Mathematical modelling of flow, pesticide and nutrient transport for fish-farm planning and management
Abstract In recent years, there has been a rapid growth in fish farming, particularly salmon farming, in UK and Eire coastal waters. This increase in production has also led to an awareness by the fish-farming industry that over-production could have a deleterious effect on the hydro-ecology of coastal waters, which would inhibit the maintenance of current production farming levels. In planning a fish-farm configuration for coastal basins, complex deterministic mathematical models can provide invaluable information for farm optimisation, with the models predicting the tidal current structure and solute levels in the basin. Details are given herein of a refined mathematical model for predicting tidal current and Nuvan, biochemical oxygen demand (BOD) and nitrogen levels for a proposed fish-farm configuration in a bay off the Eire coastline. The model accurately predicts field-measured velocities at two sites within the bay, and further predicts Nuvan, BOD and nitrogen levels that are well below those levels which would be known to affect adversely the hydro-ecology of the bay.
Modelling environmental impacts of marine finfish aquaculture
Summary Our understanding of the interactions between fish farms and the environment has reached the stage where it is reasonable to expect that quantitative estimates of the possible environmental consequences of aquaculture development can be provided for regulatory and mitigation purposes. This paper summarizes recent developments in this area and provides several case histories of areas where theoretical analyses appear to have direct practical relevance. Fish wastes
Morpho-biometric Relationship, Relative Condition Factor and Meat Yield of Distant Scallop Bractechlamys vexillum (Reeve, 1853) in Asid Gulf, Philippines
Understanding the relationships of morphometric and biometric characters of a species allows the prediction of one trait from the other and generate a measure of relative condition. These relationships were studied for the Distant scallop Bratechlamys vexillum (Reeve, 1853) in Asid Gulf. Representative samples collected during the dry season (May 2018, n = 99) and wet season (September 2018, n = 100) were used to analyse these relationships through models of simple linear and power regression analyses, revealing allometric growth patterns. For both periods, it was revealed that shell width (SW) is a slightly better predictor than the height (SH) for total weight (TW) (R2 = 0.90 and 0.92) and the adductor muscle weight (AW) (R2 = 0.78 and 0.80). The strong functional relationship was also observed between TW and AW (R2 = 0.80 and 0.81). The relative condition factors (Kn) were high in both seasons. High meat yields were also observed in May (12.77 %) and September (14.26 %). The significant difference in meat yields (P < 0.05) can be a result of the seasonal difference manifested by the dynamics of energy partitioning during gametogenesis and spawning. These biological metrics are vital inputs in analysing mariculture prospects for the resource and a contribution to the scarce information on the biology of the species.