Abstract: The control of ammonia build-up and its by-product is a limiting factor for a successful commercial aquaculture in a developing country like Nigeria. The technology for an advanced treatment of fish tank effluent is uneconomical to local fish farmers which have led to indiscriminate disposal of aquaculture wastewater, thereby increasing the concentrations of these nitrogenous compound and other contaminants in surface and groundwater above the permissible level. Phytoremediation using water lettuce could offer cheaper and sustainable alternative. On the first day of experimentation, approximately 100 g of water lettuce were replicated in four hydroponic units containing aquaculture effluents. The water quality parameters measured were concentration of ammonium–nitrogen (NH4+-N), nitrite-nitrogen (NO2--N), nitrate-nitrogen (NO3--N), and phosphate–phosphorus (PO43--P). Others were total suspended solids (TSS), pH, electrical conductivity (EC), and biomass value. At phytoremediation intervals of 7, 14, 21 and 28 days, the biomass recorded were 361.2 g, 498.7 g, 561.2 g, and 623.7 g. Water lettuce was able to reduce the pollutant concentration of all the selected parameter. The percentage reduction of pH ranged from 3.9% to 14.4%, EC from 49.8% to 96.2%, TDS from 50.4% to 96.2%, TSS from 38.3% to 81.7%, NH4+-N from 38.9% to 90.7%, NO2--N from 0% to 74.9%, NO3--N from 63.2% to 95.9% and PO43--P from 0% to 76.3%. At 95% confidence level, the analysis of variance shows that F(critical) is less than F(cal) and p < 0.05; therefore, it can be concluded statistically that the inequality between the pre-treatment and post-treatment values are significant. This suggests the potency of water lettuce for remediation of aquaculture effluent.
Abstract: Waste load allocation (WLA) policies may use multiobjective
optimization methods to find the most appropriate and
sustainable solutions. These usually intend to simultaneously
minimize two criteria, total abatement costs (TC) and environmental
violations (EV). If other criteria, such as inequity, need for
minimization as well, it requires introducing more binary
optimizations through different scenarios. In order to reduce the
calculation steps, this study presents value index as an innovative
decision making approach. Since the value index contains both the
environmental violation and treatment costs, it can be maximized
simultaneously with the equity index. It implies that the definition of
different scenarios for environmental violations is no longer required.
Furthermore, the solution is not necessarily the point with minimized
total costs or environmental violations. This idea is testified for Haraz
River, in north of Iran. Here, the dissolved oxygen (DO) level of river
is simulated by Streeter-Phelps equation in MATLAB software. The
WLA is determined for fish farms using multi-objective particle
swarm optimization (MOPSO) in two scenarios. At first, the trade-off
curves of TC-EV and TC-Inequity are plotted separately as the
conventional approach. In the second, the Value-Equity curve is
derived. The comparative results show that the solutions are in a
similar range of inequity with lower total costs. This is due to the
freedom of environmental violation attained in value index. As a
result, the conventional approach can well be replaced by the value
index particularly for problems optimizing these objectives. This
reduces the process to achieve the best solutions and may find better
classification for scenario definition. It is also concluded that decision
makers are better to focus on value index and weighting its contents
to find the most sustainable alternatives based on their requirements.
Abstract: The textile industry plays a major role in the economy
of India and on the other side of the coin it is the major source for
water pollution. As azo dyes is the largest dye class they are
extensively used in many fields such as textile industry, leather
tanning industry, paper production, food, color photography,
pharmaceuticals and medicine, cosmetic, hair colorings, wood
staining, agricultural, biological and chemical research etc. In
addition to these, they can have acute and/or chronic effects on
organisms depending on their concentration and length of exposure
when they discharged as effluent in the environment. The aim of this
study was to assess the genotoxic and histotoxic potentials of
environmentally relevant concentrations of C. I. Reactive Red 120
(RR 120) on Catla catla, important edible freshwater fingerlings. For
this, healthy Catla catla fingerlings were procured from the
Government Fish Farm and acclimatized in 100 L capacity and
continuously aerated glass aquarium in laboratory for 15 days.
According to APHA some physic-chemical parameters were
measured and maintained such as temperature, pH, dissolve oxygen,
alkalinity, total hardness. Water along with excreta had been changed
every 24 hrs. All fingerlings were fed artificial food palates once a
day @ body weight. After 15 days fingerlings were grouped in 5 (10
in each) and exposed to various concentrations of RR 120 (Control,
10, 20, 30 and 40 mg.l-1) and samples (peripheral blood and gills,
kidney) were collected and analyzed at 96 hrs. All results were
compared with the control. Micronuclei (MN), nuclear buds (NB),
fragmented-apoptotic (FA) and bi-nucleated (BN) cells in blood
smears and in tissues (gills and kidney cells) were observed.
Prominent histopathological alterations were noticed in gills such as
aneurism, hyperplasia, degenerated central axis, lifting of gill
epithelium, curved secondary gill lamellae etc. Similarly kidney
showed some detrimental changes like shrunken glomeruli with
increased periglomerular space, degenerated renal tubules etc. Both
haematological and histopathological changes clearly reveal the toxic
potential of RR 120. This work concludes that water pollution
assessment can be done by these two biomarkers which provide
baseline to the further chromosomal or molecular work.
Abstract: The aim of present study was to monitor the presence
of Trichodina sp. in Rainbow trout, Oncorhynchus mykiss collected
from various fish farms in the western provinces of Iran during
January, 2013- January, 2014. Out of 675 sampled fish 335, (49.16%)
were infested with Trichodina. The highest prevalence was observed
in the spring and winter followed by autumn and summer. In general,
the intensity of infection was low except in cases where outbreaks of
Trichodiniasis endangered the survival of fish in some ponds. In light
infestation Trichodina is usually present on gills, fins and skin of
apparently healthy fish. Clinical signs of Trichodiniasis only appear
on fish with heavy infections and cases of moderate ones that are
usually exposed to one or more stress factors including, rough
handling during transportation from ponds, overcrowdness,
malnutrition, high of free ammonia and low of oxygen concentration.
Clinical signs of Trichodiniasis in sampled fish were sluggish
movement, loss of appetite, black coloration, necrosis and ulcer on
different parts of the body, detached scales and excessive
accumulation of mucous in gill pouches. The most obvious
histopathological changes in diseased fish were sloughing of the
epidermal layer, aggregation of leucocytes and melanine-carrying
cells (between the dermis and hypodermis) and proliferative changes
including hyperplasia and hypertrophy of the epithelial lining cells of
gill filaments which resulted in fusion of secondary lamellae. Control
of Trichodiniasis, has been achieved by formalin bath treatment at a
concentration of 250 ppm for one hour.
Abstract: The purpose of the present work is to review some
data for the management challenges that the aquaculture industry in
Greece is currently facing. The results indicate that Greek
aquaculture fish farms apply Human Resources Management (HRM)
practices which can increase motivation, commitment and job
satisfaction of their personnel. In turn, these practices can increase
the productivity of the business. The Greek fish farms appear to
invest in research and technological innovation with a good record in
research activities and the generation of patents. Interestingly, the
results of the present work were carried out during the period of the
recent economic crisis in Greece. Several sectors of the Greek
economy were severely affected by the financial problems of the
Greek government and the Greek banks. Under the adverse
economical conditions created by the Greek economic crisis, even the
Greek aquaculture industry, which historically is considered as a
thriving national exporting business sector, experienced harsh
economic and market conditions. As a result of the global, European
and national economic crisis, consumption of fish dropped while
companies had to hold most of their stocked fish in order to regulated
the flow to the market and the price. This occurred at a time where
Banks in Greece had their own financial crisis – banking crisis -
which resulted in limited access to lending for the all business sectors
of the national economy including the Greek aquaculture industry. In
spite of these economic conditions, the Greek aquaculture industry,
after a series of mergers and acquisitions, has now stabilized
production and exhibits very good prospects for future growth.
Evidently, the firms had to cut salaries and on some occasions even
pay their staff in arrears. Nevertheless, the results presented in this
paper indicate that during the economic crisis, the surveyed fish
farms maintained their HRM practices, investing in their human
capital and technological input. In fact, human capital and
technological input are the ticket for future success of companies in
any business sector.
Abstract: Although the Vietnamese catfish farming has grown
at very high rates in recent years, the industry has also faced many
problems affecting its sustainability. This paper studies the
perceptions of catfish farmers regarding risk and risk management
strategies in their production activities. Specifically, the study aims
to measure the consequences, likelihoods, and levels of risks as well
as the efficacy of risk management in Vietnamese catfish farming.
Data for the study were collected through a sample of 261 catfish
farmers in the Mekong Delta, Vietnam using a questionnaire survey
in 2008. Results show that, in general, price and production risks
were perceived as the most important risks. Farm management and
technical measures were perceived more effective than other kinds of
risk management strategies in risk reduction. Although price risks
were rated as important risks, price risk management strategies were
not perceived as important measures for risk mitigation. The results
of the study are discussed to provide implications for various
industry stakeholders, including policy makers, processors, advisors,
and developers of new risk management strategies.
Abstract: In Croatia, the majority of cultured marine fish species are reared in net cages. The intensive production of the fish in net cages may generate the considerable amount of bio waste and change water quality especially in enclosed and semi-enclosed coastal areas. The aim of this paper is to assess the potential impact of sea bass (Dicentrarchus labrax L.) cage farm on water quality. The weak relationship between food supply and water quality parameters (nutrient content and phytoplankton biomass) was found, but significant changes in oxygen saturation was observed in the cages during the warmer period of a year especially in the morning (occasionally it dropped below 70 %). Despite of, satisfactory results of water quality parameters, it is necessary to establish comprehensive monitoring process, especially to include quality assessment of fouling communities.
Abstract: Periphyton development and composition were
studied in three different treatments: (i) two fishpond units of
wetland-type wastewater treatment pond systems, (ii) two fishponds
in combined intensive-extensive fish farming systems and (iii) three
traditional polyculture fishponds. Results showed that amounts of
periphyton developed in traditional polyculture fishponds (iii) were
different compared to the other treatments (i and ii), where the main
function of ponds was stated wastewater treatment. Negative
correlation was also observable between water quality parameters
and periphyton production. The lower trophity, halobity and
saprobity level of ponds indicated higher amount of periphyton. The
dry matter content of periphyton was significantly higher in the
samples, which were developed in traditional polyculture fishponds
(2.84±3.02 g m-2 day-1, whereby the ash content in dry matter 74%),
than samples taken from (i) (1.60±2.32 g m-2 day-1, 61%) and (ii)
fishponds (0.65±0.45 g m-2 day-1, 81%).
Abstract: The growth of the aquaculture industry has been
associated with negative environmental impacts through the
discharge of raw effluents into the adjacent receiving water bodies.
Macrophytes from natural saline lakes, which have adaptability to the
high salinity, can be suitable for saline effluent treatment. Eight
emergent species from natural saline area were planted in an
experimental gravel bed hydroponic mesocosm (GBH) which was
treated with effluent water from an intensive fish farm using
geothermal water. In order to examine the applicability of the
halophytes in treatment processes, we tested the relative efficacy of
total nitrogen (TN), total phosphorus (TP), potassium (K), sodium
(Na), magnesium (Mg) and calcium (Ca) removal for the saline
wastewater treatment. Four of the eight species, which were
Phragmites australis, Typha angustifolia, Glyceria maxima, Scirpus
lacustris spp. tabernaemontani could survive and contribute the
experimental treatment.
Abstract: The present study was designed to demonstrate the seasonal variations in physico-chemical parameters of fish farm at Govt. Nursery Unit, Muzaffargarh, Department of Fisheries Govt. of Punjab, Pakistan for a period of eight months from January to August 2008. Water samples were collected on fifteen days basis and have been analyzed for estimation of Air temperature, Water temperature, Light penetration, pH, Total dissolved oxygen, Clouds, Carbonates, Bicarbonates, Total carbonates, Total dissolved solids, Chlorides, Calcium and Hardness. Seasonal fluctuations were observed in all the physico-chemical parameters of fish farm. The overall physicochemical parameters of fish pond water remained within the tolerable range throughout the study period.