水産および畜産生産

抽象的な

Predictive Eel Population Model Based on Fish Habitat Dependency and Fishing Pressure on Pisodonophis boro (Hamilton) in the Godavari Delta, India

Babu DE*, Ratna MR, Lakshmikantamma K and Tarun K

The habitat dependency of the rice-paddy eels, Pisodonophis boro is described in this paper with emphasis on natural production. The eels use mangrove mudflats as homing ground for feeding and breeding; perform anadromous migration during breeding season; total mangrove dependency of the eels has been confirmed from field observations on eel fishery and mangrove degradation during the period 1981-2012. Total loss of mangrove habitat resulted in migration or mortality of the species and recruitment of the fish populations preceded rejuvenation and ramification of mangrove flora and associated fauna. Pisodonophis boro needs perennial freshwater inflow for successful reproduction; thus, the annual breeding cycle is triggered and regulated by the freshwater release from the river dam, and the artisanal fishery is correlated to these events. Sexes are separate and females with bilobed ovaries grow larger. The fish is being caught by trap nets and hooks as these have a sediment burrowing behavior and carnivorous food habits. A novel method of estimating eel population by applying Mini Tab. 16 software and the unique SARIMA, 1.1.1 model is highlighted. Critical factors influencing/triggering migration of eels from the Godavari estuary to the freshwater canals and paddy fields were seasonality, temperature and salinity. Smoked eels are delicacies of the entire central delta with a total population of 12,00,438; the proximate composition of the fish was analysed and health problems if any in smoked fish consumers was assessed by documenting health symptoms.