Abstrac: Microplastics represent one of the most current global concern issues for environmental and human health. The main concern is for aquatic ecosystems, a very large increase in the number of microplastics has recently transformed these compounds and their degradation products into one of the most common marine debris. To decompose plastic waste requires 50-100 years to be completely degraded so that it becomes a threat to aquatic ecosystems. This research aims to determine the concentration and characteristics of microplastics pollution at estuaries at Kendari Bay. The data of this research were sourced from water and sediment samples from 3 estuaries at Kendari Bay including the Punggaloba estuary, Lahundape estuary, and Wanggu estuary. The analytical methods used in this research include National Oceanic and Atmospheric Administration (NOAA), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Origin Software and SPSS Software. The results showed that the Kendari Bay was contaminated by microplastics. The highest concentration of microplastic pollution is found at the Lahundape estuary, which is 10.07 particles/liter of water and Punggaloba estuary, which is 96 particles/kg of sediment. Microplastic characteristics are based on morphological analysis and particle size. It can be seen that the shape of microplastic particles from water and sediments includes fragments, fibers, and pellets. The range of microplastic sizes in water samples ranges from 0.24-20.34 μm while the size range in sediment samples ranges from 0.12-16.53 μm. The most dominant source of microplastic polymers found at Kendari bay is polystyrene type.

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Analysis of the Concentration and Characteristics of
Microplastic Pollution at Estuaries, Kendari Bay
La Baco Sudia1
, La Ode Siwi1
, Lies Indriyani1
, Asramid Yasin1
, Ridwan Adi Surya1
,
L.O.A.N. Ramadhan2
, Siti Nuraliza1
, Muhammad Nurdin2*
Department of Environmental Science, Faculty of Forestry and Environmental Science, Universitas Halu
Oleo, Kendari 93231 – Southeast Sulawesi, Indonesia1
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universities Halu Oleo, Kendari
93231 – Southeast Sulawesi, Indonesia2
Corresponding Authors: 2*
ABSTRACT— Microplastics represent one of the most current global concern issues for environmental and
human health. The main concern is for aquatic ecosystems, a very large increase in the number of
microplastics has recently transformed these compounds and their degradation products into one of the most
common marine debris. To decompose plastic waste requires 50-100 years to be completely degraded so that
it becomes a threat to aquatic ecosystems. This research aims to determine the concentration and
characteristics of microplastics pollution at estuaries at Kendari Bay. The data of this research were sourced
from water and sediment samples from 3 estuaries at Kendari Bay including the Punggaloba estuary,
Lahundape estuary, and Wanggu estuary. The analytical methods used in this research include National
Oceanic and Atmospheric Administration (NOAA), Scanning Electron Microscopy (SEM), Fourier
Transform Infrared (FTIR), Origin Software and SPSS Software. The results showed that the Kendari Bay
was contaminated by microplastics. The highest concentration of microplastic pollution is found at the
Lahundape estuary, which is 10.07 particles/liter of water and Punggaloba estuary, which is 96 particles/kg
of sediment. Microplastic characteristics are based on morphological analysis and particle size. It can be seen
that the shape of microplastic particles from water and sediments includes fragments, fibers, and pellets. The
range of microplastic sizes in water samples ranges from 0.24-20.34 µm while the size range in sediment
samples ranges from 0.12-16.53 µm. The most dominant source of microplastic polymers found at Kendari
bay is polystyrene type.
KEYWORDS: Estuary, Kendari bay, marine debris, microplastic, pollution.
1. INTRODUCTION
Plastic waste is now one of the problems that are quite serious and concerning, especially in the coastal areas
of the sea, the amount of waste generated from year to year is higher because of the increasing number of
human needs. One of the most common types of waste found in the sea is plastic waste. According to NOAA
[14] plastic waste is a solid object, produced or processed by humans, directly or indirectly, intentionally or
unintentionally discarded or left in the marine environment [5]. Marine waste is a global issue and is a
challenge for Indonesia as a maritime country. Marine waste or better known as marin e debris is a solid object
that is persistent, produced or processed by humans, directly or indirectly, intentionally or unintentionally,
discarded or left in the marine environment [19]. Plastic is the most common piece of waste found in the ocean
because of its durability to be decomposed. Plastic waste is a major environmental problem faced by Indonesia
and the world. Plastic materials that enter the environment as plastic waste, will not decompose in a short time
[15]. Plastic waste is currently one of the most widely produced waste and its management is still less than
optimal. Nearly 60-80% of marine waste consists of plastic and will break down into smaller pieces. Plastic
contamination in the sea can have an impact on the surrounding environment, including fishponds [18].

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According to [11]. Indonesia ranks second as the largest contributor to waste in the world [11]. Waste
production produced by the Indonesian population every day is 0.52 kg/person. With an estimate of each
resident producing 0.52-0.7 kg of waste per day, the total waste that we produce is 134.5-181.1 thousand tons
per day or equivalent to 49.1-66.1 million tons per year. Every day a lot of plastic waste is dumped and enters
the marine environment, because the degradation process takes a long time, besides that these particles are
very resistant for very long periods in the marine environment [16, 17]. The smallest part of plastic that has
undergone a process of degradation is known as microplastic. Microplastic is a small plastic size (≤5 mm) that
is difficult to decompose, thus making this material will remain for a long time. Currently, plastic waste from
the people is spread and piled up everywhere, most of the plastic waste in our environment cannot be recycled
[7]. One source of waste input is from rivers. [1] has an area of ± 11.36 km2 which is crossed by 13 rivers
that flow into [1]. A large number of rivers flowing into [1] causes a large amount of garbage to accumulate
so that it enters the estuarine waters at [1] bay that are carried by the flow of water. Microplastic carried by
water flow will accumulate in estuarine waters at [1] and hover or float on the surface of the water and when
the seawater recedes, the microplastic will also settle along with sediment, apart from the waste originating
from estuary, plastic waste will also be sourced from the economic activities of the people who are around
[1]. The large amount of plastic waste that is around [1], causing the potential for microplastic contamination.
Microplastic itself is a plastic fragment that has a size of ≤ 5 mm whose source comes from human activity
waste, because of its small size and difficult to be seen directly so that it easily enters the body of animals
(fish, turtles, shellfish) that are around [1], because of its nature which is difficult to decompose and if the
animal is consumed by humans will cause damage to the function of organs in the body such as the digestive
tract, reduce growth rates and affect reproduction. So that research needs to be done to determine the
concentration and characteristics of microplastic pollution around [1] so that its spread in the future can be
prevented or minimized given the many negative impacts caused to the surrounding environment and the
community itself.
2. Research Methodology
2.1 Research Location
This research was carried out at the Punggaloba estuary, Lahundape estuary and Wanggu estuary at Kendari
bay located in Southeast Sulawesi, for more details can be seen in Figure 1 below.
2.2 Research Procedure
Initial Survey: An initial survey was conducted to determine the selection of sampling locations with the
Purposive Stratified Sampling approach based on water flow conditions and sediment conditions, each of
which is divided into 3 stations, namely station 1 (Punggaloba estuary), station 2 (Lahundape estuary) and
station 3 (Wanggu estuary) located at Kendari bay.

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Figure 1. Location of research
2.3 Samples Collection
Water samples collection locations are 0 metre and 100 metres from the edge of the Kendari bay at each
research station. Water sampling was carried out using the samples holder and plankton net with a diameter
of 30 cm, mesh size was 30 μm and the filter volume was 50 liters. The Plankton net is placed into a body of
water for 5 minutes in the opposite direction to the current. Then the water samples that has been taken, put
into the samples bottle is 200 mL that has been labeled and brought to the laboratory for further analysis.
Water sampling can be seen in Figure 2. While the location for taking sediment samples is 0 metre from the
edge of the Kendari bay at each research station. Sediment sampling was carried out using pipes with a
diameter of 4 inches based on two levels (0-10 cm and 10-20 cm) and then the results of the sediment were
put into a heat-resistant plastic that has been labeled and taken to the laboratory for further analysis. Sediment
sampling can be seen in Figure 3 below.

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Figure 2. Water sampling using the samples holder and plankton net
Figure 3. Sediment sampling using pipes with a diameter of 4 inches
2.4 Measurement of Water Flow Velocity
The speed of water flow is one of the factors that can affect the spread of microplastics. Retrieval of data for
the speed of water flow carried out as many as 3 times the experiment in each stations location of research
using simple equipment namely plastic bottles tied with a rope along the 10 metres and stopwatch to determine
the time, as for the water flow velocity formula is v = s / t, v = speed of water flow (m/sec), s = distance
traveled (metres) and t = time used (seconds).

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2.5 Water Samples Preparation
The identification of microplastic particles in water samples using the NOAA method was carried out in
several stages. The step taken is to increase the density by mixing 90 grams of salt solution in 250 ml of the
water samples, then stirring until the solution is saturated and allowed to stand for ± 24 hours. The floating
sediment is then filtered using Whatman filter paper (size 45 μm). The filtered precipitate is then dried using
an oven at 102 0C until the precipitate is completely dry, after drying the samples is mixed with aquadest
solution to separate the saline solution still attached to the filtered samples. Then the samples are dried again
using an oven, after drying then the microplastic particles are sorted visually using a microscope. Microplastic
abundance can be calculated by comparing the number of particles found with the volume of filtered water.
To find out the type of polymer contained in the samples, a FTIR analysis was performed and the Origin
software was used to determine the wave peaks from the FTIR characterization analysis results. SEM analysis
is used to determine the microplastic shape and size of the samples. Then do a T-test on the samples using
SPSS software. According to Ayuningtyas et al. microplastic abundance in waters can be determined from
the following formula [2]:
𝑀𝑖𝑐𝑟𝑜𝑝𝑙𝑎𝑠𝑡𝑖𝑐 𝐴𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 =
NumberofMicroplasticParticles(Particles)
Filtered Water Volume (m3) (1)
Sediment Samples Preparation
The first step is to dry the sediment sample. The next step is the dried sediment is filtered using a minimum
of 5mm to separate the microplastic from other plastic waste [13]. A 1 kg wet sediment sample was dried in
an oven at 1000°C for 48 hours of dry sediment then 100g of duplicate was taken and then dissolved with
NaCl solution of 400 mL mixture then stirred for 2 minutes using a stirring spoon. After stirring, the samples
are allowed to stand until they are no longer visible floating between supernatants. The material floating in
the supernatant was then filtered using a vacuum pump on Whatman GF / C (Glass microfiber 1.2 mm) filter
paper [8, 12]. The screening stage is carried out by taking sedimentary deposits that float and filtered using
Whatman filter paper (size 45 μm). The filtered precipitate is then dried using an oven at 102°C until the
precipitate is completely dry, after drying the samples is mixed with aquadest solution to separate the saline
solution still attached to the filtered samples. Then the samples are dried again using an oven, after drying
then the microplastic particles are sorted visually using a microscope. To find out the type of polymer
contained in the samples, the FTIR analysis was performed and the Origin software was used to determine the
wave peaks from the results of the FTIR analysis. SEM analysis to determine the microplastic shape and size
of the samples. Then do samples T-test use SPSS software.
3. Results and Discussion
3.1 Water Current Speed
The results of measurements of the speed of water flow at each stations can be seen in Table 1 below. Based
on Table 1 shows that at a distance of 0 metre from the edge of the bay of Kendari obtained the highest water
flow velocity is at station 3 which is 0.030 m/sec. While at a distance of 0 metre from the edge of the Kendari
bay, the lowest water flow velocity is at station 1, which is 0.014 m/sec. At a distance of 100 metres from the
edge of the Kendari bay, the highest water flow velocity was at station 3, which was 0.046 m/sec. While at a
distance of 100 metres from the edge of the Kendari bay the lowest water flow velocity was obtained at station
2 at 0.012 m/sec.
Table 1. Results of measurements of water flow velocity at each stations

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Station
Distance from the Edge
of Kendari Bay (metre)
Water Flow Speed (metre/second)
Punggaloba Estuary
0 0.014
100 0.017
Lahundape Estuary
0 0.021
100 0.012
Wanggu Estuary
0 0.030
100 0.046
Microplastics have been detected in organisms at all levels of the sea food chain. The amount of microplastics
ingested varies between species and locations, and can vary significantly even within the same area. In the
North Sea and the Big Belt, micro plastic has been found in the stomach, intestines, and / or other seal tissue,
herring, cod, whiting and clams. It is well known that sea animals ingest microorganisms with food, and there
are indications that certain animals ingest microplastics because they are the same size as their normal food,
such as algae. Studies also show that almost all marine animals ingest microplastics, but there are large
variations between different species in terms of the amount they consume. Likewise, there are studies on crabs
that show that plastic accumulates in the food chain [4]. Microplastic distribution is influenced by several
factors including water waves, water currents and tides [14]. Microplastic sources found in the Kendari bay
come from human activities and natural activities such as natural disasters that originate from several rivers
that flow into the Kendari bay, including the Lahundape river, Punggaloba river, and the Wanggu river. When
heavy rains and floods occur, plastic rubbish along the river will be carried by the flow of water towards the
estuary waters of the Kendari bay.
3.2 Microplastic Concentration in Water Samples
The results of the analysis of water samples showed differences in the number of microplastic particles
contained from each stations. From Figure 4 shows that at a distance of 0 metre from the edge of the bay of
Kendari obtained microplastic particles in water samples with the highest concentration found at station 2
which is 5.4 particles/liter, while the lowest concentration is at station 3 which is 3 particles/liter. At a distance
of 100 metres from the edge of the Kendari bay obtained microplastic particles in water samples with the
highest concentration found at station 2 at 4.67 particles/liter, while the smallest concentration was at station
3 at 3.26 particles/liter. So that the data shows that the most polluted microplastic is at station 2 among other
stations, this is because, in the Lahundape estuary conditions, there are mangrove tourist attractions, close to
residential and hospitality areas, as well as many economic activities of the existing people around the
Lahundape river. After all, the garbage produced by traders, buyers, and visitors of mangrove tourism is
dumped around the Lahundape river which flows into the estuary waters of the Kendari bay.

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Figure 4. Microplastic concentrations in water samples at each stations
3.3 Microplastic Concentration in Sediment Samples
The results of the analysis of sediment samples showed differences in the number of microplastic particles
contained from each stations. For more details, can be seen in Figure 5 below.
Figure 5. Microplastic concentrations in sediment samples at each stations
From Figure 5 it shows that at a distance of 0 metre from the edge of the bay of Kendari obtained microplastic
particles in sediment samples with the highest concentration found at station 1 which is 96 particles/kg, while
the lowest concentration is at station 3 which is 61 particles/kg. So that the data shows that the most polluted
microplastic is at station 1 among other stations, this is due to the condition of the Punggaloba estuary there
are many plastic waste deposits contained in sediments, due to community activities that dispose of trash in
the Punggaloba river flow, so carried by the flow of water and settles in estuarine waters at Kendari Bay.
3.4 Microplastic Characteristics of Water Samples
Indicators of microplastic characteristics in this research based on aspects of morphology include the shape
and type, as well as the abundance and size range at each stations of the Kendari bay. The results of the visual

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inspection on microplastic forms in water samples using a light microscope (magnification of 40x) at each
stations from Kendari bay can be seen in Figure 6 below.
Figure 6. (a) Station 1 in the form of fiber; (b) Station 2 in the form of fiber; (c) Station 3 in the form of
fiber
The results of the visual inspection on microplastic forms in water samples using SEM at each stations from
Kendari bay can be seen in Figure 7 below.
Figure 7. (a) Station 1 originating from a distance of 0 metre from the edge of the Kendari bay; (b) Station 1
originating from a distance of 100 metres from the edge of the Kendari bay; (c) Station 2 originating from a
distance of 0 metre from the edge of the Kendari bay; (d) Station 2 originating from a distance of 100 metres
from the edge of the Kendari bay; (e) Station 3 originating from a distance of 0 metre from the edge of the
Kendari bay; (f) Station 3 originating from a distance of 100 metres from the edge of the Kendari bay
Based on Figure 6 and 7 shows that the microplastic form in the dominant water samples found at the three
stations of the Kendari bay is fiber. According to Ayuningtyas, et al. fibers are thin and long shaped like
synthetic fibers [2]. Fiber-type microplastic sources are thought to come from synthetic fabrics, fishing boat
waste and fishing gear such as fishing nets and fishing lines [5]. The results of detection and analysis on the
types of microplastics in water samples using FTIR and Origin software at each stations from Kendari bay
can be seen in Figure 8 below.

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(a) (b)
(c) (d)
(e) (f)
Figure 8. (a) Microplastic type at station 1 originating from a distance of 0 metre from the edge of Kendari
bay; (b) Microplastic type at station 1 originating from a distance of 100 metres from the edge of Kendari
bay; (c) Microplastic type at station 2 originating from a distance of 0 metre from the edge of Kendari bay;
(d) Microplastic type at station 2 originating from a distance of 100 metres from the edge of Kendari bay;
(e) Microplastic type at station 3 originating from a distance of 0 metre from the edge of Kendari bay; (f)
Microplastic type at station 3 originating from a distance of 100 metres from the edge of the Kendari bay
Figure 8 shows that the type of microplastic in the dominant water samples found from the three stations at
Kendari bay is the type of polystyrene (PS). Based on the results of the FTIR analysis, several functional

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groups of images and wave-number data are seen that polypropylene (PP) is indicated by the peak of the
wave-number 2910 cm-1 which is prominent and shows the type of asymmetrical vibration (CH2). Based on
the results of the reference according to Syakti et al., (2017) polypropylene (PP) where the wave-number is
asymmetric vibration (CH3) of PS. For the peak wave of 1468 cm-1 that shows prominent asymmetric
deformation vibrations (δa-CH3), while symmetrical deformation vibrations (δs- CH3) are characterized by
prominent absorption bands in other polymers. At the peak of wave-number 3439 cm-1, it was suspected that
OH function groups were associated with aromatic CeH stretching vibrations and were marked with the
discovery of fabric fibers in water samples. Thus the dominant microplastic polymer content at Kendari bay
is PS. Polyethylene is the main ingredient in making bags and plastic containers. From all microplastic data
found, the microplastic colors found are black and the microplastic color is transparent. The black color can
indicate the amount of contaminants absorbed in microplastics and other organic particles, the color of
microplastics found is still concentrated, which means that microplastics have not undergone significant
discolouring. Also found microplastic with transparent colors. Transparent colored microplastics are the initial
identification of polypropylene (PP) polymers. This type of polymer is one of the polymers most commonly
found in waters. Transparent color also indicates how long the microplastic has been photodegradated by UV
light [3]. Human health problems and large changes in the ecosystem will arise as a result of the toxicity of
plastic polymers [9]. The results of the analysis on the abundance and size range of microplastics in water
samples using SEM at each stations from Kendari bay can be seen in Figure 9 below.
Figure 9. (a) Abundance and size range of microplastics at station 1 originating from a distance of 0 metre
and 100 metres from the edge of the Kendari bay; (b) Abundance and size range of microplastics at station 2
originating from a distance of 0 metre and 100 metres from the edge of the Kendari bay; (c) Abundance and
size range of microplastics at station 3 originating from a distance of 0 metre and 100 metres from the edge

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of the Kendari bay
Figure 9 shows that the highest microplastic abundance in the water samples is found at station 2, which is 63
particles/m3 with a size range of 0-5 µm, while the lowest microplastic abundance is found at station 1 is 53
particles/m3 with a size range of 0-5 µm. From the three stations, the range of microplastic sizes found was
around 0.24-20.34 µm. According to Efendi et al. almost all types of plastic will float or float in a body of
water [6]. This will cause the plastic to be torn and degraded by sunlight (photo- degradation), oxidation, and
mechanical abrasion to form plastic particles. Small plastic particles (≤ 5 mm) are called microplastics.
Microplastics scattered in the ocean will settle and be carried by the currents of the waves so that they are
mixed with beach sand. Microplastic size is very small and a large amount in the ocean makes it (ubiquitous)
and (bioavailability) for high aquatic organisms. As a result, microplastics can be consumed by marine biota.
The concern is that due to its very small size, microplastics allow it to enter the body of marine biotas such as
fish and bivalves, consequently, this pollutant can enter the food chain system (aquatic food chain) [10, 22].
3.5 Microplastic Characteristics of Sediment Samples
Indicators of microplastic characteristics in this research based on aspects of morphology include the shape
and type, as well as the abundance and size range at each stations of the Kendari bay. The results of the visual
inspection on microplastic forms in sediment samples using a light microscope (magnification 40x) at each
stations from Kendari bay can be seen in Figure 10.
Figure 10. (a) Station 1 in the form of a fragment; (b) Station 2 in the form of pellets; (c) Station 3 in the
form of a fragment
The results of the visual inspection on microplastic forms in sediment samples using SEM at each stations
from Kendari bay can be seen in Figure 11.

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Figure 11. (a) Station 1 originating from a distance of 0 metre from the edge of the Kendari bay; (b) Station
2 originating from a distance of 0 metre from the edge of the Kendari bay; (c) Station 3 originating from a
distance of 0 metre from the edge of the Kendari bay
Figure 10 and 11 shows that the microplastic forms in the dominant sediment samples found at the three
stations of the Kendari bay are fragments and pellets. According to Horton (2017), fragments are fragments
of larger sized plastic. Source of microplastic fragment type obtained from bottles, plastic bags and pipe pieces
[2]. According to Dewi et al. pellets are raw materials for making plastics that are made directly by factories,
this type includes primary microplastics [5]. Pellet micro waste is more commonly found on the surface
because it has a low density so it floats on the surface of the water [9]. The results of detection and analysis
of the types of microplastics in sediment samples using FTIR and Origin software at each stations of Kendari
bay can be seen in Figure 12 below.
(a) (b)
(c) (d)

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(e) (f)
Figure 12. (a) Microplastic type at station 1 originating from a distance of 0 metre from the edge of Kendari
bay; (b) Microplastic type at station 1 originating from a distance of 100 metres from the edge of Kendari
bay; (c) Microplastic type at station 2 originating from a distance of 0 metre from the edge of Kendari bay;
(d) Microplastic type at station 2 originating from a distance of 100 metres from the edge of Kendari bay;
(e) Microplastic type at station 3 originating from a distance of 0 metre from the edge of Kendari bay; (f)
Microplastic type at station 3 originating from a distance of 100 metres from the edge of the Kendari bay
Figure 12 depits that the type of microplastic in the dominant sediment samples found at the three stations of
the Kendari bay is the type of PS. Based on the results of the FTIR analysis, some functional groups of the
images and wave-number data that appear to be suspected of polyester (PE) display vibration bands at 2910
cm-1 and 2847 cm-1 which are similar to polypropylene (PP) but has no peak at 2852 cm-1. Subsequent peaks
at wave-numbers 2910 cm-1 and 2847 cm-1 correspond to CeH stretching showing symmetrical asymmetric
vibrations (CH3), these peaks may overlap with arising from the presence of several other particles in the
samples (H2O). Peaks below 1024 cm-1 correspond to the aromatic deformation of CeH aromatics. At the
peak of wave-number 3449 cm-1, an OH function group was associated with aromatic CeH stretching
vibrations and was characterized by the discovery of fabric fibers in sediment samples. Thus the dominant
microplastic polymer content at Kendari bay is PS or commonly known as styrofoam is a high molecular
weight synthetic hydrophobic polymer that is included in the thermoplastic type [20].

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Figure 13. (a) Abundance and size range of microplastic at station 1 originating from a distance of 0 metre
from the edge of the Kendari bay; (b) Abundance and size range of microplastics at station 2 originating
from a distance of 0 metre from the edge of the Kendari bay; (c) Abundance and size range at of
microplastic station 3 originating from a distance of 0 metre from the edge of Kendari bay
The PS can be recycled but it is difficult to do biodegradation. It is used in foam packaging, food containers,
plastic cups, plates, spoons, and forks [13]. Figure 13 shows that the highest microplastic abundance in
sediment samples is found at station 1, which is 81 particles/m3 with a size range of 0-5 µm while the lowest
microplastic abundance is found at station 2, namely 72 particles/m3 with a size range of 0-5 µm. From the
three stations, the range of microplastic sizes found was around 0.12-16.53 µm. According to Septian et al.
microplastic is divided into two types, namely microplastic and secondary microplastic, primary microplastic
when entering a direct micro-sized environment such as cosmetic waste and facial wash soap and secondary
microplastic which is the result of degradation and fragmentation of larger pieces of plastic [21].
3.6 Testing of T-test for Water Samples
The results of the analysis of the T-test on water samples using SPSS software at each stations from Kendari
bay can be seen in Table 2.
Table 2. T-test results on microplastic concentrations in water samples from each stations at Kendari bay
One-Sample Test
Test scores=3

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T Df Significant
(2-tailed)
Average Distance Trust Degree 95%
Total Microplastic 18.570 2 0.003 2911.66667 2237.0308
Table 2 shows that the value of sig (significant) (2-tailed) is 0.003 < 0.05 so that it can be interpreted that the
microplastic content at each stations is not the same or significantly different. In deciding the T-test, the
normality test is carried out first to find out the data produced is normally distributed or not normally
distributed. In the normality test, if the sig value ˂ 0.05 then the data is normally distributed. If the sig value
is > 0.05 then the data is not normally distributed. In the normality test results of water samples have a
significant value of 0.077 greater than 0.05 so that the results of the number of microplastic data at each
stations at Kendari bay are normally distributed. If the samples used is above 50 samples then we refer to the
Kolmogorov-Smirnov value, whereas if the samples value used is below 50 samples then it refers to the
Shapiro-Wilk value in the normality test. The basis for decision making is based on the sig value, because the
sig (2-tailed) value is 0.003 ˂ 0.05, so according to the decision-making basis above, it can be interpreted that
the microplastic content at each stations is not the same or significantly different.
3.7 Testing of T-test for Sediment Samples
T-test analysis results on sediment samples using SPSS software at each stations from Kendari bay can be
seen in the following Table 3.
Table 3. T-test results on microplastic concentrations in sediment samples from each stations at Kendari bay
One-Sample Test
Test Scores=3
T Df Significant
(2-tailed)
Average Distance Trust Degree 95%
Total Microplastic 7.564 2 0.017 82.667 35.64
The basis for decision making is based on the sig (significant) value, the decision because the sig (2-tailed
value) is 0.017 ˂ 0.05, so according to the decision-making basis above, it can be interpreted that the micro
plastic content at each stations is not the same or significantly different. Based on T-test analysis on sediment
samples, it shows that the normality test results on sediment samples have a significant value of 0.253, greater
than 0.05 so that the results of the number of microplastic data at each stations are normally distributed. In the
sediment samples based on the sig (2-tailed) value of 0.017 ˂ 0.05, it is following the basis of decision making
so that it can be interpreted that the micro plastic content at each stations is not the same or significantly
different.
4. Conclusion
The conclusion in this research was the concentration of microplastics in estuaries at Kendari bay, namely in
water samples (Punggaloba estuary) with a concentration of microplastic 8.33 particles/liter of water. Then
(Lahundape estuary) with a microplastic concentration of 10.07 particles/liter of water and (Wanggu estuary)
with a microplastic concentration of 6.26 particles/liter of water. Whereas the microplastic concentration in
sediment samples is (Punggaloba estuary) with a microplastic concentration of 96 particles/kg of sediment.
Then (Lahundape estuary) with a microplastic concentration of 91 particles/kg of sediment and (Wanggu
estuary) with a microplastic concentration of 61 particles/kg of sediment. Microplastic characteristics of
estuaries at Kendari Bay based on morphological analysis and particle size shows that the shape of
microplastic particles from water samples and sediment samples are granules with varying shapes and ranges

16. Sudia, et.al, 2020 Technology Reports of Kansai University
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of microplastic sizes in water and sediment samples ranging from 0.24-20.34 µm while the size range in
sediment samples ranged from 0.12-16.53 µm. Microplastic forms found at Kendari Bay are in the form of
fragments, fibers and pellets, and the most dominant microplastic found at Kendari bay is PS type.
5. Acknowledgement
Our gratitude goes to the Rector of Halu Oleo University for the financial support sourced from the Halu Oleo
University Budget Implementation List (DIPA) for the Fiscal Year 2019. The special thanks are also delivered
to The Head of Research and Community Service Institution (LPPM) and the government of Kendari City of
Southeast Sulawesi Province for their cooperation. Our appreciation is given to the Head of the Water Quality
Laboratory of the Institut Teknologi Bandung (ITB) for their willingness to become partners so that the
research runs smoothly and well.
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