Abstract. Shakawi AMHA, Hassan R, Mustapah DS. 2022. Effects of water parameters on population structure of mud crab from Buntal Mangroves, Kuching, Sarawak, Malaysia: A GLM analysis. Biodiversitas 23: 2580-2585. Buntal Mangroves, Kuching, Sarawak, Malaysia, is an area that is abundant with biological resources but contains minimal biodiversity information. Mud crab fisheries by the locals exist on small scales at Buntal Mangroves, but there is a tendency to overfish due to the increasing demand for this resource. The relationship between the population structure of mud crabs and the environmental factors in Buntal Mangroves has not been explored. Therefore, this study aimed to apply the generalized linear models (GLM) for analyzing the population structure of mud crabs with selected water parameters in Buntal Mangroves. Scylla olivacea (Herbst, 1796) has the highest abundance in Buntal compared to S. tranquebarica (Fabricius, 1798) and other types of mud crab. Three GLM with carapace length, carapace width, and body weight as dependent variables were constructed. These GLMs with gamma-distributed response variables indicated that depth, pH, salinity, and turbidity positively affected body weight, carapace width, and carapace length, while temperature had a negative impact on the dependent variables. The results emphasized the importance of adopting the GLM to describe a relationship where the response variable followed a non-normal distribution. The findings provide a basis for future studies at Buntal Mangroves, not only for conservation purposes but also to support the utilization of this valuable resource sustainably.

The sergestid shrimp (Acetes spp.) shows the annual peak season from February to April. This krill-like shrimp, locally known as ‘bubok’, is one of the commercially important fisheries in Miri, Sarawak, Malaysian Borneo. Previous researchers had reported patchy data on the environmental factors and Acetes distribution in Miri-Bintulu adjacent areas. Moreover, insufficient analysis has led to the inability to conduct sustainable management strategies for Acetes fisheries. Therefore, this study is designed to explore the mathematical model usage to understand the interaction between selected water quality parameters and zooplankton assemblages with the Acetes population in the coastal water of Miri. Selected temporal biotic and abiotic data were collected using standard methods and later subjected to mathematical time series analysis called the Granger causality test. The results show bi-directional Granger causality between the abundance of Acetes and dissolved oxygen (DO). Interaction between other water quality parameters (temperature, salinity, turbidity, pH, TSS and Chlorophyll a) with the abundance of Acetes has also emerged. The number of zooplankton in the water column, namely Centropages, Euterpina, Oithona rigida, and Oncaea shows a significant causality towards the abundance of Acetes. The findings imply that complex interaction between biotic and abiotic factors exists during the bloom of Acetes in Miri; thus, relevant agencies should step up measures to ensure sustainable management of the coastal areas where Acetes bloom occurs.