Fisheries Journal, 15 .
, 1881-1891 .
http://doi.
org/10.
29303/jp.
ESTIMATION OF FISH PRODUCTION THROUGH NUTRIENT
ANALYSIS OF MANGROVE LITTER Avicennia Sp.
AT THE
WONOREJO-SURABAYA MANGROVE INFORMATION CENTER
Estimasi Produksi Ikan Melalui Analisis Nutrien Seresah Mangrove Avicennia Sp.
Kawasan Mangrove Information Center Wonorejo-Surabaya Rindya Fery Indrawan1.
Hariyadi2* Program Studi Akuakultur.
Fakultas Pertanian Peternakan.
Universitas Muhammadiyah Malang Malang.
Jawa Timur.
Indonesia, 65144.
Corresponding author: hariyadi@umm.
(Received March 22th 2024.
Accepted July 23th 2.
ABSTRACT Mangrove forest is a very fertile ecosystem and is located in the coastline so that it has a major contribution to the surrounding environment.
Mangrove tree litter that falls will be a food source for aquatic biota and nutrients that greatly determine the productivity of marine The purpose of this study was to analyze the production of nutrients (N.
P) from mangrove leaf litter, suspect the primary production of phytoplankton from nutrients released from mangrove leaf litter, and to estimate the carrying capacity of the mangrove ecosystem on fish production.
This research station determination method uses a purposive randome sampling method with reference to the mangrove density and determination of the sampling Litter production measurements using themethod litter trap and decomposition rate using themethod litter bag.
Estimation of fish production using the Beveridge .
method The amount of nutrients released by mangrove Avicennia sp.
per day at the mangrove Information Center which is 0.
0503 g N / m / day and the release of Phosphorus ranges 0053 g P / m2 / day.
The value of primary production in the mangrove ecosystem information center Wonorejo-Surabaya is quite high ranging from 460 to 690 g C / m2 / yr, and is included in the category of fertile to very fertile.
Herbivor fish production ranges 04 to 690 kg / ha / yr.
Carnivorous fish ranged from 46.
20 to 69 kg / ha / yr and total fish production ranged from 595.
80 kg / ha / yr.
The total fish production illustrates the potential of fish production contributed from the mangrove ecosystem at 595.
80 kg / year.
Keywords: Mangrove Ecosystem.
Litter.
Litter Nutrient.
Primary Productivity.
Fish Stock
ABSTRAK
Hutan mangrove merupakan ekosistem yang sangat subur dan berada di daerah garis pantai sehingga memiliki kontribusi besar terhadap lingkungan sekitarnya.
Serasah pohon mangrove yang jatuh akan menjadi sumber makanan bagi biota perairan dan unsur hara yang sangat menentukan produktivitas perikanan laut.
Tujuan penelitian ini adalah untuk menganalisis produksi nutrien (N.
P) dari serasah daun mangrove, menduga produksi primer fitoplankton e-ISSN : 2622-1934, p-ISSN : 2302-6049 Fisheries Journal, 15 .
, 1881-1891.
http://doi.
org/10.
29303/jp.
Indrawan & Hariyadi, .
dari nutrien hasil pelepasan serasah daun mangrove, menduga daya dukung ekosistem mangrove terhadap produksi ikan.
Metode penentuan stasiun penelitian ini menggunakan metode purposive randome sampling dengan mengacu pada kerapatan mangrove dan penentuan titik sampling.
Pengukuran produksi serasah menggunakan metode litter trap dan laju dekomposisi menggunakan metode litter bag.
Pendugaan produksi ikan menggunakan pendekatan metode Beveridge .
Jumlah nutrien yang dilepaskan mangrove Avicennia sp.
per harinya di mangrove Information Center yaitu 0,0350Ae0,0503 g N /m /hr dan pelepasan Fosfor berkisar antar 0,0018Ae0,0053 g P/mA/hr.
Nilai produksi primer di ekosistem mangrove information center Wonorejo-Surabaya cukup tinggi berkisar 460-690 g C/mA/th, dan termasuk dalam kategori subur sampai sangat subur.
Produksi ikan herbivor berkisar 462,04-690 kg/ha/th.
ikan karnivor berkisar 46,20-69 kg/ha/th dan produksi total ikan berkisar 595,80 kg/ha/th.
Produksi total ikan tersebut menggambarkan potensi produksi ikan yang disumbang dari ekosistem mangrove sebesar 595,80 kg/th.
Kata Kunci: Ekosistem Mangrove.
Serasah.
Nutrien Serasah.
Produktivitas Primer.
Stok Ikan
INTRODUCTION
Mangrove forests are one of the most fertile ecosystems located along the coastline, thus contributing significantly to the surrounding environment.
In addition to supporting various ecosystem services, including fisheries production, mangroves also provide nutrients (Prayitno.
The largest production from the mangrove ecosystem is mangrove leaf fall.
Important information regarding litter production, decomposition rates, and nutrient cycling can be obtained if mangrove tree litter is calculated correctly and combined with other biomass Mangrove forests are one of the most fertile ecosystems located along the coastline, thus contributing significantly to the surrounding environment.
In addition to supporting various ecosystem services, including fisheries production, mangroves also provide nutrients (Prayitno.
The largest production from the mangrove ecosystem is mangrove leaf fall.
Important information regarding litter production, decomposition rates, and nutrient cycling can be obtained if mangrove tree litter is calculated correctly and combined with other biomass Primary productivity in waters influences the food chain for organisms within an In a body of water, the level of primary productivity indicates that the body of water is sufficiently productive in producing plant biomass, including the oxygen supply generated by photosynthesis.
The development of an aquatic ecosystem, particularly regarding fisheries production, is closely linked to the availability of plant biomass and sufficient oxygen in the water (Amri et al.
, 2.
The mangrove leaf litter nutrient release approach can be used to estimate fish production in waters.
The results of these primary productivity values will ultimately determine fisheries production in waters.
Based on this, this study needs to analyze nutrient production (N.
P) from mangrove leaf litter, estimate aquatic primary production from the results of mangrove litter nutrient release, and estimate fisheries production using the nutrient release approach.
RESEARCH METHODS
This research was conducted at the Wonorejo Mangrove Information Center.
Surabaya City.
East Java Province, and the UMM Fisheries Laboratory.
This research was conducted for one .
month, from April to May 2020.
The determination of research stations was carried out intentionally using a purposive random sampling method, where research stations were taken with consideration referring to mangrove density and the determination of sampling points.
The sampling area was divided e-ISSN : 2622-1934, p-ISSN : 2302-6049 Fisheries Journal, 15 .
, 1881-1891.
http://doi.
org/10.
29303/jp.
Indrawan & Hariyadi, .
into 3 station sections with different mangrove densities, namely each station has low, medium and high density groups.
(Santya et al.
, 2.
at each observation station, there are 3 line transects from the river towards the land .
erpendicular to the coastline along the existing mangrove forest zonatio.
in the intertidal area.
Each line transect was placed randomly in a square plot with a size of 10 x 10 mA according to the width of the mangrove forest.
Litter productivity calculations can be performed after detailed analysis of the data obtained from observations.
The data analysis included the average litter yield .
/m2/da.
(Utami et al.
, 2.
The first step taken to calculate the rate of litter decomposition is to observe the percentage of litter decomposition on mangrove leaves using the Boonruang .
BA Oe BK y 100% Information:
: Percentage of decomposed litter (%) : Initial weighing of dry weight .
: Initial weighing of dry weight .
Total nitrogen content can be calculated using the Kjelldahl method (Mukhlis, 2.
ycA ycaycuycuycyceycuyc ycnycu ycoyceycaycyceyc = a y 0,02 y 14 Information :
: Volume difference .
: Weight of dry matter in 0.
1g of leaf flour 0,02 : HCl normality .
reviously standardized to determine the exact normal value.
Calculation of the determination of phosphorus elements is carried out by wet destruction (Mukhlis, 2.
P leaf (%) = P late y y 10!" 0,25 0,25 = P solution x 0,2 The release of litter nutrients .
g/mA/h.
can be calculated based on the statement of Nga et al.
, namely:
Nutrient # .
= (BW$ y N$ ) Oe (BW% y N% ) Information :
BW$ : Initial dry litter weight .
BW% : Weight of dry litter remaining at observation time t.
: Initial nutrient content : Final nutrient content remaining on t-day.
: Incubation time .
Estimating fish production in waters can be done using the nutrient release approach from leaf litter.
The steps for estimating fish production include determining the nutrient (N and P) production results from leaf litter (Haris et al.
, 2.
e-ISSN : 2622-1934, p-ISSN : 2302-6049 Fisheries Journal, 15 .
, 1881-1891.
http://doi.
org/10.
29303/jp.
Indrawan & Hariyadi, .
M Nutrien .
/mA /h.
M Nutrien = M.
aya& y ycIycA& ) .
aya& y ycIycE& ) Information:
: Total leaf litter production.
RN.
RP : Potential release of nitrogen (N) from litter.
: Potential release of phosphorus (P) from litter.
: Mangrove species.
The C:N ratio for protein production is 17:1 (Carbon:Nitroge.
The amount of nitrogen converted to dry weight .
C) is 1 gC = 2 g dry weight (Haris et al.
, 2.
According to de Weir et al.
, .
, primary production is determined based on litter decomposition.
Oc PP .
C/mA /h.
from nutrient production, namely:
Oc PPCe = Oc Nutrien x 2 x 17 Herbivorous fish production .
fresh fish weight/mA/da.
can be calculated from Oc PPCe using the primary production conversion efficiency from Beveridge .
, as follows:
Herbivorous fish production (HB)= 10 x .
x OcPPL) Information:
: Value (%) conversion into grams .
C-fish/mA /h.
10 % : The C content in fish is based on the weight of the fish/wet weight of the fish.
The production of carnivorous fish produced by the mangrove ecosystem is calculated with an efficiency of 10% in energy flow.
CF is 10% of HF (Utami et al.
, 2.
Total fish production can be known if the value of herbivorous and carnivorous fish production is obtained from Beveridge .
, namely:
Total fish production (FB) = HF CV
RESULTS
Decomposition Rate The decomposition rate values at each station showed differences in each period.
The highest average decomposition rate occurred during the first 10 days of observation and then decreased until the end of the observation.
According to (Hastuti et al.
, 2024.
Raynaldo & Saputra, 2.
marina and R.
mucronata mangroves experienced a significant weight loss at the beginning of the study, and then the decomposition rate decreased for the remainder of the period.
The dry weight of mangrove litter is presented in the graph below.
e-ISSN : 2622-1934, p-ISSN : 2302-6049 Fisheries Journal, 15 .
, 1881-1891.
http://doi.
org/10.
29303/jp.
Indrawan & Hariyadi, .
7,00
Dry weight .
6,00 5,00 5,27 5,06 4,98 4,00 3,55 2,77 3,12 3,00
2,32
ST 1
2,08
1,79
2,00
ST 2
ST 3
1,00
0,00
TIME
Figure 1.
Litter Dry Weight Graph Based on the data above, the dry weight of mangrove litter in the first 10 days of observation, namely station I was 5.
27, station II 4.
98 and station i was 5.
Observations on the 20th day showed that station 1 was 3.
12, station II 3.
55 and station i 2.
Observations on the 30th day showed that the dry weight of station 1 was 2.
08, station II 2.
77 and station i The high dry weight of the litter decomposition rate in the first 10 days of observation is thought to be due to the loss of organic and inorganic material content in the litter.
The highest dry weight of the remaining litter on the 30th day of observation was station 2 at 2.
77 and the lowest residue at station 3 at 1.
80 grams.
The dry weight of the remaining litter explains that the decomposition process at station 2 is lower than the other stations.
Station 3 obtained the lowest dry weight because at station 3, many macrozoobenthos such as gastropods, decapods, aphepods, and crustaceans were found, which are thought to play a significant role in the decomposition process.
According to (Redjeki, 2.
, the decomposition and simplification of organic and inorganic material content occurs when mangrove leaves fall and are trapped.
The availability of organic and inorganic materials will be consumed/decomposed by decomposers.
The highest activity of fungal cellulolytic enzymes occurs at the beginning of the mangrove litter decomposition process.
Bacteria are one of the components that play an important role in the decomposition process of mangrove litter.
According to (Kusuma, 2023.
Nolan et al.
, 2019.
Rejeki & Hisyam, 2.
stated that the bacteria produced from mangrove leaf litter have diversity, but there are the most dominant ones found in all types of decomposed mangrove leaf litter such as Bacillus.
In the Avicennia mangrove species, the bacteria found include Bacillus.
Clostridium.
Enterobacteria.
Bacteroides.
Plesiomonas.
Bordella.
Streptococcus and Neisseria.
The percentage of litter decomposition rate is presented in the graph below.
e-ISSN : 2622-1934, p-ISSN : 2302-6049
(%)
Fisheries Journal, 15 .
, 1881-1891.
http://doi.
org/10.
29303/jp.
Indrawan & Hariyadi, .
90,00
80,00
70,00
60,00
50,00
40,00
30,00
20,00
10,00
0,00
64,49
76,80
68,85
82,06
72,29
79,16
50,21
47,29
49,39
ST 1
ST 2
ST 3
TIME
Figure 2.
Percentage of Litter Decomposition Rate The high percentage of decomposition rate on the 30th day of observation is suspected to be due to the role of decomposer organisms found in the litter bag.
These decomposer organisms were found from the beginning of the observation, namely in the first 10 days of the Apdhan et al.
, .
the high decomposition rate occurred at the beginning of the observation, this is thought to be closely related to the loss of easily soluble organic and inorganic materials .
and also the discovery of microorganisms that play a role in the breakdown of several substances contained in mangrove litter.
In addition to the presence of decomposer organisms, the leaf structure of the Avicennia mangrove and the components that make up the leaves also affect the decomposition process.
As is known.
Avicennia leaves are Rainfall and tides also influence the rate of decomposition.
During the rainy season, the environment tends to be more humid, allowing bacteria and decomposers to thrive.
However, during high tide, physical mechanisms occur, causing mangrove litter to be inundated by seawater and affected by current movements.
(Yusal et al.
, 2.
state that tides in waters can accelerate the process of litter decomposition.
Through the process of slowly weathering the litter, sunlight and salt content can destroy the organic material.
According to (Haris et al.
Siegers, 2015.
Widhitama et al.
, 2.
, in water areas, the litter decomposition process is assisted by physical mechanisms, namely tidal movements and prolonged seawater The mechanism for the loss of soluble material from mangrove litter is caused by rainwater or water flow.
DISCUSSION