Distribution, abundance and biological studies of economically important fishes in the South China Sea, Area II: Sarawak, Sabah and Brunei Darussalam waters

The studies were carried out between 9th July and 3rd August 1996 (3rd cruise) and 30th April and 30th May, 1997 (4th cruise) in the Exclusive Economic Zone of Sarawak and the western part of Sabah. The species distribution, abundance, composition and length-weight relationships of some commercially important fish were investigated and compared for both cruises. The results indicate that the overall catch rate ranged from 3.5 to 194 kg/hr and averaged at 55.9 kg/hr during the 3rd cruise. For the 4th cruise, it ranged from 10.9 to 90.5 kg/hr and averaged at 50.2 kg/hr. During the 3rd cruise, 46.9% of the catch were dominated by demersal fish followed by 41.6% trash fish, 7.8% pelagic fish and 3.1% cephalopod. Priacanthidae was the most dominant family, which made up of 14.1% of the catch followed by Nemipteridae (10.8%), Carangidae (5.0%), Lutjanidae (3.7%) and Mullidae (2.1%). The ten most dominant species found during the 3rd cruise were 1. Priacanthus macracanthus (13.2%), 2. Nemipterus bathybius (3.3%), 3. Abalistes stellaris (2.8%), 4. Arius spp.(2.5%), 5. N. nematophorus (2.2%), 6. Gymnocranius griseus (1.9%), 7. N. marginatus (1.7%), 8. Sepia spp. (1.7%), 9. Decapterus spp. (1.6%) and 10. Carcharhinus spp (1.3%). During the 4th cruise, the family Nemipteridae (12.7%) formed the most dominant fish family followed by Carangidae (8.7%), Mullidae (7.1%), Lutjanidae (4.9%) and Priacanthidae (2.2%). The ten most dominant species were: 1. Loligo spp. (5.7%), 2. Nemipterus bathybius (4.2%), 3. Abalistes stellaris (4.0%), 4. Upeneus moluccensi (3.8%), 5. Nemipterus nemurus (3.8%), 6. Gymnocranius griseus (3.2%), 7. Carangoides malabaricus (3.2%), 8. Plectorhynchus pictus (3.1%), 9. Upeneus bensasi (2.4%) and 10. Arius spp. (1.8%). The morphometric study shows that the population of fish are normally distributed

Physicochemical Parameters of Surface Seawater in Malaysia Exclusive Economic Zones Off the Coast of Sarawak

Physicochemical characteristics of seawater play crucial role for productive marine ecosystem and fisheries activities. The limited information of Sarawak surface seawaters provide objective to determine the physicochemical characteristics in Malaysia Exclusive Economic Zone off the Coast of Sarawak. A total of 38 samples were collected using Van Dorn Waals Sampler and the physicochemical characteristics were measured using physicochemical parameter probes. Ranges for dissolved oxygen (DO) was 3.73-6.83 mg/l, temperature was 27.03-30.13ºC, pH was 7.63-7.82, salinity was 33.77-36.77 ppt, turbidity was 0.01-1.01 NTU, chlorophylla concentration was 0.01-4.52 mg/l, nitrate was 0.01–0.08 mg/l, nitrite was 0.001–0.012 mg/l and phosphate was 0.01–5.95 mg/l. There was positive correlation between chlorophyll-a and nutrients that indicated the biological uptake by biota (e.g. phytoplankton). In conclusion, the present study shows that the Malaysia Exclusive Economic Zone off the Coast of Sarawak had minimal pollution based on Malaysia Marine Water Quality Criteria. An update for physicochemical characteristics of surface seawaters in the coverage areas is required as future work

Fishing Gears in Sarawak: A Preliminary Survey

Unique to Sarawak, the fishing gears double-rig trawl, paka, panau, and rantau were gears that could only be found here. The focus of the present study was to catalog the diversity of fishing equipment across two regions, Wilayah II (Belawai, Daro, Mukah, Sarikei, Sibu and Tg Manis) and Wilayah III (Bintulu, Lawas, Limbang and Miri), via the interview method. A total of 163 respondents participated in the survey. In Wilayah II, 12 distinct types of fishing gears were identified, with monofilament gill nets (43.90%), fish trawl nets (30.49%), rentang (4.88%), bottom longlines (3.66%), and nylon gill nets (3.66%) being the most prevalent. Less common gears included paka, panau, shrimp trawl nets, rentang for jellyfish, modern bubu, and rantau. In Wilayah III, 14 different types of fishing gears were recorded, with monofilament gill nets (46.91%) and three-layer shrimp nets (20.99%) being predominant, followed by fish trawl nets (6.17%) and shrimp trawl nets (6.17%). Other less dominant gears included were modern bubu, panau, rantau, nylon gill nets, and bottom longlines. The mesh sizes of monofilament gill nets in both regions ranged from 25 to 170 mm, adhering to the regulations and guidelines set by the Department of Fisheries, Malaysia

Checklist of gastropods from the exclusive economic zone (EEZ), Sarawak, Malaysia

This study provides the first marine gastropod checklist from the Sarawak Exclusive Economic Zone (EEZ). Gastropod samples were collected from selected stations in the Sarawak EEZ using an otter trawl net with a stretched mesh size of 38 mm at the cod end. The trawling operations were conducted more than 12 nautical miles from the coast, and the area was divided into three depth strata: I) 20–50 m, II) 50–100 m and III) 100–200 m. A total of 23 gastropod species were identified during the two-month sampling period from 16 August until 6 October 2015, representing 8 superfamilies, 15 families and 20 genera. Superfamily Tonnoidea was represented by 7 species, followed by Muricoidea (5 species), Cypraeoidea (4 species), and Buccinoidea and Conoidea (both with 2 species). Other superfamilies were represented by a single species. Only 3 species were obtained in 2 depth strata, namely Melo melo, Murex aduncospinosus and Tonna galea. In addition, 9, 13 and 4 species of gastropods were found in strata I, II and III, respectively. The information on gastropod distributions at different depth strata in the Sarawak EEZ could be useful in updating the Malaysian species diversity databas

Underwater fiber laser removal of synthetically cultured Caulobacter crescentus biofilms on aluminium using response surface methodology

Biofouling can be considered the accumulation of microorganisms and other organisms on submerged surfaces. It poses operational and economic challenges across marine, industrial, and freshwater systems. Despite its relevance, freshwater biofilm removal remains understudied compared to marine biofouling. This study evaluates the use of fiber laser treatment to remove synthetically cultured Caulobacter crescentus biofilms formed on aluminium substrates submerged in a nutrientrich microbiological growth medium. A response surface methodology was applied to optimize three laser processing parameters: laser power, laser speed, and repetition loops. The aim was to maximize biofilm removal efficiency while minimizing substrate damage. Results revealed that the number of repetition loops was the most significant factor, as multiple repetition loops compensated for energy losses caused by water absorption and the high thermal conductivity of aluminium. While increased laser power enhanced removal, its individual impact was less pronounced, and laser speed had minimal effect due to rapid thermal dissipation and water interference. A distinct white line, visible both macroscopically and microscopically, appeared in some laser-treated areas. Its origin is hypothesized to involve oxidation or material ablation, warranting further analysis. Response surface analysis demonstrated a non-linear relationship between biofilm removal width and both laser power and repetition loops, with peak efficiency observed at intermediate laser power levels. The observed curvature is attributed to the interplay of water turbulence, microbubble formation, and localized heat transfer dynamics. These findings highlight the complex nature of laser–biofilm interactions in submerged environments. This study contributes to the optimization of non-contact laser cleaning techniques for submerged applications and offers practical insights for industries such as water treatment, biomedical device maintenance, and antifouling surface design

Taburan dan penspesiesan hidrokarbon dalam sedimen di Perairan Kelantan dan Terengganu

Kajian mengenai taburan kandungan karbon, nitrogen, hidrogen, dan hidrokarbon serta penspesiesannya telah dijalankan di Perairan Kelantan dan Terengganu. Sebanyak 26 stesen kajian telah dipilih iaitu 20 stesen di perairan persisiran pantai dan 6 stesen jauh dari pantai

Distribution, Abundance and Biological Studies of Economically Important Fishes in the South China Sea, Area II: Sarawak, Sabah and Brunei Darussalam Waters

The studies were carried out between 9th July and 3rd August 1996 (3rd cruise) and 30th April and 30th May, 1997 (4th cruise) in the Exclusive Economic Zone of Sarawak and the western part of Sabah. The species distribution, abundance, composition and length-weight relationships of some commercially important fish were investigated and compared for both cruises. The results indicates that the overall catch rate ranged from 3.5 to 194 kg/hr and averaged at 55.9 kg/hr during the 3rd cruise. For the 4th cruise, it ranged from 10.9 to 90.5 kg/hr and averaged at 50.2 kg/hr. During the 3rd cruise, 46.9% of the catch were dominated by demersal fish followed by 41.6% trash fish, 7.8% pelagic fish and 3.1% cephalopod. Priacanthidae was the most dominant family, which made up of 14.1% of the catch followed by Nemipteridae (10.8%), Carangidae (5.0%), Lutjanidae (3.7%) and Mullidae (2.1%). The ten most dominant species found during the 3rd cruise were 1. Priacanthus macracanthus (13.2%), 2. Nemipterus bathybius (3.3%), 3. Abalistes stellaris (2.8%), 4. Arius spp.(2.5%), 5. N. nematophorus (2.2%), 6. Gymnocranius griseus (1.9%), 7. N. marginatus (1.7%), 8. Sepia spp. (1.7%), 9. Decapterus spp. (1.6%) and 10. Carcharhinus spp (1.3%). During the 4th cruise, the family Nemipteridae (12.7%) formed the most dominant fish family followed by Carangidae (8.7%), Mullidae (7.1%), Lutjanidae (4.9%) and Priacanthidae (2.2%). The ten most dominant species were: 1. Loligo spp. (5.7%), 2. Nemipterus bathybius (4.2%), 3. Abalistes stellaris (4.0%), 4. Upeneus moluccensi (3.8%), 5. Nemipterus nemurus (3.8%), 6. Gymnocranius griseus (3.2%), 7. Carangoides malabaricus (3.2%), 8. Plectorhynchus pictus (3.1%), 9. Upeneus bensasi (2.4%) and 10. Arius spp. (1.8%). The morphometric study shows that the population of fish are normally distributed

2019 Udang Geragau (Acetes)

Describe the types of Acetes fishing gear in Sarawak waters, its morphology and spawning season

2020 Operation Method of Automatic Squid Jigging (ASJ)

Operation procedure of Automatic Squid Jigging