Pollution In Marine Ecosystems Research Articles

Rainfall is a significant environmental factor of microplastic pollution in inland waters

Worldwide, increasing attention is being paid to the issue of microplastic pollution in marine ecosystems, yet there is a relative lack of knowledge concerning the pollution of microplastic in inland water systems, although these microplastics are major sources of ocean pollution. In aquatic environments, previous efforts have mainly been devoted to exploring the impact of human-related activities on microplastic pollution, but little is known about non-anthropogenic effects on microplastic distribution. In this paper, the relationship between rainfall and the microplastic concentration of surface water was studied for the first time. The investigation was conducted in Lake Donghu (the largest urban lake in China) from July 23 to September 1, 2019. The abundance of microplastics in the lake water ranged from 7.4 to 29.6 items/L. The dominant size of the collected microplastics was less than 2 mm, with a dominant fiber shape and a dominant transparent color. Our results demonstrated that microplastic concentration was significantly related to rainfall. Therefore, high frequency sampling and rainfall data are needed to accurately evaluate microplastic pollution as well as its consequences.

Plastic pollution in croplands threatens long-term food security.

Plastic pollution is a global concern given its prevalence in aquatic and terrestrial ecosystems. Studies have been conducted on the distribution and impact of plastic pollution in marine ecosystems, but little is known on terrestrial ecosystems. Plastic mulch has been widely used to increase crop yields worldwide, yet the impact of plastic residues in cropland soils to soil health and crop production in the long term remained unclear. In this paper, using a global meta-analysis, we found that the use of plastic mulch can indeed increase crop yields on average by 25%-42% in the immediate season due to the increase of soil temperature (+8%) and moisture (+17%). However, the unabated accumulation of film residues in the field negatively impacts its physicochemical properties linked to healthy soil and threatens food production in the long term. It has multiple negative impacts on plant growth including crop yield (at the mean rate of -3% for every additional 100kg/ha of film residue), plant height (-2%) and root weight (-5%), and soil properties including soil water evaporation capacity (-2%), soil water infiltration rate (-8%), soil organic matter (-0.8%) and soil available phosphorus (-5%) based on meta-regression. Using a nationwide field survey of China, the largest user of plastic mulch worldwide, we found that plastic residue accumulation in cropland soils has reached 550,800tonnes, with an estimated 6%-10% reduction in cotton yield in some polluted sites based on current level of plastic residue content. Immediate actions should be taken to ensure the recovery of plastic film mulch and limit further increase in film residue loading to maintain the sustainability of these croplands.

Accumulation of 13C-labelled phenanthrene in phytoplankton and transfer to corals resolved using cavity ring-down spectroscopy.

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants in marine ecosystems including threatened and potentially sensitive coral reefs. Lower organisms such as phytoplankton, known to bioconcentrate PAHs, could serve as potential entry points for these chemicals into higher trophic levels. Here, we present a novel method using a 13C-labelled PAH and cavity ring-down spectroscopy (CRDS) to investigate accumulation, uptake rates and trophic transfer of PAHs in corals, which are key organisms to sustain biodiversity in tropical seas. We quantified the accumulation of 13C-phenanthrene in the marine microalga Dunaliella salina, and in the coral Acropora millepora after diffusive uptake from seawater or dietary uptake via labelled D. salina. Additionally, we monitored the photophysiological health of D. salina and A. millepora during phenanthrene exposure by pulse-amplitude modulation (PAM) fluorometry. Dose-dependent accumulation of 13C-phenanthrene in the microalga showed a mean bioconcentration factor (BCF) of 2590±787Lkg-1 dry weight. Corals accumulated phenanthrene from both exposure routes. While uptake of 13C-phenanthrene in corals was faster through aqueous exposure than dietary exposure, passive diffusion showed larger variability between individuals and both routes resulted in accumulation of similar concentrations of phenanthrene. The 13C-PAH labelling and analysis by CRDS proved to be a highly sensitive method. The use of stable isotopic label eliminated additional toxicity and risks by radioactive isotopic-labelling, and CRDS reduced the analytical complexity of PAH (less biomass, no extraction, fast analysis). The simultaneous, precise quantification of both carbon content and 13C/12C ratio (δ13C) enabled accurate determination of 13C-phenanthrene accumulation and uptake rate. This is the first study to provide empirical evidence for accumulation of phenanthrene in a phytoplankton-coral food chain.

The Levels of Plastic-associated Heterotrophic Bacteria on Three Different Types of Plastics

Plastic pollution in marine ecosystems is one of the most important study topics in recent years. The toxicity, mobility and long-term persistence characteristics of plastics create risk in ecosystems, biota and human health. In this study, the levels of heterotrophic bacteria attached to the surfaces of commonly used plastic types; polyvinylchloride (PVC), polyethylene (PE), and polypropylene (PP) were tested in a mechanical experimental system prepared with seawater under controlled conditions in laboratory. The seawater, which was used in the experimental system, was taken under aseptic conditions from the Golden Horn Estuary, located in the Istanbul region of Turkey. Three different types of plastic (PVC, PE and PP), in two different (glass slide (76x26 cm) and virgin micro pellets (5mm diameter) size, were placed in the experiment setup filled with seawater and incubated for 28 days at ambient temperature. At the end of 28 days, the counts of heterotrophic bacteria were tested using the spread plate technique on Marine Agar (Difco), in both plastic surfaces and surrounding seawater. The levels of heterotrophic bacteria were recorded to be lower in the seawater surrounding the micropellets and lam-size plastic samples. The seawater sample bacterial levels were recorded as 12x109 CFU/ml, at the start of the experiment. At the end of the 28th days, it was recorded to be 83x109 CFU/ml. The highest levels of heterotrophic bacteria were recorded as 41x1010 CFU /cm-2 and 61x1010 CFU /cm-2 on the lam-size surfaces and the micropellet surface of the polypropylene samples, respectively. In the experiments, the PP plastic type has been recorded as a more preferred plastic derivative by heterotrophic bacteria according to the PVC and PE plastic types, but there has been no significant difference in the bacterial adhesion rates on the surfaces. The study contributed increasing knowledge on the bacterial approach to microplastics types. However, there is a need for long term studies related to the mechanism of bacteria attached to microplastics.

Optimization of Biodegradation of Long Chain n-Alkanes by Rhodococcus sp. Moj-3449 Using Response Surface Methodology

Oil spills and subsequent pollution of marine ecosystems are associated with oil exploitation. The ultimate fate of unrecoverable portion of spilled oil is biodegradation by microorganisms. Rhodococcus sp. Moj-3449 has proven ability of growth on aliphatic hydrocarbons. In this study Response Surface Methodology was employed to optimize the biodegradability of Moj-3449 by changing salinity, pH, temperature and n-C16 concentration. The duplicate experiments conducted were based on a 5-levels rotatable and orthogonal central composite design (CCD) done in 2 separate blocks. The effect of each factor and their interactions on the biodegradation of n-C16 revealed that the optimal conditions for the biodegradation are 0 % salinity at pH= 6.97, T=28°C and 52.98 % wt/V n-C16 concentration. Under these conditions, the maximum biodegraded amount was predicted at 45.52 % wt/V out of 52.98 % wt/V. The experimentally obtained biodegradation amount at the optimum condition was 44.27 ±0.07 % wt/V. The ability of the strain to effectively break down long-chain n-alkanes at concentration up to 55 % wt/V shows at that this strain is an outstanding candidate for industrial bioremediation of crude oil spills in marine environment.

Multi-criteria decision analysis (MCDA) method for assessing the sustainability of end-of-life alternatives for waste plastics: A case study of Norway

Plastic, and its pollution of marine ecosystems, has emerged as a global concern. Among the several other sources, plastics from abandoned, lost, or discarded fishing gears (ALDFG), and ropes are considered the most dangerous for marine wildlife. In EU states, the management ALDFG is prioritized through a dedicated action plan owing to the hazardous nature of ALDFG and the increase in commercial fishing activity in EU waters. The action plan demands to close the loop of plastics from fishing to ensure sustainable resource management using strategies of the circular economy (CE). Commercial fishing is a crucial sector in Norway, generating 4000 tons of waste plastic annually from fishing gears and ropes. While recycling, landfilling, and incineration are the standard end-of-life management options, the recycling industry in the region is immature. The lack of recycling capacity and inadequate infrastructure results in exporting most of the recyclable fraction out of Norway for further processing. Although within the framework of CE, the transboundary export of waste for recycling misses the opportunity to create value out of waste within the region. Therefore, in the pursuit of CE strategies, it is essential to ensure regional sustainability.In this study, we assess the environmental, economic, and social impacts of landfilling, incinerating, and recycling of waste fishing gears in Norway. To represent the current state, we include two existing recycling scenarios for the assessment, namely, recycling (inland) and recycling (export). Based on qualitative and quantitative data from relevant stakeholders, we adapted multi-criteria decision analysis (MCDA) to rank the end-of-life (EOL) alternatives through their ability to sustainably manage 4000 tons of waste plastics from fishing gears in Norway. The ranking and insights from stakeholder interaction were used to ascertain potential barriers in realizing principles of CE and to further recognize opportunities for establishing circular business models in the region.

Ecological risk assessment of heavy metal contamination in mangrove habitats, using biochemical markers and pollution indices: A case study of Avicennia marina L. in the Rabigh lagoon, Red Sea.

Contamination of mangrove ecosystems, including those of the Red Sea area, has caused serious concern globally. Spatial distribution of heavy metals and their bioaccumulation in one of the common mangrove plants of Saudi Arabia, Avicennia marina L., was evaluated in 8 stations at the Rabigh lagoon to assess the ecological risks due to heavy metal contamination. Among all the heavy metals, Fe concentration was recorded highest (8939.38 ± 312.63 mg/kg) at station S4. Contamination factor (CF) values for all heavy metals determined in this study were recorded in ascending order as Cu < Cr < Mn < Zn < Fe < Ni < Pb < Cd, with the pollution load index pattern recorded in descending order as S6 > S4 > S3 > S5 > S7 > S1 > S8 > S2. Bio-concentration factor (BCF) was <1 for all the heavy metals and there was a positive correlation between the antioxidants and lead (Pb), which can be a result of the ability of A. marina to exclude or detoxify this metal by its mechanism of exclusion or detoxification. A significant correlation existed between the heavy metals concentration in sediment and A. marina leaves at one combination or the other, except for Cu and Cd, which do not correlate with any other metal concentration. The information provided in the present study can be used in the monitoring and measurement of heavy metal pollution in marine ecosystems or other aquatic environments, to prevent several ecological risks to the mangrove ecosystem.

Impact of historical contamination on meiofaunal assemblages: The case study of the Bagnoli-Coroglio Bay (southern Tyrrhenian Sea)

The effects of contaminants on marine organisms have been documented since decades, but the long-term responses and recovery rates of benthic communities to mixtures of contaminants, several years after the cessation of industrial activities, need to be further investigated. Bagnoli-Coroglio Bay (Gulf of Naples, Tyrrhenian Sea) is a typical example of historically contaminated coastal area due to industrial activities stopped at the beginning of nineties. In the present study we carried out a fine spatial scale analysis of the distribution of meiofaunal (and nematodes) assemblages along five bathymetric transects located at increasing distance from the historical source of contamination in relation with the polycyclic aromatic hydrocarbon and heavy metal concentrations present in the sediment. Meiofaunal abundance and biomass changed widely along transects but independent from the distance from the source of contamination. Even when the contamination levels were expected to induce significant detrimental biological consequences, meiofaunal abundance and biomass were similar to those reported in unpolluted benthic coastal areas worldwide. Conversely, biodiversity in terms of meiofaunal taxa richness was generally low (range: 5–8 taxa in 12 of the overall 15 stations investigated). This was explained by the lack of sensitive groups such as ostracods, gastrotrichs and tardigrades commonly encountered in benthic coastal ecosystems, thus reflecting an overall poor/moderate environmental quality of the investigated area. Nematode (structural and functional) diversity was also low, particularly at stations characterized by higher contamination levels. At the same time, nematode species composition did not change significantly among stations suggesting a widespread effect of contaminants able to reduce the variability (i.e., turnover diversity) within the assemblages of the whole study area. Overall, our results indicate that even decades after the cessation of contaminant emissions, benthic biodiversity was affected in terms of both meiofaunal taxa and nematode species. These findings strongly reinforce the call for reducing sources of chronic pollution in marine ecosystems and provide new insights for a better understanding of the ecological recovery of historically contaminated marine environments.

Adverse Effect of TiO2 Nanoparticles on Antioxidant System and Antitumor Activities of Macroalgae Gracilaria lemaneiformis

Recently, the widespread use of TiO2 nanoparticles (nano-TiO2) has attracted the global concern regarding their adverse effects to aquatic organisms. Nanoparticles may get to the aquatic environments and harm the growth of algae. This paper presents the studies of nano-TiO2 concentrations influence on the photosynthetic characteristics, antioxidant system and antitumor activity of marine macroalgae Gracilaria lemaneiformis after exposed to 0, 5, 10, 20 or 40 mg L-1 of nano-TiO2. Results showed that the photosynthetic pigment content of G. lemaneiformis obviously decreased and the antioxidant defense system was significantly disturbed after exposure to nano-TiO2. Compared with control, the maximum level of malondialdehyde showed 3.3-fold increase for 15 days exposure to nano-TiO2. The activity of superoxide dismutase and catalase enhanced obviously by 1.10–2.24-fold. The aqueous extract of G. lemaneiformis (AEGL) possesses anticancer activity against HepG2 liver cancer cells proliferation and the 48 h-cell inhibition exceeds 35%. But the toxicity of nano-TiO2 would inhibit the anticancer activity of AEGL. When G. lemaneiformis was exposed to nano-TiO2, the effect of the aqueous extract of G. lemaneiformis on the cell inhibition, reactive oxygen species production, apoptosis, cycle arrest of HepG2 cells significantly lessened, and which were linearly associated with nano-TiO2 exposure concentration. Those results further confirmed that nano-TiO2 can inhibit the anticancer activity of G. lemaneiformis. The results in this work imply that macroalgae can be an effective biomarker of nano-TiO2 contaminant, and can be useful indicator to evaluate ecological effects of increasing pollutants in marine ecosystem.

Assessment of heavy metals contamination in selected tropical marine fish species in Bangladesh and their impact on human health

•Chemical pollution in marine ecosystems is leading towards an increase in the concentrations of heavy metals in fish body, which might have a negative impact on human health through consumption of fish. Here, five commercially important marine fishes (i.e. Sillaginopsis panijus, Trichiurus lepturus, Harpadon nehereus, Rita rita and Coilia dussumieri) were collected from the Kutubdia Channel of the northern Bay of Bengal, Bangladesh. Samples were collected during pre-monsoon and post-monsoon for the year of 2016 to measure the heavy metal concentrations in edible part (flesh) of the fishes; and finally to assess the human health risk due to consumption of those fishes. Heavy metal concentrations (i.e. Cr, Cu, Pb, Mn, Sn and As) in the collected fish species were determined using energy dispersive X-ray fluorescence (EDXRF) method. Subsequently, for assessing the human health risk, the target hazard quotient (THQ) values were estimated. This study found that the heavy metal concentration for Cr, Cu, Pb, Mn, Sn and As in fish samples were 1.51 to 2.53, 2.14 to 5.08, 2.89 to 3.41, 14.54 to 18.45, 23.04 to 32.21 and < 0.41 mg/kg respectively as dry weight basis. This study also revealed that the THQ values for all studied metals in five species of fishes for both seasons were < 1, which indicating no cancer risk due to consumption of those fishes. On the other hand, the target cancer risk for Pb was found within an acceptable level (10−4 to 10-6). Therefore, it has been suggested that the selected tropical marine fishes might be free from contamination and human might be in safe from any risk due to consumption of those fishes.

Pectin based finishing to mitigate the impact of microplastics released by polyamide fabrics

Washing processes of synthetic clothes have been identified as the main source of microplastic pollution in marine ecosystems. Textile microfibres have been found in marine sediments and organisms, posing a real threat for the environment. The development of mitigation approaches is strongly needed to prevent the impact of microplastics. In this work, an innovative finishing treatment of polyamide fabrics is proposed to mitigate the microplastic impact, by preventing the damage of fabrics during washings. The treatment is based on the use of pectin, a natural polysaccharide present in the cell walls of plants. To functionalize the fabric, pectin was firstly modified with glycidyl methacrylate (GMA) and then grafted on polyamide. Washing tests of treated fabrics showed the effectiveness of the treatment in reducing of about 90% the amount of microfibres released by untreated fabrics. Post-wash analysis of the treated fabrics revealed a promising resistance to the washing process.

Microplastic ingestion by Daphnia magna and its enhancement on algal growth

The rapid increase in plastic use over the last few decades has resulted in plastic pollution in freshwater and marine ecosystems. However, more attention has been paid to plastic pollution in marine ecosystems than to freshwater ecosystems. This research determined microplastic ingestion by Daphnia magna and the potential effect of microplastics on the organism's survival and reproduction. The study also examined the potential of microplastics to enhance algal growth in support of understanding effects of microplastic ingestion on the organism. When exposed to 25, 50, and 100mg/L fluorescent green polyethylene microbeads at size of 63–75μm, D. magna ingested significant amount of plastic microbeads. The number of ingested beads increased with increasing particle concentration and exposure time. However, no significant effect on survival and reproduction was observed although the gut of D. magna was filled with plastic microbeads. In the algal experiment, Raphidocelis subcapitata grew more in the exposure media with the present of plastic microbeads than without plastic microbeads. This result suggests that plastic microbeads could serve as substrates for R. subcapitata to grow. Raphidocelis subcapitata then could be transferred to the organism's gut and provided energy for survival and reproduction. Results of the present study add to the literature of microplastic ingestion by aquatic organisms. Caution should be taken when interpreting hazards of microplastics based on ingestion, such as the measurement unit and the presence of algae in the environment.

First report of Toxoplasma gondii sporulated oocysts and Giardia duodenalis in commercial green-lipped mussels (Perna canaliculus) in New Zealand.

Pollution of marine ecosystems with the protozoan parasites Toxoplasma gondii, Cryptosporidium spp. and Giardia duodenalis can be studied using bivalve shellfish as biosentinels. Although evidence suggests that these parasites are present in New Zealand coastal waters, the extent of protozoal pollution has not been investigated. This study used optimised molecular methods to detect the presence of Cryptosporidium spp., G. duodenalis and T. gondii in commercially sourced green-lipped mussel (Perna canaliculus), an endemic species found throughout coastal New Zealand. A nested polymerase chain reaction was validated for detection of T. gondii DNA and applied to 104 commercially sourced mussels. Thirteen mussels were positive for T. gondii DNA with an estimated true prevalence of 16.4% using Bayesian statistics, and the presence of T. gondii in mussels was significantly associated with collection during the summer compared with that in the winter (P = 0.003). Consumption of contaminated shellfish may also pose a health risk for humans and marine wildlife. As only sporulated T. gondii oocysts can be infectious, a reverse transcriptase-polymerase chain reaction was used to confirm presence of a sporozoite-specific marker (SporoSAG), detected in four mussels. G. duodenalis assemblage B, known to be pathogenic in humans, was also discovered in 1% mussels, tested by polymerase chain reaction (n = 90). Cryptosporidium spp. was not detected in the sampled mussel haemolymph. Results suggest that New Zealand may have high levels of coastal contamination with T. gondii, particularly in summer months, and that naturally exposed mussels can ingest and retain sporulated oocysts, further establishing shellfish consumption as a health concern.

Adverse effect of nano-TiO2 on the marine macroalgae Gracilaria lemaneiformis (Gracilariales, Rhodophyta): growth and antioxidant activity.

Macroalgae, the major contributor of primary productivity in coastal seas, contribute to the material cycle and energy flow in marine ecosystems. The purpose of this work was to evaluate the toxic effect of nano-TiO2 on the growth and antioxidant activity of Gracilaria lemaneiformis. An obvious inhibition of growth was observed in this study. The algae exposed to nano-TiO2 showed a negative growth rate at 20 mg L−1 and 40 mg L−1 during the 15 days exposure. The concentration of soluble protein increased slightly during the first 3 days of exposure, but it gradually diminished thereafter due to the high concentrations of nano-TiO2 and to prolonged exposure. Nano-TiO2 caused oxidative damage in G. lemaneiformis; superoxide anions accumulated, and nitrate reductase activity decreased linearly with the increase in nano-TiO2. Furthermore, extracts of G. lemaneiformis can scavenge DPPH· and hydroxyl radicals for their antioxidant capacity. However, the capacity to scavenge DPPH· and hydroxyl radicals in vitro decreased slightly with the increase in nano-TiO2. The results from this work imply that macroalgae can be an effective biomarker of nano-TiO2 contamination and can be useful indicators to evaluate the oxidative damage of increasing pollutants in marine ecosystems.

Micro-plastic ingestion by waterbirds from contaminated wetlands in South Africa

Despite a large literature on the impacts of micro-plastic pollution in marine ecosystems, very little research has focused on these pollutants in freshwater ecosystems. Recently, however, a few studies have demonstrated that micro-plastic pollutants are ingested by freshwater taxa, including birds. To explore this potential environmental threat in African freshwater systems we quantified micro-plastic pollutants in the faeces and feather brushings of seven southern African duck species. We analysed 283 faecal samples and 408 feather brushings, and found that 5% of faecal samples and 10% of feather samples contained micro-plastic fibres. The presence and abundance of micro-fibres differed between sampling sites, with significantly higher amounts recorded for the site that received effluent from a sewage treatment facility. Additionally, micro-fibre presence differed across duck species, indicating that foraging behaviour affects plastic ingestion. Our study confirms that African freshwater ecosystems and the biodiversity they support are under threat from micro-plastic contamination.

Marine plastic pollution as a planetary boundary threat – The drifting piece in the sustainability puzzle

The exponential increase in the use of plastic in modern society and the inadequate management of the resulting waste have led to its accumulation in the marine environment. There is increasing evidence of numerous mechanisms by which marine plastic pollution is causing effects across successive levels of biological organization. This will unavoidably impact ecological communities and ecosystem functions. A remaining question to be answered is if the concentration of plastic in the ocean, today or in the future, will reach levels above a critical threshold leading to global effects in vital Earth-system processes, thus granting the consideration of marine plastic pollution as a key component of the planetary boundary threat associated with chemical pollutants. Possible answers to this question are explored by reviewing and evaluating existing knowledge of the effects of plastic pollution in marine ecosystems and the ‘core planetary boundaries’, biosphere integrity and climate change. The irreversibility and global ubiquity of marine plastic pollution mean that two essential conditions for a planetary boundary threat are already met. The Earth system consequences of plastic pollution are still uncertain, but pathways and mechanisms for thresholds and global systemic change are identified. Irrespective of the recognition of plastic as a novel entity in the planetary boundaries framework, it is certain that marine plastic pollution is closely intertwined with global processes to a point that deserves careful management and prevention.

Molecular oxidative stress markers in olive ridley turtles (Lepidochelys olivacea) and their relation to metal concentrations in wild populations.

Due to their longevity and extensive migration areas, marine turtles are able to accumulate diverse contaminants over many years and as a consequence they represent an interesting bioindicator species for marine ecosystem pollution. Metals provoke toxicological effects in many aquatic animal species, but marine turtles have been under-investigated in this area. Thus, we have determined the presence of certain inorganic elements (As, Cd, Cu, Ni, Pb, Se and Zn) in olive ridley turtles (Lepidochelys olivacea) and related them to metallothionein (MT), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) transcription and/or enzymatic activities. Gene expression of sod, cat and gr was found to be higher in blood than liver or kidney but most of the significant relationships were found in liver, not only for gene expression but also for enzyme activities. This must be related to the role the liver has as the first filter organ. Several positive relationships of sod, cat and gr gene expression in the different tissues were found in this population, as well as very high Cd concentrations. This could mean that these turtles are adapting to the metals-production of ROS and damage through a high transcription of these antioxidants. Multiple positive relationships with GR seem to be part of its compensatory effect due to the decrease of SOD production against the high and chronic exposure to certain xenobiotics. CAT, on the other hand, seems not to be used much, and glutathione detoxification of H2O2 may be more important in this species. Finally, despite the very high Cd concentrations found in this population, no significant relationship was found in any tissue with metallothionein gene expression. These results, along with very high Cd concentrations and a negative relationship with Cu, lead us to consider some kind of disruption in mt gene expression in these turtles.

Natural and anthropogenic events influence the soundscapes of four bays on Hawaii Island

The soundscapes of four bays along the Kona Coast of Hawaii Island were monitored between January 2011 and March 2013. Equivalent, unweighted sound pressure levels within standard 1/3rd-octave bands (dB re: 1μPa) were calculated for each recording. Sound levels increased at night and were lowest during the daytime when spinner dolphins use the bays to rest. A tsunami provided an opportunity to monitor the soundscape with little anthropogenic component. We detected a decrease in sound levels and variability in one of the busiest bays. During the daytime in the 3.15kHz 1/3rd octave band, we detected 92 loud outliers from vessels, aquaculture, and military mid-frequency active sonar. During one military mid-frequency active sonar event sound levels reached 45.8dB above median ambient noise levels. The differences found in the bays illustrate the importance of understanding soundscapes to effectively manage noise pollution in marine ecosystems.

In vitro exposure of Ulva lactuca Linnaeus (Chlorophyta) to gasoline – Biochemical and morphological alterations

Refined fuels have considerable share of pollution of marine ecosystems. Gasoline is one of the most consumed fuel worldwide, but its effects on marine benthic primary producers are poorly investigated. In this study, Ulva lactuca was chosen as a biological model due to its cosmopolitan nature and tolerance to high levels and wide range of xenobiotics and our goal was to evaluate the effects of gasoline on ultrastructure and metabolism of that seaweed. The experimental design consisted of in vitro exposure of U. lactuca to four concentrations of gasoline (0.001%, 0.01%, 0.1%, and 1.0%, v/v) over 30 min, 1 h, 12 h, and 24 h, followed by cytochemical, SEM, and biochemical analysis. Increase in the number of cytoplasmic granules, loss of cell turgor, cytoplasmic shrinkage, and alterations in the mucilage were some of the ultrastructural alterations observed in thalli exposed to gasoline. Decrease in carotenoid and polyphenol contents, as well as increase of soluble sugars and starch contents were associated with the time of exposure to the xenobiotic. In combination, the results revealed important morphological and biochemical alterations in the phenotype of U. lactuca upon acute exposure to gasoline. This seaweed contain certain metabolites assigned as candidates to biomarkers of the environmental stress investigated and it is thought to be a promise species for usage in coastal ecosystems perturbation monitoring system. In addition, the findings suggest that U. lactuca is able to metabolize gasoline hydrocarbons and use them as energy source, acting as bioremediator of marine waters contaminated by petroleum derivatives.

Endocrine Disruptors as Pollutants in Marine Ecosystem: A Case Study in Egypt

Growing populations and increasing industry and agriculture activates have increased the existence of chemicals in the aquatic environment. The variety of anthropogenic chemicals that have been identified as potential endocrine disruptors (EDCs) in the environment and the problems arising from their use as human and livestock pharmaceuticals are discussed. Sewage effluents have been identified as a source of a diverse mixture of EDCs to the aquatic environment. These waters from homes and industries include natural and synthetic hormones (estrogens, androgens), active ingredients in pharmaceuticals, metals, pesticides, personal care product additives, and industrial chemicals. Once effluents are discharged to aquatic environments, EDCs will be diluted in stream or river waters so that organisms living very close to the discharge will have the highest exposure. Aquatic organisms also readily take up and store EDCs and its metabolites. Exposure to endocrine active compounds remains poorly characterized in developing countries despite the fact that behavioral practices related to westernization have the potential to influence exposure. Thus, in Egypt for example, it is likely that women in urban areas have a higher exposure to environmental hormonal risk factors, possibly xenoestrogens (EDCs) with regards to known risk factors of uterine and breast cancer.