days of plant growth, soil samples were widely characterized, including microbial biomass carbon, enzymatic activity and metal content. In addition, plant biomass production, bioconcentration factor, translocation factor and metal uptake were determined. Experimental results showed that addition of biochars improved the As uptake by Brassica napus in both soils but just in the roots increasing bioconcentration factor between 22.1 and 39.5% for GAM soil and between 28.6 and 53.4% for PORT soil. Brassica napus cannot be considered as Zn accumulator in GAM soil samples and in the case of PORT samples, only the addition of BMW600 and HMW240 enhanced the phytoextraction process of Zn on the roots. Soil enzyme activity improved in hydrochar amended soils.

Indoor Plumbing Drains Are Important Sources for Invasive Fusariosis in Patients with Hematological Disorders: Culture-Based and Metagenomic Analysis

Despite the advances in antifungal drugs, the number of invasive fusariosis (IF) has been increasing in patients with hematological disorders, especially hematopoietic stem cell transplantation (HSCT) patients. IF is still a severe infection and refractory to treat because Fusarium is naturally resistant to most of the antifungal drugs. Therefore, prior to infection, avoidance of contact with Fusarium would be critical in immunocompromised patients. However, little is known about the source of Fusarium infection. The purpose of this study is to investigate the epidemiology of IF in patients with hematological disorders in Japan and to find out the infectious source of Fusarium and the relationship between Fusarium species isolated from clinical samples and the ones from environment using culture-based and metagenomic methods. In our center, a total of 99 clinically isolated Fusarium were stored and maintained. They were obtained from hospitals in 33 prefectures in Japan. 50 and 49 strains were recovered from IF patients and superficial fusariosis (SF) patients, respectively. In this study, we analyzed 42 IF cases which developed in patients with hematological disorders. The most common underlying disease was AML (35.7%), followed by ALL (23.8%). About 60% of the patients received HSCT, and most of them became infected with Fusarium in the early phase after HSCT (within eight weeks). This result indicated that IF infection mostly occurred in indoor environments. As the next step, we performed the surveys in indoor environments such as air and plumbing drains in medical institutions and residences to figure out the source of infection. Few Fusarium species were collected from air samples. From the indoor air, we collected 142 filamentous fungi isolates. Only 2/142 strains (1.4%) were Fusarium species (Fusarium fujikuroi species complex 1, F. nisikadoi 1). In contrast, among the 72 drain port samples collected from 6 medical institutions (hematology wards, including bone marrow transplantation units, and ICU/NICU) and 15 residences, Fusarium species were positive at 26 (36.1%) sampling points. One hundred and eight filamentous fungi were isolated from the drain samples, and 29/108 isolates (27%) were Fusarium species. In details, 20 strains were Fusarium solani species complex (F. petroliphilum 7, F. keratoplasticum 4, F. sensu stricto 4, F. falciforme 1, others 4) and nine strains were Fusarium oxysporum species complex. Interestingly, the FSSC compositions of drain port samples were similar to those of IF samples from patients with hematological disorders and different from those of SF samples. In contrast, no Fusarium strains were detected in the places where the regular sink-cleaning was performed. Likewise, the samples for the metagenomic analysis were obtained in the places where the culture samples were collected. DNA extraction from samples was performed by the PowerLyzer Powersoil Kit (QIAGEN, Hilden, Germany). Fungal ITS regions were amplified with modified ITS1F and ITS2 primer set and sequenced with Illumina Miseq platform. After filtering and denoising, we were able to analyze 8 air samples and 23 drain samples (10 culture-positive samples and 13 culture-negative samples). It is also revealed that a lot of Fusarium live indoor plumbing drains but few Fusarium spp. inhabit indoor air (less than 0.1%). In summary, we investigate the epidemiology of IF in patients with hematological disorders in Japan and the distribution of Fusarium species in indoor environments. Our survey has demonstrated that a lot of Fusarium inhabits the indoor plumbing drains, not the indoor air using the culture-based and metagenomic methods. The similarity of FSSC distribution between the drain samples and causative species of IF cases indicated that the indoor plumbing drains would be potential sources of IF infection. We suggested that regular sink-cleaning was critical to prevent patients with hematological disorders from Fusarium infection. Disclosures No relevant conflicts of interest to declare.

Retrospective eDNA assessment of potentially harmful algae in historical ship ballast tank and marine port sediments.

Microalgal bloom events can cause major ecosystem disturbances, devastate local marine economies, and endanger public health. Therefore, detecting and monitoring harmful microalgal taxa is essential to ensure effective risk management in waterways used for fisheries, aquaculture, recreational activity, and shipping. To fully understand the current status and future direction of algal bloom distributions, we need to know how populations and ecosystems have changed over time. This baseline knowledge is critical for predicting ecosystem responses to future anthropogenic change and will assist in the future management of coastal ecosystems. We explore a NGS metabarcoding approach to rapidly identify potentially harmful microalgal taxa in 63 historic and modern Australian marine port and ballast tank sediment samples. The results provide a record of past microalgal distribution and important baseline data that can be used to assess the efficacy of shipping guidelines, nutrient pollution mitigation, and predict the impact of climate change. Critically, eDNA surveys of archived sediments were able to detect harmful algal taxa that do not produce microscopic fossils, such as Chattonella, Heterosigma, Karlodinium, and Noctiluca. Our data suggest a potential increase in Australian harmful microalgal taxa over the past 30years, and confirm ship ballast tanks as key dispersal vectors. These molecular mapping tools will assist in the creation of policies aimed at reducing the global increase and spread of harmful algal taxa and help prevent economic and public-health problems caused by harmful algal blooms.

Composition of Ballast Water from Ships Arriving at Kertih Port, Malaysia with Observations on Port and Offshore Waters, and Notes on Settlement Patterns of Fouling Organisms

We investigated plankton composition and water quality of ballast water from seven international ships docked at Kertih Port, Malaysia. Coscinodiscophyceae and cyanobacteria were the dominant phytoplankton found in ballast water samples, whereas copepod nauplii, Oithona sp., Microstella sp. and Paracalanus sp. were the dominant zooplankton. The densities for both phytoplankton and zooplankton in ships’ ballast and port waters were higher than those of offshore samples. All water quality parameters (except Cr) of port samples were within the safety levels prescribed for ports, oil and gas fields (Class 3) by the Malaysia Marine Water Quality Criteria Standard. The study of fouling organisms using PVC panels revealed that brown algae covered 87–95% of the panels’ surface area but they were subsequently succeeded by barnacles, bivalves and red encrusting algae. Barnacle recruitment, however, was greatly influenced by crab predation which left behind a high percentage cover of barnacle bases as calcareous deposits on panels.

Bacterial colonization of peripheral intravenous cannulas in a tertiary care hospital: A cross sectional observational study

BackgroundThe use of intravenous (IV) cannulas is an integral part of patient care in hospitals. These intravenous cannulas are a potential route for microorganisms to enter the blood stream resulting in a variety of local or systemic infections. Studies showing the actual prevalence of colonization of peripheral IV cannulas and its role in BSI are lacking. Hence, this study was aimed to estimate the prevalence of colonization of the injection ports of peripheral IV cannulas. MethodsThis cross sectional study was conducted on patients admitted in ICU and wards in an 800 bedded tertiary care hospital. Swabs were taken from lumens of peripheral IV cannulas and cultured. Patient demographic data and practices followed for maintenance of IV line were noted. ResultsA total of 196 injection port samples were taken, out of which 11 tested positive for microbial growth (5.61%). Staphylococcus aureus was the predominant organism contributing 64% of the microbial growth. A significant association was seen between presence of local signs, old age and positive cultures. Flushing IV cannula every 6h was associated with negative cultures. ConclusionPeripheral IV cannulation has significant potential for microbial contamination and is largely ignored. Most of the risk factors associated with growth of microorganisms in the injection ports of peripheral intravenous cannulas (which has a potential to cause catheter-related blood stream infections) can be prevented by improving protocols for management. To prevent infection from occurring, practitioners should be educated and trained about the care and management of IV.

Dynamic changes of organic content over time in the sea sludge collected from the Gobo/Hidaka coastal area in Wakayama, southwest Japan

The Gobo/Hidaka coastal area is known for its pristine nature and biodiversity, but recent urban developments might have affected its environmental condition. In previous study, we found a relatively low amount of organic matter from the Hidaka Port samples. In this study, we determine the possible cause of such an anomalous low organic matter content. Sludge samples were collected from the bottom of the sea of Hidaka Port monthly for one year (July 2016 to June 2017). The result showed the lowest content of organic matter in July 2016 (0.89%) and almost repeated in November 2016 (1.47%), February 2017 (1.08%), and May 2017 (1.42%). Meanwhile, the highest record was in June 2017 (3.93%). The fluctuating organic contents are in congruent with the water temperature data. The possible interactions among the seawater temperature, monthly rainfall amount of the corresponding months, possible abundance of marine microbes, and farming in the surrounding area might have caused the fluctuations. Our result would certainly be useful to infer the interrelationships of anthropogenic activities and other biotic and abiotic factors to the sea sludge, and eventually, the oceanic environment. Future studies needed to analyze inorganic content and data collections over multiple years.

Analysis of seaports efficiency in supporting inter-island transportation

This study analyzes the efficiency of 15 ports in Indonesia that connect the islands; users' perceptions on the needs of sea transport facilities both in ships and terminals; and a network of passenger facility needs based on preference. The research uses the sequential mixed method. The results show that 4 of the 15 port samples have not yet reached efficiency. The main reasons why users choose ships are because ships have complete facilities and are therefore more convenient, allow them to carry more goods, at affordable ticket prices, and users usually travel in groups. Users are most concerned with and want complete facilities, comfort, safety and order, viability and accessibility to reach the ports and board the ships.

Biannual otolith zonation of Cape hake (Merluccius capensis) in response to fish physiology and environment in the northern Benguela

Abstract Understanding and validating annual structures in fish otoliths are important for stock assessments and fisheries ecology. Biannual translucent zone formation has been demonstrated for 3–21 months old Namibian shallow-water hake Merluccius capensis. This paper addresses the hypothesis that the pattern continues in older fish. Otolith zone periodicity was studied for four cohorts hatched in July of 1996, 1998, 2002 and 2005, based on modal progression analysis (n = 1059). Edge analysis and marginal increment analysis were performed on otoliths representing eleven months of the year from port samples (n = 1153) from the years 2007–2015. Two to three translucent (T)-zones are formed on the hake otoliths each year, one or two between austral summer and autumn (January to April) and one in winter–spring (between July and October). Annual zones are usually the T2, T5, T8 zones (likely every third T-zone). Annual zones are not distinguishable from pseudo-annuli under the light microscope, and therefore otolith length measurements (OL) at each T-zone should be used as a guide for assigning age (9, 15 and 19 mm OL for ages 1, 2 and 3 respectively). Otolith T-zones are associated with both warm and cold periods, when they are presumably limited by temperature or dissolved oxygen concentration as well as food availability and feeding efficiency at both ends of their tolerance range. The most noticeable factor influencing the formation of translucent zones in otoliths is fish condition, not always linked with spawning (not always linked with high GSI). M. capensis otolith zonation is thus linked with their endogenous adaptation to the ecosystem, their fish physiology and also regulated by environmental variability.

Prospective Study of Novel Peripheral Intravenous Catheter System With Nitinol Guidewire Compared to Published Literature for Conventional Intravenous Catheters

The use of intravenous (IV) cannulas is an integral part of patient care in hospitals. These intravenous cannulas are a potential route for microorganisms to enter the blood stream resulting in a variety of local or systemic infections. Studies showing the actual prevalence of colonization of peripheral IV cannulas and its role in BSI are lacking. Hence, this study was aimed to estimate the prevalence of colonization of the injection ports of peripheral IV cannulas.This cross sectional study was conducted on patients admitted in ICU and wards in an 800 bedded tertiary care hospital. Swabs were taken from lumens of peripheral IV cannulas and cultured. Patient demographic data and practices followed for maintenance of IV line were noted.A total of 196 injection port samples were taken, out of which 11 tested positive for microbial growth (5.61%). Staphylococcus aureus was the predominant organism contributing 64% of the microbial growth. A significant association was seen between presence of local signs, old age and positive cultures. Flushing IV cannula every 6 h was associated with negative cultures.Peripheral IV cannulation has significant potential for microbial contamination and is largely ignored. Most of the risk factors associated with growth of microorganisms in the injection ports of peripheral intravenous cannulas (which has a potential to cause catheter-related blood stream infections) can be prevented by improving protocols for management. To prevent infection from occurring, practitioners should be educated and trained about the care and management of IV.

A Single Center's Experience with Candida parapsilosis Related Long-Term Central Venous Access Device Infections: The Port Removal Decision and Its Outcomes

Pediatric cancer patients have an increased risk of potentially life-threatening fungal infections such as Candida parapsilosis, associated with long-term CVADs. The Infectious Diseases Society of America (IDSA) guidelines on Candida catheter-related bloodstream infections recommend systemic antifungal therapy and catheter removal. In this study, we focused on our experience with antifungal failure due to totally implanted catheter-associated C. parapsilosis bloodstream infections. We investigated cases leading to port removal in pediatric malignancy patients and the associated patient outcomes. In the first phase of the study, a retrospective chart review was performed to collect patient information, including primary disease; time from hospitalization to port-related candidemia; antifungal drug choice; and the time at which port removal occurred. During the second phase, antifungal susceptibility tests for C. parapsilosis were performed in our microbiology laboratory. All patients had fevers and were neutropenic at the time of candidemia diagnosis. The mean duration between the first isolation of Candida parapsilosis from the port samples to the port removal was 9.75 ± 5.29 days for 11 patients. Patient fevers lasted for a mean time of 16.22 ± 6.51 days. The median recovery duration from fever after CVC removal was four days (range 2–12 days). The median duration for achieving negative blood cultures, following antifungal treatment was 18 days (range 10–27 days). Our data favored the removal of catheters in the presence of ongoing fever, as suggested by the guidelines, independent of the chosen antifungal treatment. Future studies with large samples are needed to evaluate the effects of catheter removal on mortality rates and patient outcomes.

Assessment of TBT and organic booster biocide contamination in seawater from coastal areas of South Korea

Seawater samples from major enclosed bays, fishing ports, and harbors of Korea were analyzed to determine levels of tributyltin (TBT) and booster biocides, which are antifouling agents used as alternatives to TBT. TBT levels were in the range of not detected (nd) to 23.9ng Sn/L. Diuron and Irgarol 1051, at concentration ranges of 35–1360ng/L and nd to 14ng/L, respectively, were the most common alternative biocides present in seawater, with the highest concentrations detected in fishing ports. Hot spots were identified where TBT levels exceeded environmental quality targets even 6years after a total ban on its use in Korea. Diuron exceeded the UK environmental quality standard (EQS) value in 73% of the fishing port samples, 64% of the major bays, and 42% of the harbors. Irgarol 1051 levels were marginally below the Dutch and UK EQS values at all sites.

Efficacy of decontamination and sterilization of a single-use single-incision laparoscopic surgery port

To determine the efficacy of decontamination and sterilization of a disposable port intended for use during single-incision laparoscopy. 5 material samples obtained from each of 3 laparoscopic surgery ports. Ports were assigned to undergo decontamination and ethylene oxide sterilization without bacterial inoculation (negative control port), with bacterial inoculation (Staphylococcus aureus, Escherichia coli, and Mycobacterium fortuitum) and without decontamination and sterilization (positive control port), or with bacterial inoculation followed by decontamination and ethylene oxide sterilization (treated port). Each port underwent testing 5 times; during each time, a sample of the foam portion of each port was obtained and bacteriologic culture testing was performed. Bacteriologic culture scores were determined for each port sample. None of the treated port samples had positive bacteriologic culture results. All 5 positive control port samples had positive bacteriologic culture results. One negative control port sample had positive bacteriologic culture results; a spore-forming Bacillus sp organism was cultured from that port sample, which was thought to be an environmental contaminant. Bacteriologic culture scores for the treated port samples were significantly lower than those for the positive control port samples. Bacteriologic culture scores for the treated port samples were not significantly different from those for negative control port samples. Results of this study indicated standard procedures for decontamination and sterilization of a single-use port intended for use during singleincision laparoscopic surgery were effective for elimination of inoculated bacteria. Reuse of this port may be safe for laparoscopic surgery of animals.

Free-Living and Plankton-Associated Vibrios: Assessment in Ballast Water, Harbor Areas, and Coastal Ecosystems in Brazil

Ballast water (BW) is a major transport vector of exotic aquatic species and pathogenic microorganisms. The wide-ranging spread of toxigenic Vibrio cholerae O1 from harbor areas has been frequently ascribed to discharge of contaminated BW into eutrophic coastal environments, such as during the onset of the seventh cholera pandemic in South America in the early 1990s. To determine the microbiological hazards of BWs transported to Brazilian ports, we evaluated water and plankton samples taken from (i) BW tanks of recently arrived ships, (ii) port areas along the Brazilian coastline from ∼1 to 32°S and (iii) three coastal areas in São Paulo State. Vibrio concentration and toxigenic V. cholerae O1 occurrence were analyzed. Plankton-associated vibrios were more abundant than free-living vibrios in all studied environments. V. cholerae was found in 9.5% of ballast tanks and 24.2% of port samples, both as free-living and attached forms and, apart from the Santos harbor, was absent off São Paulo State. Toxigenic V. cholerae O1 isolates (ctxA+, tcpA+), involved in cholera disease, were found in BW (2%) and harbor (2%) samples. These results confirm that BW is an important carrier of pathogenic organisms, and that monitoring of vibrios and other plankton-attached bacteria is of paramount importance in BW management programs.

South from Alaska: A Pilot aDNA Study of Genetic History on the Alaska Peninsula and the Eastern Aleutians

The Aleutian Islands were colonized, perhaps several times, from the Alaskan mainland. Earlier work documented transitions in the relative frequencies of mtDNA haplogroups over time, but little is known about potential source populations for prehistoric Aleut migrants. As part of a pilot investigation, we sequenced the mtDNA first hypervariable region (HVRI) in samples from two archaeological sites on the Alaska Peninsula (the Hot Springs site near Port Moller, Alaska; and samples from a cluster of sites in the Brooks River area near Katmai National Park and Preserve) and one site from Prince William Sound (Mink Island). The sequences revealed not only the mtDNA haplogroups typically found in both ancient and modern Aleut populations (A2 and D2) but also haplogroups B2 and D1 in the Brooks River samples and haplogroup D3 in one Mink Islander. These preliminary results suggest greater mtDNA diversity in prehistoric populations than previously observed and facilitate reconstruction of migration scenarios from the peninsula into the Aleutian archipelago in the past.

South from Alaska: A Pilot aDNA Study of Genetic History on the Alaska Peninsula and the Eastern Aleutians

The Aleutian Islands were colonized, perhaps several times, from the Alaskan mainland. Earlier work documented transitions in the relative frequencies of mtDNA haplogroups over time, but little is known about potential source populations for prehistoric Aleut migrants. As part of a pilot investigation, we sequenced the mtDNA first hypervariable region (HVRI) in samples from two archaeological sites on the Alaska Peninsula (the Hot Springs site near Port Moller, Alaska; and samples from a cluster of sites in the Brooks River area near Katmai National Park and Preserve) and one site from Prince William Sound (Mink Island). The sequences revealed not only the mtDNA haplogroups typically found in both ancient and modern Aleut populations (A2 and D2) but also haplogroups B2 and D1 in the Brooks River samples and haplogroup D3 in one Mink Islander. These preliminary results suggest greater mtDNA diversity in prehistoric populations than previously observed and facilitate reconstruction of migration scenarios from the peninsula into the Aleutian archipelago in the past.

Evaluating contamination of dredges and disposal criteria in Greek coastal areas

Sediments were collected from areas that were going to be dredged located at six small Greek ports, as well as from possible disposal areas. In order to assess the contamination level of dredged material, the samples were analysed for pH, organic matter, the metals Cd, Pb, Hg, Cr, Ni, Cu, Zn and major organic compounds (PAHs, PCBs). The sediments’ quality was evaluated by two approaches: (i) by classifying each area according to two sets of Sediment Quality Guidelines (SQGs) and (ii) by calculating the contamination factors and degree for each area. The results showed that organic compounds were detected in trace amounts in 14% of the port samples belonging to the PAHs group. The characterization of the sediment samples was based on the metals’ concentration showing that the majority of the areas to be dredged (80%) are classified as of medium–low contamination according to the SQGs. However, according to the contamination degree, only 30% of the areas are classified as of low contamination, while 40% as of moderate contamination and 30% of the areas as of considerable contamination. From the point of view of “no disturbance” of the ecosystem, decisions about dumping should be taken only after evaluating the material to be dredged. If the SQGs are exceeded, dumping must be forbidden. Otherwise, further evaluation is needed based on the comparison with the receiving area, i.e. by estimating the contamination degree. Dumping could be allowed if the contamination degree is found to be below moderate.

Multivariate optimization of a solid-phase microextraction method for the analysis of phthalate esters in environmental waters

A solid-phase microextraction method (SPME) coupled to gas chromatography–mass spectrometry (GC–MS) has been developed for the determination of the six phthalate esters included in the US Environmental Protection Agency (EPA) Priority Pollutants list in water samples. These compounds are dimethyl phthalate (DMP), diethyl phthalate (DEP), di- n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and di- n-octyl phthalate (DOP). Detailed discussion of the different parameters, which could affect the extraction process, is presented. Main factors have been studied and optimized by means of a multifactor categorical design. Different commercial fibers, polydimethylsiloxane (PDMS), polydimethylsiloxane–divinylbenzene (PDMS–DVB), polyacrylate (PA), Carboxen–polydimethylsiloxane (CAR–PDMS) and Carbowax–divinylbenzene (CW–DVB), have been investigated, as well as the extraction mode, exposing the fiber directly into the sample (DSPME) or into the headspace over the sample (HS-SPME), and different extraction temperatures. The use of this experimental design allowed for the evaluation of interactions between factors. Extraction kinetics has also been studied. The optimized microextraction method showed linear response and good precision for all target analytes. Detection limits were estimated considering the contamination problems associated to phthalate analysis. They were in the low pg mL −1, excluding DEHP (100 pg mL −1). The applicability of the developed SPME method was demonstrated for several real water samples including mineral, river, industrial port and sewage water samples. All the target analytes were found in real samples. Levels of DEP and DEHP were over 1 ng mL −1 in some of the samples.

Effects of exploitation by two co-existing fleets on the bluefish, Pomatomus saltatrix, in southern Brazil: an application of a seasonal catch-at-age model

This paper describes 20 years in the exploitation of the bluefish, Pomatomus saltatrix, in southern Brazil and investigates the effects of the commercial fleets on stock structure. Port samples were obtained from the commercial fisheries based at Rio Grande do Sul for the period 1992–1998. In addition, data derived from the exploitation during the period 1977–1983 (Krug and Haimovici 1991) were included in this analysis. A statistical catch-at-age model is proposed to estimate population size and exploitation rates for both periods of study. This model incorporates both the seasonal characteristic and multi-fleet nature of the P. saltatrix fishery. During the most recent time period, fishery mortality has increased and spawning stock biomass has reduced in comparison to the earlier period 1977–1983. Currently, the exploitation of P. saltatrix relies on fish of all age classes. Adults have been intensively exploited and juveniles may not be abundant enough to maintain the stock at the current high level of exploitation. Management options for the stock are presented based on a redistribution of effort between fleets. Simulations indicate that a ban on fishing in shallow waters for either one or both gears would restore the level of spawning stock biomass.