Marine Pollution and Toxicology

In this research, we shed light on renewable energy and its sources, which represent the global standard for the advancement and prosperity of societies. A mathematical model was designed that includes differential equations .In this model, energy factors (clean-non-renewable) and climate factors were used, and a theoretical analysis of the solution was conducted and the results were compared with previous studies. We also presented formulas for the dimensions of sustainable development (economic dimension-environmental dimension) and clarified the relationship of energy sources to the dimensions of sustainable development.

Owing to the increase of pollutant sources in oceans, seas, and lakes, there is an expected effect on growth and metabolism of planktonic algae which are considered primary producers in the ecosystem. Therefore, it becomes urgent to carry out laboratory studies to test to what extent these pollutants can affect the growth of algae which is necessary as a food for marine fishes. Spirulina is considered the most important algal species due to its high nutritional value for humans and animals. Therefore, this work investigated the effect of different concentrations of Ni2+, Zn2+, and Cu2+ metal ion pollutants on growth of the blue-green alga Spirulina platensis. EC50 was identified to be around 2 mg/l for the three heavy metals. The suitability of Idku Lake for Spirulina platensis growth was investigated using multi-criteria spatial modeling integrated with remotely sensed data processing. Spatial distribution maps of turbidity, water nutrients, and phytoplankton were the input criteri...

Background and Aim: Heavy metal pollution in freshwater ecosystems poses a serious threat to aquatic biodiversity and food safety. This study assessed the bioaccumulation of lead, cadmium (Cd), iron (Fe), and copper, as well as their effects on histopathological alterations in vital organs and gamete quality, in female Nile tilapia (Oreochromis niloticus) from the Brantas River Basin, East Java, Indonesia.

Materials and Methods: Water and fish samples were collected from five sites with varying levels of industrial and residential activity. Heavy metal concentrations were analyzed through atomic absorption spectrophotometry. Histopathological evaluations were performed on gills, liver, and ovaries, and gamete quality was assessed based on oocyte diameter, germinal vesicle breakdown (GVBD), survival, and abnormality rate. Statistical analyses included a one-way analysis of variance, Kruskal-Wallis tests, and Spearman correlation.

Results: The highest concentrations of Cd and Fe were found in Kalisari, corresponding with pronounced histopathological lesions in fish, including necrosis, inflammation, and hyperplasia in vital organs. Oocytes from heavily polluted sites exhibited significantly reduced diameters, GVBD rates, and survival rates, alongside increased abnormalities. Cd and Fe levels exhibited strong positive correlations with organ damage and negative correlations with gamete quality, particularly oocyte survival (Fe: r = −0.900).

Conclusion: Exposure to elevated levels of Cd and Fe significantly impairs the physiological and reproductive health of female Nile tilapia in the Brantas River. The observed tissue damage and reproductive disruption underscore the ecological and public health risks associated with unchecked industrial discharge. Long-term biomonitoring and targeted pollution control strategies are urgently required to safeguard aquatic life and reduce health risks under the One Health framework.


Keywords: Brantas River, cadmium, heavy metal contamination, histopathology, iron, Nile tilapia, oocyte quality, reproductive toxicity.

In all living cells, phosphorus plays an important function in the transport of metabolic energy and as a structural component of nucleotide and phospholipid molecules. Ni2+ is found in industrial water effluent and has the potential to harm aquatic ecosystems. The study was designed to assess the effect of phosphorous-limiting conditions in combination with the absence or presence of different concentrations of nickel on growth, pigment content, photosynthesis, and respiration activities of the studied alga Dunaliella tertiolecta. The EC50 for dissolved nickel was around 15 mg/L. Results obtained showed that, growth and chlorophyll content under phosphorus limiting conditions increased under low concentrations of dissolved nickel. The amount of O2-evolution with phosphorus limiting conditions was lower than those of untreated normal cultures. Lower dissolved nickel concentrations resulted in higher photosynthesis rates in the treated phosphorus-starved cultures than higher concentr...

This work aims to measure the role of zinc as an essential micronutrient for algal growth and the effect of using different concentrations of this heavy metal on growth and essential metabolites of Dunaliella tertiolecta. The EC50 obtained was around 15 mg/l. The results obtained proved that lower concentrations of the element increased growth and the content of the measured metabolites (photosynthesis pigments, fatty acids, and protein) but with different responses. The increase in content of these metabolic products with low concentrations of the tested heavy metal may be attributed to inhibition to these metabolites’ export out of cells by heavy metals. The obtained infrared peaks of the major cell constituents of the treated cells revealed the emergence of new peaks and the removal of others, indicating changes in cell constituents due to changing zinc concentrations.

The small pelagic fishery, locally known as uvuvi wa dagaa, plays a significant role in supporting livelihoods, ensuring food security, and contributing to the economy of Zanzibar. Anchovies (dagaa), a key component of this fishery, provide employment opportunities for men and women along the value chain, including fishing, processing, and trade. This study aimed to examine the anchovy value chain, identify its challenges, and assess the roles of various actors, particularly women, in anchovy processing. Conducted between January 2021 and December 2022, the study focused on key processing sites in Unguja, Zanzibar, using both qualitative and quantitative methods. Findings revealed that while anchovy production has expanded, the sector faces significant challenges, including post-harvest losses, outdated processing technologies, and limited export markets. Women are pivotal in processing and transporting anchovies, though they face barriers to leadership and decision-making. The export market is primarily dominated by Congo, with limited regional diversification. Enhancing processing technologies and providing training on quality improvement could reduce losses and open new markets. Additionally, investing in infrastructure, such as processing plants, would further support economic growth and sustainability in the sector. This study underscores the importance of improving anchovy production processes and market access to enhance livelihoods and promote sustainable fisheries in Zanzibar.

The purpose of this study was to analyze production costs and profits; analyze financial feasibility, and analyze the practice of green supply chain management in pineapple farming in Kualu Village, Tambang District, Kampar Regency. The method used in this study is descriptive, namely a method that focuses on solving existing problems at present by collecting data, analyzing, explaining, and concluding it. The results of the study indicate that all aspects of business feasibility have been met. The result also in line with sustainability theory. By implementing Green Supply Chain Management (GSCM) in pineapple farming in Kualu Village, environmental sustainability can be achieved without sacrificing economic benefits. Future studies should focus on the long-term effects of implementing GSCM in pineapple farming.

This research investigates The effects of biofouling on fuel consumption and
environmental impact. The influence of biofouling on the ship's hull from both an
environmental and economic standpoint, as well as the requirement for new, cutting-edge
antifouling technologies to meet future demand. The study reveals the various types of antifouling
paints under the two main mechanisms self-polishing copolymers (SPCs) and fouling
release coatings (FRCs) that were developed following the 2001 Tributyltin (TBT) ban. These
mechanisms increased pressure on paint manufacturers to create an effective substitute for
TBT-based paint as well as on shipping companies to find the most effective anti-fouling
systems. Through Strength Weaknesses Opportunities Threats (SWOT) analysis, the study
presents a methodology to help shipping companies choose the most effective anti-fouling
system among several options. The outcome reveals the strengths and weaknesses of the
potential anti-fouling systems.

Pollution rates in ports areas should be monitored on a regular basis in order to protect marine environment.
This study focused on the inhibitory effects of copper and zinc, and cybutryne (an antifouling
agent) discharged from the dry-dock cleaning process of ship hulls on the growth and amino acid content
of Dunaliella salina, a unicellular green marine alga. In addition, the metal concentrations in effluents
were assessed in order to know the potential threats and possible consequences of the effluent discharge
on the marine habitats. The antifouling cybutryne was found to be the most potent inhibitor of growth
and amino acid content in D. salina, followed by copper and zinc, which were present at very high concentrations
in the study area. However, the lowest concentration (5 mg/L) of the two heavy metals
increased the algae growth and amino acid content, and the results showed that Cu2+ produced more
growth inhibition effect on D. salina than Zn2+.

The presence of heavy metal ions in water is hazardous to one's health and the environment. Algae
are frequently exposed to heavy metal pollution as a result of industrial waste dumping into water
environments. Spirulina platensis, a significant kind of algae utilized commercially (especially for fish
feeding) as a good source of protein, amino acids, minerals, vital unsaturated fatty acids, and a number
of vitamins, was selected for this study because of its high nutritional value. This study examined how
S. platensis responded to five different concentrations of the three heavy metals (nickel, copper, and
zinc) in terms of its growth, fatty acid IR spectra, content, and total soluble protein profile. The
remaining four doses (two higher and two lower) for each element were selected to evaluate the
findings of 5 different concentrations of the three heavy metals because the EC50 for those three was
almost at 2.0 mg/l. Compared to zinc and nickel, copper demonstrated a greater growth inhibitory
impact as determined by optical density. Cu2+ was more noticeable than Zn2+ and Ni2+ when compared
to control cells in the IR spectra, which showed the creation of new molecules and the lack of other
compounds. Total fatty acids decreased under stress at all concentrations examined, while saturated
fatty acids outnumbered unsaturated fatty acids. Cu2+ stress resulted in a more marked destructive
effect of the heavy metal ions the protein profile than Zn2+ or Ni2+ stress.

as a structural component of nucleotide and phospholipid molecules. Ni2+
is found in industrial water
effluent and has the potential to harm aquatic ecosystems. The study was designed to assess the
effect of phosphorous-limiting conditions in combination with the absence or presence of different
concentrations of nickel on growth, pigment content, photosynthesis, and respiration activities of the
studied alga Dunaliella tertiolecta. The EC50
for dissolved nickel was around 15 mg/L. Results obtained
showed that, growth and chlorophyll content under phosphorus limiting conditions increased
under low concentrations of dissolved nickel. The amount of O2-
evolution with phosphorus limiting
conditions was lower than those of untreated normal cultures. Lower dissolved nickel concentrations
resulted in higher photosynthesis rates in the treated phosphorus-starved cultures than higher
concentrations. The degree of response to metal toxicity in phosphorus-starved medium is depending
mainly on the concentration of the element and the length of the culturing period and it was less than
those in normal control culture containing phosphorus.

This work aims to measure the role of zinc as an essential micronutrient for algal growth and the effect of using different
concentrations of this heavy metal on growth and essential metabolites of Dunaliella tertiolecta. The EC50 obtained was
around 15 mg/l. The results obtained proved that lower concentrations of the element increased growth and the content of
the measured metabolites (photosynthesis pigments, fatty acids, and protein) but with different responses. The increase in
content of these metabolic products with low concentrations of the tested heavy metal may be attributed to inhibition to
these metabolites’ export out of cells by heavy metals. The obtained infrared peaks of the major cell constituents of the
treated cells revealed the emergence of new peaks and the removal of others, indicating changes in cell constituents due to
changing zinc concentrations.

Owing to the increase of pollutant sources in oceans, seas, and lakes, there is an expected effect on growth and metabolism
of planktonic algae which are considered primary producers in the ecosystem. Therefore, it becomes urgent to carry out
laboratory studies to test to what extent these pollutants can affect the growth of algae which is necessary as a food for
marine fishes. Spirulina is considered the most important algal species due to its high nutritional value for humans and
animals. Therefore, this work investigated the effect of different concentrations of Ni2+,
Zn2+,
and Cu2+
metal ion pollutants
on growth of the blue-green alga Spirulina platensis. EC50 was identified to be around 2 mg/l for the three heavy metals.
The suitability of Idku Lake for Spirulina platensis growth was investigated using multi-criteria spatial modeling integrated
with remotely sensed data processing. Spatial distribution maps of turbidity, water nutrients, and phytoplankton were the
input criteria used to assess Idku Lake’s suitability. The results obtained proved that low concentrations of the tested heavy
metals stimulated growth and pigment fractions (chlorophyll a, carotenoids, and total phycobilins content) but to different
degrees. The inhibitory effect was more prominent in the case of copper ions than zinc and nickel ions with all concentrations
used. The overall suitability map of Spirulina platensis in Idku Lake showed that the whole lake is suitable for growth
and proliferation except for the northwestern corner due to the high salinity levels. The present paper helps to understand
the behavior of algae responding to environmental pollution, which supports environmental planners with the necessary
baseline for investigating the fate of pollutants and the potential risk.

Microalgae are rich source of protein
containing necessary amino acids at different levels.
The present study was designed to assess stimulatory
and/or inhibitory impact of five different concentrations
(5, 10, 15, 20, and 25 mg/L) of three
essential heavy metals (nickel, zinc, and copper) on
protein content (soluble, insoluble, and total) of the
marine unicellular green alga Dunaliella tertiolecta.
Further, geospatial analyses were used to assess the
suitability of Qaroun Lake for D. tertiolecta proliferation.
The experimental results showed a gradual
increase in protein content of D. tertiolecta with low
concentrations of the three investigated heavy metals.
However, increasing levels of heavy metals led to inhibitory effect on protein synthesis in alga with
different grades. Ni, Zn and Cu levels in Qaroun lake
were found suitable for the proliferation of Dunaliella
(Lower than 5 mg/L). The present study highly recommends
the necessity to encourage site selection of
optimal marine environments suitable for the proliferation
of marine algae rich in protein content.

This study focused on heavy metal pollution as one of the most dangerous type of pollutants. The
presence of heavy metal ions in water can create a serious damage to the aquatic life because
they are accumulated through the food chain and produce toxic effects in plants, animals and
human. Port operations can lead to environmental impacts on air, water and land. Many
communities with environmental justice concerns also experience disparities in health outcomes
that they attribute to exposure to emissions from port operations. The biomarker concept has
been associated with an 'early warning' of pollution-induced stress. The work designed to
estimate the stimulatory or inhibitory effects of three heavy metals (nickel, zinc and copper) on
the growth of the marine unicellular green alga Dunaliella tertiolecta which used as biological
biomarker for different pollutants. Three heavy metals were selected during the present study
based on their abundance in the industrial waste water around Alexandria, as well as, their effect
on the receiving aquatic ecosystems, also they considered essential micro-element for growth of
different algal species. The results proved that Ni2+ were less toxic than both Zn2+ and Cu2+,
while Cu2+ is the most toxic one on growth of Dunaliella tertiolecta. Stimulatory effect of the
three heavy metals obtained at low concentrations only but increasing of heavy metal
concentration led to cause inhibitory effect but with different degrees depending on metal type
and concentration used.

The pollution increases, industrialization and rapid economic development impose serve risks to availability and quality of water resources in many areas worldwide. Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.
Great focus is being put on the research into improving the quality of wastewater by using of microalgae. The basic aim of the present study was to evaluate the possibilities and the performance of Chlorella salina (green alga) for bio-removal of heavy metals from wastewater before discharging in marine environment by studying the effect of the treatment process on its growth and the ability to remove different heavy metals (Zn, Ni, Mn, Fe and Cr) as toxic pollutants in wastewater.

The herbicide Irgarol which is used now in ship paints as antifouling agent was introduced after the restriction of using TBT as antifouling agent. Micro- organisms including microalgae have been usually used as powerful tools to assess in vitro the toxicity of several environmental pollutants. Data of the toxic effects on microorganisms may be used to define the upper limits for concentration of pollutants and to predict environmental toxicity risk. So, the aim of this work was concentrated on the effect of the booster biocide Irgarol 1051 (antifouling agent) on growth of two green unicellular marine planktonic algae: Chlorella salina and Dunaliella bardawil, that usually used for fish feeding. The obtained results reveal that the antifouling Irgarol 1051 was a strong growth inhibitor for the two studied microalgae Chlorella salina and Dunaliella bardawil. It became apparent from the laboratory results that water polluted by these leached toxins caused a substantial inhibition of growth for the two algal species.

The herbicide Irgarol which is used now in ship paints as antifouling agent was introduced after the restriction of using TBT as antifouling agent. Micro- organisms including microalgae have been usually used as powerful tools to assess in vitro the toxicity of several environmental pollutants. Data of the toxic effects on microorganisms may be used to define the upper limits for concentration of pollutants and to predict environmental toxicity risk. So, the aim of this work was concentrated on the effect of the booster biocide Irgarol 1051 (antifouling agent) on growth of two green unicellular marine planktonic algae: Chlorella salina and Dunaliella bardawil, that usually used for fish feeding. The obtained results reveal that the antifouling Irgarol 1051 was a strong growth inhibitor for the two studied microalgae Chlorella salina and Dunaliella bardawil. It became apparent from the laboratory results that water polluted by these leached toxins caused a substantial inhibition of growth for the two algal species.

Nigerian aquatic systems have been contaminated at various levels since the discovery and exploitation of crude oil and its byproducts began in the Niger Delta area. In September and October 2023, the physiochemical parameters, benthic macrofauna assemblage, and heavy metal levels in sediment of the Okerenkoko water body were studied. Based on accessibility and proximity gradient from expected pollution sources, five sample stations were established along the major estuary flow. Water samples were tested in the lab using normal procedures. Heavy metal levels in sediment (Cr, Cu, Hg, Zn, Cd, and Pb) were measured using a Varian 220 (rapid sequential) Atomic Absorption Spectrometer (AAS). The ANOVA Output: indicates significant changes in heavy metals in sediments among stations, with a p-value of (0.033). Using post hoc analysis, the surface water temperature revealed little change (27.4-29.8 °C), with a significant difference identified between TDS, pH, and EC with high p-values.TDS appears to be considerably lower, indicating a TDS level comparison with pH and EC with a p-value of (0.006).Furthermore, post hoc analysis reveals that EC differs significantly from DO, BOD, and COD; EC demonstrates substantial variance in their interplay.A high DO of (7.7 0.853) was reported, which was ascribed to tidal influxes from nearby streams and fast water flow from the Escravos river distributary. Because of differences in physiochemical parameters and heavy metals in sediments of the Okerenkoko water body, linear regression analysis suggests a strong negative connection that as physiochemical factors grow, benthic fauna is likely to decline. A total of 30 macrobenthic fauna members were recorded, representing 6 species, 5 genera, 5 families, 4 orders, 3 classes, and 2 phyla. The Phylum Mollusca recorded the most individuals (88.2%) and (84.6%) in September and October, respectively, with Tympanotonus fuscatus var fuscatus being the most dominant species, and the Phylum Arthropoda recorded the fewest individuals (11.8%) and (15.4%) in September and October, respectively. The study stations' low species diversity and distribution patterns reflect anthropogenic causes and human activities (artisanal distilleries). And, according to Levene's Test for Equitability, there is a high level of species preference in the study stations, with a p-value of (0.048) and a significant difference between station 1 and station 5. The presence of a more adaptable species, Tympanotonus fuscatus var fuscatus, was established and emulates the hypothesis of habitat change, as were the presence of sensitive arthropod species, Calllinectes similis and Penaeus monodon. Anthropogenic stressors in the environment cannot be emphasized, the Niger delta atrophy ecosystem is not completely covered and hidden from the world, and a more conscious effort aimed at direct conservation of natural biotas and aquatic media management be implemented for future water quality issues.

Moldanová, Jana; Fridell, Erik; Matthias, Volker; Hassellöv, Ida-Maja; Jalkanen, Jukka-Pekka; Tröltzsch, Jenny ; Quante, Markus; Johansson, Lasse; Karl, Matthias; Malutenko, Ilja; Ytreberg, Erik; Eriksson, Martin; Sigray, Peter; Karasalo, Ilkka; Peltonen, Heikki; Hasenheit, Marius; Granhag, Lena; Mawdsley, Ingrid; Aulinger, Armin; Tang, Lin; Ramacher, Martin; Uppstu, Andreas; Jutterström, Sara; Moldan, Filip; Gustavsson, Malin; Demirdjian, Benjamin; Magnusson, Kerstin; Raudsepp, Urmas; Roth, Eva; Piotrowicz, Jakub

Heavy metals are naturally occurring elements that have a high atomic weight and a density at least 5 times greater than that of water. Their multiple industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment; raising concerns over their potential effects on human health and the environment. Their toxicity depends on several factors including the dose, route of exposure, and chemical species, as well as the age, gender, genetics, and nutritional status of exposed individuals. Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and mercury rank among the priority metals that are of public health signi icance. These metallic elements are considered systemic toxicants that are known to induce multiple organ damage, even at lower levels of exposure. They are also classi ied as human carcinogens (known or probable) according to the U.S. Environmental Protection Agency, and the International Agency for Research on Cancer. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, genotoxicity, and carcinogenicity.

The global population surge increases the demand for daily protein requirements, emphasizing the
need for cost-effective and readily available protein sources. The study investigated the amino acid,
proximate, and mineral compositions of meat powders from four gastropod species (Archachatina
marginata, Achatina achatina, Tympanotanus fuscatus, and Pachymelania aurita) procured from
Offiong Market in Essien Udim Local Government Area of Akwa Ibom State, Nigeria. The samples
were removed from their shells, and washed with deionized water and dilute acid. The meats were
then dried at 65 – 70°C for 24 hours, ground into fine powder, and sieved to achieve uniformity in
particle size. Amino acid, proximate, and mineral analyses were conducted. Significant differences
(p<0.05) were observed in amino acid, proximate, and mineral compositions among the meat
powders of the studied gastropod species. Most essential amino acids such as Leucine, histidine,
isoleucine, phenylalanine, threonine, methionine, lysine, and valine were present. Proximate
analysis revealed high protein and carbohydrate, and low fat and fibre contents among the
gastropod species. Mineral analysis indicated high levels of Ca, P, Mg, K, and N, while Zn and Fe
were significantly low across all species. The high protein and low fat and fiber contents suggest
that gastropod meat powder could be used as additives for food fortification to meet the global
demand for protein.

Introduction: Ciguatera fish poisoning (CFP) is a common Poisoning in the tropical countries. France is directly concerned with French tourists in endemic area and with French citizens living in the French overseas territories. Method: Retrospective, descriptive study of CFP cases handled by the French Poison Control Centre Network from 2012 through 2019. Results: Fifty-two events were studied concerning 130 patients. The fish species was identified for 41 events, mainly belonging to five fish families: 14 groupers, 11 snappers, 5 jacks, 4 parrotfishes, 4 barracudas. The origin of the fish was the Atlantic Ocean (23 events), the Indian Ocean (17 events) and the Pacific Ocean (12 events). 91% of the poisonings occurring in the Atlantic Ocean began with gastrointestinal effects while in 44% of events occurring in the Pacific Ocean, the patients had no gastrointestinal effects (onset with neurological symptoms: paraesthesia and dysesthesia). The evolution of the 130 patients has been classic for CFP with persistent symptoms during 1 to 45 weeks. Numerous patients reported exacerbation of neurological signs several months after poisoning following consumption of alcoholic beverages (23 patients) or seafood (19 patients). Discussion: Medical practitioners in Europe must be trained to manage CFP as cases are reported with tourists returning from endemic areas but also with poisoned patients far from tropical areas after consumption of imported fish.

Discharges from the wastewater treatment plants (WWTPs) are among the main sources of contamination to receiving surface water, therefore the quality of treated wastewater needs to be properly monitored. However, not only the effluents of larger WWTPs employing advanced treatment processes have been considered, but also those from more conventional WWTPs. In this study, the occurrence and behavior of pharmaceuticals have been investigated in a conventional WWTP which receives wastewater from an urban area and a nearby hospital. 24-h composite samples were collected during one week before (influent wastewater, IWW) and after (effluent wastewater, EWW) treatment along three monitoring campaigns distributed over one year. Moreover, seven daily IWW samples discharged from a hospital were also collected. A preliminary wide-scope screening using liquid chromatography (LC) coupled to high resolution mass spectrometry allowed to identify a wide number of pharmaceuticals in the samples. Based on the screening findings, a list of 40 compounds was established for subsequent target quantitative analyses by LC-tandem mass spectrometry. Up to 75% of the compounds investigated were present in all wastewater samples. Analyte concentrations in hospital discharge samples were significantly higher, evidencing an important contribution in terms of pharmaceuticals content. Antibiotics showed the highest concentrations during the winter season, which could be related to the increase in the prescription of these compounds to treat respiratory infections. Data from this work show that the biological treatment applied was able to eliminate nearly half of the compounds under study, although still 12 pharmaceuticals were not or poorly removed.

The influence of the water-soluble fraction of petroleum (WSF) on prey consumption and growth of juvenile trahira Hoplias aff. malabaricus was investigated. Juveniles were submitted to either WSF or Control treatment over 28 days, and jewel tetra Hyphessobrycon eques adults were offered daily as prey for each predator. Total prey consumption ranged from 16 to 86 individuals. Despite the initially lower prey consumption under WSF exposure, there were no significant differences in overall feeding rates between the two treatments. Water-soluble fraction of petroleum had a negative effect on the growth in length of H. aff. malabaricus juveniles. Although unaffected, prey consumption suggested a relative resistance in H. aff. malabaricus to WSF exposition and the lower growth of individuals exposed to WSF than the Control possibly reflects metabolic costs. The implications of the main findings for the individual and the food chain are discussed, including behavioral aspects and the role played by this predator in shallow aquatic systems.

In British Columbia, inadequate regulations and laws currently allow for ships and vessels to discharge various waste streams directly into the ocean, without consequence, if they are more than 3 nautical miles offshore. In this report, we focus on three main waste streams (sewage, greywater, and scrubber washwater) which are commonly discharged by vessels into the ocean. We quantify the amounts of waste generated by commerical vessels along the coast of British Columbia and analyze the risks associated with these waste streams, focusing on the potential ecological, sociocultural and financial impacts of marine dumping in the Great Bear Sea.

This study aimed to set up an anaerobic treatment system for the treatment of wastewater derived from the farming of African Catfish (Clarias gariepinus). In this current study, anaerobic treatment of wastewater derived from the African catfish (Clarias gariepinus) aquaculture was conducted in semi-continuous reactor as well as batch reactor under mesophilic condition at 35 °C. The results revealed that the semi-continuous reactors generated higher biogas yield (69.27 mL/g VS) compared with batch reactor (22.81 mL/g VS). High conversion rate of anaerobic treatment process operated in semi-continuous reactor was also represented in higher percentage of COD removal (82.6%) compared with batch reactor which was only 62.76%. After conducting anaerobic treatment process on the wastewater derived from the catfish aquaculture, some parameters including total dissolved solids (TDS), Phosphorous (P), potassium (K) and electrical conductivity (Ec) increased in both batch and semi-continuous r...

The proximate and elemental compositions of various body parts of Macrobrachium macrobranchion (prawn) obtained from the Great Kwa River, a major tributary of Cross River estuary in Cross River State, Nigeria were investigated using standard methods of AOAC. Results showed that the flesh had significantly higher (p < 0.05) levels of protein, fat and moisture (22.32, 7.70 and 58.40%, respectively) than the other body parts analyzed. Equally high in protein were the head (20.11%) and appendages (19.28%), while the exoskeleton recorded the least protein content (14.02%). The flesh had the least (p < 0.05) crude fibre (0.03%) and carbohydrate (7.22%) contents, and conversely had the least energy value (187.50 kcal/g) among the body parts. Ash content was significantly higher (p < 0.05) in the exoskeleton (7.14%), the appendages (7.01%) and the head (6.05%) than in the flesh (4.30%). Individual elements were also unequally distributed among the four body parts investigated: sodium and potassium were more concentrated in the flesh (189.27 mg/100 g and 114.70 mg/100 g, respectively), while calcium and magnesium were highest in the appendages (99.02 mg/100 g and 171.40 mg/100 g, respectively). The concentration of iron was generally low among the body parts; however, it was highest (p < 0.05) in the head. The usual practice of retaining the flesh and discarding the "hard" parts (head, exoskeleton and appendages) of prawn during food preparation should be discouraged as this may promote wastage of important nutrients.

Periwinkle shells of Tympanotonus fuscatus, Pachymelania aurita, and Thais coronata were analyzed for their proximate composition, nutritionally significant minerals, trypsin inhibitors, and carotenoids. The mean values obtained were compared using an ANOVA test. The results showed that T. fuscatus had the highest mean moisture content of 0.96 ± 0.14% and a mean value of 0.49 ± 0.13% for crude fibre but was not significantly different (P &gt; 0.05) from P. auritus. The crude protein and fibre content of T. fuscatus was significantly higher (P &lt; 0.05) than other periwinkle samples. T. coronata had the highest mean total ash content and was significantly different (p &lt; 0.05) from other periwinkle samples. T. fuscatus had the highest mean value for Mg (0.32 ± 0.03 mg/kg) and differed significantly (P &lt; 0.05). The mean Ca content of P. aurita was not significantly different (P &gt; 0.05) from that of T. coronata. The mean values of CaCO3 in T. fuscatus, P. aurita, and T. corona...

Groundwater is considered as the most important source of freshwater for human consumption and activities in the urban environment. The assessment of groundwater quality is critical to avoid the negative effects of polluted groundwater on human health, agriculture, and the economy. In this study, the quality of groundwater in Aba (Abia State), Nigeria was assessed. Thirty-two water samples were taken from sixteen boreholes during the rainy and dry seasons, and analysed for pH, Electrical Conductivity, Total Hardness, Turbidity, Temperature, BOD5, COD, Pb, Cd, Cr, NH3, TDS, SO4, NO3 and PO4. The Weighted Average Water Quality Index (WAWQI) approach was used to compute the Water Quality Index (WQI). Geostatistical analysis methods such as Ordinary Kriging, Empirical Bayesian Kriging (EBK), Inverse Distance Weighting (IDW) and Spline interpolation methods were compared in the spatial evaluation of variable concentrations using ArcGIS. In the dry season, 100% of the borehole locations h...

The activities and emissions from leisure boats in the Baltic Sea have been modeled in a comprehensive approach for the first time, using a new simulation model leisure Boat Emissions and Activities siMulator (BEAM). The model utilizes survey data to characterize the national leisure boat fleets. Leisure boats have been categorized based on their size, use and engine specifications, and for these subcategories emission factors for NO x , PM 2.5 , CO, nonmethane volatile organic compounds (NMVOCs), and releases of copper (Cu) and zinc (Zn) from antifouling paints have been estimated according to literature values. The modeling approach also considers the temporal and spatial distribution of leisure boat activities, which are applied to each simulated leisure boat separately. According to our results the CO and NMVOC emissions from leisure boats, as well as Cu and Zn released from antifouling paints, are significant when compared against the emissions originating from registered commercial shipping in the Baltic Sea. CO emissions equal 70 % of the registered shipping emissions and NMVOC emissions equal 160 % when compared against the modeled results in the Baltic Sea in 2014. Modeled NO x and PM 2.5 from the leisure boats are less significant compared to the registered shipping emissions. The emissions from leisure boats are concentrated in the summer months of June, July and August and are released in the vicinity of inhabited coastal areas. Given the large emission estimates for leisure boats, this commonly overlooked source of emissions should be further investigated in greater detail.

tal fin, se establecieron 21 estaciones para la toma de muestras líquidas, superficie y fondo, y tres anclajes correntométricos, uno con un perfilador acústico "mirando hacia arriba" y dos con un correntímetro doppler puntual operando durante 14 días. Las muestras líquidas se tomaron con botellas Niskin de 5 l, manejada mediante el sistema guaya-mensajero. Las muestras se analizaron utilizando las metodologías establecidas para agua de mar. Los valores de pH oscilaron entre 7,93 y 8,31 unidades; la temperatura entre 22,0-24,0 ºC, la salinidad entre 36,56-37,17 unidades; el color entre 15 y 30 unid. Pt-Co; la demanda bioquímica de oxígeno varió entre 4,05-68,98 mg/L; el nitrógeno total entre 0,53-1,27 mg/L. El fósforo total fluctuó entre 0,02 y 0,16 mg/L; los aceites y grasas entre 0,08 y 0,39 mg/L; los hidrocarburos alifáticos entre 0,01-0,12 mg/L; los detergentes no superaron el valor de 0,02 mg/L. En algunos casos los coliformes totales y fecales alcanzaron valores muy superiores al límite de 1000 NMP/100 ml para coliformes totales establecido por el Ministerio del Ambiente para aguas tipo 4 (contacto humano parcial y total). La calidad de estas aguas refleja el impacto de las descargas de aguas superficiales residuales en el sector de Campo Ajuro, que son transportadas por la corrientes media superficial que fluye predominantemente de este a oeste. Las condiciones físico-químicas de las aguas de esta ensenada pueden variar durante todo el año, como consecuencia de las condiciones hidrodinámicas que predominan en la región. Se recomienda realizar estos estudios, al menos dos veces al año, durante el período de sequía (diciembre a mayo), cuando se incrementan los vientos alisios, y durante el período lluvioso (junio-noviembre).

The hydrographic conditions and sanitary quality of the waters of the coastal region of Playa Grande Baywere studied during May 2003. We set up 21 stations to collect surface and bottom samples and three current meters – anupward-mounted hydroacoustic profiler and two single-point Doppler current sensors that operated for 14 days. Samples werecollected in 5-L Niskin bottles equipped with a lid-closing device operated through a cable. The samples were studied accordingto established methods for seawater analysis. The pH ranged between 7.93 and 8.31; the temperature, between 22.0 and 24.0ºC; the salinity, between 36.56 and 37.17 units; the color, between 15 and 30 Pt-Co units. The biochemical oxygen demandranged between 4.05 and 68.96 mg/L; and total nitrogen, between 0.53 and 1.27 mg/L. Total phosphate fluctuated between0.02 and 0.16 mg/L; lipids, between 0.08 and 0.39 mg/L; aliphatic hydrocarbons, between 0.01 and 0.12 mg/L. Detergents didnot exceed the value of 0.02 mg/L. In some c...

Hundred pieces each of two genera of freshly harvested Nigerian Periwinkles-Tympanotonus fuscatus var radula (a brackish water habitat) and Pachymelania aurita (a fresh water species) collected from lshiet and Oron creeks in Akwa Ibom State, Nigeria were evaluated for bacteriological quality, proximate nutrient and mineral composition. The results showed that all the periwinkle contain unacceptable levels of bacteria with P. aurita from Oron creeks carrying up to 1.46 x 10 cfµ g. The level of coliform was generally high ranging 5 1 from 1.5 x 10 cfµ g of the total load in T. fuscatus from Oron creek to 2.8 x 10 cfµ g in P. aurita (from Oron 5 1 5 1 creeks). The Salmonella count ranged from 8 x 10 cfµ g inT. fuscatus to 1.9x10 cfu g in P. aurita (from Oron 5 1 6 1 creeks). The organisms isolated from the periwinkle samples include Escherichia coli, Proteus vulgaris, Salmonella paratyphi, Pseudomonas aeruginosa, Bacillus cereus, Micrococcus varians and Enterobacter aerogenes. Salmonella paratyphi and Pseudomonas aeruginosa from Oron and Ishiet creeks respectively had the highest rate of occurrence among the isolated bacteria, while Proteus vulgaris was the least encountered. Proximate analysis revealed that periwinkle samples from Oron creek were nutritionally richer than that of Ishiet creek Protein content ranged from 40.

Length frequency distribution, weight-length relationship, Fulton's, and relative condition factors of the common sole (Solea sloea) in Lake Manzalah were investigated. The fish was caught by trammel nets from the northern region of Lake Manzalah near Bughaze El-Gamil where the marine species were found. The results of the length-weight relationship for 361 common soles showed a positive allometric growth  (W= 0.0029 L3.3777) indicating the suitability of the area for the species growth. The mean value of the relative condition factor (Kn)  of the common sole was 1.013, while the average value of Fulton's condition factor was 0.911. These values suggested a good condition in the northern Manzalah lake for Solea solea. Such results may be helpful for S. Solea management. It's worth mentioning that during the study period, only two Red Sea hardyhead silverside fish (Atherinomorous forskalii) of 9.4 cm were recorded. Therefore, more extensive studies are needed to assess the actual status of marine fish and to manage the fishery of common soles at Lake Manzalah. Also, a monitoring program should be established to detect any ecological and biological changes after deepening and cleansing processes

The aim of this work was to develop a novel, simple, inexpensive, sensitive an electrochemical DNA biosensor based on interdigitated electrodes (IDEs) integrated gold nanoparticle modified electrode by electro less deposition for HPV 18. The biosensor was designed with a 30 mer E6 region of HPV 18 DNA modified probe. The E6 region has been used for their clinical importance properties and suitable as recognition biomarker region. Three different target types were tested which complementary target, non-complementary target and mismatch target. All target were analyzed for detection of HPV 18 in early stages by using Dielectric Analyzer (DA), Alpha-A High-performance Frequency Analyzer, Novocontrol Technologies, Handsagen, Germany associated with the software package Windeta. Complementary target gives a positive result in HPV detection, while non-complementary and mismatch target give negative results. IDE device with 5 nm gap sizes has demonstrated a high performance towards the det...

Drinking water quality is a critical factor affecting human health particularly in natural resource-dependent countries including Nigeria. Hydrocarbon related pollution, mining waste, microbial load, industrial discharge and other anthropogenic stressors degrade drinking water quality in coastal communities and pose serious public health and ecological risks. This study evaluated the physicochemical properties of drinking water in selected communities (Okerenkoko, Kurutie and Oporoza) in Gbaramatu Kingdom, in the Niger Delta region of Nigeria, to assess the water quality using the water quality index (WQI) and pollution models. Nitrate, chromium, cadmium, copper, lead, aluminium, pH, total hardness, total dissolved solids, cyanide and residual chlorine were measured in twelve selected locations across three communities. WQI results of 139 to 44180 indicated that analyzed water samples exceeded the critical WQI value of 100, in addition the mean pH of the water samples recorded 8.11 ± 0.32, indicating unsuitability for consumption. Nickel ranging from 0.014 to 0.176 mg/L and residual chlorine 11.6 to 7407 mg/L were the major contributors to the degradation of water quality and exceeded the WHO recommended limit of 0.02 and 0.25 respectively. While groundwater had better organoleptic properties compared to surface and rain water, the geo-accumulation index showed that water sources vary from moderately to heavily contaminated with Ni and Cd. The WQI and pollution model results indicate that immediate action is required by stakeholders to address water quality deterioration (e.g., providing alternative water supply) as existing water resources in the area pose signi cant health risks to the local population. Introduction Access to safe and potable drinking water is a basic need of mankind and a human right, including health and food. This justi es the United Nations Sustainable Development Goal 6, which seeks to achieve access to clean water and sanitation for all by 2030. The goal seeks to improve water quality by limiting contamination, eliminating dumping and reducing release of chemical substances and materials into the water, to increase safe use and reuse of water globally (WHO 2019; UNEP 2021). Water is needed and used globally by humans irrespective of nationality, tribe, region, religion, color or societal status because it is one of the greatest factors that determine human health and development (Li and Wu 2019; Delpla et al. 2020). Despite its importance, the quality of available drinking water is often compromised due to pressures exerted on it by growing population, agricultural production, natural resource exploration and mining, urbanization, and industrialization (Naeem et al. 2013; Li and Wu 2019). With increasing climate change challenges, rivers drying up, and wetlands being reclaimed, the continuous pollution of water resources by anthropogenic activities has cumulative impacts on humans. Anthropogenic activities including dumping of mixed waste in water bodies, onshore and offshore hydrocarbon spillages, and open defecation contribute potentially toxic elements (PTEs) to water resources (Naeem et al. 2013). Hydrocarbon contamination for example, exposes surface and underground water to toxic elements including benzene (which is a carcinogenic substance), and affects the quality of drinking water (UNEP 2011). Considering that water quality is a health determinant, consumption of water contaminated either by biological or chemical means may likely pose serious health risks to public health. An estimated 2.3 billion people suffer from waterborne diseases globally (Ahmed et al. 2020), while 485,000 people die from diarrhea as a result of contaminated drinking water yearly (WHO 2019). The World Health Organization (WHO) reports that water contamination contributes to 70% of different diseases and 20% of cancers on a global scale (WHO 2022). Discharge of domestic and industrial e uent wastes, leakage from water tanks, marine dumping, and radioactive waste into water bodies constitute contamination, and degrades water quality. When this happens, these water bodies accumulate heavy metals and pose harm to humans, animals and entire ecosystem. The toxicity of PTEs or speci cally, heavy metals (e.g., cadmium, zinc, lead, copper, manganese, magnesium, iron, arsenic, silver, and chromium) from mining, smelting or hydrocarbon exploration activities can have lethal and harmful effects on human health and the ecosystem (Vanloon and Duffy 2005). In addition, toxins in industrial waste have been identi ed as a major cause of immune suppression, cancer, reproductive failure and acute poisoning. Infectious diseases, like cholera, typhoid fever, dysentery, polio, trachoma, and abdominal pain (Juneja and Chauhdary, 2013) and other gastroenteritis, including diarrhea, vomiting, skin and kidney problem are spreading through contaminated water (Khan and Ghouri 2011; Chima and Digha 2009; Digha and Abua 2016). Considering the importance of water quality, many nations have developed systems and agencies to establish water quality monitoring programs. These systems help decision-makers to understand, interpret and use available data to enhance the protection of water resources (Behmel et al. 2016). As a result of effective monitoring and access to water quality data to protect the resources and human health, many countries have reformed their water regulatory framework towards sustainable development as recommended by Agenda 21 (UNEP 1992). In Nigeria for example, government have developed a number of initiatives to protect water resources. In November 2018, the Nigeria government declared a state of emergency in the water, sanitation and hygiene (WASH) sector, as part of measures to protect increasingly degraded water resources and the upsurge of water borne diseases (Wada et al., 2021). However, this initiative is yet to yield desired outcomes due to limited nance, poor service delivery, lack of stakeholder collaboration and adhoc implementation (Musa et al. 2021). Nigeria intends to achieve 100% access to clean water and sanitation by 2030, with focus on rural communities. Although these efforts have focused on biological contaminants, achieving this will require signi cant investments in building necessary infrastructure, maintaining existing ones and awareness creation. Also, it will require a stringent monitoring of PTEs as they constitute a major contributor to water contamination. In terms of investment, Nigeria needs an estimated $2.7 billion USD to achieve outlined targets by 2030 (Musa et al. 2021), and the government is expected to provide 25% of the funds, while 75% will be incurred by households to build toilets. Households in the face of the current economic woes are focused on basic needs (i.e., shelter and food) and would likely continue open defecation in the nearest future. The Niger Delta and water quality Since the late 1950s when Nigeria discovered commercial quantity of oil and commenced exportation, the Niger Delta region has experienced several oil spill incidences. For example, the 2008/09 Bodo oil spill affected surface and underground water sources, farmlands and impacted over 69,000 households (Pegg and OPZ-3. Speci cally, OPZ-3, a surface water source, recorded Aluminum concentration (0.369 mg/l) above the WHO guideline value of 0.2 mg/l. Cadmium concentrations were found in both surface and groundwater sources, with more of the surface waters being contaminated than the groundwater. While cadmium signi cantly originates from hydrocarbon exploration and extraction, the dumping of mixed wastes containing batteries, and electronic waste, and the discharge of substances including paints, pigments and phosphate fertilizers into surface waters constitute to cadmium levels in the water bodies. Cadmium bioaccumulates in water and considered toxic to aquatic life and humans. It has an impact on sh endocrine function and behavior, which could impact breeding and sh population. Also, cadmium exposure lowers bone density and composition and poses cancer risk. Children exposed to cadmium are 2015; Ramirez et al. 2017; Sah et al. 2019). Nickel has also been linked to greenhouse gas emissions and habitat destruction (Han et al. 2021). Residual chlorine constitutes an important safeguard against the risk of subsequent microbial contamination after water treatment, and could be a signi cant bene t for public health. However, an excessive amount of it in water could be toxic and lead to stomach aches, vomiting, diarrhoea, and dry and itchy skin in humans (Health line 2018). Nickel concentration in this study ranged from 0.014 mg/l to 0.171 mg/l, exceeding the maximum permissible limit of 0.02 mg/l, while the residual chlorine ranged from 11.6 mg/l to 7407 mg/l and has maximum permissible limit of 0.25 mg/l (Table 3); and thus, could pose risk to locals consuming water from the sampled area. Although cadmium concentrations were not detected in most groundwater sources, they were found in surface and rain water ranging from 0.005 mg/l to 0.369 mg/l. Cadmium was observed as a contributory parameter to water contamination beside residual chlorine and Ni in OKO-2, OKO-4 and OKO-5. The roo ng sheets of the buildings where rainwater was collected were made up of asbestos and covered by soot, resulting in faintly dark water. Cadmium concentration in ground water sources OKO-2, OKO-5 and OPZ-2, as well as surface water OKO-4, KRU-4 and OPZ-3 indicated the impacts of ared gas in the area. The cadmium concentration ranged from 0.005 to 0.369 mg/l (Table 3). The WHO permissible level for Cd is 0.005 mg/l. The local population drink water from these cadmium-contaminated sources, especially during water scarcity, as there are no alternative water supplies. A striking observation and health concern from the results is the presence of Cd in a minute quantity (0.005 mg/l) in a major treated tap water source in OKO-2...

The shipping sector contributes significantly to increasing emissions of air pollutants. In order to achieve sustainable shipping, primarily through new regulations and techniques, greater knowledge of dispersion and deposition of air pollutants is required. Regional model calculations of the dispersion and deposition of sulphur, nitrogen and particulate matter from the international maritime sector in the Baltic Sea and the North Sea have been made for the years 2009 to 2013. In some areas in the Baltic Sea region the contribution of sulphur dioxide, nitrogen oxide and nitrogen dioxide from international shipping represented up to 80&thinsp;% of the total near surface concentration of the pollutants. Contributions from shipping of PM&lt;sub&gt;2,5&lt;/sub&gt; and PM&lt;sub&gt;10&lt;/sub&gt; were calculated to a maximum of 21&thinsp;% and 13&thinsp;% respectively. The contribution of wet deposition of sulphur from shipping was maximum 29&thinsp;% of the total wet deposition, and for...

Two sampling campaigns (dry period and rainy period) were carried out in seven points located within the Bay of Chame, province of Panama Oeste. The objective was to determine the water quality of this site, subject to different pressures such as: large number of urban settlements, construction of large tourism projects, presence of high amounts of fecal coliforms, enterococci and total coliforms, using the quality index of Coastal marine water (ICAMpff) which is a status indicator, through which a general analysis of water quality can be performed at different levels, as it facilitates the interpretation of natural conditions and determines the vulnerability of the marine water resource and coastal, facing potential threats such as the anthropogenic impact of human activities, and is focused on the preservation of flora and fauna. In the seven points chosen seven variables were analyzed between physicochemical and biological to know the quality of the water. Statistical analysis was also carried out whose results indicate that the variables that most influence ICAMpff are dissolved oxygen and fecal coliforms (E. coli). In general, it was concluded that the waters of Chame Bay obtained a score of 72.44, which according to ICAMpff are classified as adequate to sustain high aquatic biodiversity.

The hydrographic conditions and sanitary quality of the waters of the coastal region of Playa Grande Baywere studied during May 2003. We set up 21 stations to collect surface and bottom samples and three current meters – anupward-mounted hydroacoustic profiler and two single-point Doppler current sensors that operated for 14 days. Samples werecollected in 5-L Niskin bottles equipped with a lid-closing device operated through a cable. The samples were studied accordingto established methods for seawater analysis. The pH ranged between 7.93 and 8.31; the temperature, between 22.0 and 24.0ºC; the salinity, between 36.56 and 37.17 units; the color, between 15 and 30 Pt-Co units. The biochemical oxygen demandranged between 4.05 and 68.96 mg/L; and total nitrogen, between 0.53 and 1.27 mg/L. Total phosphate fluctuated between0.02 and 0.16 mg/L; lipids, between 0.08 and 0.39 mg/L; aliphatic hydrocarbons, between 0.01 and 0.12 mg/L. Detergents didnot exceed the value of 0.02 mg/L. In some c...

Periwinkle shells of Tympanotonus fuscatus, Pachymelania aurita, and Thais coronata were analyzed for their proximate composition, nutritionally significant minerals, trypsin inhibitors, and carotenoids. The mean values obtained were compared using an ANOVA test. The results showed that T. fuscatus had the highest mean moisture content of 0.96 ± 0.14% and a mean value of 0.49 ± 0.13% for crude fibre but was not significantly different (P &gt; 0.05) from P. auritus. The crude protein and fibre content of T. fuscatus was significantly higher (P &lt; 0.05) than other periwinkle samples. T. coronata had the highest mean total ash content and was significantly different (p &lt; 0.05) from other periwinkle samples. T. fuscatus had the highest mean value for Mg (0.32 ± 0.03 mg/kg) and differed significantly (P &lt; 0.05). The mean Ca content of P. aurita was not significantly different (P &gt; 0.05) from that of T. coronata. The mean values of CaCO3 in T. fuscatus, P. aurita, and T. corona...

There are pressures on existing centralized water infrastructures in urban centers which justify the search for alternatives. An increasingly important alternative is to shift from centralized to hybrid systems, often in response to climate variability and demographic changes. In a hybrid system, water is supplied and discharged through a mix of centralized and decentralized systems. There is usually no single objective that justifies the choice of hybrid water systems, but they typically are justified based on the consideration of a number of different criteria in order to evaluate the overall quality of service provision. The most important criteria include meeting water demand, as well as reducing demand for fresh water and instead using local alternative water supplies. Integration of multiple objectives to evaluate the hybrid water supply systems can be accomplished by multi-criteria decision aid techniques. This paper evaluates a number of hybrid water supply scenarios using a case study based on the Northern Growth Area of Melbourne, Australia. It uses the Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEE) and Geometrical Analysis for Interactive Decision Aid (GAIA), one of the multi-criteria decision-making methods through D-Sight software, to rank the hybrid water supply scenarios, and this ranking is validated by means of sensitivity analysis. The centralized system combined with stormwater harvesting and the centralized system combined with treated wastewater and rainwater tanks yielded the first and second most preferred scenarios, while the centralized water supply system combined with treated wastewater yielded the worst hybrid water supply option.

The aim of this work was to develop a novel, simple, inexpensive, sensitive an electrochemical DNA biosensor based on interdigitated electrodes (IDEs) integrated gold nanoparticle modified electrode by electro less deposition for HPV 18. The biosensor was designed with a 30 mer E6 region of HPV 18 DNA modified probe. The E6 region has been used for their clinical importance properties and suitable as recognition biomarker region. Three different target types were tested which complementary target, non-complementary target and mismatch target. All target were analyzed for detection of HPV 18 in early stages by using Dielectric Analyzer (DA), Alpha-A High-performance Frequency Analyzer, Novocontrol Technologies, Handsagen, Germany associated with the software package Windeta. Complementary target gives a positive result in HPV detection, while non-complementary and mismatch target give negative results. IDE device with 5 nm gap sizes has demonstrated a high performance towards the det...

The comparative study of persistent toxic metal levels of two species of crab Cardiosoma armatum and Callinectes amnicola were studied from June 2009 to October 2009. This work provides information on the concentration of Cd, Zn, Ni, Fe and Pb in the limb, shell, flesh and gills of the two species of crab, their environment-water and sediments, and also analysis with a view to assessing accumulation of metals in the organisms. Metal concentration was determined following wet digestion and analyzed using Atomic Absorption Spectrophotometer (AAS). The concentrations observed in crab samples were lower than the WHO permissible level of 2.00µg/g for Lead (Pb) and Cadmium (Cd) in foods. The mean values obtained fell in the ranges: Fe (0.041-0.219µg/g); Zn (0.647-1.774µg/g); Cd (0.093-0.635µg/g); Ni (0.261-0.825µg/g); Pb (0.160-0.261µg/g) for Callinectes amnicola and Fe (0.071-0.313µg/g); Zn (0.807-1.731µg/g); Cd (0.022-0.663µg/g); Ni (0.181-1.279µg/g); Pb (0.151-0.501µg/g) for Cardiosoma armatum. Although, the levels were lower than the permissible levels, it was observed that Cardiosoma armatum and Callinectes amnicola accumulated more than the environment. There was no significant difference in the distribution of metals between the two crabs at 95% confidence level. This is indicative of bioaccumulation of the persistent toxic metals in the organism.

The present study investigated aspects of the biology and heavy metals concentrations in the flesh of Penaeus monodon from the Lagos Lagoon. 183 samples were collected between July-September 2018 and they were used to study the ageing and growth pattern using length-frequency distribution and length-weight relationship. Food and feeding habits were determined by numerical and occurrence methods while heavy metals concentration was assayed by atomic absorption spectrophotometry. The samples consisted of 61 females and 122 males and their total length, carapace length and total weight ranged from 11.5 to 33.0 cm, 4.1 to 14.0 cm and 8.0 to 271.7 g, respectively. Three age groups were obtained from length-frequency distribution. The b values of 3.09 and 3.27 for the carapace length/weight relationship and the total length/weight relationship obtained respectively showed a positive allometric growth pattern of the species. P. monodon fed on green algae, diatoms, crustaceans and fish fragments and their condition factor ranged between 0.6 and 0.9. The sex ratio (1:0.5) showed that males were significantly (p < 0.05) more males than females in the study area. Heavy metals accumulated in the flesh in decreasing order of Fe > Zn > Pb > Mn > Cd > Cu > Cr. The concentrations of Pb, Mn and Cr were higher than the FAO/WHO maximum acceptable values for consumption. This study suggested a potential health risk which could arise from consumption of P. monodon from the lagoon, if relevant mitigating strategies are not enforced.

Cuprous oxide-based antifouling paint is now the most common type in use, especially in the shipping industry. Anti-fouling paints prevent or slow down the growth of organisms attached to the hull, in order to improve a vessel's performance and durability. However, copper is a scarce resource and never can be retrieved or recycled after leaching into the sea. The need to protect sensitive marine areas from elevated levels of copper and to reduce the amount of copper emitted into the environment has led to the search for an alternative. A new product has been developed by I-Tech as a replacement for cuprous oxide in antifouling paint, trademarked as Selektope. It is based on biological knowledge and does not kill the target organism but instead deters it away from attaching to the ship hull. It is an organic synthetic biocide that can degrade in the marine environment and its mode of action makes it effective at very low concentrations (about 0.1% mass of paint). This is in sharp contrast to copper-based paints which need to be 40-60% copper by mass. This master thesis aims to compare the sustainability profiles of the innovative Selektope paint system with traditional copper-based paint. Life-Cycle Assessment (LCA) is performed to analyse and compare the energy demand, global warming potential (GWP), and marine aquatic ecotoxicity potential (MAETP) of the two paint system. The effect of ecotoxicity on the marine environment on the use of cuprous oxide and Selektope has also been studied using MAMPEC model. Despite some of uncertainties from assumptions and data availability, the results from LCA indicate an overall higher environmental impact from copper-based paint than from Selektope paint, in terms of all impact categories. The production of cuprous oxide appears to be the dominant burden in the life-cycle impact of copper-based paint, except that the release of copper during user phase has a much larger contribution to the MAETP. The impact generated by the Selektope paint has a relatively even distribution among different phases. However, the choice of transportation method can largely influence the result even though it would still be insignificant compared to copper-based paint. The results from the ectoxicological risk analysis show no potential risk in the leaching of both copper and Selektope.