1
Marine and Fishery sciences 38 (2): xxx-xxx (2025)
https://doi.org/10.47193/mas.3822025010109
ABSTRACT. Fishermen from Indonesia are uncertain whether the timing and placement of Belats
(guiding barrier traps) affects their catch. To answer this question and improve the long-term viability
and productivity of the Belat shery, this study described the catch composition, productivity, and
efciency of Belat in Tanjung Batu Village, Kotabaru Regency, Indonesia. Two Belats consisting of
a leader net, playground, and chamber net, were used in this study: Belat-A was larger than Belat-B
in both length and breadth. Belat-A was deployed at 2 km from the shoreline, while Belat-B was
installed at 1.5 km away, starting at 10 a.m. over a 24-h and a 48-h period, respectively. Results
showed that Belat-A outperformed Belat-B, capturing twice the number of catch (970 versus 460)
and 1.6 times the weight (92.6 kg versus 59.1 kg) across ten sh species between 14-50 cm of total
length. However, Belat-B achieved similar productivity rates in half the operational time, making it
more time-efcient. All sh caught were fresh and marketable, while the method itself was consid-
ered environmentally friendly. Several factors that affected the Belat catch and recommendation for
upcoming Belat studies are also discussed.
Key words: Belat performance, eco-friendly, productiveness, time-efcient, sustainability.
Pesca sostenible: un estudio sobre las trampas de barrera en Indonesia
RESUMEN. Los pescadores de Indonesia no están seguros de si el momento y la ubicación de
los Belats (trampas de barrera) afectan sus capturas. Para responder a esta pregunta y mejorar la
viabilidad y productividad a largo plazo de la pesquería de Belats, este estudio describió la composi-
ción de la captura, la productividad y la eciencia de estos dispositivos en la aldea de Tanjung Batu,
Regencia de Kotabaru, Indonesia. En este estudio se utilizaron dos Belats que consisten en una red
líder, una red de juegos y una red de cámara: el Belat-A era más grande que el Belat-B, tanto en
longitud como en anchura. El Belat-A se desplegó a 2 km de la costa, mientras que el Belat-B se
instaló a 1,5 km de distancia, comenzando a las 10 a.m. durante un período de 24 h y 48 h, respec-
tivamente. Los resultados mostraron que el Belat-A superó al Belat-B, capturando el doble de peces
(970 frente a 460) y 1,6 veces el peso (92,6 kg frente a 59,1 kg) de diez especies de peces de entre
14-50 cm de longitud total. Sin embargo, el Belat-B logró índices de productividad similares en la
mitad del tiempo operativo, lo que lo hizo más eciente en términos de tiempo. Todos los peces
capturados eran frescos y comercializables, mientras que el método en sí se consideró respetuoso
con el medio ambiente. También se discuten varios factores que afectaron la captura de los Belats y
se recomiendan futuros estudios.
Palabras clave: Desempeño del Balat, eco-amigable, productividad, eciente en el tiempo, susten-
tabilidad.
NOTE
Sustainable shing: a study on barrier traps in Indonesia
ahMadi*, iriansyah and cahyani Lestiani
Faculty of Fisheries and Marine Sciences, Lambung Mangkurat University, 70714 - Banjarbaru, Indonesia.
ORCID Ahmadi https://orcid.org/0000-0001-9691-9107
Marine and
Fishery Sciences
MAFIS
*Correspondence:
ahmadi@ulm.ac.id
Received: 28 November 2024
Accepted: 9 January 2025
ISSN 2683-7595 (print)
ISSN 2683-7951 (online)
https://ojs.inidep.edu.ar
Journal of the Instituto Nacional de
Investigación y Desarrollo Pesquero
(INIDEP)
This work is licensed under a Creative
Commons Attribution-
NonCommercial-ShareAlike 4.0
International License
Marine and Fishery sciences 38 (2): xxx-xxx (2025)
2
Kotabaru Regency, spanning 9,442 km2, is a
prominent marine shing region in South Kalim-
antan, Indonesia. Local shermen utilize 19 diverse
shing gear types, among which is the Belat, a pas-
sive guiding barrier trap. This eco-friendly method
involves permanently positioning the gear in tidal
areas that serve as sh migration routes. As the tide
rises, sh move towards the shore, and as it recedes,
they follow the fence-like structure into the trap (As-
min et al. 2023). This technique, similar to set-net
shing, has minimal environmental impact (Aki-
yama and Arimoto 2000). The Belat is a communi-
ty-friendly solution, offering low investment cost,
protability, respect for local culture, and compli-
ance with local regulations (Lindawati et al. 2024).
Tanjung Batu, a traditional shing village in
Kotabaru Regency, relies on Belat to catch sh.
This technique, which involves strategically plac-
ing traps in sh-rich areas, has proven effective in
a number of regions, including Waetuo and Pal-
lette in Bone Regency, southern Sulawesi Province
(Surachmat et al. 2017), and Dakiring in Bang-
kalan, eastern Java Province (Yunita and Zainuri
2021). Several factors such as gear size, geographi-
cal location, sh behavior, moon phase, and shing
time, can affect Belat productivity (Milardi et al.
2018; Lindawati et al. 2024). Pinpointing the exact
locations for Belat can signicantly enhance the
efciency and productivity of shing operations
(Hamriani et al. 2021). Siregar et al. (2015) found
that night-time Belat catches were signicantly
higher than daytime catches. Fishers are currently
uncertain if the timing and location of Belat shing
affect their catch. While research might seem coun-
terintuitive to Belat-friendly practices, its aim is to
enhance the long-term viability and productivity of
the Belat shery.
Fieldwork was conducted between May and
June 2024 at Tanjung Batu Village (2° 59' 177" S,
116° 12' 640" E) (Figure 1), Indonesia. Physical
oceanographic conditions encompassed water
temperature of 29-30 °C, water brightness (Sec-
chi depth) of 34-55 cm, current speed of 0.13-
0.15 m s-1, and salinity level of 34-40.
A V-shaped Belat structure was constructed with
polyethylene netting and sungkai wood to intercept
Figure 1. Geographic location of Tanjung Batu Village, Kotabaru Regency, Indonesia, where Belats were deployed.
Scale1:220,000
AhmAdi et Al.: BelAt fishing in indonesiA 3
schools of migratory sh and guide them into a
chamber net using a seine system (Figure 2). Two
different Belat sizes were used to compare their
productivity rates (Table 1).
The leader net height was adjusted to accommo-
date the maximum water depth during high tide,
ensuring optimal gear performance. Conical play-
grounds were situated on both sides of the gear to
intercept incoming sh and direct them towards
the chamber net. The chamber net was designed
with two doors: a primary door of 35 cm in width
leading to the main chamber, and a secondary trap
door of 15 cm in width leading to a smaller trap
chamber. The exterior of the chamber net mesh was
covered with bamboo for easier access. Belat-A
was deployed 2 km from the coast, while Belat-B
was deployed 1.5 km away, starting at 10 a.m. for
a period of 24 and 48 h, respectively. Water depth
varied between 4 m and 5 m during high tide and
1 m during low tide. Fishers used a small boat to
access these gears. Fish trapped in the chamber net
were scooped and transferred to sh boxes, identi-
ed, weighted and sorted by species. Subsequently,
the proportion of each sh type, both by number
and weight, was calculated as a percentage using a
standard formula (Simbolon et al. 2011):
Pi = ni × 100%
N
where Pi represents the relative abundance of catch
(%), ni is the number of catches for species i (sh
or kg), and N is the total catch (sh or kg). The
productivity of each Belat was estimated using the
following formula (Dahle 1989):
P = C
t
where P is the productivity, C is the total daily
catch (kg), and t is the effective shing time (h).
Data were analyzed using SPSS version 18 and
presented as mean ± standard error (SE) or percent-
age. Normality homogentiy of the data were test-
ed using the Lilliefors test (Dallal and Wilkinson
1986). A t-test was applied to compare the catch
proportion and productivity rate between Belats.
Statistical signicance was determined at p < 0.05.
Ten commercial sh species were caught by this
shing method (Table 2). The average daily catch
of Belat-A and Belat-B over a 15-day period was
65 ± 5.0 sh and 31 ± 6.0 sh, respectively. In
terms of average daily weight, Belat-A caught 6.2
± 0.6 kg, while Belat-B caught 3.9 ± 0.5 kg. All sh
caught were fresh and marketable. Belat catches
were primarily composed of high-value species
such as Siganus javus, Lates calcarifer, Lutjanus
sanguineus, L. analis, and Epinephelus coioides,
accounting for 50% of the total catch, with an es-
timated price of USD 2.5-3.0 kg-1. The remaining
half consisted of less commercial, more abundant
species of lower market demand, priced at USD
1.0-1.5 kg-1 (Table 2).
Figure 2. Belat installation in Tanjung Batu waters, Kotabaru Regency, Indonesia. A) Leader net. B) Playground. C) Chamber net.
ABC
Marine and Fishery sciences 38 (2): xxx-xxx (2025)
4
A comparative analysis of catch proportions
between Belat-A and Belat-B revealed signi-
cant differences in both catch number and weight
(p < 0.01) (Tables 3 and 4). Belat-A outper-
formed Belat-B, capturing twice the number of
sh (970 versus 460) and 1.6 times the weight
(92.5 kg versus 59.1 kg) across various sh spe-
cies. Gerres erythrourus was the most abundant
species in both methods, accounting for 80.0%
and 61.1% of the total catch in Belat-A and Be-
lat-B, respectively. It also made up the largest
portion by weight in Belat-A (34.4%), but less
pronounced in Belat-B (18.0%). Lutjanus fulvi-
amma was the second most numerous species,
representing 8.1% and 17.0% of the total catch
number in Belat-A and Belat-B, respectively. It
also contributed signicantly to the weight, espe-
cially in Belat-B (14.0%). Meanwhile, L. analis
and E. coioides were substantial contributors to
the weight, particularly in Belat-A (25.0% and
13.7%, respectively).
Statistical analysis revealed no signicant dif-
ference in the average daily productivity of Be-
lat-A and Belat-B, both in terms of catch number
and weight (p > 0.05). Over a 15-day period, Be-
lat-A daily productivity varied between 0.3 and
1.9 sh h-1 (1.4 ± 0.1 sh h-1), with an average
weight of 0.1 ± 0.0 kg h-1 (from 0.1 to 0.2 kg h-1)
Table 1. Technical specications of both Belat gears used in Tanjung Batu, Kotabaru, Indonesia.
Gear construction Material Belat-A (m) Belat-B (m)
Length Breadth Height Length Breadth Height
Leader net Polyethylene # 2.5-inch 150 - 7 130 - 6
Playground Polyethylene # 2.5-inch 20 - - 10 -
Chamber net Polyethylene # 1.5-inch 10 - 5 10 - 5
Table 2. Belat catch compositions and sell prices at local markets in Tanjung Batu Village, Kotabaru Regency.
Scientic name Average size (cm) Total catch (sh) Total catch (kg) Price (USD kg-1)
Siganus javus 35 25 12.2 2.5
Lates calcarifer 30 17 11.8 3.0
Lutjanus sanguineus 45 4 6.8 3.0
Epinephelus coioides 35 27 19.4 2.5
Sphyraena jello 50 23 5.5 1.0
Lutjanus analis 30 60 30.2 3.0
Alectis ciliaris 19 26 3.3 1.0
Gerres erythrourus 15 1,039 42.4 1.0
Lutjanus fulviamma 15 155 16.5 1.5
Caranx papuensis 14 32 3.7 1.5
AhmAdi et Al.: BelAt fishing in indonesiA 5
(Figure 3). Similarly, the daily productivity of Be-
lat-B varied between 0.3 and 3.0 sh h-1 (1.3 ± 0.3
sh h-1), with an average weight of 0.2 ± 0.1 kg h-1
(from 0.1 to 0.3 kg h-1) (Figure 4).
Table 3. Catch proportions by species and number of catch between Belat-A and Belat-B.
Scientic name Belat-A Belat-B
Fish Percentage Fish Percentage
Siganus javus 9 1.0 16 3.5
Lates calcarifer 8 0.8 9 2.0
Lutjanus sanguineus 1 0.1 3 0.7
Epinephelus coioides 16 1.7 11 2.4
Sphyraena jello 5 0.5 18 3.9
Lutjanus analis 44 4.6 16 3.5
Alectis ciliaris 10 1.1 16 3.5
Gerres erythrourus 758 80.0 281 61.1
Lutjanus fulviamma 77 8.1 78 17.0
Caranx papuensis 20 2.1 12 2.6
Total 970 100 460 100
Table 4. Catch proportions by species and weight between Belat-A and Belat-B.
Scientic name Belat-A Belat-B
kg Percentage kg Percentage
Siganus javus 5.6 6.1 6.55 11.1
Lates calcarifer 5.5 5.9 6.25 10.6
Lutjanus sanguineus 1.2 1.3 5.6 9.5
Epinephelus coioides 12.65 13.7 6.7 11.3
Sphyraena jello 0.7 0.8 4.8 8.1
Lutjanus analis 23.1 25.0 7.1 12.0
Alectis ciliaris 1.4 1.5 1.9 3.2
Gerres erythrourus 31.8 34.4 10.6 17.9
Lutjanus fulviamma 8.2 8.9 8.3 14.0
Caranx papuensis 2.4 2.6 1.3 2.2
Total 92.55 100 59.1 100
Marine and Fishery sciences 38 (2): xxx-xxx (2025)
6
Overall, Belat-A caught 970 sh and 92.6 kg
over a 48-h period, corresponding to productivity
rates of 20,208 sh h-1 and 1,928 kg h-1, respective-
ly. Although Belat-B captured fewer sh (460) and
less weight (59.1 kg) in a 24-h period, its produc-
tivity rates (19,167 sh h-1 and 2,463 kg h-1) were
not signicantly different from those of Belat-A (p
> 0.05). This suggests that Belat-B is more time-ef-
cient, requiring only half the operational time to
achieve comparable productivity levels (Table 5).
Fishermen expected that the longer the shing time,
the higher the abundance of sh. However, this is
not necessarily true. While it is possible that longer
shing time could lead to higher catches, espe-
cially if sh are abundant, other factors can also
inuence the relationship between shing time and
catch, such as sh behavior, water depth, weather
condition and shing techniques. Therefore, more
detailed studies conducted in different coastal areas
are needed to understand factors that affect catch.
Figure 3. Daily productivity rates of Belat-A and Belat-B based on catch number.
Figure 4. Daily productivity rates of Belat-A and Belat-B based on catch weight.
Productivity (fish h )
-1
Belat-A Belat-B
0
1
2
3
4
5
12345678910 11 12 13 14 15
Daily ishingf
12345678910 11 12 13 14 15
Daily ishingf
0.5
0.4
0.3
0.2
0.1
0.0
Productivity (fish h )
-1
Belat-A Belat-B
AhmAdi et Al.: BelAt fishing in indonesiA 7
In addition to food availability and sh behav-
ior, tidal patterns also play an important role in
the success of Belat shing. The rising and fall-
ing tides create currents that push sh towards
the shoreline (Milardi et al. 2018). When the tide
recedes, the sh swim back to the sea, guided
by the barrier, making them easier targets for the
Belat, resulting in increased catches compared to
low tide periods, and the results aligned with the
previous investigations. Yunita and Zainuri (2021)
found that large tidal ranges correlated with in-
creased catch in terms of weight, species diver-
sity, and individual numbers. Likewise, smaller
tidal ranges lead to decreased catch. The largest
(spring) tides typically occurr during the full
moon, driven by the stronger gravitational pull
of the moon. Numerous empirical studies have
demonstrated that the rhythmic patterns of tides
and lunar phases directly inuence sh behav-
ior and the supply of natural nutrients in aquatic
ecosystems (Zhang et al. 2021; Li et al. 2024).
Lindawati et al. (2024) found that lunar phases of
the new moon and the second quarter resulted in
the highest productivity rates. Although Hamriani
et al. (2021) emphasized the signicant inuence
of water temperature and current velocity on the
Belat catch, no evidence of a relationship with
water depth was observed. Conversely, Asmin et
al. (2023) found that Belat productivity was higher
at 5 m depth than 3 m in areas closer to productive
coral reefs and seaweed farms that attract larger
numbers of pelagic sh.
Further studies will be needed to assess catch
and productivity of Belats as well as their impact
on local livelihoods. Expanding the spatial scope
to different seasons and coastal areas, monitoring
times with varying environmental conditions to
optimize catch and minimize environmental im-
pact, and utilizing underwater cameras and acoustic
telemetry to monitor sh behavior and trap ef-
ciency in real-time are all research activities that
will be required.
ACKNOWLEDGEMENTS
This research was self-funded. The authors
thank Mr Ali, the Belat owner, for his assistance
and support during eldwork. Special thanks also
go to the anonymous reviewers for their valuable
feedback.
Table 5. Comparison analysis of Belat effectiveness based on catch numbers and weight.
Belat Total catch (ind.) Duration (h) Productivity (ind. h-1) Percentage
A 970 48 20,208 51.3
B 460 24 19,167 48.7
Total 1,430 72 39,375 100
Belat Total catch (kg) Duration (h) Productivity (kg h-1) Percentage
A 92.55 48 1,928 43.9
B 59.10 24 2,463 56.1
Total 151.65 72 4,391 100
Marine and Fishery sciences 38 (2): xxx-xxx (2025)
8
Conict of interest
The authors declare that there is no conict of
interest and that the research meets the required
ethical guidelines.
Author contributions
Ahmadi: conceptualization; data curation; for-
mal analysis; investigation; writing-original draft.
Iriansyah: methodology; writing-review and edit-
ing. Cahyani Lestiani: data collection; writing-re-
view and editing; documentation.
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