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136 Marine Ecology: Current and Future Developments, 2019, Vol. 1, 136-172
CHAPTER 7
An Overview of Pollution Dynamics along the
Pakistan Coast with Special Reference of Nutrient
Pollution
Noor U. Saher*, 1, Asmat S. Siddiqui1, Nayab Kanwal1, Altaf Hussain Narejo1,
Ayesha Gul2, Muhammed A. Gondal2 and Fakhar I. Abbass3
1 Centre of Excellence in Marine Biology, University of Karachi, Karachi, Pakistan
2 Department of Biosciences COMSATS Institute of Information Technology Park Road,
Islamabad, Pakistan
3 Bioresource Research Centre Bazar road, Islamabad, Pakistan.
Abstract: Pollution in coastal waters is quickly becoming a conspicuous problem
throughout the world and the coastal areas of Pakistan are also included in severely
affected and therefore no exception. Anthropogenic activities are generally accountable
for the deprivation of the marine environment along with their resources across the
ocean bodies. The oceans economy not only offers significant development
opportunities but also raise some challenges. Not only marine sources, the land-based
sources are the prominent contributor of pollution as add in the pollution through direct
and indirect wastes discharge as well as effluents in the adjacent coastal waters from
untreated domestic and industrial sources. In this chapter, the magnitude of pollution
(organic and inorganic) in coastal environments of Pakistan was discussed including
plastic pollution as in recent days, it’s a hot issue and a detailed topic itself. The
weathering material, river runoff, industrial and domestic waste water enter through
different channels and take part in coastal pollution. Most of the pollutants like
pesticides, herbicides, heavy metals and macro-nutrients, presented intensification in a
marine environment, Nutrient dynamics and their cycling influence the process of
eutrophication in the adjacent coastal waters and an enrichment of macro-nutrients in
coastal waters reveals an increment in the explosion frequency of harmful algal blooms
were reported. The animal manure, sewage treatment, runoff of fertilizers, storm water
runoff, plant discharges, and power plant emissions, and failing septic tanks are the
primary sources of nutrient pollution. The algal blooms are responsible to produce algal
toxins or red-tide toxins and these naturally-derived toxins harm the organisms,
including humans. These bloom toxins initially contaminated the fish or seafood
species, then responsible for significant loss of fish and shellfish species and ultimately
economy damage.
* Corresponding author Noor U. Saher: Centre of Excellence in Marine Biology, University of Karachi,
Karachi, Pakistan; Tel: +92-21-9261397, +92-21-9261551; Fax: +92-21-9261398; E-mail:
noorusaher@gmail.com
De-Sheng Pei & Muhammad Junaid (Eds.)
All rights reserved-© 2019 Bentham Science Publishers
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 137
Keywords: Marine Environment, Coastal Pollution, Nutrient Dynamics, Heavy
metal Contamination, Pollution Impacts.
INTRODUCTION
Coastal and estuarine ecosystems always remain sturdily subjective by the
activities of mankind through pollution and habitat loss throughout the world. The
environmental degradation, climate change, over-exploitation, pollution, poverty,
lack of basic (Health, Water as well as education) facilities are the conspicuous
issues for the coastal areas including the associated population. Pollution, now
become one of the most significant challenges to the health of coastal ecology and
systems. The pollution sources mainly include the land affected by agricultural or
industrial activities, livestock or domestic waste discharge and also from coastal
waters by aquaculture as well as other anthropogenic activities. The direct and
untreated discharge of industrial and agricultural effluents and domestic sewage
are the main contributor of pollution for the 990 km long coastline of Pakistan.
The impacts of coastal pollution appeared as a consequence of various
environmental issues mainly includes; the enrichment of organic matter leading to
eutrophication, pollution through chemicals (metals and oil), sea level rise due to
the global climate change and sedimentation as a result of land-based activities.
According to preliminary estimation, the fisheries and allied resources are the
primary livelihood for 80% of the coastal population of Pakistan as fishery-related
exports acquiesce per year on average sum of PKR 8.8 billion (US$ 838 million)
for the country. but this trade benefits are significantly dependent on the
sustainable utilization of these marine resources. Over 75% of all marine pollution
originates from land-based sources, which are primarily industrial, agricultural
and urban. Point and non-point source pollutions continue globally, resulting in
the steady degradation of coastal and marine ecosystems. There are various means
of Pollution incorporated through various human activities, including offshore oil
and gas production and marine oil transportation. Other contaminants produced
either naturally or anthropogenically ultimately flow into marine waters.
Pharmaceuticals are also an important pollution source, mostly due to
overproduction and incorrect disposal. Ship breaking and recycle industries
(SBRIs) can also release various pollutants and substantially deteriorate habitats
and marine biodiversity of adjacent coastal areas of Sindh and Balochistan coast.
AN OVERVIEW OF POLLUTION AND POLLUTANTS IN MARINE
ECOSYSTEM OF PAKISTAN
In Pakistan marine pollution is primarily restricted to the areas, which receive
waste from the industrial, municipal, agriculture and oil spill sources. The coast of
Pakistan faces semi-diurnal tides, therefore, washed twice a day and taking away
138 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
the pollutants, however inside the harbors or creeks; the pollutants are oscillating
for several days until they dispersed, washed or settle down at the bottom (Rizvi
et al., 1988; Sayied, 2007; Saher and Siddiqui, 2016). The 800 Km coastline of
Balochistan is almost free from marine pollution from land-based activities as it is
sparingly populated. Sonmiani Bay is one of the most populated city along the
Balochistan coast, located about 90 km away from Karachi (Saifullah and Rasool,
1995; Gondal et al., 2012; Saher and Siddiqui, 2016). The sources of fresh water
are the seasonal runoff of the Porali and Windor Rivers (Rasool et al., 2002).
These rivers receive effluents of around 122 industries, functioning at the Hub and
Windor Industrial Trading Estate, which include textile weaving, plastic,
chemical, food preservation, engineering, paper and paper product industries, etc.,
and mainly contribute to coastal contamination (LGB, 2008; Saleem et al., 2013;
Saher and Siddiqui, 2016). The close adjoining area is from industrial sites of
Karachi city and the few locations at the Hub industrial areas of Balochistan are
the major waste receiving areas. Karachi is the most urbanized and industrialized
city along the coast of Pakistan that has about 167 km long shoreline along the
Sindh coast. By the virtue of the biggest city of Pakistan, it has the highest risk
towards the environmental pollution, which insert from the diverse point and non-
point sources (Rizvi et al., 1988; Saher and Siddiqui, 2016). Solid waste
discharged into the marine environment is also a conspicuous serious threat to
marine life. A substantially large quantity of solid waste from the coastal towns
enters the sea on a regular basis, which is accumulated on beaches as well as in
the shallow coastal waters, making the coastal area polluted (MFF, 2016). It is
estimated that Karachi produces approximately 8000 tons of solid waste per day
and a substantial portion, i.e. around 60% of uncollected solid waste mixes up
with wastewater and enter in the sea at Karachi harbor. It along with the ships,
jetties, and inlets, thus compound the existing problem. The entered amount of
solid wastes spreads in the harbor and accumulates in different points of the
harbor and is expected to substantially increase with the rapid growth of
population and economic activity. According to an estimation by the year 2020,
solid waste generation in Karachi may come up to 16,000 to 18,000 tons each day
and therefore, there is a need to improve present solid waste management
practices and make them more effective and modernized according to acquired
demand (MFF, 2016).
There are four (Karachi Harbour, located on the Lyari River, Port Qasim on the
Indus deltaic region, Gizri Creek near the Malir River and a Cape Monze area a
side of Hub River) are the main coastal areas of Karachi which continuously
receive the land-based pollution. The more than six thousand functional industries
present in six different industrial estates and their untreated effluent along with
300 MGD municipal wastewater continuously discharged into coastal waters of
Karachi (WWF, 2002; Mashiatullah et al., 2016). Two rivers (Malir and Lyari)
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 139
are the seasonal rivers and flow during southwest monsoon and main point
sources of coastal contamination. Both rivers act as an exposed sewage channel
that loaded with highly polluted industrial and domestic wastewater. The Lyari
River annually releases the 90 tons of phosphate compounds, 160,000 tons
organic matter, 800 tons of nitrogenous compounds, 130,000 tons of solid
nitrogen, and 12,000 tons of suspended solids into the Manora Channel (JICA,
2007; Mashiatullah et al., 2016). It is estimated that more than 430 (MGD) of
untreated sewage dumped into the adjacent coastal environment of Karachi
through the tributaries of Malir and Lyari rivers. These rivers are polluted through
organic and inorganic pollutants which come from diverse sources such as
agricultural runoff, industrial effluents, urban and domestic waste that ultimately
drain into the Arabian Sea through the beaches of Karachi (Rizvi et al., 1988;
Sayied, 2007; Siddique et al., 2009; Saher and Siddiqui, 2016).
According to an estimation >1,500 tons/day of Biochemical Oxygen Demand
(BOD) is added into the Karachi coastal waters through associated industries. In
addition, along with inorganic pollutant the sewage generated quantity has
increased up to 350 MGD during the previous years. The combined treatment
capacity of the treatment plants is approximately less than 50% of the total
sewage generated (Sayied, 2007). The adjacent coastal waters and various creeks
in Karachi show evidence of eutrophication due to elevated levels of organic
pollution. Due to the discarding of a huge quantity of untreated effluents and
sewage, the few habitats mainly Manora Channel and Gizri Creek has been near
to completely destroy as mostly areas of these water bodies are now devoid of any
marine fauna (Fig. 1).
In addition, a major portion of the creek system near to to Port Qasim is also
observed as heavily polluted due to receive of heavy metal discharge from the
Steel Mill and tanneries, thermal discharges from power plants, and organic
discharge of the cattle colony (MFF, 2016).
The coastal (Fig. 2) developments or the unscientific infrastructural development
along the shoreline also considered a threat towards the coastal environments.
Karachi is the largest industrial and commercial estate situated near the proximity
of the Indus delta along the coastal belt of Pakistan and continues to expand
rapidly. However; rapid establishment of new housing sectors, industrial estates
and construction activities contribute to waste generation.
A navigational channel of about 45 km in length is the connection between the
Phitti Creek connects Port Bin Qasim to the open Arabian Sea. The widening and
deepening of this channel also a cause of severe coastal erosion problem and
therefore resulted in the substantial destruction of barrier islands which used to act
140 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
as the nature’s first line of defense against coastal erosion (Muzaffar et al. 2017).
Indications are that erosional forces continue to alter the hydraulic regime in the
area even though the remedial measures to stabilize coastal sediment erosion
through the plantation of mangrove have been taken. Prior to developmental
activities in this area, all coastal processes were naturally controlled (Muzaffar et
al. 2017). For instant economic profit, the developers also use sand as excavated
from the adjacent beach as infill material as lack of awareness that beach sand
provides protection from high energy waves (Muzaffar et al. 2017).
Fig. (1). The solid waste material distribution along the Korangi Gizri creek area and in adjacent Korangi
harbor waters.
Fig. (2). Some ongoing construction activities along the coastal areas of Sindh.
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 141
The coastal erosion over the centuries is a result of natural processes and sea level
change. In recent times, the rate of erosion appears to have increased at certain
specific points along the coast. The coastal erosion hotspot areas in Balochistan
coast include Jiwani, ShadiKor, and Damb, where intensity is very severe. In the
Sindh coast, severe erosion intensity has estimated at various points of Karachi
(Phitti and Gizri Creeks, Hawksbay, Clifton, DHA phase-8 and RasMurai), Thatta
(KharoChann, KetiBundar, Mirpursakao, Ghorabari, Gharo Creek), Sujjawal (Jati
and Shah Bunder) and Badin. These areas are display severe to very severe
erosion issues resulting either by natural processes or human activities, which is
mainly attributed to reduced freshwater flows and seawater intrusion (MFF,
2016).
Pollution Hotspots along with Pollution Types
The biggest port of Pakistan, Port Bin Qasim is located at the South of Karachi in
the Indus Delta Region. The port related activities and associated industries are
the main contributors of pollution in the deltaic region. The shipping activities at
the port Qasim and contaminated water from Power Generation Plants and
Pakistan Steel Mill are the major sources of pollution, the. However, the industrial
effluent, domestic sewage, wastes from the Landhi cattle colony and the Korangi
fish harbor. Hub Industrial Trading Estate (HITE) and the HUBCO power plant
are also the major sources of marine pollution in the vicinity of Malir River and
Gizri Creek area. The Industries operating in HITE and the HUBCO power plant
continuously discharged effluent into the Hub River that ultimately dumped into
the Arabian Sea (Sayied, 2007).
Radioactive Waste
Nuclear Power Plant (KANUPP) is the causative source of artificial radioactivity
along the Karachi coast. The periodic monitoring of radioactivity also done
through survey of the adjacent vegetation and soil material and shown that
radioactivity has not increased in the water environment. Another larger, nuclear
power plant is being built upcountry near Chashma in the district Mianwali.
Through this source some radioactivity may reach the coastal waters of Pakistan
via the river Indus, but the level is expected to be insignificant.
Oil Pollution, Shipping, and Accidents
The oil pollution can be evidenced through the tar-balls on different beaches
throughout the the coast. Oil spills can be caused by release of crude oil from
drilling rigs and wells, offshore platforms, oil tankers, and spills of refined
petroleum products and their by-products. The intertidal areas are also blackened
with oil in the vicinity of the oil refineries along Korangi and Gizri creeks. The
142 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
Indus Delta is located at a safe distance from another source of oil pollution:
mechanized fishing boats as relatively small in number (Akhter, 1995). Annually
more than 200 oil tankers and 2,500 ships visit the Karachi harbor through the
Manora Channel. There is large scale shipping traffic at Port Qasim. The bilges,
washings from engine rooms of vessels, discharges, leaks and small spills
occurring during loading and unloading at oil piers are the sources of oil pollution
in Manora channel. Although a great deal of oil pollution is present in the Manora
Channel (flushed daily by the tide) virtually no trace can be found along the
beaches in the vicinity of the channel. This may be due to the large-scale dilution
because of the direction of the current as occurs along the watercourse when the
effluent reaches to the Sea. Oily waste from city-based sources, including service
stations, also ends up in the harbor area (MFF, 2016).
No information is available for the southeast coast. The sandy and rocky intertidal
zones at Gadani are smeared with oil, which flow from the oil tanks of vessels
scrapped at the ship-breaking yard. The country’s largest ship breaking industry is
located at Gadani only 50 km northwest of the Karachi. The ships are brought for
scrap since last 50 years and causing all sorts of organic and inorganic pollution
along the coast. A gradual building of heavy metals has been reported in the
sediments from the Gadani coastal area. Light refined oil is known to be more
toxic to adult fish than crude and heavy fuel oil. It is generally believed that oil
spilled at sea, in small or large quantities, does not immediately affect stocks of
fish and shellfish, but oil pollution may be gradual and chronic, resulting in the
long-term reduction of fish production and can be hazardous for inland and
coastal water fauna. The new naval harbor at Ormara and the upcoming Harbor in
Gwadar would contribute towards pollution if strict measures are not taken to
prevent pollution (Sayied, 2007). The recent oil spillage from the tanker Tasman
Spirit, which went aground on 30 July 2003 as spilled approximately 35,000 tons
of oil into the Arabian sea, attracted a great deal of criticism from medical circles
concerning the effects, livelihood of 90,000 registered fishermen of Sindh were
affected as the oil slick in the fishing zone led to a sharp decline in the sale of
seafood in the city markets. Prices of different fish species came down by 60-70%
and the both short-term and long-term on the health of people, living or working
in the vicinity of the affected area (Khurshid et al., 2008; Sayied, 2007).
Thermal Pollution
Hot water discharges from power plants such as the Karachi Nuclear Power Plant
(KANUPP), and plants owned by the Steel Mills and the Karachi Electric Supply
Corporation affect the fauna and flora immediately around the outfall; but since
the emission is relatively small compared to the receiving environment, the
damage is localized (Akhter, 1995). In addition, a major part of the creek system
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 143
adjacent to Port Qasim is also heavily polluted because of thermal discharges
from power plants, heavy metal discharge from the Steel Mill and tanneries, and
organic discharge from the cattle colony (MFF, 2016).
Marine Debris
Marine debris along the beach fronts is another foremost constituent of marine
pollution and major portion of debris enters from the adjacent land, inland water
channel and through beach visitors. According to the United Nations Joint Group
of Experts on the Scientific aspects of Marine Pollution (GESAMP, 1991); land-
based sources accounted for about 80% of the worldwide marine pollution.
However, significant quantities of plastic trash are buoyant, resilient and slow to
degrade (Williams and Simmons, 1996). Apart from municipal sewage and
industrial wastes, the Lyari river also brings in a heavy load of floating garbage. It
is estimated that the 50% pollution of the Karachi harbor is brought in by the
Lyari River. Ali and Shams (2015) quantified and characterized the debris along
the most popular recreational sandy beach front beach Clifton (Karachi). The
study reveals the high abundance and composition of various man-induced debris
(Fig. 3).
Fig. (3). Mean composition of debris km-1 of beach front (Clifton) Karachi (modified from Ali and Shams,
2015).
MAJOR POLLUTANTS
Pakistan has been struggling to develop and improve its industrial as well as
agricultural sectors and the rapid urbanization and indiscriminate industrialization
pose an impact and numerous environmental issues have been originating related
to the ecological integrities. About 80% of the industrial growth is restricted to
major cities of the country like Hyderabad, Multan, Faisalabad, Karachi, Lahore,
-1
010 20 30 40 50 60
Plastic
Food
Paper
Glass
Metal
Wood
Cloth
Styrofoam
Masonry
Rubber
Percent Composition
Type of marine debris
Marine Debris
% Weight
144 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
Sialkot, Gujranwala, Rawalpindi, Peshawar, and Kasur (Aftab et al. 2000;
Mehmood et al. 2017).
Persistent Organic Pollutants/Polycyclic Aromatic Hydrocarbons/ Pesticides
Thousands of persistent organic pollutants (POP) chemicals remain migrating to
the environment for certain families of chemicals (for example, about 209
different polychlorinated biphenyls with a wide range of difference in chlorination
and substitution position) and having long half-lives in the air, soil, sediments,
and biota. POPs are lipophilic and hydrophobic chemicals and have the capability
to be stored in fatty tissues. These POPs persistence in the biota and can easily
accumulate them in the food chain (Jones and de-Voogt, 1999; Mehmood et al.
2017). Karachi is one of the highest emerging sites, for POPs along the coastal
zone followed by Thatta in the Deltic zone (Fig. 4), which pose a serious threat to
the marine environment (Mehmood et al. 2017).
Fig. (4). Map of Pakistan showing density of population and locations of studies reported for newly emerging
POPs (1: Karachi, 2: Thatta, 3: Haiderabad, 4: Multan, 5: Lahore, 6: Sialkot, 7: Gujranwala, 8: Gujrat, 9:
Faisalabad, 10: Nowshehra, 11: Islamabad, 12: River Ravi, and 13: River Chenab) (modify from Mehmood et
al. 2017).
Polycyclic aromatic hydrocarbons (PAHs) represent another group of conspicuous
persistent organic pollutants (more than 100 congeners) renowned due to
mutagenic, carcinogenic and immuno-toxic properties (Din et al. 2013; Callen et
al. 2011; Jang et al. 2013; Hamid et al. 2015). The occurrence of PAHs in various
environments is recognized as through natural (volcanoes and forest fires) and
anthropogenic sources (coal and coke incineration, purifying and emission of
petroleum and its related products, exhaust of motor vehicles, etc.) (Ravindera et
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 145
al. 2007; Zhang and Tao, 2009; Hamid et al. 2015). The thousands of glaciers of
the Himalayas are also known as the third Pole in the world and also act as a
condenser for PAHs similarly in the Arctic region (Kang et al. 2009; Hamid et al.
2015).
In Pakistan, the chemical pesticides are also used specifically the use of agro-
chemical pesticides started in 1954 with 254 metric tons (MT) however, the
formulations and its consumption increased over 7000 tons/year. Pesticide
consumption has been increasing from 16,226 MT in 1976–77 and increase each
year, reached to a maximum of 20,648 MT in 1986–87 (Baloch, 1985) and further
increased up to 78,132 tons/annum (Syed and Malik, 2011). The use of pesticide
has been increased 100 times in Pakistan during 1980–2002 (Khan et al. 2002;
Mehmood et al. 2017). Insecticides (74%) are the commonly used pesticides in
the country followed by 14% of herbicides (), 9% of fungicides, 2% and 1% of
acaricides and fumigants respectively (). in Pakistan about 69% of total pesticides
used for cotton crop and the rest are used for wheat, maize, rice, etc. (Economic
Survey of Pakistan, 2005–2006). Presently, about 108 types of insecticides, 30
types of fungicides, 39 types of weedicides, 5 types of acaricides and 6 different
types of rodenticides, are commonly used pesticides in Pakistan (PPSGDP, 2002).
The use of pesticide has almost increased by 1169% in the country and the
number of sprays has reached 10/crop that can pose the drastic effect to human
health (Mehmood et al. 2017).
In 2003, Pakistan imported 78,133 metric tons (MT) of pesticides belong to
organochlorine, organophosphate, and pyrethroid groups, while in the same year
sales of Endosulfan were 117.98 MT in Pakistan (Khooharo et al. 2008). Despite
the importance, there only few studies are reported regarding the chlorinated
pesticides in the coastal environment of Pakistan (Saleem et al. 2013). In Fig. (5),
the analysis of 16 organochlorine pesticides (OCP’s) was presented in coastal
waters of Pakistan (Saleem et al. 2016). Traces of these pesticides were also
reported in human foods and marine biota of Karachi coast (Munshi et. al. 2004;
Sanpra et al. 2003). Khan et al. (2010) reported the environmental safe limits of
organochlorine pesticides (OCPs) in Karachi harbor and adjoining areas as
compared to regional countries. The impact and toxicity of pesticides on marine
organisms in Pakistan has been studied and well documented (Naqvi et al. 2017;
Shoaib et al. 2013; Shoaib et al. 2012; Shoaib and Siddiqui, 2015).
Heavy Metals
Heavy metals are toxic, persistence and non-biodegradable in nature, therefore,
considered as potentially hazardous materials in marine environments (Ali et al.
2014; Saher and Siddiqui, 2016; Çoğun et al. 2017). They originate from natural
146 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
(weathering of parent rock) as well as anthropogenic (mining, agricultural
activities, industrial applications, and atmospheric deposition) sources into coastal
environments (Bryan and Langston, 1992; Callender, 2005; Saher and Siddiqui,
2016). Few metals (for instance Se, Fe, Cu, Cr, Zn, Co, Mo, V, Mn, and Ni) play
a role as essential micronutrients for organisms in several metabolic processes but
become toxic, if in excess level. On the other hand, some metals (Hg, Cd, Ag, and
Pb) are considered as nonessential and can cause toxicity in small dosage (Bryan,
1979; Eisler, 2010; Saher and Siddiqui, 2016; Duarte et al. 2017). Due to their
nature, they easily accumulate in organisms and biomagnified in the food web and
possess the severe threats to aquatic fauna (Ahearn et al. 2004; Rainbow, 2007;
Vilhena et al. 2012; Duarte et al. 2017; Kanwal and Saher 2018).
Fig. (5). Percent composition of organochlorine pesticides from coastal waters of Pakistan (modified from
Saleem et al. 2016).
Heavy metals could be circulated through blood within the body and reside or
accumulate in the organs of consumer and then appear in toxic forms, both for the
organisms and humans that consume contaminated seafood (Wang et al. 2005;
Çoğunet al. 2017). The concentration levels of heavy metals in water, sediment
and biota are studied from a coastal environment in Pakistan (Table 1). Heavy
metals concentrations in sediments of Pakistan extensively evaluated in recent
decades as the sediment considered as the primary indicator for pollution
monitoring (Saifullah et al. 2002; Qari et al. 2005; Siddique et al. 2009;
Mashiatullah et al. 2013; Chaudhary et al. 2013a, b; Ali et al. 2014; Saher and
Siddiqui, 2016).
0% 20% 40% 60% 80% 100%
Alpha-HCH
Delta-HCH
Aldrin
Endrin aldehyde
Endosulfan sulfate
4,4-DDT
Organochlorine Pesticides in coastal
water
Balochistan (Off shore) Karachi (Off shore)
Indus delta (Creeks)
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 147
Table 1. The literature review on the study of heavy metals and Heavy metal concentrations in water,
sediments and fauna along the coastal areas of Pakistan.
Co Ag Cd Cr Cu Fe Mn Ni Pb Zn Hg Mg Ref.
COASTAL WATER - 15 4 29 38 93 161 19 109 1215 87 - [1]
- - 0.0006 - 0.0014 - - - 0.0007 0.130 - - [2]
MARINE SEDIMENTS [1]
- 0.53 0.44 32.3 24.4 23,
259
238 76.4 7.9 65.3 0.95 -
0.07 - 0.01 0.03 0.01 6.75 5.19 0.03 0.07 0.06 - 10.95 [3]
22.18 - 2.27 83.27 30.93 1.85% 39.88 27.91 24.80 65.91 - - [4]
- - - 96.75 - 3.07 500 31.39 23.24 204.79 - [5]
1.1 - 0.4 171 64.2 - - 34 45 68 - [6]
- - 1.43 - 52.23 - - - 59.99 111.87 - - [2]
Monitoring Year I (MY-I) 9.225 - 0.958 31.66 57.43 865.6 - 34.50 40.38 100.67 - - [7]
Monitoring Year II (MY-
II)
8.51 - 1.20 107.2 82.6 978.13 - 46.23 53.40 100.7 - - [7]
SEAWEED
Cladophora - 0.76 2.94 4.58 4.73 592 3.30 6.13 5.70 12.36 0.24 - [1]
Dictyota sp. - 0.40 0.32 7.93 0.99 124 7.15 19.24 1.87 2.87 0.21 - [1]
Lyngeriastellata - 0.45 0.32 7.93 0.99 124 7.15 19.01 0.15 2.61 0.21 - [1]
Padinapavonia - 0.42 0.76 9.12 1.70 373 10.03 19.16 0.44 4.10 0.23 - [1]
MANGROVES
Pnuematophores - - 1.04 - 11.78 - - - 14.75 90.40 - - [2]
Bark - - 0.70 - 15.37 - - - 9.956 80.08 - - [2]
Leaves - - 0.46 - 5.36 - - - 0.681 61.28 - - [2]
Flowers - - 0.40 - 1.87 - - - 0.178 18.08 - - [2]
Fruits - - 0.38 - 1.80 - - - 0.433 37.76 - - [2]
Twigs - - 0.24 - 4.89 - - - 0.59 39.54 - - [2]
FISH
Chactadonjayakeri - 0.29 0.35 5.10 0.89 937 4.87 12.12 0.59 4.99 0.09 - [1]
Rastrelligerkanagurta - 0.53 0.36 8.51 1.56 1791 7.68 18.28 0.14 19.83 0.16 - [1]
Pornadysismaculaturn - 0.30 0.26 5.20 0.83 889 6.65 12.09 11.63 7.22 0.15 - [1]
Oreochromismossambicus - - 25.4–33.7 6.8–6.94 2.87–3.6 27.42–66.2 2.24–2.69 [8]
Cyprinuscarpio - - 1.12–4.82 1.65–2.09 1.08–1.52 36.6–39.7 4.98–8.72 [9]
Megalaspiscordyla [10]
Liver - - 1.86 1.90 - 439.17 8.92 - 1.62 - - -
Kidney - - 1.81 1.90 - 31.51 3.31 - 1.72 - - -
Gills - - 1.84 1.33 - 31.12 4.40 - 1.71 - - -
Muscle - - 0.45 0.32 - 41.23 2.49 - 0.41 - - -
Sardinellaalbella [11]
Liver - - 1.835 - 14.74 433.1 9.77 - 2.08 51.78 - -
Gills - - 1.897 - 2.97 41.48 3.42 - 1.62 14.86 - -
Muscles - - 0.81 - 1.97 6.16 1.77 - 0.48 2.5 - -
CRAB
Macrophthalmusdepressus 11.02 - 1.76 14.36 85.26 654.4 - 27.21 68.8 88.2 - - [12]
148 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
Co Ag Cd Cr Cu Fe Mn Ni Pb Zn Hg Mg Ref.
Ilyoplax frater 14.54 - 2.22 10.8 122.06 373.8 - 26.93 72.7 94.91 - - [13]
Opusiaindica 22.1 - 1.94 9.2 69.1 409.8 - 19.91 25.56 78.07 - - [14]
Austrucasindensis 6.77 - 1.54 7.3 58.2 33.1 - 25.92 94.13 39.3 - - [15]
SHRIMP
Metapeneaus monocerous 0.29 0.47 5.90 1.20 806 6.42 12.64 1.71 4.21 0.15 - [1]
Penaeus japonicus 0.25 0.47 0.18 4.55 837 3.14 13.10 1.60 7.11 0.13 - [1]
Reference: [1] Tariq et al. (1993); [2] Ismail et al. (2014); [3] Qari et al. (2005); [4] Siddique et al. (2009);
[5] Mashiatullah et al. (2013); [6] Ali et al. (2014); [7] Saher and Siddiqui, 2016; [8] Jabeen and Chaudhry
(2009); [9] Jabeen and Chaudhry (2010); [10] Ahmed et al. (2014a); [11] Ahmed et al. (2014b); [12] Saher
and Siddiqui (2019); [13] Siddiqui and Saher (2019); [14] Siddiqui and Saher (2016); [15] Saher and Siddiqui
(2017)
The severity level of metal toxicity in organisms, in both cases (essential and
nonessential), primarily depends on the concentrations, persistence, mobility and
bioavailability of metals in water or/and sediments (Ahearn et al. 2004; Luoma
and Rainbow, 2008; Vilhena et al. 2012; Duarte et al. 2017). During the past
decades, the severity of heavy metal contamination in the marine environment of
Pakistan has been intensified mainly due to anthropogenic activities and lack of
management towards the dumping of contaminants in river bank and coastal areas
(Fig. 6).
Fig. (6). Comparison of heavy metals pollution in coastal sediments between the two monitoring years by
single metal pollution indices.
Heavy metal pollution in coastal sediment evaluated by means of various multiple
pollution indices Geo-accumulation index (Igeo), contamination factor (CF), the
enrichment factor (EF), and potential ecological risk factor (ER) each based on
single metal to illuminate the pollution elevation or relegation during two
monitoring years. The Geo - accumulation index showed negative or less than
zero Igeo values of Zn, Co, Fe, Cu, Cr, and Ni specify overall an unpolluted
condition. However, few sites presented specific contamination, such as moderate
(Table 1) cont .....
0
500
1000
1500
Fe Cu Zn Co Ni Cr Pb Cd
Metal Concentration (µg/g)
(a) Metal levels in coastal
sediments
MY-I
MY-II
0
500
1000
Fe Cu Zn Co Ni Cr Pb Cd
Metal Flux
(b) Metal Flux in coastal
sediments
MY-I
MY-II
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 149
pollution of Zn and Cu evaluated in the Sandspit mangrove area during both years
(Fig. 7). The enrichment factor indicates the extremely high enrichment (>50) for
Cu, Pb, Zn, and Cd during both monitoring years, suggesting potential threats by
these metals to the marine environment and biodiversity. The contamination
factor showed the low contamination of Fe, Co and Ni perceived during the last
decade. The ecological risk factor estimated to scrutinize the heavy metal eco-
toxicology and their influence on benthic fauna. Low risk of all metals was
perceived along the coastal sediment of Pakistan, except Cd, that showed the
considerable risk in both monitoring years.
Fig. (7). The industrial pollution traces evidenced in Sandspit backwater areas during some ongoing
ecological studies.
For MY-I, contamination degree was ranged from 1.53 to 20.8, indicating low to a
considerable degree of contamination along the coastal sediment of Pakistan.
Whereas, it varied from 7.21 to 33.21 for MY-II, indicated low to very high
degree of contamination along the coastal sediment of Pakistan (Fig. 8e).
However, PERI varied from 55 to 272 during the MY-II, indicated low to
moderate risk of heavy metals in the coastal sediments of Pakistan (Fig. 8f).
Nutrients Dynamics in Marine Environment of Pakistan
The nutrients (Phosphate, Nitrate, Nitrite, and Ammonia) play an imperative role
in the marine food chain while to consider and act fertilizers of the sea chiefly in
primary production of marine waters. Nutrient cycling is essential for the
maintenance of any ecosystem as it’s generally known as the chemical alteration
of nutrients and/or the flux of nutrients between different compartments or stages,
such as organisms, habitats or even ecosystems (Vanni, 2002). These nutrient
alterations sustain and stimulate the growth of phytoplankton (primary
productivity in the marine habitat and basic constituent of the marine food chain)
primarily serve as the food for primary consumers (zooplankton community,
larval stages of various invertebrates and vertebrates organism, juveniles of fish
150 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
and crustaceans) and for filter feeders (EMC, 2013). They need nutrients for their
growth and nourishment thus the seasonal changes in nutrients may effect on
phytoplankton production (Shoaib et al., 2017). Nutrients can also be pulsed
during storm-mediated increases in mixing (Wetz and Paerl 2008), transport
(Lovelock et al., 2011) and upwelling events (Field et al., 1980). The changes in
the phytoplankton communities size and structure influence the providence of Net
primary production NPP (Malone, 1980; Legendre and Rassoulzadegan, 1996;
Pomeroy et al., 2007; Marañón, 2009).
Fig. (8). Comparison of heavy metals pollution in coastal sediments between the two monitoring years by
single and combined metal pollution indices.
-10
-5
0
5
Fe Cu Zn Co Ni Cr Pb Cd
(a) Geoaccumulation Index
MY-I MY-II
0
50
100
150
200
Fe Cu Zn Co Ni Cr Pb Cd
(b) Enrichment Factor
MY-I MY-II
0
2
4
6
Fe Cu Zn Co Ni Cr Pb Cd
(c) Contamination Factor
MY-I MY-II
0
50
100
150
Cu Zn Ni Cr Pb Cd
(d) Ecological Risk Factor
MY-I MY-II
0.0
10.0
20.0
30.0
DH BH PC KC SP SO SB
(e) Contamination Degree
MY-I MY-II
0
100
200
300
DH BH PC KC SP SO SB
(f) Potential Ecological Risk
MY-I MY-II
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 151
The NPP is the entire photosynthetic fixation of inorganic carbon into autotrophic
biomass. NPP sustains the life and energizes the global cycles of carbon, nitrogen,
phosphorus, and other nutrients, and is also a main factor of atmospheric CO2 and
O2 levels. An estimated Global NPP is about ~105Pg C yr-1 and half of this
includes marine plants (Field et al., 1998; Falkowski and Raven, 1997; West berry
et al., 2008). In the upper ocean, euphotic zone the macrophytes and
phytoplankton, respectively account for ~6 percent (~3.0 Pg C yr-1) and ~94
percent (~50 ± 28 Pg C yr-1) of NPP (Duarte et al., 2005; Carr et al., 2006;
Schneider et al., 2008; Chavez et al., 2011; Ma et al., 2014; Rousseaux and
Gregg, 2014). In the marine environment, the bioavailability of nitrogen (N) is
necessary for biological production and is mostly depleted at the surface of the
world ocean (Montoya et al., 2004; Ahmed et al., 2017). Therefore, the supply of
nitrate from deep water is the major source of new nitrogen sustaining primary
productivity, Marine biological N2 fixation accounts for ~50 percent of N2
fixation globally (Ward, 2012). The Arabian Sea always remains identified as site
for active N2 fixation dynamics (Devassy et al., 1978; Capone et al., 1998; Ahmed
et al., 2017). The excess level of phosphate in surface waters arising through
denitrification is the main factor that favors the growth of nitrogen fixers in the
Arabian Sea (Bange et al., 2005; Ahmed et al., 2017) as the bloom and a recurring
phenomenon of filamentous diazotrophic cyanobacteria (Trichodesmium sp.) are
well documented in this region (Desa et al., 2005; Parab et al., 2006; Basu et al.,
2011; Ahmed et al., 2017). The incorporation of nutrient through river runoff
increase the NPP in coastal waters throughout the growing season (Seitzinger et
al., 2005; Seitzinger et al., 2010) therefore, account for the largest part of NPP
during spring blooms at high latitudes (Malone, 1980). The nutrient supply pattern
and variation in sunlight duration predominantly related to annual cycles of NPP
and are likely to raise the amplitude. In addition, the seasonal amplification in
NPP in general follow the winter mixing and when nutrient concentrations
amplify, then the cycles are also more evident in coastal waters in accordance to
seasonal upwelling. The Arabian Sea considered as a high productive zone due to
the intense upwelling phenomenon caused by the southwest monsoon (Qasim,
1982). The high production of organic matter leads to an intense oxygen
minimum zone (OMZ) at 150–1200 m water depth in the Arabian Sea (Wyrtki,
1973; DeSousa et al., 1996; Linsy et al., 2018). Higher concentrations of nutrients
result in overproduction and utilization of dissolved oxygen in the seawater
(Amjad and Rizvi, 1999). In addition, the high phytoplankton and zooplankton
productivities lead to high fish production in the Arabian Sea (Schenau and De-
Lange, 2000; Linsy et al., 2018). The huge amount of nutrients supplied to the
coastal areas by the Indus River, Hub River and seasonal rivers such as Malir
River, Lyari River, Windor River, Porali River, Hingol River, ShadiKhor and
Dasht River (Amjad and Rizvi, 1999). The coastal upwelling wind-induced
152 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
mixing and nutrient-rich water is the major factor for phytoplankton abundance in
the northern Arabian Sea during northeast (winter) monsoon period (Banse and
Mc Clain, 1986; Levy et al., 2007; Shoaib et al., 2017). However, these
phenomena were opposed in the backwater area due to high load of domestic and
industrial effluents (Harrison et al., 1997; Mashiatullah et al., 2004; Saifullah et
al., 2004; Iftikhar et al., 2015).
Phosphorus (P) is another vital nutrient for life, found in forms of phosphate and
organic phosphate and plays a key role in regulating primary productivity over
geological time scales in both terrestrial and aquatic ecosystems (Correll, 1998;
Elser et al., 2007; Civan et al., 2018; Defforey and Paytan, 2018). The
conspicuous role of Phosphorus is also well documented in the regulation of bio-
community structure and act as a limiting factor (affects the primary production
rate, species structure and distribution) in primary productivity (Smith, 1984;
Bastami et al., 2018) therefore, determine the productivity of aquatic ecosystems
(Karl et al., 2001; Paytan and McLaughlin, 2010; Bastami et al., 2018).
Biologically active Phosphorous (BAP) in natural waters occurs in the form of
phosphate (PO4-3); an organic form (organically bound phosphates) and in
dissolved inorganic form (i.e. orthophosphates and polyphosphates). The longer
time scales BAP entrance in the ecosystem occur through weathering of rocks
followed by multifaceted biogeochemical interactions with as compared to
anthropogenic P inputs (Benitez-Nelson, 2000). An industrial fertilizer, animal
wastes and sewage are the main Primary anthropogenic sources of BAP (Jarvie et
al., 2006). However, at the global scale the particulate form of Phosphorus mainly
contributes in the eutrophication and impairment of surface water quality which
comes from point and diffuse sources (Hecky and Kilham, 1988; Mainstone and
Parr, 2002; Civan et al., 2018). An estimated BAP, which reaches to the open
ocean from rivers, ranges from a few tenths to perhaps 1 Tg P yr-1 (Seitzinger et
al., 2005; Meybeck, 1982; Sharpies et al., 2013). Mahowald et al., (2008)
estimated that atmospheric inputs of BAP are ~0.1 Tg P yr-1. Together all inputs
would support ~0.1 percent of NPP annually. Therefore, like N, all NPP is
propping up by BAP as recycled within the ocean on a global scale.
The nitrogen (N) and phosphorus (P) is used as fertilizer and the major nutrients
responsible for aquatic eutrophication, their providence and consequence are site-
specific (Finnveden and Potting 1999; Henryson et al., 2018). The physio-
chemical characteristics of the Arabian Sea make it an appropriate site to study
the pathways of P accretion in sediments thus, extensive studies has been done on
the variation and dynamics of total P in the sediments of Arabian Sea (Murty et
al., 1968; Setty and Rao, 1972 and Rao et al., 1978, 1987; Linsy et al., 2018) as
well as P fractionation and cycling in the Eastern Arabian Sea (Babu and Nath,
2005; Acharya et al., 2016), the Oman Margin and northern part of the Eastern
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 153
Arabian Sea (Schenau and De Lange, 2001), and the Western Arabian Sea (Kraal
et al., 2012, 2015). The high rate of benthic flux of phosphate is accounted with
the degradation of organic matter and dissolution of fish debris and may escort the
P to authigenic phases (Schenau and De Lange, 2001; Babu and Nath, 2005;
Linsy et al., 2018). In addition to organic matter, iron also was found to play a
major role in the P cycling and authigenesis in the Arabian Sea sediments (Kraal
et al., 2012; Linsy et al., 2018).
Some areas of Karachi Creek receive large quantities of nutrients (such as Karachi
Harbour, Gharo Creek, Gizri Creek, and Korangi Creek) in the form of liquid as
well as solid waste. There has been a severe reduction observed in the nutrients
load as brought by Indus River for the last fifty years.
This reduction in Indus discharge has a negative impact on the Indus estuary and
the productivity of the mangrove forest and fisheries (Amjad and Rizvi, 1999;
Inam et al., 2017). The nutrient distribution in the Karachi Harbor area is also
presented in Table 2, show that nutrient enrichment, particularly of inorganic
phosphate over the entire harbor area, which is the influence of industrial and
sewage discharges on nutrient salt concentrations in surface and near-bottom
layers. Excessive nutrient in coastal waters may cause eutrophication in coastal
areas (EMC, 2013).
Table 2. The concentrations of various nutrients in coastal areas of Pakistan.
Locations Ammonia
(NH3)
Nitrite
(NO2)
Nitrate
(NO3)
Phosphate
(PO4)
References
Sandspit (µgL-1) 0.05-18.07 0.03-0.05 0.16-5.64 0.11-2.95 Shoaib et al., 2017
Korangi creek (µgL-1) 1.81–12.30 >0.20 0.45–1.69 1.00–23.60 Saleem et al., 2014
Kemari (µgL-1) 17-33 0.56-1.1 7.8-27.0 11-48 NIO Data Archive
Clifton (µgL-1) 31-41 1.4-4.9 25-26 12-68 NIO Data Archive
Clifton Beach (µgL-1) 59-60 3.9-5.0 8.4-28.0 11-70 NIO Data Archive
Sea View (µgL-1) 57-110 3.6-11.0 16-59.0 16-140 NIO Data Archive
Gizri Creek (µgL-1) 36-160 9.8-14 30-81.0 36-77 NIO Data Archive
West Wharf (gmL-1) - 2.44 3.81 10.35 Khan and Saleem, 1988
Fish Harbour (gmL-1) - 0.1 0.18 23.25 Khan and Saleem, 1988
Lyari River Mouth
(gmL-1)
-
0.83 1.35 4.6
Khan and Saleem, 1988
Chari Kund (gmL-1) - 5.16 8.74 6.7 Khan and Saleem, 1988
Manora Channel (gmL-1) - 1.02 2.05 14.05 Khan and Saleem, 1988
Mausa Channel (gmL-1) - 1.29 1.19 4.4 Khan and Saleem, 1988
154 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
Some areas of Karachi Creek receive higher nutrients (phosphate, silicate, nitrate,
and ammonia) values occurred during low tides and low values occurred during
high tide. Moreover, the concentrations of nitrite were relatively higher in the
bottom waters, but in general, nitrate concentration was not high i.e. 0.45–1.69
μM and its concentration inversely correlated with tidal fluctuations. Results of
dissolved nutrients (phosphate, silicate, nitrate, and ammonia) showed a positive
correlation with salinity, while the negative correlation with the tide (Saleem et
al., 2014). A substantial variation in nutrient concentrations was recorded at
different sites during different time periods as high surface nitrate concentration
was recorded at French Beach (2.657 μM/L) and low at MV (0.743 μM/L). High
surface phosphate concentration was noted at Hawkes Bay (0.203 μM/L) and low
(0.135 μM/L) at French Beach (Ali et al., 2017).
Nutrients from the urban wastes and land run-off also reach the coastal waters,
however, the sewage from the urban wastes bring a sizable amount of nutrients
from Karachi City (Amjad and Rizvi, 1999). Recently, Inam et al., 2017 reported
major nutrients (nitrite, ammonia, phosphate and silicate) along the Indus River
water over a distance of about 1000 km from Terbela Dam to Khobar Creek
through which the river water discharges into the Arabian Sea and also reported
the excessive loads of silicates along the Indus River as compared to nitrite and
phosphate levels (Inam et al., 2017). According to Malone (1980), larger
phytoplankton (diatoms), mainly prefer nitrate, whereas smaller cells favor
utilizing ammonium ion. Shoaib et al., (2017) shown a negative correlation of
phytoplankton abundance with ammonium and confirms the above statement
Cyclotella cf. meneghiniana, planktonic species were recorded in both seasons
(summer and winter) and showed a preference for higher nutrient levels. C. cf.
meneghiniana has also been reported as bio-indictor of many metal pollutants in
aquatic ecosystems. The high abundance of this species was also recorded from
both marine and freshwater area and their association with low dissolved oxygen
concentration suggests poor water quality (Bestawy, 2000; El-Kassas and Gharib,
2016; Shoaib et al., 2017).
Nutrient Pollution and Belonging Hazards
Whilst nitrogen and phosphorus are essential for maintenance and sustainable Net
Primary production as well as important components of a healthy ecosystem; an
excess amount of these nutrients can result to an overgrowth of algae and known
as Nutrient pollution. The emergence of blooms and eutrophication are the two
main conspicuous outcomes of Nutrient pollution as can alter the whole
ecosystem structure and function in almost all types of aquatic habitats. The
Pakistan Agriculture sector is the backbone of Pakistan’s economy and accounts
for 24% of the GDP and employs 48.4% of the entire labor demand. The percent
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 155
of the total population depends upon the fishery sector. The coastal zones already
confronted the several concerned issues that can be resulted in intense variation in
the marine environment. The global warming, changes in biochemical cycles,
acidification, hypoxia and alterations in the physicochemical stipulation and
circulation patterns are conspicuous under the climate change regime; however,
the habitat loss and degradation also associated with climate change and result in
thrashing of intertidal areas, terrestrial shoreline areas and decline in freshwater
body likely respond in biodiversity changes. The nutrients found in excessive
amounts in underground waters, lakes, rivers, and coastal waters, and in the Indus
Basin of Pakistan, water pollution is most important problem associated with
agriculture and the contamination of various chemical substances is another
immense challenge faced by the marine environment of country; Metropolitan
municipal sewage and industrial effluent are two major sources of coastal water
pollution. Nutrient input can be increased by humans or can occur naturally and
termed eutrophication. Because of the disposal of a huge quantity of sewage, the
habitat in Manora Channel and Gizri Creek has been completely destroyed and
most of the area in these two water bodies is devoid of any marine life. The
eutrophication likely due to an increase of nutritional resources to meticulous
waters includes the supply of mineral nutrients (nitrogen, phosphorus, silicon,
trace elements) as well as organic carbon. In the current era, the eutrophication
has been most pronounced in the developed world, but it has to be expected that it
will become more significant in the developing countries of Africa, Asia, and
Latin America in the near future[REMOVED HYPERLINK FIELD] (Dolbeth et
al., 2007). The accession of nutrients leads to anoxic conditions, which triumphs
approximately 40% of the regions of Karachi Harbour, whereas 60% areas of the
Gizri Creek (Rizvi et el., 1999; Amjad and Rizvi, 1999). Municipal and industrial
sewage is one of the major sources of eutrophication in these adjacent coastal
areas, which includes domestic wastewater that contains a wide variety of
dissolved and suspended impurities, this nutrient-rich sewage water becomes a
source of excessive algal growth. As algae die, decomposition of organic matter is
enhanced through the bacterial activity, which consumes dissolved oxygen in the
water, leading to depletion of oxygen in the water, making it difficult for other
aquatic organisms to survive (MFF, 2016). This nutrient enrichment,
eutrophication, initially stimulate growth of phytoplankton, microalgae, and
macroalgae, and ultimately cause algal bloom, hypoxia which in turn can lead to
other impacts such as: decrease and loss of other vegetation, variability and
reduction in biodiversity, dominance of gelatinous organism, coral reef damage or
reef growth inhibition, change in phytoplankton species composition, Low
dissolved oxygen and formation of hypoxic or “dead” zones (oxygen-depleted
waters), which in turn can lead to ecosystem collapse due to mass fish kills.
156 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
In the Arabian Sea, inorganic nutrients (P, S, and N) and sunlight are the
auspicious aspects for the increase of flagellates and dinoflagellates during high
upwelling as during the Northeast monsoon season, the nutrients lead to the
upper-column building suitable condition for the growth of dinoflagellates
(Banse, 1987; Smith and Bottero, 1997; Landry, 2000; Brown et al., 2002; Tanget
al., 2002). The water recirculation in spring monsoon increases the growth of
phytoplankton to some extent (Gomes et al., 2000). Some recent work on seasonal
variations in abundance, diversity, and growth of phytoplankton community
including diatoms and dinoflagellates has been reported from coastal waters of
Karachi, Pakistan (Munir et al., 2012, 2013a, b, 2015a, b; Naz et al., 2010, 2012,
2013a, b, 2014; Khokhar et al., 2016). The highest amount of nitrogen can
enhance the production of dinoflagellates and the cells can multiply and
strengthen the toxin synthesis or change in cells chemical composition; result as
the immediate explosion of harmful algal bloom specifically dinoflagellates
known as Red tides.
The unexpected and colossal growth of Algae or phytoplankton is known as Red
tide or Harmful Algal Bloom (HAB). Production of algal toxins or red-tide toxins
during algal blooms has been increasing worldwide mainly because of the effects
of organic matter (OM) pollution and (GW) global warming (Prince et al., 2008;
Castle and Rodgers Jr., 2009; Yates and Rogers, 2011; Mostofa et al., 2013b)
Marine surface waters are undergoing acidification (Doney et al., 2009; Beaufort
et al., 2011; Cai et al., 2011; Xiao et al., 2011), which is well known to instigate
the changes in marine chemistry and ultimately production of algal toxins (Gao et
al., 2012). The occurrence, abundance and geographical distribution of toxin-
producing algae or cyanobacterial blooms have substantially increased during the
last few decades, because of increased anthropogenic contribution of organic
matter pollution, nutrients and because of global warming (Yan and Zhou, 2004;
Luckas et al., 2005; McCarthy et al., 2007; Mostofa et al., 2013). According to
D’Silva et al., (2012) total 101 harmful algal blooms (39 spp.) were recorded
during 1908 to 2009, and Padmakumar (2012) described 15% increment in HAB
frequency during last twelve years in the Indian Ocean. Algal toxins or red tide
toxins produced during algal blooms in surface waters are responsible for various
ecological, physiological and environmental adverse effects e.g.: Decline of water
quality, Depletion of dissolved oxygen below the pycnocline, Loss of benthos,
Loss of phytoplankton, Mortality of fish, coral reefs, livestock and wildlife
Inhibition of enzymes and photosynthesis, Cell and membrane damage (Howarth,
2008; Castle and Rodgers Jr., 2009; Bricelj and Lonsdale, 1997; Imai and Kimura,
2008; Southard et al., 2010; Yates and Rogers, 2011). In addition, the shellfish or
finfish poisoning by neurotoxic compounds (brevetoxins) produced by red-tide
dinoflagellates (Backer et al., 2005, 2008; Moore et al., 2008). Illness or even
death of higher organisms or humans, associated with consumption of
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 157
contaminated fish, seafood and water as well as Adverse health effects (e.g.
eczema or acute respiratory illness) from direct contact with, ingestion, or
inhalation of cyanobacteria or various toxins (Fleming et al., 2005; Moore et al.,
2008; Backer et al., 2005, 2008; Mostofa et al., 2013b and references therein).
Currently, more than two thousand dinoflagellate species have been recorded
worldwide and approximately 200 species are toxic and accountable for harmful
algal blooms in various coastal areas (Banse, 1987; Eppley et al, 1970; Smayda,
1997, 2002; Landry, 2000; Brown et al., 2002; Gómez, 2005). In Pakistan since
the 1970s, many researchers have been studying about the effects causing by the
red tide and various species have been recognized, such as Saifullah, 1973; 1978
(Gonialax), Saifullah, 1990 (Noctiluca scintillans), Chaghtai, 1997 (Phaeocystis)
and Hassan, 1973 (Peridinium). However, extensive work has been done on the
distribution and taxonomy of dinoflagellates in Pakistani coastal waters such as
Korangi creek and Manora Channel (Taylor, 1976; Hassan and Saifullah, 1971,
1972; Hassan, 1976; and the Balochistan coast (Ghazala et al., 2006). A few
putative bloom-forming species have been previously reported from the Pakistan
coastal water, such as Prorocentrum micans, Ceratium shurunk, Gonyaulax
Diesing, and Noctiluca scintillans (Chaghtai et al., 2006). According to Munir et
al. (2013), most of the planktonic and toxic epiphytic dinoflagellates species
belonging to a Prorocentrales group (genus Prorocentrum and genus Mesoporos)
cause potentially harmful blooms in the coastal water of Pakistan. The species of
the genus Gambierdiscus recently reported in coastal waters of Karachi, Pakistan,
which produces the toxin ciguatera (Munir et al., 2011; Munir et al., 2013). A
recent study on the distribution and abundance of dinoflagellates from Manora
channel reported the sixty-six bloom forming (non-toxic) and 28 toxic species
(Khokar et al., 2018).
In the Arabian Sea, the Algal blooms explosion is a normal practice and has been
observed during the monsoon seasons and usually emerges in two (Red or Orange
and Green) different colors (Fig. 9) but it was also observed that all blooms are
not severely harmful to biodiversity. However, in the last few years, numerous
incidences of mass-mortality of fishes by red tides or bloom have been reported in
the coastal areas of Pakistan. Type and source of bloom monitored at distinct sites
along the coast differs: it may be set up locally or may have developed at some
remote site and later transferred by coastal currents.
The fish mortalities and economic damages are reported due to the bloom of
Prorocentrum minimum Gwadar Bay, Balochistan during Nov. 1987 (Rabbani et
al., 1990). It is further recognized that remarkable mortality of fish in the Arabian
Sea experiences risen in the last few years, which yet adversely affects fish
marketing and fisheries production and is of growing social involvement. these
158 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
blooms are common in Korangi as well as Gizri Creeks (Harrison, 1997), and in
coastal waters adjacent to Clifton beach that reported Asterionella japonica bloom
(Khan, 1986), and dinoflagellates bloom reported in the waters of Sandspit and
Hawkes bay beaches (Saifullah and Chaghtai, 1990).
Fig. (9). The harmful algal bloom (Green) observed along the coastal areas of Karachi.
An incidence of red tide from 1999 – 2000 year in Pakistan’s coastal waters
where different species of the wild fish population were affected by red tide
including Bottlenose and Rough-toothed Dolphins, Filefish, Speckled Siderial
Moray, Parrot fishes, and baleen whale were found dead. The water sample during
these years showed that the concentration of Noctiluca and Gymnodinium species
are responsible for the emergence of bloom. The fish mortalities and economic
damages are reported due to the bloom of Prorocentrum minimum Gwadar Bay,
Balochistan and in Kuwait Bay (Gilbert, 2007) and in the Arabian Sea, a bloom of
Cochlodinium polykrikoides has been generated in UAE (August 2008), and
extended to coasts of Qatar and Iran and killing of tons of fish (Anon., 2008) as
well as destruction of the coral reefs ecosystem and fish farm were recorded
(Richlen et al., 2010).
In Gawader Bay, Pakistan, mass mortality of Terapon puta, Congresox sp and
Pomadasys maculatus were reported due to toxic dinoflagellate Prorocentrum
minimum (Rabbani et al., 1990). The Noctiluca scintillans, which forms both
green and red tides, have been reported in Pakistan by various researchers
(Subrahmanyan, 1954; Saifullah and Chaghtai, 1990; Chaghtai and Saifullah,
2006) and some toxic species has also been reported from the coast of Pakistan
(Chaghtai and Saifullah, 2001; Gul and Saifullah, 2010; Munir et al., 2011; Gul
and Saifullah., 2011). The algal bloom of Synedraacus was observed in Karachi
coastal waters (Luqman et al., 2015). Massive blooms of stinging Jellyfish has
recorded in the Karachi offshore waters in the sample area at the mouth of the
River Indus (about 140 km south of Karachi) and Ormara along Sindh and
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 159
Balochistan coast which influenced the fishing activities (DAWN, 2016). Jellyfish
blooms are yet not well known in Pakistan. It is expected that climate change and
ocean condition are two constituents, which are supporting components of most
jellyfish blooms increasing in wide areas. The release of untreated sewage having
nutrient enter coastal waters can lead to eutrophication make possible better feed
for jellyfish polyps and supporting to form bloom. In 2013, along with open
coastal waters of Clifton beach, sea breams, mullets, John croaker, Tiger tooth
croaker, Tiger tooth croaker, and other small fish species were noticed to have
been influenced by red tide. In 2013, along with open coastal waters of Clifton
beach, sea bream, mullets, John croaker, Tiger tooth croaker, Tiger tooth croaker,
and other small fish species were noticed to have been influenced by red tide. In
August and September 2015, the red algal bloom appeared along the Sindh-
Balochistan coast that killed a number of marine fishes. Except for fish mortality
by the red tide in Pasni and Ormara in Balochistan, coast and coral reefs were also
severely affected in Churna Island, Karachi. (DAWN, 2015). The most recent
incidence of algal bloom of Noctiluca scintillans was observed during May-June
2017 and the bloom was noticed by the foul smell as felt in various adjacent areas
however no mass mortality was observed during the stench decaying of bloom.
Over the previous twenty years or so, harmful algal blooms have raised around
the world in their number, intensity, and geographic scope. Due to the rise of the
bulk of nutrients (P and N) that are brought into coastal waters or estuaries
through sewage and industrial discharge, agricultural runoff and climate change
the frequency of algal bloom, which has been increasing in coastal areas of
Pakistan.
CONCLUSION
Oceans and coastal areas have unique interactions of numerous anthropogenic
(Urbanization, Industrialization and Pollution discharge) and natural progressions.
Unfortunately, in Pakistan, not much detailed surveys and research work have
been done to understand the pollution impact and interactions in chemical,
physical, hydrological and biological processes in estuaries, marine habitats,
coastal waters and the inter-dependency among various marine resources.
There is a paucity of important information such as run-off from inorganic
fertilizer and pesticides to water bodies, economic valuation of important features
such as wetlands, Seasonal and annual variations in pollution loads from land-
based activities, impact and expected consequence of contamination in coastal
sediments, waters and associated living web, bioaccumulation, bio-concentration,
biomagnification and trophic transfer of hazardous pollutants and the recycling
and biosorption of nutrients and other pollutant at their early discharge stage etc.
160 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
An integrated research-based approach is required for the assessment, evaluation,
regular monitoring and sustainability of ocean space and resources. The
development of a more consistent, integrated and structured framework that takes
account of the economic potential of all exploited marine natural resources, which
include energy sources from the oceans. Various pressures resulting from urban
and industrial development include pollution from the disposal of solid waste and
sewage are the widespread concerns along the coast. There is a factual lack of
information about pollution hotspots and on how and where pollution is attenuate
on land, in rivers, and in the sea as essential for managing and reducing pollution
along the coast. There is no structural baseline for the estimation of coastal
pollution types, pollutant and level of intensity in various hotspots and
vulnerability to available living resources of adjacent coastal areas and the earlier
initiatives and ongoing efforts are still not sufficient for the development and
betterment of the coastal waters including resources.
The clean technologies need to be introduced for industry and treatment of wastes
at earliest discharge source with best practices for agriculture and lack of uniform
standards for the establishment of permissible limits of toxic discharge by the
relationships between specific activities, the types and amount of discharge
pollutants and discharge sources and attenuation rates or carrying capacity of
receiving environments
CONSENT FOR PUBLICATION
Not applicable.
CONFLICT OF INTERESTS
The authors confirm that this chapter contents have no conflict of interest.
ACKNOWLEDGEMENT
Declare None.
REFERENCES
Acharya, SS, Panigrahi, MK, Kurian, J, Gupta, AK & Tripathy, S (2016) Speciation of phosphorus in the
continental shelf sediments in the Eastern Arabian Sea. Cont Shelf Res, 115, 65-75.
[http://dx.doi.org/10.1016/j.csr.2016.01.005]
Adachi, R & Fukuyo, Y (1979) The thecal structure of a marine toxic dinoflagellate Gambierdiscus toxicus
gen. et sp. nov. collected in a ciguatera-endemic area. Nippon Suisan Gakkaishi, 45, 67-71.
[http://dx.doi.org/10.2331/suisan.45.67]
Aftab, Z, Ali, L & Khan, AM (2000) Industrial Policy and the Environment in Pakistan United Nations
Industrial Development Organization United Nations Industrial Development Organization-UNIDO,
(2000).Industrial Policy and the Environment in Pakistan, Pakistan.
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 161
Agawin, NSR, Duarte, CM & Agustí, S (2000) Nutrient and temperature control of the contribution of
picoplankton to phytoplankton biomass and production. Limnol Oceanogr, 45, 591-600.
[http://dx.doi.org/10.4319/lo.2000.45.3.0591]
Ahearn, GA, Mandal, PK & Mandal, A (2004) Mechanisms of heavy-metal sequestration and detoxification
in crustaceans: a review. J Comp Physiol B, 174, 439-52.
[http://dx.doi.org/10.1007/s00360-004-0438-0] [PMID: 15243714]
Ahmed, Q, Khan, D & Ali, QM (2014) Heavy metals (Fe, Mn, Pb, Cd, and Cr) concentrations in muscles,
liver, kidneys and gills of Torpedo Scad [Megalaspis cordyla (Linnaeus, 1758)] from Karachi waters of
Pakistan. Int J Biol Biotechnol, 11, 517-24. b
Ahmed, Q, Khan, D & Elahi, N (2014) Concentrations of heavy metals (Fe, Mn, Zn, Cd, Pb, and Cu) in
muscles, liver and gills of adult Sardinella albella (Valenciennes, 1847) from Gwadar water of Balochistan,
Pakistan. FUUAST Journal of Biology, 4, 195-204. a
Ahmed, A, Gauns, M, Kurian, S, Bardhan, P, Pratihary, A, Naik, H, Shenoy, DM & Naqvi, SWA (2017)
Nitrogen fixation rates in the eastern Arabian Sea. Estuar Coast Shelf Sci, 191, 74-83.
[http://dx.doi.org/10.1016/j.ecss.2017.04.005]
Khooharo, AA, Memon, RA & Mallah, MU (2008) An empirical analysis of pesticide marketing in Pakistan.
Pak Econ Soc Rev, 46, 57-74.
Akhtar, M, Ahmad, N & Hussain, SP (2005) Climate change in upper Indus basin of Pakistan, A case study
In: Muhammad, A, Hussain, SS, (Eds.), Proceedings of National workshop on global change perspective in
Pakistan-Challenges, Impacts, Opportunities and Prospects.
Ali, S, Begum, F, Hussain, SA, Khan, AS, Ali, H, Khan, T, Raza, G, Ali, K & Karim, R (2014)
Biomonitoring of heavy metals availability in the marine environment of Karachi, Pakistan, using oysters
(Crassostrea sp). Int J Biosci, 4, 249-57.
Ali, U, Malik, RN, Syed, JH, Mehmood, ChT, Sánchez-García, L, Khalid, A & Chaudhry, MJI (2014) Mass
burden and estimated flux of heavy metals in Pakistan coast: sedimentary pollution and eco-toxicological
concerns. Environ Sci Pollut Res Int a
[http://dx.doi.org/10.1007/s11356-014-3612-2] [PMID: 25296937]
Ali, A, Siddiqui, PJA & Aisha, K (2017) Characterization of macro algal communities in the coastal waters
of Sindh (Pakistan), a region under the influence of reversal monsoons. Reg Stud Mar Sci, 14, 84-92.
[http://dx.doi.org/10.1016/j.rsma.2017.05.008]
Ali, R & Shams, ZI (2015) Quantities and composition of shore debris along Clifton Beach, Karachi,
Pakistan. J Coast Conserv
[http://dx.doi.org/10.1007/s11852-015-0404-x]
Amjad, S & Rizvi, SHN (1999) Pakistan’s national program of action under the global program of action for
the protection of the marine environment from land based activities.Ministry of Environment and Local
Government and Rural Development, Government of Pakistan and National Institute of Oceanography,
Clifton, Karachi, Pakistan.
Anderson, DM & White, AW (1989) Toxic dinoflagellates and marine mammal mortalities. Proceedings of
an Expert Consultation held at the Woods Hole Oceanographic Institution
Babu, CP & Nath, BN (2005) Processes controlling forms of phosphorus in surficial sediments from the
eastern Arabian Sea impinged by varying bottom water oxygenation conditions. Deep Sea Res Part II Top
Stud Oceanogr, 52, 1965-80.
[http://dx.doi.org/10.1016/j.dsr2.2005.06.004]
Backer, LC, Carmichael, W, Kirkpatrick, B, Williams, C, Irvin, M, Zhou, Y, Johnson, TB, Nierenberg, K,
Hill, VR, Kieszak, SM & Cheng, YS (2008) Recreational exposure to microcystins during a Microcystis
aeruginosa bloom in a small lake. Marine Drugs, 6, 389e406.
Banse, K (1987) Seasonality of phytoplankton chlorophyll in the central and northern Arabian Sea. Deep-Sea
162 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
Res, 34, 713-23.
[http://dx.doi.org/10.1016/0198-0149(87)90032-X]
Banse, K & McClain, CR (1986) Winter blooms of phytoplankton in the Arabian Sea as observed by the
Coastal Zone Color Scanner. Ecological Progress Series, 34, 201-11.
[http://dx.doi.org/10.3354/meps034201]
Bastami, KD, Neyestani, MR, Raeisi, H, Shafeian, E, Baniamam, M, Shirzadi, A, Esmaeilzadeh, M,
Mozaffari, S & Shahrokhi, B (2018) Bioavailability and geochemical speciation of phosphorus in surface
sediments of the Southern Caspian Sea. Mar Pollut Bull, 126, 51-7.
[http://dx.doi.org/10.1016/j.marpolbul.2017.10.095] [PMID: 29421132]
Brown, SL, Landry, MR, Christensen, S, Garrison, D, Gowing, MM, Bidigare, RR & Campbell, L (2002)
Microbial community dynamics and taxon specific phytoplankton production in the Arabian Sea during 1995
monsoon seasons. Deep-Sea Res, 49, 2345-76.
Bryan, GW & Langston, WJ (1992) Bioavailability, accumulation and effects of heavy metals in sediments
with special reference to United Kingdom estuaries: a review. Environ Pollut, 76, 89-131.
[http://dx.doi.org/10.1016/0269-7491(92)90099-V] [PMID: 15091993]
Bryan, GW (1979) Bioaccumulation of marine pollutants. Philos Trans R Soc Lond B Biol Sci, 286, 483-505.
[http://dx.doi.org/10.1098/rstb.1979.0042] [PMID: 40274]
Buitenhuis, ET, Li, WKW, Vaulot, D, Lomas, MW, Landry, MR, Partensky, F, Karl, DM, Ulloa, O,
Campbell, L, Jacquet, S, Lantoine, F, Chavez, F, Macias, D, Gosselin, M & McManus, GB (2012)
Picophytoplankton biomass distribution in the global ocean. Earth Syst Sci Data, 4, 37-46.
[http://dx.doi.org/10.5194/essd-4-37-2012]
Cai, WJ, Hu, X, Huang, WJ, Murrell, MC, Lehrter, JC, Lohrenz, SE, Chou, WC, Zhai, W, Hollibaugh, JT &
Wang, Y (2011) Acidification of subsurface coastal waters enhanced by eutrophication. NatureGeosciences,
4, 766-70.
[http://dx.doi.org/10.1038/ngeo1297]
Callen, MS, De la Cruz, MT, Lopez, JM & Mastral, AM (2011) PAH in airborne particulate matter.
Carcinogenic character of PM10 samples and assessment of the energy generation impact. Fuel Process
Technol, 92, 176-82.
Callender, E (2005) Heavy metals in the environment-historical trends.Journal of Treatise on Geochemistry
Elsevier, Pergamon Oxford 67-106.
Chaghtai, F & Saifullah, SM (2001) Harmful Algal bloom (HAB) organisms of the northern Arabian Sea
bordering Pakistan-1 Gonyaulax Diesing. Pak J Bot, 33, 69-75.
Chaghtai, F & Saifullah, SM (2006) On the occurrence of green Noctiluca scintillans blooms in the coastal
waters of Pakistan, Northern Arabian Sea. Pak J Bot, 38, 893-8.
Chaghtai, F & Saifullah, SM (1997) Occurrence of Phaeocystis in mangrove creeks near Karachi. Pakistan
Journal of Marine Sciences, 6, 105-8.
Chapman, PM (2017) Assessing and managing stressors in a changing marine environment. Mar Pollut Bull,
124, 587-90.
[http://dx.doi.org/10.1016/j.marpolbul.2016.10.039] [PMID: 27760713]
Chaudhary, MZ, Ahmad, N, Mashiatullah, A, Ahmad, N & Ghaffar, A (2013) Geochemical assessment of
metal concentrations in sediment core of Korangi Creek along Karachi Coast, Pakistan. Environ Monit
Assess, 185, 6677-91. a
[http://dx.doi.org/10.1007/s10661-012-3056-4] [PMID: 23279880]
Chaudhary, MZ, Ahmad, N, Mashiatullah, A, Munir, S & Javed, T (2013) Assessment of metals
concentration and ecotoxicology of the sediment core of Rehri Creek, Karachi Coast, Pakistan. Acta Geol Sin,
87, 1434-43. b
[http://dx.doi.org/10.1111/1755-6724.12140]
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 163
Chaudhry, Q & Sheikh, MM (2003) Climatic change and its impact on the water resources of mountain
regions of Pakistan. Journal of Pakistan Meteorology, 1, 28-34.
Clark, R (2001) Marine pollution.Oxford University Press.
Codispoti, LA, Brandes, JA, Christensen, JP, Devol, AH, Naqvi, SWA, Paerl, HW & Yoshinari, T (2001)
The oceanic fixed nitrogen and nitrous oxide budgets: Moving targets as we enter the anthropocene? Sci Mar,
65, 85-105.
[http://dx.doi.org/10.3989/scimar.2001.65s285]
Çoğun, HY, Firat, Ö, Aytekin, T, Firidin, G, Firat, Ö, Varkal, H, Temiz, Ö & Kargin, F (2017) Heavy Metals
in the Blue Crab (Callinectes sapidus) in Mersin Bay, Turkey. Bull Environ Contam Toxicol, 98, 824-9.
[http://dx.doi.org/10.1007/s00128-017-2086-6] [PMID: 28409194]
Comber, S, Gardner, M, Georges, K, Blackwood, D & Gilmour, D (2013) Domestic source of phosphorus to
sewage treatment works. Environ Technol, 34, 1349-58.
[http://dx.doi.org/10.1080/09593330.2012.747003] [PMID: 24191467]
Correll, DL (1998) The role of phosphorus in the eutrophication of receiving waters: a review. J Environ
Qual, 27, 261-6.
[http://dx.doi.org/10.2134/jeq1998.00472425002700020004x]
Cullen, JJ (2008) Observation and prediction of harmful algal blooms.Real-Time Coastal Observing Systems
for Marine Ecosystem Dynamics and Harmful Algal Blooms: Theory, Instrumentation and Modelling
Monographs on Oceanographic Methodology SeriesUNESCO 1-41. b
https://www.dawn.com/news/1304629
D’Silva, MS, Anil, AC, Naik, RK & D’Costa, PM (2012) Algal blooms: a perspective from the coasts of
India. Nat Hazards, 63, 1225-53.
[http://dx.doi.org/10.1007/s11069-012-0190-9]
Ud Din, I, Rashid, A, Mahmood, T & Khalid, A (2013) Effect of land use activities on PAH contamination in
urban soils of Rawalpindi and Islamabad, Pakistan. Environ Monit Assess, 185, 8685-94.
[http://dx.doi.org/10.1007/s10661-013-3204-5] [PMID: 23595691]
Dodds, WK, Bouska, WW, Eitzmann, JL, Pilger, TJ, Pitts, KL, Riley, AJ, Schloesser, JT & Thornbrugh, DJ
(2009) Eutrophication of U.S. freshwaters: analysis of potential economic damages. Environ Sci Technol, 43,
12-9.
[http://dx.doi.org/10.1021/es801217q] [PMID: 19209578]
Dolbeth, M, Cardoso, PG, Ferreira, SM, Verdelhos, T, Raffaelli, D & Pardal, MA (2007) Anthropogenic and
natural disturbance effects on a macrobenthic estuarine community over a 10-year period. Mar Pollut Bull,
54, 576-85.
[http://dx.doi.org/10.1016/j.marpolbul.2006.12.005] [PMID: 17240405]
(1991) Global strategies for marine environmental protection. Rep Stud GESAMP, 36.Global strategies for
marine environmental protection,
Ghazala, B, Ormond, R & Hannah, F (2006) Phytoplankton communities of Pakistan: I. Dinophyta and
Bacillariophyta from the coast of Sindh (Pakistan). Int J Phycol Phycochem, 2, 183-96.
Glibert, PM (2007) Eutrophication and harmful algal blooms: a complex global issue, examples from the
Arabian Seas including Kuwait Bay, and an introduction to the global ecology and oceanography of harmful
algal blooms (GEOHAB) programme. International Journal of Oceans and Oceanography, 2, 157-69.
Glibert, PM & Bouwman, L (2012) Land-based Nutrient Pollution and the Relationship to Harmful Algal
Blooms in Coastal Marine Systems, 2, 5-7.
Glibert, PM, Anderson, DM, Gentien, P, Granéli, E & Sellner, KG (2005) The global, complex phenomena of
harmful algal blooms. Oceanography (Wash DC), 18, 136-47.
[http://dx.doi.org/10.5670/oceanog.2005.49]
164 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
Glibert, PM (2016) Why nutrient ratios matter: global and regional changes and consequences for
phytoplankton community structure. 8th International Conference on Marine Pollution and
EcotoxicologyUniversity of Hong Kong, Hong Kong.
Gomes, HR, Goes, JI & Saino, T (2000) Influence of physical processes and freshwater discharge on the
seasonality of phytoplankton regime in the Bay of Bengal. Cont Shelf Res, 20, 313-30.
[http://dx.doi.org/10.1016/S0278-4343(99)00072-2]
Gómez, F (2005) A list of free-living dinoflagellates species in the world’s oceans. Acta Bot Croat, 64, 129-
212.
Gondal, MA, Saher, NU & Qureshi, NA (2012) Diversity and biomass distribution of intertidal fauna in
Sonmiani Bay (Miani Hor), Balochistan (Pakistan). Egyptian Academic Journal of Biological Sciences, 4,
219-34.
[http://dx.doi.org/10.21608/eajbsz.2012.14304]
González-De Zayas, R, Merino-Ibarra, M, Soto-Jiménez, MF & Castillo-Sandoval, FS (2013)
Biogeochemical responses to nutrient inputs in a Cuban coastal lagoon: runoff, anthropogenic, and
groundwater sources. Environ Monit Assess, 185, 10101-14.
[http://dx.doi.org/10.1007/s10661-013-3316-y] [PMID: 23856810]
Greene, RM, Lehrter, JC & Hagy, JD, III (2009) Multiple regression models for hindcasting and forecasting
midsummer hypoxia in the Gulf of Mexico. Ecol Appl, 19, 1161-75.
[http://dx.doi.org/10.1890/08-0035.1] [PMID: 19688924]
Gul, S & Saifullah, SM (2010) Taxonomic and ecological studies of three marine genera of Dinophysiales
from Arabian Sea shelf of Pakistan. Pak J Bot, 42, 2647-60.
Gul, S & Saifullah, SM (2011) The Dinoflagellate Genus Prorocentrum (Prorocentrales, Prorocentracea)
from the northern Arabian Sea. Pak J Bot, 43, 3061-5.
Hallegraeff, GM (2010) Ocean climate change, phytoplankton community responses, and harmful algal
blooms: a formidable predictive challenge. J Phycol, 46, 220-35.
[http://dx.doi.org/10.1111/j.1529-8817.2010.00815.x]
Hamid, N, Syed, JH, Kamal, A, Aziz, F, Tanveer, S, Ali, U, Cincinelli, A, Katsoyiannis, A, Yadav, IC, Li, J,
Malik, RN & Zhang, G (2015) A Review on the Abundance, Distribution and Eco-Biological Risks of PAHs
in the Key Environmental Matrices of South Asia. Rev Environ Contam Toxicol
[http://dx.doi.org/10.1007/398_2015_5007] [PMID: 26809717]
Harrison, PJ, Khan, N, Yin, K, Saleem, M, Bano, N, Nisa, M, Ahmed, SI, Rizvi, N & Azam, F (1997)
Nutrient and phytoplankton dynamics in two mangrove tidal creeks of the Indus River Delta, Pakistan. Mar
Ecol Prog Ser, 157, 13-9.
[http://dx.doi.org/10.3354/meps157013]
Hassan, D & Saifullah, SM (1971) Some thecate Dinophyceae from inshore waters of Karachi. Pak J Bot, 3,
61-70.
Hassan, D & Saifullah, SM (1974) The genus Ceratium Schrank from coastal waters of Karachi: I. The
subgenera Amphiceratium and Biceratium. Bot Mar, 17, 82-7.
[http://dx.doi.org/10.1515/botm.1974.17.2.82]
Hassan, D (1976) The genus Ceraitum schrank from coastal water of Karachi. Part II. The subgenus
Euceratium. Bot Mar, 19, 287-94.
[http://dx.doi.org/10.1515/botm.1976.19.5.287]
Hassan, D & Saifullah, SM (1972) Genus Peridinium from inshore waters of Karachi. Pak J Bot, 4, 157-70.
Hecky, RE & Kilham, P (1988) Nutrient limitation of phytoplankton in freshwater and marine environments:
a review of recent evidence on the effects of enrichment. Limnol Oceanogr, 33, 796-822.
[http://dx.doi.org/10.4319/lo.1988.33.4part2.0796]
Iftikhar, M, Ayub, Z & Siddiqui, G (2015) Impact of marine pollution in green mussel Perna viridis from
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 165
four coastal sites in Karachi, Pakistan, Northern Arabian Sea: Hisopathological observation. Indian J Exp
Biol, 3, 222-7.
Imai, I & Kimura, S (2008) Resistance of the fish-killing dinoflagellate Cochlodinium polykrikoides against
algicidal bacteria isolated from the coastal Sea of Japan. Harmful Algae, 7, 360-7.
[http://dx.doi.org/10.1016/j.hal.2007.12.010]
Imai, I, Yamaguchi, M & Hori, Y (2006) Eutrophication and occurrences of harmful algal blooms in the Seto
Inland Sea, Japan. Plankton Benthos Res, 1, 71-84.
[http://dx.doi.org/10.3800/pbr.1.71]
Inam, A, Muzaffar, M, Awan, KM, Hasany, SI, Zia, I & Hashmi, M (2017) An assessment of nutrient,
sediment and carbon fluxes to the Indus Delta. J Biodivers Environ Sci, 10, 27-37.
Ismail, S, Saifullah, SM & Khan, SH (2014) Bio-geochemical studies of Indus Delta mangrove ecosystem
through heavy metal assessment. Pak J Bot, 46, 1277-85.
Jang, E, Alam, MS & Harrison, RM (2013) Source apportionment of polycyclic aromatic hydrocarbons in
urban air using positive matrix factorization and spatial distribution analysis. Atmos Environ, 79, 271-85.
[http://dx.doi.org/10.1016/j.atmosenv.2013.06.056]
Jarvie, HP, Neal, C & Withers, PJ (2006) Sewage-effluent phosphorus: a greater risk to river eutrophication
than agricultural phosphorus? Sci Total Environ, 360, 246-53.
[http://dx.doi.org/10.1016/j.scitotenv.2005.08.038] [PMID: 16226299]
Jarvie, HP, Sharpley, AN, Flaten, D, Kleinman, PJA, Jenkins, A & Simmons, T (2015) The pivotal role of
phosphorus in a resilient water-energy-food security nexus. J Environ Qual, 44, 1049-62.
[http://dx.doi.org/10.2134/jeq2015.01.0030] [PMID: 26437086]
(2007) Study on Water Supply and Sewerage System in Karachi, JICA, February 2007
Jones, KC & de Voogt, P (1999) Persistent organic pollutants (POPs): state of the science. Environ Pollut,
100, 209-21.
[http://dx.doi.org/10.1016/S0269-7491(99)00098-6] [PMID: 15093119]
Kamal, T, Tanoli, MAK, Mumtaz, M, Ali, N & Ayub, S (2015) Bioconcentration potential studies of heavy
metals in Fenneropenaeus penicillatus (Jaira or Red Tail Shrimp) along the littoral states of Karachi City. J
Basic Appl Sci, 11, 611-8.
[http://dx.doi.org/10.6000/1927-5129.2015.11.82]
Khan, N, Muller, J, Khan, SH, Amiad, S, Nizamani, S & Bhanger, MI (2010) Organochlorine pesticides
(OCPs) contaminants from Karachi Harbour, Pakistan. J Chem Soc Pak, 32, 542-9.
Khan, SH (1986) Nontoxic bloom of Asterionella japonica on Clifton beach. Pak J Bot, 18, 361-3.
Khan, TMA, Razzaq, DA, Chaudhry, QZ, Quadir, DA, Kabir, A & Sarker, MA (2002) Sea Level Variations
and Geomorphological Changes in the Coastal Belt of Pakistan. Mar Geod, 25, 159-74.
[http://dx.doi.org/10.1080/014904102753516804]
Khattak, MI & Khattak, MI (2013) Evaluation of heavy metals (As and Cd) contamination in the edible fish
along Karachi-Makran Coast. Pak J Zool, 45, 219-26.
Khurshid, R, Sheikh, MA & Iqbal, S (2008) Health of people working/living in the vicinity of an oil-polluted
beach near Karachi, Pakistan. East Mediterr Health J, 14, 179-82.
[PMID: 18557466]
Legendre, L & Rassoulzadegan, F (1996) Food-web mediated export of biogenic carbon in oceans:
hydrodinamic control. Mar Ecol Prog Ser, 145, 179-93.
[http://dx.doi.org/10.3354/meps145179]
Lehninger, AL, Nelson, DL & Cox, MM (1993) Principles of Biochemistry.Worth Publishers, New York.
Levy, L, Shankar, D, Andre, J-M, Shenoi, SSC, Durand, F & Montegut, CB (2007) Basin wide seasonal
evolution of the Indian Ocean’s phytoplankton blooms. J Geophys Res, 112, 1-14.
166 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
[http://dx.doi.org/10.1029/2007JC004090]
Lewis, MR, Hebert, D, Harrison, WG, Platt, T & Oakey, NS (1986) Vertical nitrate fluxes in the oligotrophic
ocean. Science, 234, 870-3.
[http://dx.doi.org/10.1126/science.234.4778.870] [PMID: 17758109]
Linsy, P, Nath, NB, Mascarenhas-Pereira, MBL, Vinitha, PV, Ray, D, Babu, CP, Rao, BR, Kazip, A,
Sebastian, T, Kocherla, M & Miriyala, P (2018) Benthic cycling of phosphorus in the Eastern Arabian Sea:
Evidence of present day phosphogenesis. Mar Chem, 199, 53-66.
[http://dx.doi.org/10.1016/j.marchem.2018.01.007]
Luoma, SM & Rainbow, PS (2008) Metal Contamination in Aquatic Environments: Science and Lateral
Management 573.
Luqman, M, Javed, MM, Yousafzai, A, Saeed, M, Ahmad, J & Chaghtai, F (2015) Blooms of pollution
indicator micro-alga (Synedra acus) in northern Arabian Sea along Karachi, Pakistan. Indian J Geo-Mar Sci,
44, 1377-81.
Marañón, E (2009) Phytoplankton Size Structure.Encyclopedia of Ocean Science Academic Press.
Mashiatullah, A, Ahmad, N & Mahmood, R (2016) Stable Isotope Techniques to Address Coastal Marine
Pollution.Applied Studies of Coastal and Marine Environments.InTech.
[http://dx.doi.org/10.5772/62897]
Mashiatullah, A, Chaudhary, MZ, Ahmad, N, Javed, T & Ghaffar, A (2013) Metal pollution and ecological
risk assessment in marine sediments of Karachi Coast, Pakistan. Environ Monit Assess, 185, 1555-65.
[http://dx.doi.org/10.1007/s10661-012-2650-9] [PMID: 22580789]
Mashiatullah, A, Qureshi, LM, Ahmad, N, Javed, T & Shah, Z (2004) Distribution of trace metals in
intertidal sediment along Karachi coast, Pakistan. Geological Bulletin. University of Peshawar, 37, 215-23.
McCarthy, MJ, Lavrentyev, PJ, Yang, LY, Zhang, L, Chen, YW, Qin, BQ & Gardner, WS (2007) Nitrogen
dynamics and microbial food web structure during a summer cyanobacterial bloom in a subtropical, shallow,
well-mixed, eutrophic lake Lake Taihu, China. Hydrobiologia, 581, 195-207.
[http://dx.doi.org/10.1007/s10750-006-0496-2]
Mehmood, A, Mahmood, A, Eqani, SAMAS, Ishtiaq, M, Ashraf, A, Bibi, N, Qadir, A, Li, J & Zhang, G
(2017) A review on emerging persistent organic pollutants: Current scenario in Pakistan. Hum Ecol Risk
Assess, 23, 1-13.
[http://dx.doi.org/10.1080/10807039.2015.1133241]
(2016) A Handbook on Pakistan’s Coastal and Marine Resources 78.
Mohiuddin, S & Naqvi, II (2014) Marine Sediment’s Profile for Mercury as Pollution Indicator at Karachi
Coast. International Journal of Economic and Environmental Geology, 5, 15-24.
Montoya, JP, Holl, CM, Zehr, JP, Hansen, A, Villareal, TA & Capone, DG (2004) High rates of N2 fixation
by unicellular diazotrophs in the oligotrophic Pacific Ocean. Nature, 430, 1027-32.
[http://dx.doi.org/10.1038/nature02824] [PMID: 15329721]
Moore, SK, Trainer, VL, Mantua, NJ, Parker, MS, Laws, EA, Backer, LC & Fleming, LE (2008) Impacts of
climate variability and future climate change on harmful algal blooms and human health. Environ Health, 7
(Suppl. 2), S4.
[http://dx.doi.org/10.1186/1476-069X-7-S2-S4] [PMID: 19025675]
Morrice, JA, Valett, HM, Dahm, CN & Campana, ME (1997) Alluvial characteristics, groundwater-surface
water exchange and hydrological retention in headwater streams. Hydrol Processes, 11, 253-67.
[http://dx.doi.org/10.1002/(SICI)1099-1085(19970315)11:3<253::AID-HYP439>3.0.CO;2-J]
Mostofa, KMG, Liu, CQ, Vione, D, Gao, K & Ogawa, H (2013) Sources, factors, mechanisms and possible
solutions to pollutants in marine ecosystems. Environ Pollut, 182, 461-78.
[http://dx.doi.org/10.1016/j.envpol.2013.08.005] [PMID: 23992682]
Mostofa, KMG, Liu, CQ, Li, S & Mottaleb, A (2013) Impacts of global warming on biogeochemical cycles
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 167
in natural waters.Photobiogeochemistry of Organic Matter: Principles and Practices in Water Environment
Springer, New York 851-914. d
[http://dx.doi.org/10.1007/978-3-642-32223-5_10]
Mostofa, KMG, Liu, CQ, Pan, XL, Yoshioka, T, Vione, D, Minakata, D, Gao, K, Sakugawa, H &
Komissarov, GG (2013) Photosynthesis in nature: a new look.Photobiogeochemistry of Organic Matter:
Principles and Practices in Water Environment Springer, New York 561-686. b
[http://dx.doi.org/10.1007/978-3-642-32223-5_7]
Chaghtai, F (2001) Harmful algal bloom (HAB) organisms of the north Arabian Sea bordering Pakistan-I.
Gonyaulax diesing. Pakistan Journal of Botany, 33, 69-75. 34.
Chaghtai, F & Saifullah, S M (2006) On the occurrence of green Noctiluca scintillans blooms in coastal
waters of Pakistan, North Arabian Sea. Pakistan Journal of Botany, 38, 893-8. 35.
Munir, S, Naz, T, Burhan, Z, Siddiqui, PJA & Morton, SL (2012) Potentially harmful dinoflagellates
(Dinophyceae) from the coast of Pakistan. Proceedings of the 14th International Conference on Harmful
Algae. International Society for the Study of Harmful Algae and Intergovernmental Oceanographic
Commission of UNESCO, 36. ISBN 978- 87-990827-3-5.
Munir, S, Naz, T, Burhan, Z, Siddiqui, PJA & Morton, SL (2013) Seasonal abundance, biovolume and
growth rate of the heterotrophic Dinoflagellate (Noctiluca scintillans) from coastal waters of Pakistan. Pak J
Bot, 45, 1109-13.
Munir, S, Naz, T, Burhan, Z, Siddiqui, PJA & Morton, SL (2016) Species composition and abundance of
dinoflagellates from the coastal waters of Pakistan. J Coast Life Med, 4, 448-57.
[http://dx.doi.org/10.12980/jclm.4.2016J6-58]
Munir, S, Siddiqui, PJA & Morton, LS (2011) The occurrence of ciguatera fish poisoning producing
dinoflagellate genus Gambierdiscus in Pakistan waters. Algae, 26, 317-25.
[http://dx.doi.org/10.4490/algae.2011.26.4.317]
Munir, S, Burhan, Z, Naz, T, Siddiqui, PJA & Morton, SL (2013) Morphotaxonomy and seasonal distribution
of planktonic and benthic Prorocentrales in Karachi waters, Pakistan Northern Arabian Sea. Chin J
Oceanology Limnol, 31, 267-81.
[http://dx.doi.org/10.1007/s00343-013-2150-y]
Munshi, AB, Detlef, SB, Schneider, R & Zuberi, R (2004) Organochlorine concentrations in various fish
from different locations at Karachi Coast. Mar Pollut Bull, 49, 597-601.
[http://dx.doi.org/10.1016/j.marpolbul.2004.03.019] [PMID: 15476838]
Murty, PSN, Reddy, CVG & Varadachari, VVR (1968) Distribution of total phosphorus in the shelf
sediments off the west coast of India. Proceedings of the National Academy of Sciences, India134-41.
Muzaffar, M, Inam, A, Hashmi, MA, Mehmood, K, Zia, I & Hasaney, IM (2017) Climate change and role of
anthropogenic impact on the stability of Indus deltaic Eco-region. J Biodivers Environ Sci, 10, 164-76.
Naqvi, G, Shoaib, N & Ali, AM (2017) Pesticides impact on protein in fish (Oreochromis mossambicus)
tissues. Indian J Geo-Mar Sci, 46, 1864-8.
Nasira, K, Shahina, F & Kamran, M (2010) Response of free-living marine nematode community to heavy
metal contamination along the coastal areas of Sindh and Balochistan, Pakistan. Pak J Nematol, 28, 263-78.
Naz, T, Burhan, Z, Munir, S & Siddiqui, PJA (2014) Growth rate of diatoms in natural environment from the
coastal waters of Pakistan. Pak J Bot, 46, 1129-36.
Naz, T, Munir, S, Burhan, Z & Siddiqui, PJA (2013) Seasonal abundance and morphological observations of
a raphid pennate diatom Asterionella glacialis castracane from the coastal waters of Karachi, Pakistan. Pak J
Bot, 45, 677-80.
Parab, SG, Matondkar, SP, Gomes, HDR & Goes, JI (2006) Monsoon driven changes in phytoplankton
populations in the eastern Arabian Sea as revealed by microscopy and HPLC pigment analysis. Cont Shelf
Res, 26, 2538-58.
168 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
[http://dx.doi.org/10.1016/j.csr.2006.08.004]
Paytan, A & McLaughlin, K (2007) The oceanic phosphorus cycle. Chem Rev, 107, 563-76.
[http://dx.doi.org/10.1021/cr0503613] [PMID: 17256993]
Pomeroy, LR (2007) The microbial loop. Oceanography (Wash DC), 20, 28-33.
[http://dx.doi.org/10.5670/oceanog.2007.45]
Prince, EK, Myers, TL & Kubanek, J (2008) Effects of harmful algal blooms on competitors: allelopathic
mechanisms of the red tide. Limnol Oceanogr, 53, 531-41.
[http://dx.doi.org/10.4319/lo.2008.53.2.0531]
(2002) Environmental Assessment and Water Quality Monitoring Program. Irrigation and Power
Department, Government of the Punjab, Pakistan Technical Report 54
Qari, R, Olufemi, A, Rana, M & Rahim, AA (2015) Seasonal variation in occurrence of heavy metals in
Perna Viridis from Manora Channel of Karachi, Arabian Sea. Int J Mater Sci, 5, 1-13.
Qari, R & Ahmed, S (2014) Heavy metal distribution in Avicennia marina from Sonmiani, Pakistan Coast.
Journal of Shipping and Ocean Engineering, 4, 38-42.
Qari, R, Siddiqui, SA & Qureshi, NA (2005) A comparative study in surficial sediment from coastal areas of
Karachi, Pakistan. Mar Pollut Bull, 50, 583-608.
[http://dx.doi.org/10.1016/j.marpolbul.2005.01.024]
Qasim, SZ (1982) Oceanography of the northern Arabian Sea. Deep-Sea Res A, Oceanogr Res Pap, 29, 1041-
68.
[http://dx.doi.org/10.1016/0198-0149(82)90027-9]
Rabbani, MM, Rehman, AU & Harms, CE (1990) Mass mortality of fishes caused by dinoflagellate blooms
in Gawader Bay, Southwest Pakistan.Toxic Marine Phytoplankton Elsevier, New York 209-14.
Rabbani, MM, Inam, A, Tabrez, AR, Sayed, NA & Tabrez, SM (2008) The impact of sea level rise on
Pakistan’s coastal zones–in a climate change scenario. National Institute of Oceanography, Clifton,
Karachi.Conference PaperMarch 2008
Rainbow, PS (2007) Trace metal bioaccumulation: models, metabolic availability and toxicity. Environ Int,
33, 576-82.
[http://dx.doi.org/10.1016/j.envint.2006.05.007] [PMID: 16814385]
Rao, CM, Paropkari, AL, Mascarenhas, A & Murty, PSN (1987) Distribution of phosphorus and
phosphatisation along the western continental margin of India. J Geol Soc India, 30, 423-38.
Rao, CM, Rajamanickam, GV, Paropkari, AL & Murty, PSN (1978) Distribution of phosphate in sediments
of the northern half of the western continental shelf of India. Indian J Geo-Mar Sci, 7, 146-50.
Rasool, F, Tunio, S, Hasnian, SA & Ahmad, E (2002) Mangrove conservation along the coast of Sonmiani,
Balochistan, Pakistan. Pak J Bot, 16, 213-7.
Ravindra, K, Sokhi, R & Vangrieken, R (2008) Atmospheric polycyclic aromatic hydrocarbons: source
attribution, emission factors and regulation. Atmos Environ, 2895-921.
[http://dx.doi.org/10.1016/j.atmosenv.2007.12.010]
Richlen, MA, Morton, SL, Jamali, EA, Rajan, A & Anderson, DA (2010) The catastrophic 2008-2009 red
tide in the Arabian Gulf region, with observations on the identification and phylogeny of fish-killing
dinoflagellate Cochlodinium polykrikoides. Harmful Algae, 9, 163-72.
[http://dx.doi.org/10.1016/j.hal.2009.08.013]
Rizvi, SHN, Nisa, M & Haq, SM (1999) Environmental degradation and Marine Pollution along the Karachi
coast and adjacent creeks in the Indus Delta.The Indus River (Biodiversity, Resources, human kind) Oxford
University Press, Karachi 77-90.
Rizvi, SHN, Saleem, M & Baquer, J (1988) Steel mill effluents: influence on the Bakran Creek
environment.Proceedings of Marine Science of the Arabian Sea American Institutes of Biological Sciences
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 169
549-69.
Rousseaux, CS & Gregg, WW (2014) Inter annual variations in phytoplankton primary production at a global
scale. Remote Sens, 6, 1-19.
[http://dx.doi.org/10.3390/rs6010001]
Saher, NU & Siddiqui, AS (2016) Comparison of heavy metal contamination during the last decade along the
coastal sediment of Pakistan: Multiple pollution indices approach. Mar Pollut Bull, 105, 403-10.
[http://dx.doi.org/10.1016/j.marpolbul.2016.02.012] [PMID: 26876559]
Saher, NU & Kanwal, N (2018) Heavy metal contamination and human health risk indices assessment in
Shellfish species from Karachi coast Pakistan. Academia Journal of Food Research, 6, 012-20. a
Saher, NU & Kanwal, N (2018) Some biomonitoring studies of heavy metals in commercial species of
crustacean along Karachi coast, Pakistan. Int J Biol Biotechnol, 15, 269-75. b
Saher, NU & Siddiqui, AS (2017) Evaluation of heavy metals contamination in mangrove sediments and their
allied fiddler crab species (Austruca sindensis Alcock 1900) from Hawks Bay, Karachi, Pakistan. Int J Biol
Biotechnol, 14, 411-7.
Saifullah, SM & Chaghtai, F (1990) Incidence of Noctiluca scintillans (Mac Cartney) Ehernb blooms along
Pakistan’s Shelf. Pak J Bot, 22, 94-9.
Saifullah, SM & Hassan, D (1973) Planktonic dinoflagellates from inshore waters of Karachi: 1. Gonyaulax
Diessing. Pak J Zool, 5, 143-7. a
Saifullah, SM & Hassan, D (1973) Planktonic dinoflagellates from inshore waters of Karachi: II.
Amphisolenia Stein. Pak J Zool, 5, 149-55. b
Saifullah, SM (1973) A preliminary survey of the standing crop of seaweed form Karachi coast. Bot Mar, 16,
139-44.
[http://dx.doi.org/10.1515/botm.1973.16.3.139]
Saifullah, SM (1978) Inhibitory effects of copper on marine dinoflagellates. Mar Biol, 44, 299-308.
[http://dx.doi.org/10.1007/BF00390893]
Saifullah, SM, Ismail, S, Khan, SH & Saleem, M (2004) Land use iron pollution in mangrove habitat of
Karachi, Indus Delta. Earth Interact, 8, 1-9.
[http://dx.doi.org/10.1175/1087-3562(2004)8<1:LUPIMH>2.0.CO;2]
Saifullah, SM, Khan, SH & Ismail, S (2002) Distribution of nickel in a polluted mangrove habitat of the
Indus Delta. Mar Pollut Bull, 44, 570-6.
[http://dx.doi.org/10.1016/S0025-326X(02)00088-7] [PMID: 12146841]
Saifullah, SM & Rasool, F (1995) A Preliminary Survey of Mangroves of Balochistan. WWF-Pakistan
Project Report
Saleem, M, Rizvi, SHN, Aftab, J, Kahkashan, S, Khan, AA & Qammaruddin, M (2013) Short Assessment
Survey of Organochlorine Pesticides in Marine Environment of Damb (Sonmiani) Balochistan. Pakistan
Journal of Chemical Society, 3, 107-15.
[http://dx.doi.org/10.15228/2013.v03.i03.p03]
Saleem, M, Aftab, J, Kahkashan, S, Kalhoro, NA & Ahmad, W (2014) Diurnal variation of nutrients, water
quality and plankton composition in the Hajamro creek (Indus delta) during north east monsoon period.
Nucleus, 51, 51-61.
Sanpera, C, Ruiz, X, Llorente, GA, Jover, L & Jabeen, R (2002) Persistent organochlorine compounds in
sediment and biota from the Haleji lake: a wildlife sanctuary in South Pakistan. Bull Environ Contam Toxicol,
68, 237-44.
[http://dx.doi.org/10.1007/s001280244] [PMID: 11815794]
Sattar, A, Kroeze, C & Strokal, M (2014) The increasing impact of food production on nutrient export by
rivers to the Bay of Bengal 1970-2050. Mar Pollut Bull, 80, 168-78.
170 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
[http://dx.doi.org/10.1016/j.marpolbul.2014.01.017] [PMID: 24467860]
Savage, C, Thrush, SF, Lohrer, AM & Hewitt, JE (2012) Ecosystem services transcend boundaries: estuaries
provide resource subsidies and influence functional diversity in coastal benthic communities. PLoS One,
7e42708
[http://dx.doi.org/10.1371/journal.pone.0042708] [PMID: 22880089]
Sayied, N (2007) Environmental issues in coastal waters, Pakistan as a case study.http://commons.wmu.se/
all_dissertations/201
Sharpies, J, Middelburg, JJ, Fennel, K & Jickells, TD (2013) Riverine delivery of nutrients and carbon to the
oceans. Nature, 504, 61-70.
[http://dx.doi.org/10.1038/nature12857]
Shoaib, N & Siddiqui, PJA (2015) Acute Toxicity of Organophosphate and Synthetic Pyrethroid Pesticides to
Juveniles of the Penaeid Shrimps, Metapenaeus Monoceros. Pak J Zool, 47, 1655-61.
Shoaib, M, Burhan, Z, Shafique, S, Jabeen, H & Siddiqui, PJA (2017) Phytoplankton composition in a
mangrove ecosystem at Sandspit, Karachi, Pakistan. Pak J Bot, 49, 379-87.
Shoaib, N, Siddiqui, PJA & Khalid, H (2012) Acute toxic effect of pesticides on brine shrimp and opossum
shrimp. Pak J Zool, 44, 1753-7. b
Shoaib, N, Siddiqui, PJA & Khalid, H (2013) Toxicity of synthetic pyrethroid pesticides, fenpropathrin and
fenvalerate, on killifish Aphanius dispar juveniles. Pak J Zool, 45, 1160-4.
Siddique, A, Mumtaz, M, Zaigham, NA, Mallick, KA, Saied, S, Zahir, E & Khwaja, HA (2009) Heavy metal
toxicity levels in the coastal sediments of the Arabian Sea along the urban Karachi (Pakistan) region. Mar
Pollut Bull, 58, 1406-14.
[http://dx.doi.org/10.1016/j.marpolbul.2009.06.010] [PMID: 19616812]
Siddiqui, AS & Saher, NU (2015) Heavy metals distribution in sediments and their transfer rate to benthic
fauna in mangrove area near Hawks Bay Karachi, Pakistan. Pakistan Journal of Marine Science, 24, 09-17.
Siddiqui, AS & Saher, NU (2016) Assessment of heavy metal accumulation in Opusiaindica (Alcock, 1900)
(Ocypodoidea: Camptandriidae) with Reference to sediment contamination from Coastal areas of Pakistan.
International Journal of Biology Research, 4, 56-61.
Smayda, TJ (2002) Adaptive ecology, growth strategies and global expansion of dinoflagellates. J Oceanogr,
58, 281-94.
[http://dx.doi.org/10.1023/A:1015861725470]
Smayda, TJ (1997) Harmful algal blooms: their ecophysiology and general relevance to phytoplankton
blooms in the sea. Limnol Oceanogr, 42, 1137-53.
[http://dx.doi.org/10.4319/lo.1997.42.5_part_2.1137]
Syed, JH & Malik, RN (2011) Occurrence and source identification of organochlorine pesticides in the
surrounding surface soils of the Ittehad Chemical Industries Kalashah Kaku, Pakistan. Environ Earth Sci, 62,
1311-21.
[http://dx.doi.org/10.1007/s12665-010-0618-z]
Tang, DL, Kawamura, H & Luis, AJ (2002) Short-term variability of phytoplankton blooms associated with a
cold eddy in the northwestern Arabian Sea. Remote Sens Environ, 81, 82-9.
[http://dx.doi.org/10.1016/S0034-4257(01)00334-0]
Tariq, J, Jaffar, M, Ashraf, M & Moazzam, M (1993) Heavy metal concentrations in fish, shrimp, seaweed,
sediment, and water from the Arabian Sea, Pakistan. Mar Pollut Bull, 26, 644-7.
[http://dx.doi.org/10.1016/0025-326X(93)90504-D]
Taylor, FJR (1976) Dinoflagellates from International Indian Ocean Expedition. Bibl Bot, 132, 1-234.
Ulloa, O, Canfield, DE, DeLong, EF, Letelier, RM & Stewart, FJ (2012) Microbial oceanography of anoxic
oxygen minimum zones. Proc Natl Acad Sci USA, 109, 15996-6003.
An Overview of Pollution Marine Ecology: Current and Future Developments, Vol. 1 171
[http://dx.doi.org/10.1073/pnas.1205009109] [PMID: 22967509]
Van-Drecht, G, Bouwman, A, Harrison, J & Knoop, JM (2009) Global nitrogen and phosphate in urban waste
water for the period 1970–2050. Global Biogeochem Cycles, 23GB0A03
[http://dx.doi.org/10.1029/2009GB003458]
Vilhena, MSP, Costa, ML & Berredo, JF (2013) Accumulation and transfer of Hg, As, Se, and other metals in
the sediment-vegetation-crab-human food chain in the coastal zone of the northern Brazilian state of Pará
(Amazonia). Environ Geochem Health, 35, 477-94.
[http://dx.doi.org/10.1007/s10653-013-9509-z] [PMID: 23334486]
Voss, M, Bange, HW, Dippner, JW, Middelburg, JJ, Montoya, JP & Ward, B (2013) The marine nitrogen
cycle: recent discoveries, uncertainties and the potential relevance of climate change. Philos Trans R Soc
Lond B Biol Sci, 36820130121
[http://dx.doi.org/10.1098/rstb.2013.0121] [PMID: 23713119]
Walsh, PJ, Smith, SL, Fleming, LE, Solo-Gabriele, HM, Gerwick, WH (2008). Oceans and Human Health:
Risk and Remedies from the Sea Elsevier 644.
Wang, X, Sato, T, Xing, B & Tao, S (2005) Health risks of heavy metals to the general public in Tianjin,
China via consumption of vegetables and fish. Sci Total Environ, 350, 28-37.
[http://dx.doi.org/10.1016/j.scitotenv.2004.09.044] [PMID: 16227070]
Ward, BB (2012) The Global Nitrogen Cycle.Fundamentals of Geomicrobiology Wiley-Blackwell,
Chichester, UK 36-48.
[http://dx.doi.org/10.1002/9781118280874.ch4]
Ward, BB (2013) Oceans. How nitrogen is lost. Science, 341, 352-3.
[http://dx.doi.org/10.1126/science.1240314] [PMID: 23888027]
Wetz, MS & Paerl, HW (2008) Estuarine phytoplankton responses to hurricanes and tropical storms with
different characteristics (trajectory, rainfall, winds). Estuaries Coasts, 31, 419-29.
[http://dx.doi.org/10.1007/s12237-008-9034-y]
Williams, AT & Simmons, SL (1996) The degradation of plastic litter in rivers: implications for beaches. J
Coast Conserv, 2, 63-72.
[http://dx.doi.org/10.1007/BF02743038]
Wu, J, Sunda, W, Boyle, EA & Karl, DM (2000) Phosphate depletion in the western North Atlantic Ocean.
Science, 289, 759-62.
[http://dx.doi.org/10.1126/science.289.5480.759] [PMID: 10926534]
(2002) Study of heavy metal pollution level and impact on the fauna and flora of the Karachi and Gwadar
coast. Final Project Report, No 50022801
(2016) Unusual Jellyfish blooms affecting fishing activities in the Arabian Seahttp://www.wwfpak.org/
newsroom/261216_Jellyfish.php
Wyrtki, K (1973) Physical oceanography of the Indian Ocean.Ecological Studies: Analysis and Synthesis
Springer, Berlin 18-36.
[http://dx.doi.org/10.1007/978-3-642-65468-8_3]
Wyrtki, K (1973) Physical Oceanography of the Indian Ocean Springer, Berlin, Heidelberg 18-36.
Xiao, M, Wu, F, Zhang, R, Wang, L, Li, X & Huang, R (2011) Temporal and spatial variations of low-
molecular-weight organic acids in Dianchi Lake, China. J Environ Sci (China), 23, 1249-56.
[http://dx.doi.org/10.1016/S1001-0742(10)60567-0] [PMID: 22128530]
Yan, T & Zhou, M-J (2004) Environmental and health effects associated with Harmful Algal Bloom and
marine algal toxins in China. Biomed Environ Sci, 17, 165-76.
[PMID: 15386942]
Yates, BS & Rogers, WJ (2011) Atrazine selects for ichthyotoxic Prymnesium parvum, a possible
explanation for golden algae blooms in lakes of Texas, USA. Ecotoxicology, 20, 2003-10.
172 Marine Ecology: Current and Future Developments, Vol. 1 Saher et al.
[http://dx.doi.org/10.1007/s10646-011-0742-x] [PMID: 21809122]
Zehra, I, Kauser, T, Zahir, E & Naqvi, II (2003) Determination of Cu, Cd, Pb and Zn concentration in edible
marine fish Acanthopagurus berda (Dandya) along Baluchistan Coast, Pakistan. Int J Agric Biol, 5, 80-2.
Zhang, Y & Tao, S (2009) Global atmospheric emission inventory of polycyclic aromatic hydrocarbons
(PAHs) for 2004. Atmos Environ, 812-9.
[http://dx.doi.org/10.1016/j.atmosenv.2008.10.050]
Zinia, NJ & Kroeze, C (2015) Future trends in urbanization and coastal water pollution in the Bay of Bengal:
the lived experience. Environ Dev Sustain, 17, 531-46.
[http://dx.doi.org/10.1007/s10668-014-9558-1]
