Ridwan Sala
Universitas Negeri Papua, Marine Science, Faculty Member
Morphometric and meristic studies can be used to identify stocks and relationships between populations of fish resources. Lutjanus gibbus is a fish species commonly found in the waters of northern Papua and is one of the fishery... more
Morphometric and meristic studies can be used to identify stocks and
relationships between populations of fish resources. Lutjanus gibbus is a fish
species commonly found in the waters of northern Papua and is one of the
fishery commodities targeted by fishermen other than groupers. In this study,
the morphometric and meristic characteristics of L. gibbus snapper from
several locations in the northern Papua Seas were addressed. The study was
conducted in June and July 2022. One hundred and six fish individuals of the
L. gibbus species were examined using cluster, Pearson correlation, and
Principal Component Analysis (PCA). The findings demonstrated a
substantial correlation between these species’ morphometric traits, particularly
regarding the relationship between total length and standard length (0.960) of
the fishes’ bodies. According to PCA analysis, total length, standard length,
and distance between the ventral fin and the end of fin origin are the three
most important morphometric features. Meristic traits like anal-fin spine and
anal-fin soft ray exhibit stable numbers across all populations, but other
morphometric traits show significant individual variation. According to the
results of Pearson Correlation analysis and dendrogram reconstruction, the
populations of L. gibbus in the waters off northern Papua had a strong
correlation and a high degree of morphometric similarity. Character
relationships and a high degree of similarity indicate that there is no
morphometric structure formed between populations.
relationships between populations of fish resources. Lutjanus gibbus is a fish
species commonly found in the waters of northern Papua and is one of the
fishery commodities targeted by fishermen other than groupers. In this study,
the morphometric and meristic characteristics of L. gibbus snapper from
several locations in the northern Papua Seas were addressed. The study was
conducted in June and July 2022. One hundred and six fish individuals of the
L. gibbus species were examined using cluster, Pearson correlation, and
Principal Component Analysis (PCA). The findings demonstrated a
substantial correlation between these species’ morphometric traits, particularly
regarding the relationship between total length and standard length (0.960) of
the fishes’ bodies. According to PCA analysis, total length, standard length,
and distance between the ventral fin and the end of fin origin are the three
most important morphometric features. Meristic traits like anal-fin spine and
anal-fin soft ray exhibit stable numbers across all populations, but other
morphometric traits show significant individual variation. According to the
results of Pearson Correlation analysis and dendrogram reconstruction, the
populations of L. gibbus in the waters off northern Papua had a strong
correlation and a high degree of morphometric similarity. Character
relationships and a high degree of similarity indicate that there is no
morphometric structure formed between populations.
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The waters of South Sorong have potential shrimp resources, including abundant banana shrimp (Penaeus merguiensis de Man, 1888). This study aims to obtain information about the morphometric characteristics and growth of banana shrimp in... more
The waters of South Sorong have potential shrimp resources, including abundant banana shrimp (Penaeus merguiensis de Man, 1888). This study aims to obtain information about the morphometric characteristics and growth of banana shrimp in the fishing area around the waters of Kampung Bakoi, South Sorong Regency, West Papua Province. Data collections were carried out in June and October 2019 using descriptive methods with direct observation techniques. Based on the results of data analysis, it was found that the total length of shrimp caught in Bakoi Village was in the range of 10 - 26.8 cm and the most were caught measuring 15.2 cm to 16.4 cm. The model of the relationship between length and weight of banana shrimp in Bakoi Village follows the equation Log W= 1,630+2,659 Log (L) or the form of negative allometric growth. Analysis of the relationship between total length (Y) and carapace length (X) (including rostrum) and the relationship between total length and carapace length (Z) (e...
The presence of skipjack fish resources in a fishing area is related to the suitability of the environmental conditions of the waters. This study aims to examine the relationship of sea surface temperature (SPL) to skipjack catches and... more
The presence of skipjack fish resources in a fishing area is related to the suitability of the environmental conditions of the waters. This study aims to examine the relationship of sea surface temperature (SPL) to skipjack catches and the characteristics of skipjack catches in Manokwari waters. Data, both catch data and sea surface temperature data, are collected through field surveys by following fishing operations. Furthermore, the data were analyzed descriptively using graphs and mathematically like von Bertalanffy's growth model. The results of this study found that the very small variability of SPL could not explain the variation in the volume of fishermen's catches in Manokwari waters. However, a high SST during the May - August 2013 period is thought to affect the size of the skipjack caught, where the average size of the fish caught inhabited areas near sea level. In addition, the growth of skipjack fish in Manokwari waters is relatively fast with a growth coefficie...
Ikan layang (Decapterus spp) merupakan komponen utama dari sumberdaya ikan pelagis kecil yang sering tertangkap oleh nelayan bagan perahu di perairan Teluk Doreri, namun belum diketahui secara pasti jenis-jenis ikan layang (Decapterus... more
Ikan layang (Decapterus spp) merupakan komponen utama dari sumberdaya ikan pelagis kecil yang sering tertangkap oleh nelayan bagan perahu di perairan Teluk Doreri, namun belum diketahui secara pasti jenis-jenis ikan layang (Decapterus spp) yang tertangkap oleh nelayan bagan perahu di perairan ini, sehingga dapat berakibat terhadap jenis-jenis ikan layang (Decapterus spp) secara spesies, jika tidak dapat dikelola secara berkelanjutan, sedangkan informasi ini sangat perlu diketahui untuk menunjang pengelolaan jenis-jenis ikan layang (Decapterus spp) perairan laut Teluk Doreri Kabupaten Manokwari dalam rangka pengelolaan perikanan tangkap secara berkelanjutan dan terpadu. Untuk itu, tujuan dari penelitian ini adalah mengetahui jenis-jenis ikan layang yang tertangkap oleh nelayan bagan di Teluk Doreri, Kabupaten Manokwari, Provinsi Papua Barat. Penelitian ini dilakukan selama 7 hari di bulan April 2019. Metode yang digunakan dalam penelitian ini adalah metode observasi langsung. Survei ...
Traditional use zones (TUZ) of Misool is located within the marine protected area of Misool which has high marine biodiversity, especially coral and reef fish. Regulating the use of fishing gears in TUZ of Misool,it is essential to ensure... more
Traditional use zones (TUZ) of Misool is located within the marine protected area of Misool which has high marine biodiversity, especially coral and reef fish. Regulating the use of fishing gears in TUZ of Misool,it is essential to ensure the sustainability of marine ecosystems and fisheries in the region. The objective of this study isto determine the suitability of fishing gear inthe depth zone of less than 50 m and more than 50 m in Misool TUZ, Raja Ampat. The fishing gear suitability was assessed based on bioecological, social, and legal aspects. The method used in this research was analytic hierarchy process (AHP) whichderivesthe prioritiesfor criteria and alternative fishing gear using expert judgment. The results of the analysis showed that fishing gears that wasmost appropriate to be operated in the zone which has thewater depth of less than 50 m was handline. The most decisive criteria for thiswasthat the fishing gear was undestructive to coral reef ecosystem and seagrass...
Arfak rainbowfish, Melanotaenia arfakensis is an endemic fish on several river systems in the northeastern part of the Vogelkop peninsula. This study aims to describe the growth, age at first maturity, and sexual dimorphism of this... more
Arfak rainbowfish, Melanotaenia arfakensis is an endemic fish on several river systems in the northeastern part of the Vogelkop peninsula. This study aims to describe the growth, age at first maturity, and sexual dimorphism of this endemic fish on the Nimbai Stream and the Aimasi Stream, the Prafi River system. The fish were caught using handnet, then were measured their standard length and individual weight. Data were analyzed to estimated growth patterns, von Bertalanffy's growth rate, age at first maturity and sexual dimorphism characteristics. The results showed that male growth patterns varied, with a tendency of the increase in body length faster than that of body weight (negative allometric patterns) with b values ranging from 2.886 to 3.132. On the other hand, the female individuals had positive allometric patterns (b values ranged from 3.062 to 3.378). The growth rate (K) of male body length was faster (0.165-0.174) than that of female individuals (0.159-0.163). Male individuals reached the first maturity condition earlier (at age of 1.83-2.18 years) than female individuals (at age of 2.49-2.64 years). Sexual characteristics between the sexes are related to body height starting to appear when fish are of a standard length of larger than 18.22 mm or when male fish begin to approach the time of the first sexual maturity. Understanding of growth, age, and the characteristics of the sexual dimorphism of endemic fish has an important meaning in monitoring population conditions and for conservation efforts in their natural habitat.
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ARTICLE INFO ABSTRACT Traditional Use Zone (TUZ) within Marine Protected Area (MPA) of Misool Island, Raja Ampat is allocated for traditional fisheries. It is expected that the fisheries would be benefited from management actions taken in... more
ARTICLE INFO ABSTRACT Traditional Use Zone (TUZ) within Marine Protected Area (MPA) of Misool Island, Raja Ampat is allocated for traditional fisheries. It is expected that the fisheries would be benefited from management actions taken in the conservation area. The present study aims to assess the sustainability status of the fisheries by using multidimensional analysis. Results of the analysis showed that both handline fishery targeting groupers and liftnet fishery targeting anchovies fishing in the TUZ were categorized as "less sustainable". Nevertheless, for both fisheries, the ecology dimension and technology dimension were in the category of " acceptable " (reasonably sustainable). Priority management of attributes which influences the performance of each dimension will enhance the sustainability status of fisheries in the region. Copyright©2017, Ridwan Sala et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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The present study aims to determine whether the rate of exploitation for grouper stocks is in accordance with their biological attributes (growth and mortality). The results showed that Plectropomus maculatus and P. oligocanthus taken... more
The present study aims to determine whether the rate of exploitation for grouper stocks is in accordance with their biological attributes (growth and mortality). The results showed that Plectropomus maculatus and P. oligocanthus taken from Cenderawasih Bay National Park (CBNP) were in the size category of actively productive spawning phase. P. maculatus could reach a maximum length (L1) of 484.05 mm and growth rate (K) of 0.34 per year. P. oligocanthus was capable of reaching L1 of 481.95 mm and K of 0.66 per year. Estimation of total mortality (Z) for P. maculatus was 0.988 and P Oligocanthus was 2.056. In addition, fishing mortality (F) for P. maculatus and P. oligocanthus were 0.564 and 0.399 respectively. Based on the estimated mortality values, it was estimated that the exploitation rate (E) of P. maculatus was 0.570, and P. oligocanthus was 0.681. Management settings for P. maculatus and P. oligocanthus can be separately based on the species so that the fishing can be sustainable. The introduction of minimum size limits for fish caught can be applied as a protection from hook and hand line fishing activities in CBNP. Introduction The high demand for groupers has led to an increase in the sale value of the fish and has brought about substantially high profits for trading business of this commodities. As consequently, this has been pushing an increase in fishing intensity for groupers and become primary fishing target of fishery in coral reef areas. Groupers are caught in the wild by traditional fishermen using hook and lines, and fish traps. High fishing intensity brings consequences to grouper sustainability. That is, grouper population experiences high fishing pressure. In some regions of Indonesia, it has been reported that total catch of groupers has decreased and the stock has been overexploited (Sadovy, 2005). Fishing continuously on large sizes of fish or spawning fish stock could reduce the genetic characteristics and could change fish shape and behavior. The genetic diversity of the population would be likely affected thereby reducing its resilience in confronting with environmental change and variability (Vrijenhoek, 1998). Hurtado et al. (2005) and Nelson (2007) note that populations experiencing high exploitation is characterized by a change in the fish size composition, which is dominated by smaller sizes. This would significantly affect reproductive outcome since small fish size has less production potential than the large fish size. Large-scale of exploitation could cause structural changes in the fish. Sanchez (2000) suggests that in overfishing state of fish stock, the fish population are dominated by small sizes or young fish since fishermen tend to catch large size of fish. Aside from fishing activities, the production of groupers in nature is strongly influenced by geomorphology and hydrographic characteristics of water; these affect the overall productivity and spawning aggregation (Coleman et al., 2011). Fish spawning areas of groupers, nowadays, become the target fishing areas by fisher-men in order to increase their catch per unit effort. Although fisheries production increases in short term, such fishing practices in long term are likely to lessen fishery production as a result of the damage of spawning habitat, the decrease in reproductive output and the changes in sex ratio (Heyman
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Oil sardine (Sardinella lemuru) has an important economic value for the fishery sector in Indonesia. Until now the understanding of oil sardine fishing grounds is still limited. The present research aims to determine the composition of... more
Oil sardine (Sardinella lemuru) has an important economic value for the fishery sector in Indonesia. Until now the understanding of oil sardine fishing grounds is still limited. The present research aims to determine the composition of number and size of oil sardine, to determine the distribution of chlorophyll-a and sea surface temperature in the Muncar waters, Banyuwangi, and to evaluate the condition of fishing ground of oil sardine. Data were collected from fishing activities including time and locations of fishing, number and size of fish caught as catch recorded at each fishing location. Fish samples were randomly taken at each fishing location, and then their total body length was measured. Data of chlorophyll-a and sea surface temperature (SST) in the study sites obtained by processing images of SST and chlorophyll-a were detected by satellite Terra Aqua (MODIS). The study revealed that the catches were dominated by "protolan" group (size of 11–15 cm), only small fraction (21%) of fish with size of larger than 18 cm. In addition, it was found that the concentration of chlorophyll-a (0.126-0.259 mg m-3) in the Muncar waters and the Bali Strait affected the composition of oil sardine catches, while the sea surface temperature (SST) (27-30 o C) did not have significant effect on the catch. Finally, potential fishing grounds for oil sardine in Muncar waters and the Bali Strait during periods of February-March 2015 were found only in the waters of Sembulungan, Pengambengan, and the Strait of Bali. Introduction. Oil sardine (Sardinella lemuru) is one of the superior fishery commodities for fishermen based in Muncar fishing port, Banyuwangi. Muncar is known as the largest producer of oil sardine in Java. Oil sardine is not only strategic as source of income for local fishermen, but also as raw fish material for processing industries. Fishermen collaborate with fish processing factories for processing their catches. DMF (2014) reported that the processed products of oil sardine from Banyuwangi has been distributed to various destinations both local and export scale. The local market of this commodity are Surabaya, Yogyakarta, Malang, Jakarta, Bali and Madura, while the export markets are the US, Europe, and parts of the Middle East. Fishermen based in Muncar fishing port caught oil sardine not limited to Muncar water, but also in the surrounding water of Bali Strait (Figure 1). Catches of the fishermen were dominated by oil sardine, which was about 81.85% (DMF 2014). Wijaya & Koeshendrajana (2009) stated that oil sardine in the Strait of Bali can be found throughout the year, ranging from small size (juvenile) to adult size. According to Simbolon & Girsang (2009), juvenile fish are considered as illegal size to be captured (not worth catching). Therefore, the waters dominated by juvenile fish (illegal size) indicates that these waters are categorized as not potential fishing grounds. When the catch is dominated by juvenile fish, it will have a negative impact on the rate of recruitment of fish resources, and will lead to the degradation of fishing areas. This condition may cause a reduction in catches of fishermen because of the depletion of oil sardine stock as reported by Merta (1992). Thus, the size composition of oil sardine caught in the fishing areas needs to be known as early as possible so that the sustainability of fishery can be maintained.
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Oil sardine (Sardinella lemuru) has an important economic value for the fishery sector in Indonesia. Until now the understanding of oil sardine fishing grounds is still limited. The present research aims to determine the composition of... more
Oil sardine (Sardinella lemuru) has an important economic value for the fishery sector in Indonesia. Until now the understanding of oil sardine fishing grounds is still limited. The present research aims to determine the composition of number and size of oil sardine, to determine the distribution of chlorophyll-a and sea surface temperature in the Muncar waters, Banyuwangi, and to evaluate the condition of fishing ground of oil sardine. Data were collected from fishing activities including time and locations of fishing, number and size of fish caught as catch recorded at each fishing location. Fish samples were randomly taken at each fishing location, and then their total body length was measured. Data of chlorophyll-a and sea surface temperature (SST) in the study sites obtained by processing images of SST and chlorophyll-a were detected by satellite Terra Aqua (MODIS). The study revealed that the catches were dominated by "protolan" group (size of 11–15 cm), only small fraction (21%) of fish with size of larger than 18 cm. In addition, it was found that the concentration of chlorophyll-a (0.126-0.259 mg m-3) in the Muncar waters and the Bali Strait affected the composition of oil sardine catches, while the sea surface temperature (SST) (27-30 o C) did not have significant effect on the catch. Finally, potential fishing grounds for oil sardine in Muncar waters and the Bali Strait during periods of February-March 2015 were found only in the waters of Sembulungan, Pengambengan, and the Strait of Bali. Introduction. Oil sardine (Sardinella lemuru) is one of the superior fishery commodities for fishermen based in Muncar fishing port, Banyuwangi. Muncar is known as the largest producer of oil sardine in Java. Oil sardine is not only strategic as source of income for local fishermen, but also as raw fish material for processing industries. Fishermen collaborate with fish processing factories for processing their catches. DMF (2014) reported that the processed products of oil sardine from Banyuwangi has been distributed to various destinations both local and export scale. The local market of this commodity are Surabaya, Yogyakarta, Malang, Jakarta, Bali and Madura, while the export markets are the US, Europe, and parts of the Middle East. Fishermen based in Muncar fishing port caught oil sardine not limited to Muncar water, but also in the surrounding water of Bali Strait (Figure 1). Catches of the fishermen were dominated by oil sardine, which was about 81.85% (DMF 2014). Wijaya & Koeshendrajana (2009) stated that oil sardine in the Strait of Bali can be found throughout the year, ranging from small size (juvenile) to adult size. According to Simbolon & Girsang (2009), juvenile fish are considered as illegal size to be captured (not worth catching). Therefore, the waters dominated by juvenile fish (illegal size) indicates that these waters are categorized as not potential fishing grounds. When the catch is dominated by juvenile fish, it will have a negative impact on the rate of recruitment of fish resources, and will lead to the degradation of fishing areas. This condition may cause a reduction in catches of fishermen because of the depletion of oil sardine stock as reported by Merta (1992). Thus, the size composition of oil sardine caught in the fishing areas needs to be known as early as possible so that the sustainability of fishery can be maintained.
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This study aims to estimate relative abundance of skipjack tuna (Katsuwonus pelamis L.) in the waters around Sorong and Fak-Fak, West Papua, Indonesia by using catch and fishing effort data of commercial pole-and-line fishery. General... more
This study aims to estimate relative abundance of skipjack tuna (Katsuwonus pelamis L.) in the waters around Sorong and Fak-Fak, West Papua, Indonesia by using catch and fishing effort data of commercial pole-and-line fishery. General linear model (GLM) was used for analyzing catch per unit of effort (CPUE) data (as representation of relative abundance) to accommodate the variables and factors affecting the catch. From the results of this study it was revealed that CPUE varied according to year, month, live bait, fishing day, and engine size. In addition, fish aggregating devices (FADs) affected the CPUE. Relative abundance of skipjack tuna in the waters around Sorong and Fak-Fak decreased from 1985 to 2000 after the FADs were introduced. Introduction. Catch and effort data from commercial fisheries are often used in the analysis of fish stocks, and to assess the impact of fishing on stock abundance (Stanley 1992; Campbell 1998; McDonald et al 2001). Time series of catch per unit of effort (CPUE) can be obtained relatively easily from these fishery dependent data which are less expensive to collect than through a fishery independent survey using fishery research vessels. However, to use CPUE data generated from commercial fisheries to derive an index of stock abundance requires standardization to account for variability in the data caused by factors rather than variability in fish abundance (Kleiber & Bartoo 1998). Variability in CPUE may be due to factors affecting catchability of the target species such as inter annual and sesonal variations in oceanographical conditions, fishing areas and CPUE of other species in the catch, and factors affecting fishing power including vessel size and fishermen skills (Hilborn & Walter 1992; Pascoe & Robinson 1996). In addition, McDonald et al (2001) state factors such as fishing methods, productive inputs and frequency of zero-catch may also distort CPUE as index of fish abundance. The standardization of CPUE data, especially targeting pelagic fish which show schooling behavior such as tuna is important to reduce the risk that the trend of CPUE does not represent the trend of the fish stock. For example, the CPUE can remain stable while the stock is decreasing which is known as hyperstability (Hilborn & Walter 1992). After the standardization process, the fishing effort is expected to be proportional to fishing mortality and therefore the CPUE can be used as an index of abundance (Watters & Deriso 2000). The standardization method was used to estimate trend of index of abundance of skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) taken by skipjack tuna in water around Sorong and Fak-Fak, Indonesia. The skipjack tuna fishery in Indonesia uses a variety of fishing gears but is dominated by pole-and-line and purse-seine vessels with various level of fishing technology and productive inputs (e.g. size of vessels). In spite of recognition of this variation, there has not been any effort to standardize CPUE for the Indonesian skipjack tuna fishery. The most recent study on the status of skipjack tuna in Western and Central Pacific Ocean (WPCO) (Langley et al 2004) estimated the CPUE for Indonesian skipjack
Bawole R, Rahayu M, Rembet UNWJ, Ananta AS, Runtuboi F, Sala R. 2017. Growth and mortality rate of the Napan-Yaur Coral Trout, Plectropomus leopardus (Pisces: Serranidae), Cenderawasih Bay National Park, Indonesia. Biodiversitas 18:... more
Bawole R, Rahayu M, Rembet UNWJ, Ananta AS, Runtuboi F, Sala R. 2017. Growth and mortality rate of the Napan-Yaur Coral Trout, Plectropomus leopardus (Pisces: Serranidae), Cenderawasih Bay National Park, Indonesia. Biodiversitas 18: 758-764. Coral trout, Plectropomus leopardus, is one of the important fishery resources in Cenderawasih Bay National Park, Papua, Indonesia. The catch production of this species has declined since 2015. This study aims to assess growth, mortality, and exploitation rate parameters of P. leopardus taken from Napan Yaur water, Cenderawasih Bay National Park (CBNP), Indonesia. The data were collected during periods of February to March 2016. Growth and mortality parameters were analyzed using von Bertalanffy method. Some fish samples used in this study was 123 individuals, with the average length of 32.34 ± 5.13 cm, the maximum length of 48.00 cm and minimum length of 24.5 cm. The von Bertalanffy analysis showed that the growth coefficient (K) was 0.34 year-1 , L∞ was 47.78 cm and t 0 was-0.09 year-1. The estimation of total mortality (Z) was 1.61 year-1 , natural mortality (M) was 0,75year-1 for fishing mortality (F) was 0.86 year-1 , and exploitation rate (E) was 0.53 year-1. The results indicated that most P. leopardus caught were at the pre-maturity size (age) and have been exploited at slightly above its optimum exploitation level. Nevertheless, P. leopardus is categorized as fast growing and long-lived fish species. These findings are important to fisheries management and conservation authorities to fish exploitation in the future.
ARTICLE INFO ABSTRACT Traditional Use Zone (TUZ) within Marine Protected Area (MPA) of Misool Island, Raja Ampat is allocated for traditional fisheries. It is expected that the fisheries would be benefited from management actions taken in... more
ARTICLE INFO ABSTRACT Traditional Use Zone (TUZ) within Marine Protected Area (MPA) of Misool Island, Raja Ampat is allocated for traditional fisheries. It is expected that the fisheries would be benefited from management actions taken in the conservation area. The present study aims to assess the sustainability status of the fisheries by using multidimensional analysis. Results of the analysis showed that both handline fishery targeting groupers and liftnet fishery targeting anchovies fishing in the TUZ were categorized as "less sustainable". Nevertheless, for both fisheries, the ecology dimension and technology dimension were in the category of " acceptable " (reasonably sustainable). Priority management of attributes which influences the performance of each dimension will enhance the sustainability status of fisheries in the region. Copyright©2017, Ridwan Sala et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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Abstrak Corals are found in many parts of areas in Doreri Bay. Nowadays, the existence of the coral reef ecosystem is threatened by factors, such as illegal fishing activities and coral predators (i.e. Acanthaster planci). The later... more
Abstrak Corals are found in many parts of areas in Doreri Bay. Nowadays, the existence of the coral reef ecosystem is threatened by factors, such as illegal fishing activities and coral predators (i.e. Acanthaster planci). The later becomes focus of the present study through the assessment of its density and its relation to particular types of corals. Data from two sites (Lemon Island and Rendani) revealed that A. planci was considerably abundant and their existence was highly correlated to the presence of branching corals and masive corals but moderately correlated to soft corals.
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Abstrak Penelitian ini dilakukan sebagai respon atas semakin tingginya kerusakan terumbu karang yang disebabkan oleh penggunaan alat penangkapan ikan yang tidak ramah lingkungan. Penelitian ini dilakukan di Teluk Doreri, dengan mengambil... more
Abstrak Penelitian ini dilakukan sebagai respon atas semakin tingginya kerusakan terumbu karang yang disebabkan oleh penggunaan alat penangkapan ikan yang tidak ramah lingkungan. Penelitian ini dilakukan di Teluk Doreri, dengan mengambil lokasi contoh di Pulau Mansinam, Pulau Lemon dan Kampung Arowi, Kabupaten Manokwari. Tujuan penelitian adalah untuk mengkaji masing-masing alat tangkap, terutama dari segi hasil tangkapan, dan teknik penangkapannya. Dari hasil analisis data diperoleh bahwa alat tangkap seperti bahan peledak dan jaring insang menangkap individu per satuan ekor/unit/hari yang tinggi tetapi dalam ukuran berat (kg/unit/hari) yang rendah. Hal ini menunjukan bahwa individu ikan yang tertangkap berukuran kecil. Sebaliknya, alat tangkap seperti pancing, bubu, alat penikam, senapan ikan dan linggis dapat menangkap ikan dengan ukuran individu relatif lebih besar. Dari kajian terhadap teknik penangkapan terungkap bahwa semua alat penangkapan ikan tersebut dapat menyebabkan kerusakan ekosistem terumbu karang dengan level kerusakan yang bervariasi. Beberapa saran untuk mengurangi dampak oleh alat-alat tersebut terhadap ekosistem terumbu karang juga dibahas. Kata-kata kunci: alat penangkapan ikan, terumbu karang, hasil tangkapan, teknologi penangkapan. PENDAHULUAN Latar Belakang Terumbu karang merupakan ekosisitem yang kaya akan keanekaragaman hayati, dimana di dalamnya terkandung berbagai organisme laut yang sangat pernting untuk kehidupan manusia. Dengan demikian kelestarian ekosistem ini sangat penting untuk dipertahankan. Sayangnya keberlanjutan dari ekosistem terumbu karang pada saat ini mulai terancam oleh kegiatan manusia yang berdampak negatif baik secara langsung maupun tidak langsung yang mengakibatkan terjadinya degradasi habitat. Kegiatan manusia tersebut berupa eksploitasi ekosistem terumbu karang yang 1 Makalah dipresentasikan pada Konferensi Nasional VI pengelolaan sumberdaya pesisir dan lautan,
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The present study is focused on assessing stock of skipjack tuna by using biomass dynamic models. The models were fitted to catch and catch per unit of effort (CPUE) data of skipjack fishery in the Northeastern waters of Indonesia. The... more
The present study is focused on assessing stock of skipjack tuna by using biomass dynamic models. The models were fitted to catch and catch per unit of effort (CPUE) data of skipjack fishery in the Northeastern waters of Indonesia. The results of analyses show that there was a decreasing trend of skipjack biomass, which reached level of just below B MSY in 1999 and continued to decrease afterwards. Management implications regarding the stock status are discussed.
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Abstrak Penelitian ini bertujuan untuk mengevaluasi perubahan komposisi ukuran cakalang yang tertangkap dan asosiasi yang mungkin ada antara cakalang dan tuna yang lain pada hasil tangkapan di kawasan utara perairan Indonesia bagian... more
Abstrak Penelitian ini bertujuan untuk mengevaluasi perubahan komposisi ukuran cakalang yang tertangkap dan asosiasi yang mungkin ada antara cakalang dan tuna yang lain pada hasil tangkapan di kawasan utara perairan Indonesia bagian timur. Data penelitian ini diperoleh melalui survey lapangan dengan mengambil sampel hasil tangkapan dari perikanan komersial di lokasi penelitian. Dari hasil penelitian ini terungkap bahwa komposisi ukuran cakalang yang tertangkap oleh huhate (pole-and-liner) cenderung stabil dan didominasi oleh ukuran lebih besar dari 2,5 kg. Akan tetapi untuk cakalang yang tertangkap oleh pukat cincin didominasi oleh ukuran yang kurang dari 1 kg, terutama yang tertangkap di perairan sekitar Sulawersi Utara. Hasil penelitian ini juga mendapatkan adanya korelasi yang erat antara ikan cakalang dan tuna ekor kuning yang tertangkap oleh perikanan komersial. Kata kunci : cakalang, komposisi ukuran, perikanan komersial, perairan bagian utara kawasan timur Indonesia. Abstract The objectives of this study are to detect the changes in size composition of skipjack tuna, and to examine any association that may exist between skipjack tuna and other tunas taken from the northeastern Indonesian waters. Data were collected through a field survey by taken samples of catch of commercial fisheries in the study areas. Results of the study revealed that size composition of skipjack taken by pole-and-liners tended to be stable over the observation periods and was dominated by size class larger than 2.5 kg. However, there was a tendency of domination of skipjack for size class less than 1 kg, particularly taken by Bitung's purse-seiners fishing around North Sulawesi water. It was also revealed that skipjack taken by the commercial fishery show a strong association with other tuna, especially yellowfin tuna.
Study on estimation of optimum fishing mortality and minimum legal size of skipjack taken from the northeastern waters of Indonesia was done by using yield per recruitment analysis. The analysis adopted biological parameters of skipjack... more
Study on estimation of optimum fishing mortality and minimum legal size of skipjack taken from the northeastern waters of Indonesia was done by using yield per recruitment analysis. The analysis adopted biological parameters of skipjack taken from various sources. The results of the study reveals that optimum yield per recruits would be attained when the fishing mortality is about fishing mortality of the fishery in 1998 and minimum legal size is about 40 cm (assumed M equals to 0.82) or about 36 cm (assumed M equals to 1.2).
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Fisheries data can be used in analyses of fish stock. However the data needs to be standardized in order to reduce or to eliminate effects rather than fish abundance. The present study attempts to standardize catch and effort data... more
Fisheries data can be used in analyses of fish stock. However the data needs to be standardized in order to reduce or to eliminate effects rather than fish abundance. The present study attempts to standardize catch and effort data pole-and-line fishing in Moluccas sea by using general linear model. The results of analyses show that the catch-per-unit of effort of the pole-and-line during periods 1988 – 2002 slightly fluctuated with peaks occurred in 1992 and 2000.
Research Interests: Fisheries and Aquaculture
Roswar Island is one island among several groups of islands in the Region of Cenderawasih Bay Marine National Park and is administratively located within the Wondama Bay District. The island has very abundant coastal and marine resources,... more
Roswar Island is one island among several groups of islands in the Region of Cenderawasih Bay Marine National Park and is administratively located within the Wondama Bay District. The island has very abundant coastal and marine resources, and if managed properly, can supported the economic growth to increase incomes of local communities. The present study is an initial study to determine the potential development of alternative livelihoods as an effort to improve the economy and well-being of local communities. Survey methods and interviews with government leaders, indigenous peoples, churches, women, and youth have been conducted to obtain comprehensive data and information. Methods of implementation activities include the coordination of activities at the district level and district levels, training, processing practices and diversified products based on local resources, program evaluation and coaching. The study results show that diversification processed food products made from raw fish, bananas, potatoes (sweet potatoes, cassava, taro), black fruit, and wheat papua (Setaria italica L.), and various handicraft made from woven products of pandanus beach (Pandanus tectorius), have been potential alternative livelihoods that can be developed on the Roswar Island. Furthermore, the involvement of local government and high education institutions is very important for community empowerment which can be in form of efforts to help implement comprehensive development program for the improvement of living standards and boost the economy of local communities. Activities that have been initiated are counseling, guidance, education and training provided directly to the community. Coaching and mentoring activities are conducted on an ongoing basis and are not limited to merely the scale of the project, in which actively involve community participation, develop mental and emotional involvement and public awareness. Local economic development should prioritize the capital allowances in the form of soft loans, training and supervision of the management of coastal and marine resources, diversification of product processing / preservation of food made from local raw materials, diversification of various local handicraft products to support tourism activities, and environmental management of life. Utilization of local resources to be managed in an optimal and sustainable manner, using appropriate technology and adequate skills in production, and strengthening community organizations. Program development, education and outreach to the community, require supporting infrastructure, such as information house for community empowerment, which is expected to be a center for community development activities.
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Skipjack is an important fish resource in Indonesia since it significantly contributes to export earning, labors absorption, etc. The utilization of the resource has fast developed in East Indonesia, e.g. in Sorong, Irian Jaya, by using... more
Skipjack is an important fish resource in Indonesia since it significantly contributes to export earning, labors absorption, etc. The utilization of the resource has fast developed in East Indonesia, e.g. in Sorong, Irian Jaya, by using several kinds of fishing gears operated by traditional and industrial fisheries. This research was carried out to seek out information that can be applied to manage skipjack fisheries in the area of study. The present research showed that pole and liner were the most effective fishing units to catch skipjack tuna. Type of the pole and liner, which was higher than 61 GT, showed the highest performance, followed by pole and liner 51-60 GT, while the type of pole and liner less than 51 GT had the lowest performance. The results of the catch production functions of the poles and liners showed the combinations of all factors i.e. numbers of crews, fuel consumptions, gross tonnages of fishing vessels, numbers of fishing days, the horse power of main engine, the age of fishing vessels, numbers of live baits, fishing locations and fishing seasons which were involved in the model, had significant effect on the variation of catches (p 0.01 and R 2 = 0.74). Using t-test on these factors showed that there was only fuel consumption, number of live baits, fishing location and fishing season, which significantly affected the variation of catches. Resources allocation analysis showed that the group of pole and liner 61-70 GT gave an optimum solution. At this optimum solution, all of the allocated skipjack resource was fully utilized. The numbers of fishing units which were allowed to utilize the skipjack resource in the fishing area were equivalent to 129 units of the pole and liner 61-70 GT.
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ABSTRAK Berbagai teknik pengolahan citra untuk pemetaan ekosistem terumbu karang telah dikembang oleh banyak peneliti. Untuk tujuan itu, umumnya digunakan citra Landsat, SPOT, IKONOS, QuickBird, dan atau foto udara sebagai sumber data.... more
ABSTRAK Berbagai teknik pengolahan citra untuk pemetaan ekosistem terumbu karang telah dikembang oleh banyak peneliti. Untuk tujuan itu, umumnya digunakan citra Landsat, SPOT, IKONOS, QuickBird, dan atau foto udara sebagai sumber data. Terbukti bahwa ketepatan hasil pemetaan ditentukan oleh resolusi spasial sistem sensor yang digunakan. Secara visual, sistem sensor ber-resolusi tinggi akan memberikan kemampuan pengenalan obyek yang lebih baik. Pada pertengahan tahun 2005 perusahaan Google meluncurkan program Google Earth sebagai fasilitas untuk berkeliling dunia secara virtual di dunia maya (internet). Berbagai lokasi direkam dengan menggunakan citra ber-resolusi tinggi. Dari sini diharapkan bisa memperoleh sumber data citra penginderaan jauh dengan kualitas yang memadai. Metode yang digunakan yaitu dengan melakukan interpretasi visual citra yang diunduh dari program Google Earth. Teknik interpretasi dan klasifikasi mengikuti prosedur yang dikembangkan oleh National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Monitoring and Assessment (2002). Hasil klasifikasi diverifikasi untuk melihat ketepatan interpretasi, kemudian dilakukan uji ketepatan (validasi) menggunakan matrik kesalahan. Dari teknik ini ditemukan 9 tipe zona dan 8 tipe habitat ekosistem terumbu karang dengan luas bervariasi dan diperoleh tingkat ketepatan interpretasi lebih besar dari 80%. Dengan demikian metode ini dapat pula dipakai sebagai alternatif solusi mengenai hambatan ketersediaan data penginderaan jauh yang baik dan murah. Kata Kunci : Citra, Google Earth, Terumbu Karang, Pulau Mansinam PENDAHULUAN Pulau Mansinam merupakan pulau paling bersejarah dan salah satu pulau yang terdapat di Provinsi Papua Barat. Bagi masyarakat Pulau Mansinam, keberadaan ekosistem terumbu karang menjadi sumber kehidupan bagi mereka. Biasanya penduduk Mansinam, yang hampir seluruhnya adalah nelayan, menangkap ikan dengan cara 1 Makalah dipresentasikan pada Konferensi Nasional VI pengelolaan sumberdaya pesisir dan lautan,
Research Interests:
Skipjack tuna (Katsuwonus pelamis L) is one of economically fisheries resources in Indonesia. Hence this species has been intensively exploited. Study about the availbility of skipjack stock were hampered by data availability. The present... more
Skipjack tuna (Katsuwonus pelamis L) is one of economically fisheries resources in Indonesia. Hence this species has been intensively exploited. Study about the availbility of skipjack stock were hampered by data availability. The present study attempt to assess skipjack stock by using age-structured production model which was tuned to catch-per-unit-of-effort (CPUE) data, particularly for northeastern of Indonesian waters. The condition of stock estimated based on age-structured model has been decreased constantly since 1961 and reached below biomass that supports MSY in 1999 and afterwards. Therefore, the management of the skipjack in the northeastern Indonesian waters (NEIWs) needs to reduce the fishing mortality to the state of the fishery in 1998 where biomass still above B MSY. ABSTRAK Tuna cakalang (Katsuwonus pelamis L) merupakan salah satu sumber daya perikanan yang penting secara ekonomi di Indonesia. Spesies ini telah dieksploitasi secara intensif. Studi tentang tersedianya cakalang saham terhambat oleh ketersediaan data. Penelitian ini dirancang untuk menduga ketersediaan stok biomass cakalang dengan menggunakan " age-structure production model " yang disesuikan dengan data hasil-tangkapan-per-satuan-upaya (CPUE), terutama untuk perairan bagian utara kawasan timur Indonesia. Hasil analisis menunjukan bahwa telah terjadi kecenderungan penurunan populasi ikan cakalang dan mencapai di bawah biomassa yang mendukung MSY pada tahun 1999 dan sesudahnya. Oleh karena itu, pengelolaan cakalang di utara-timur perairan Indonesia (NEIWs) perlu untuk mengurangi tingkat mortalitas penangkapan (fishing mortality) ke level seperti pada tahun 1998 di mana biomassa masih di atas B MSY. Kata Kunci: ikan cakalang, aged-structure production model, pendugaan stok, maximum sustainable yield, Indonesis timur.
Abstrak Perairan Teluk Doreri memiliki keanekaragaman hayati yang cukup potensial dan produktif, antara lain ekosistem terumbu karang yang merupakan habitat bagi biota ascidian. Penelitian ini bertujuan untuk mengidentifikasi dan... more
Abstrak Perairan Teluk Doreri memiliki keanekaragaman hayati yang cukup potensial dan produktif, antara lain ekosistem terumbu karang yang merupakan habitat bagi biota ascidian. Penelitian ini bertujuan untuk mengidentifikasi dan mengetahui distribusi, serta faktor-faktor lingkungan yang mempengaruhi distribusi ascidian di perairan Teluk Doreri, Manokwari. Pengambilan data dilakukan pada 3 lokasi (Pulau Mansinam, Pulau Lemon, dan Pantai Rendani). Metode yang digunakan adalah visual census sepanjang belt transec yang panjangnya 100 m. Transek dipasang sejajar garis pantai pada empat kedalaman yakni 3, 5, 7, dan 10 m. Dari hasil penelitian ini diketahui 12 jenis dari 5 famili ascidian yaitu Didemnum mole, Lisoclinum patella, Atrolium robustum, Trididemnum cereum, Didemnidae sp.1 (brown), Didemnidae sp.2 (yellow), Didemnidae sp.3 (black white), Didemnidae sp.4 (white), Polycarpa aurata, Pyura sp. (brown), Ascidia sp. (yellow), Ciona intestinalis. Kelimpahan tertinggi (0,26 ind/m 2) ditemukan pada kedalaman 3 m. Keanekaragaman spesies di ketiga lokasi berdasarkan kedalaman dikategorikan sedang dan keseragaman cenderung merata serta tidak ada spesies yang mendominansi spesies lain. Pengukuran parameter fisik dan kimia air menunjukkan bahwa kondisi perairan Teluk Doreri masih tergolong baik dan menunjang kehidupan ascidian yaitu suhu rata-rata 29,6°C, salinitas 30,3 ‰, pH 7,54, DO 4,71 mg/l, arus 0,46 m/det, kecerahan 8,3 m. Pengantar Ascidian, adalah salah satu organisme asosiasi yang memanfaatkan terumbu karang sebagai substrat untuk menempel dan keberadaannya cukup melimpah di perairan Indonesia (Abrar, 2004). Ascidian merupakan hewan invertebrata atau hewan bertulang belakang paling primitif (Urochordata). Biota ascidian sering dikenal dengan hewan tunicata yang termasuk dalam kelas Ascidiacea, ditemukan hampir pada semua tipe habitat di perairan dangkal sampai perairan yang relatif dalam, dan selalu menempel (sesil) pada substrat di dasar perairan serta merupakan komponen penting dalam ekosistem perairan laut. Ascidian memiliki fungsi pemanfaatan yang cukup penting. Secara ekonomis ascidian mengandung senyawa bioaktif yang dapat dimanfaatkan oleh manusia untuk keperluan di berbagai bidang seperti farmasi dijadikan bahan obat-obatan, kosmetik dan bidang pangan sebagai bahan makanan (sea food), serta bidang lingkungan dijadikan hewan indikator kualitas perairan. Ascidian merupakan hewan penyaring air, mereka tahan terhadap berbagai berbagai bahan pencemar dan dapat menyerap bakteri serta logam berat yang berbahaya bagi terumbu karang (Mehta, 1999).Beberapa negara yang telah memanfaatkan ascidian seperti Jepang, Prancis, Australia, Italia, Yunani dan Chili (Monniot et al., 1991). Ascidian berasosiasi dengan terumbu karang yang menjadi salah satu incaran peneliti terutama untuk keperluan senyawa bioaktif maupun keperluan lainnya. Manfaat yang besar dari biota ini mendorong dilakukannya eksplorasi dan eksploitasi terhadap biota tersebut. Berbagai wilayah di Papua, belum banyak diungkapkan informasi tentang keberadaan ascidian. Pada sisi lain, untuk dapat memanfaatkan sumber daya alam (ascidian) diperlukan suatu informasi ilmiah terhadap biota ini, terutama distribusi jenis dan habitatnya.