Suitability analysis of spiny lobster mariculture zones in Sabang waters, Indonesia

The lobster aquaculture industry has a high dependence on natural catch. Hence, lobster farming has become necessary. The waters in Sabang have the potential for developing lobster mariculture, but data is not yet available on the conditions of the aquatic environment that are suitable for lobster farming. This research aims to determine which locations are suitable for lobster mariculture activities in the waters of Sabang. The research parameters are divided into geographics, physicochemical


Introduction
Lobster (Panulirus sp.) is a high-value fishery commodity with high economic potential.Due to high domestic market demand and exports to countries such as China, Hong Kong, Singapore, and Taiwan, there has been increased pressure on natural lobster stocks.The lobster fishing industry currently still relies on catching lobsters from the wild because, until now, there has been no successful attempt to hatch lobsters to meet the demand (Musbir et al., 2014).
The increasing demand for lobsters from China, especially pearl lobsters (P.ornatus), in the 1980s led to an increase in lobster fishing in Vietnam and Indonesia.However, overfishing of lobsters and a lack of management regulations have resulted in declining yields and size, especially in Vietnam.
Indonesia can potentially develop marine cultivation, including lobster farming (Mustafa, 2013).Although lobster farming has started in various provinces in Indonesia since 2000, the progress has been slow due to challenges such as the high mortality rate of lobster seeds caused by environmental factors and predators.
One important factor in the success of lobster mariculture activities is choosing the right location.Water quality levels play an important role.Therefore, accurate data and information regarding water quality in lobster cultivation zones are needed (Junaidi et al., 2018).Providing accurate and up-todate data is important to increase the chances of success in developing lobster farming.Selecting a location for mariculture activities is crucial and must be done correctly (Mustafa et al., 2018).
Depik Journal of Aquatic, Coastal and Fisheries Sciences Volume 12, Number 3, Pages 389-397 Ismail et al. (2023) Sabang is a coastal area and small islands consisting of five islands, namely Weh Island, Klah Island, Rubiah Island, Seulako Island, and Rondo Island.Besides having tourism potential, Sabang also has fishery potential, making it suitable for lobster farming and marine tourism.Lobster production in Sabang is quite large, and the lobster price tends to be stable.Based on initial observations, its aquatic environment is suitable for lobster habitat, so it has the opportunity to become a location for lobster mariculture.
Despite the potential, lobster farming in Sabang has not been optimized due to the lack of suitability studies and water quality assessments.Currently, the lobster fishery in Sabang is mostly reliant on capture fisheries, which poses long-term risks.Thus, there is an urgent need for studies related to zone suitability analysis to determine the optimal locations for lobster mariculture in Sabang.
Lobsters are hard-skinned animals belonging to the Arthropod class, with a segmented body, hard exoskeleton, and book-shaped protrusions (arthropod means 'book-footed').The characteristics of arthropods are bilateral symmetry, and the body consists of a head, thorax, and abdomen, segmented, and each has hinge joints and opposing muscles (Campbell, 2012).Taxonomically, crayfish are divided into four groups, namely: true crayfish (true lobster; Homaridae), crayfish (spiny lobster, Palirunidae), stick shrimp (crayfish, Astacidae), and sand shrimp (Spanish lobster, Astacidae).Only three of the four types of lobster have been detected in Indonesian waters.The true lobsters are not found in Indonesian waters and are only found in subtropical waters (Harris and Rani, 2013).
The natural habitat of lobsters varies by type, related to depth, currents, and water turbidity.Bamboo Lobster (P.versicolor) is found in coral reefs and rocky areas with sandy bottoms.It is active at night and, during the day, takes refuge in rock crevices and under coral reefs, living at depths of between 5-10 meters.Meanwhile, rock lobsters (P.homarus) are found in rocky areas and coral reefs at depths of 1-7 meters in murky waters and strong wavy currents (Mukminin et al., 2022).
Lobster is a fishery commodity with high economic value.However, its production still depends on capture fisheries.Lobster mariculture has not become the main choice for fishermen in Indonesia due to their lack of knowledge about ideal locations for mariculture, the technological systems used, and vulnerability to death due to disease and unsuitable waters (Prasetya and Hasidu, 2021).The low productivity of lobster farming is caused by various technical obstacles, which cause coastal communities to prefer selling their catch of clear lobster seeds directly to traders rather than growing lobsters to consumption size (Erlania et al., 2014).
One of the determining factors for the success of mariculture activities in waters is selecting the right location.The level of suitability and productivity of water is an important parameter that must be considered.For this reason, data and information regarding water quality are needed (Junaidi, 2018).
This research aims to determine the suitability of water zones for lobster mariculture using a spatial analysis approach, which includes assessing environmental conditions, water quality, temperature, salinity, and other relevant factors to determine whether the coastal area studied is suitable for lobster cultivation.The purpose of determining the suitability of lobster mariculture development zones is to increase the chances of successful lobster farming in Sabang waters.

Method Location and time of research
This research was conducted in the coastal area of Sabang using the Purposive Sampling Method, namely selecting locations based on differences in the habitat characteristics of each station, including three research stations: Lhok Krueng Raya, Teupin Sirui, and Lhok Weng (Iboih).
The research lasted for five months from   Ismail et al. (2023) The distance between research stations is as follows: Lhok Krueng Raya to Teupin Sirui is 4 km (2.15 miles), Lhok Krueng Raya to Lhok Weing is 4.82 km (2.6 miles), and Teupin Sirui to Lhok Weing is 4.1 km (2.21 miles).These distances must be noted and considered when planning any research-related activities.

Parameter used for the suitability analysis of lobster mariculture
The parameters used to analyze the suitability of waters for lobster mariculture consist of geographical parameters, including location protection, depth, and physicochemical parameters of waters in the form of water quality.Important parameters to describe the quality of marine waters are temperature, salinity, dissolved oxygen, BOD, and COD.Measurement of temperature, salinity, and dissolved oxygen parameters are inseparable in any research at sea.The reason is that temperature, salinity, and dissolved oxygen play an important role in aquatic biota (Patty, 2013).Measurement and testing of water quality parameters are presented in Table 1.Apart from geographical parameters and the physicochemical parameters of water, other supporting parameters in selecting a location for lobster mariculture are also considered.Other supporting parameters mentioned in this research are accessibility (ease of reaching the location), spatial location suitability parameters and information on spatial (water) use conflicts from each research location.

Use of geographic information systems
Geographic Information System (GIS) technology is the right solution for research on determining the suitability of lobster cultivation development zones.Remote sensing can monitor large areas periodically and can observe objects at any distance.GIS is a means of collecting, combining, and processing data for each required parameter.The existence of GIS makes it easier to process large amounts of data with complex structures efficiently.GIS can help make decisions in a timely and accurate manner (Samad, 2020).
The GIS technology can also be used to facilitate analysis of selecting suitable locations for placement of floating net cages based on measurement data of geographical, physical, and chemical parameters of waters and other supporting parameters.This method has now been developed and used worldwide to determine the suitability of cultivation zones (Purnawan et al., 2015).
The method used in this research was to compare potential locations for lobster mariculture.Furthermore, an analysis was carried out using data and information about environmental parameters supporting mariculture in the form of layers which then be overlaid with each other and produce a new thematic map regarding the suitability of water locations for the development of lobster mariculture.
Analysis of the suitability of lobster farming locations in Sabang waters was carried out by preparing a base map, which became a reference for entering spatial and attribute data, and processes using ArcGIS 10.8 tools.The base maps used were Ikonos satellite image data, administrative maps of Sabang at a scale of 1:100,000, and other thematic maps at a scale of 1:65,000 obtained from the Geospatial Information Agency and field data collected in March 2023.
After the data was collected, a database was prepared, the second step in implementing the GIS.The database contains a collection of data originating from various sources and types of data, both spatial and attributed.Compilation of the suitability map with the GIS application, the biophysical data of the waters obtained from measurements in the field are entered into a database format.This data was generally in the form of coordinate points with the X and Y axes area that do not have length and area dimensions.
Data from environmental parameter measurements and other data are formed into a layer that would be included in the base map.each parameter was formed, it was combined or overlaid with ArcGIS 10.8 software regarding the suitability parameters for lobster cultivation zones in the Sabang waters.

Method of collecting data
The data collected in this research consisted of primary data and secondary data.Primary data includes (i) geographical data, physicochemical data of the research location's waters, and (ii) interview data from the community (cultivator) of lobster mariculture in Sabang, which includes socioeconomic-technical problems of lobster mariculture.
Primary data was obtained through field observations, parameter measurements at the research location, and interviews with the cultivators.Data collection was carried out in March 2023.Meanwhile, secondary data in this research includes supporting literature and other supporting data.Secondary data collection was carried out to provide input to the geographic information system, both spatial and attribute data.
The geographical parameters referred to in this research include protectability parameters, and types of bottom-water substrate were carried out by direct observation at the location and interviews with local fishermen.In contrast, depth parameters were measured directly at the location after marking the location points with a Global Positioning System (GPS) device.Depth and location protection observations were conducted before water quality measurements and sampling.
Water quality parameters collected include temperature, salinity, pH, brightness, dissolved oxygen (DO), BOD, and COD.Water quality sample data was taken from three specified locations (purposive sampling).Coordinate positions are determined for each observation and sampling station using the GPS at potential locations for developing floating net cages for lobster mariculture.The temperature, salinity, pH, DO, and brightness parameters were measured directly in the field using a refractometer, pH meter, oximeter, and seiche disk.At the same time, COD and BOD data were carried out in the water sample testing process at the BARISTAND Laboratory (Industrial Research and Standardization Center) Banda Aceh.

Data analysis
Data were analyzed using the Analytical Hierarchy Process (AHP) to determine the weight values among parameter groups and between parameters within each group.In contrast, the score values were analyzed using the criteria for the suitability of water zones for developing lobster mariculture.The criteria for the suitability of aquatic zones for mariculture are a matrix compiled based on the results of previous studies (Fatmawati and Baharuddin, 2021), (Ghani et al., 2015) and (Lesmana, 2022).Meanwhile, the Simple Additive Weighting (SAW) method is often used to analyze the suitability area for lobster cultivation zones.
Each parameter group is given a weight value based on its contribution to the suitability of the lobster cultivation location as follows: 1. Geographic parameters weigh 35.24% 2. Physicochemical parameters weigh 29.52% 3. Other supporting parameters weigh 35.24% (Based on the AHP analysis)

Water zone suitability analysis
The criteria for suitability of the water zone used for lobster cultivation in this study used two criteria: (1) Suitability criteria for geographic and physicochemical parameters and (2) Suitability criteria for other supporting parameters.Criteria for Suitability of geophysical and physicochemical parameters can be seen in Table 2. whether a water zone is suitable to be used as a mariculture location based on considerations of ease of accessing the location, suitability of the location regarding freshwater input, sources of pollution and conflicts over the utilization or use of water location space.The criteria used for the suitability of other supporting parameter groups can be seen in Table 3.

Geographic parameters
The geographical parameters used in this research are location protection parameters, depth, and type of bottom substrate.These parameters are included in the category of physical geography (Geophysics).
Based on the results of observations and measurements at the three research stations, the following results were obtained in the Table 4.
Based on the geophysical parameter suitability category in Table 2, the location protection parameters indicate that the first station, Lhok Krueng Raya, is semi-enclosed waters.It is calm and clear, has two entrances, and is protected by Klah Island, so it is included in the Very Suitable category.The second station, Teupin Sirui, is Conditionally Appropriate, considering that this location is exposed to much wind in the east season, while the last station, Lhok Weing, is Suitable because it is in a bay with one inlet/outlet from the northeast and still exposed to the east wind.This is particularly in line with the opinion of Sulistijo ( 2002) in Schaduw and Ngangi (2015), which states that mariculture locations in the sea must be protected from waves and strong winds.The depth parameters at the three research stations display varying results.The first station with a depth of around 10-12 meters.The second station is between 5-10 meters, and the last station with a depth of 5-7 meters.These results align with Mustafa's (2013) assessment, which states that the minimum depth requirement for mariculture with floating net cages is 6-20 meters at the lowest low tide.Appropriate water depth provides opportunities for smooth water exchange, especially at the bottom of the net.The lowest tides are used as a reference in aquaculture activities to minimize the risk of friction with the bottom of the water.The depth of the water is also helpful for avoiding the buildup of food waste, disturbance of bottom organisms, and lobster droppings at the bottom of the net.According to Junaidi (2018), the distance from the bottom of the cage net to the bottom of the water at low tide is at least 1 meter, while for lobster cultivation, the height of the cage is at least 3 meters, so the ideal water depth is at least 4 meters.
Observation of bottom substrate type parameters shows that the three research stations have similarities in the form of sand and coral, so they are included in the Very Suitable category.The lobster cultivation zone categories can be seen in the suitability criteria table (Table 2).

Physicochemical parameters
The physical and chemical parameters of the waters have a significant influence in determining the lobster cultivation zone.Good water quality can support the growth of aquatic organisms, including cultivation (Lestari et al., 2018).The physical parameters of the waters tested in this study include temperature and Depik Journal of Aquatic, Coastal and Fisheries Sciences Volume 12, Number 3, Pages 389-397 Ismail et al. (2023) brightness, while the chemical parameters include salinity, pH, dissolved oxygen (DO), BOD, and COD.Reducing the concentration of O 2 will reduce the physiological metabolism of living creatures in the water (Tahir, 2016).The average value of the results of measurements and laboratory tests of the physicochemical parameters of water at the research location can be seen in Table 5.This research found that DO and COD parameters are the main factors that limit the suitability of lobster cultivation zones in Sabang from the aspect of water quality.COD levels are associated with increased organic matter and nutrient content in water, which causes a decrease in dissolved oxygen levels and increases the potential for stress on aquatic organisms (Lein et al., 2022).Guidelines for Good Fish Farming Practices emphasize the need to monitor and maintain water quality to support the growth and health of cultivators and minimize environmental impacts.It is recommended to apply suitable lobster mariculture methods and reduce the intake of domestic liquid waste from surrounding settlements.

Supporting parameters
Parameters supporting the suitability of lobster mariculture were analyzed based on observations and interviews and using standard suitability criteria in Table 3.The results of these parameter groups are presented in Table 6.

Analysis of the suitability of group parameters
The values in each parameter group are then subjected to weighting, scoring analysis, and classification using the Flag Analysis Method.The results of the group suitability analysis of geographic parameters are presented in Table 7. Analysis of the suitability of geographic parameter groups shows that the three research stations are classified as Very Suitable categories for the lobster cultivation zone.The location protection parameter is a limiting factor at station two due to the conditions of the waters exposed to winds during the east monsoon.The results of the spatial analysis of the suitability of geophysical parameters can be seen in Figure 2. Analysis of the suitability of the physicochemical parameters of the waters as a lobster cultivation zone can be seen in Table 8.By referring to the standard category of suitability for lobster cultivation in terms of geophysical and physicochemical water parameters (Table 2), the results of the suitability analysis show that the three research stations are classified as Very Suitable as lobster cultivation zones.The results of the spatial suitability analysis of the physicochemical parameters of water can be seen in Figure 3.
From the results of observations on other supporting parameter groups, suitability analysis was then carried out using the weighting and scoring method and classification using the Flag Analysis method (Table 9).
Based on the suitability category for lobster cultivation standards for supporting parameters (Table 3).The research results show that Station 1 (Lhok Krueng Raya) is classified as Very Suitable as a lobster cultivation zone, while Station 2 (Teupin Sirui) and Station 3 (Lhok Weing) are classified as Suitable Enough.The results of the spatial suitability analysis of other supporting parameters can be seen in Figure 4.

Discussion
Lobster farming is a promising source of income for coastal community groups.However, this activity requires precise calculations based on adequate data and information to determine the appropriate location for lobster cultivation.This research found that the parameters of protection, accessibility, and COD were limiting factors for determining the suitability of lobster cultivation locations in Sabang.This finding aligns with the statement of Anuraj et al. (2022) who argue that these three factors must be considered when selecting aquaculture locations in the sea, especially those using floating net cages.Keeping these limiting factors in mind is critical to the success of lobster farming operations.Choosing the right location can help ensure business sustainability and profitability while minimizing environmental impact.
Aquatic environmental conditions influence lobster growth.Suitable water conditions will accelerate the growth rate of lobsters (Suhermat et al., 2021).In addition, responsible farming practices can increase the sustainability of lobster mariculture businesses.
Aquaculture is vulnerable to environmental factors such as storms, strong currents, and extreme temperature fluctuations.Selecting locations that are protected by natural barriers (e.g., bays, straits, or other protected coastal areas) helps reduce the risk of damage to infrastructure and cultivated organisms (Sjahman et al., 2020;Amin et al., 2022;Sutaman et al., 2023).This aligns with the principle of placing aquaculture facilities in areas that are safe from physical disturbances.
Accessibility is very important in selecting an aquaculture location.Ease of access to the cultivation site is critical for efficient operations, routine monitoring and maintenance tasks.Difficult-to-reach aquaculture facilities can result in increased transportation costs, logistical challenges, and delays in responding to emergencies.The existing theory emphasizes the importance of choosing a location by considering transportation access and good infrastructure to ensure smooth operations.
Water quality is a fundamental factor in the success of any fisheries cultivation business, including lobster cultivation.Existing theory recognizes that high organic and chemical pollution, indicated by low DO levels and high COD levels, can harm cultivated species (Putra and Dedi, 2022).Increased COD levels are associated with increased organic matter and nutrient content in water, causing a decrease in dissolved oxygen levels and increasing the potential for stress on aquatic organisms.Cultivation guidelines emphasize monitoring and maintaining good water quality to support cultivar growth and minimize environmental impacts.Avoiding locations with high COD levels is in line with this principle.

Conclusion
The results of the suitability analysis for the lobster cultivation zone in Sabang Waters, considering the geophysical, physicochemical, and other supporting parameters, show that the three study sites covering an area of 467 hectares are February to June 2023.The research was carried out in three stages, namely: (1) The initial research preparation stage in February, (2) The field data collection stage began in March 2023, and (3) The data analysis stage was carried out from April to June 2023.

DepikFigure 2 .
Figure 2. Spatial analysis of geophysical parameters of the lobster cultivation zone.

Figure 3 .
Figure 3. Spatial analysis of the physicochemical conditions of the waters for the lobster cultivation zone.

Figure 4 .
Figure 4. Spatial analysis of supporting parameters for lobster cultivation zones.

Figure 5 .
Figure 5. Results of analysis of the suitability of lobster cultivation zones in the waters of Sabang.

Table 1 .
Water quality parameters Table attribute data was compiled using ©Microsoft Excel software before being entered into the ArcGIS database.After the database was formed, the existing digital map was converted into a transverse Mercator projection system with a Universal Transverse Mercator (UTM) grid.After the thematic map for

Table 2 .
Criteria for suitability of lobster cultivation zones on geophysical and physicochemical parameters.

Table 3 .
Criteria for suitability of lobster cultivation zones and other supporting parameters

Table 4 .
Results of grouping geographic parameters at the research location.

Table 5 .
Results of physicochemical parameters of water*.

Table 6 .
Supporting parameter analysis results.

Table 7 .
Analysis of the suitability of geographic parameters group.

Table 8 .
Analysis of the suitability of aquatic physicochemical parameters group.

Table 9 .
Analysis of Suitability of other supporting parameter groups.