Goa is synonymous with the three F’s – feni, fish and football. And Goan platter in incomplete without fish-curry-rice, which is the staple food of Goans since time immemorial. The Portuguese introduced chillies in Goa in 15th century and that’s how curry became the integral part of the Goan and South Asian cuisine. Recently, Herald reported a drop in catch of clupeid fish which is dominated by Indian oil sardine (Sardinella longiceps) since 2014. This variety which is called Tallo in Konkani has been in demand the world over because the fattened ones are packed with omega-3 fatty acids which boast health-promoting high density lipoprotein (HDL). The peak period for commercial catch of sardines and mackerels is June and July, when the juvenile fish have fattened themselves to prepare for their first spawning season that take place between August and September. The statistics of marine fish landing in Goa from 2001 published by Fisheries department on their web page (http://fisheries.goa.gov.in/) indicate that total fish catch (20 varieties of fish consumed in Goa) has decreased by 21 per cent from 128,107 tonnes in 2014 to 101,053 tonnes in 2016. The sardines, which forms the bulk of the commercial catch, has dropped by 58.8 per cent from 80,849 tonnes in 2014 to 33,326 tonnes in 2016 and now up to June it stands at 18,254 tonnes. The low catch of this widely-consumed fish, which has great demand for fish oil abroad, will have a significant impact on the fishing industry as highlighted in Herald editorial – Tiny sardine could determine fishing industry’s survival – dated October 19, 2017. This article highlights the important natural and anthropogenic factors that affect the migratory behaviour of the Indian oil sardines. The sardine is a highly migratory species that is found in the photic (sunlight) zone between 20200 m depth of the ocean along the continental shelf. This species feeds on microscopic plants called diatoms (Fragilaria oceanica) on the ocean surface and planktonic crustaceans such a copepods. It spawns once a year in coastal/ inshore waters from late May to August with maximum spawning taking place during June and July on the west continental shelf of India due to optimum condition of temperature (27-28 degree Celsius) and salinity (34-35 parts per thousand) created by southwest monsoon and availability of abundant food during June-September. The spawning season shows a tendency to shift depending on the early or late onset of southwest monsoon. Rising water temperature either due to warm phase of El Nino or delay in monsoon or due to other climatic indices can adversely affect the arrival of matured sardine shoals inshore for spawning. Another significant factor that contributes to the reduction in fish catch or induces fish mortality is the formation of Oxygen Minimum Zone (OMZ). The western continental shelf of India is home to the largest naturally-formed coastal hypoxic system in the world. Hypoxia is a condition wherein oxygen concentration in water falls below 80 µmol per litre within the top 50 m of the sea. This threshold is indicative of the limit under which many organisms start to suffer from physiological stress that could ultimately lead to death. It is a global phenomenon that affects fishery industry, but it is reported that hypoxia is severe along the west India continental shelf. During June-September strong alongshore winds cause surface water layer to move offshore (offshore Ekman transport) which is compensated by a process called upwelling, wherein subsurface oxygen deficient but nutrient-rich water is pumped to the near surface. Researchers have shown that year-to-year changes in both the duration and intensity of the observed seasonal oxygen deficiency over the west India shelf. This affects the migratory behaviour of the fish as well as the chances of survival of young larvae. This problem is further aggravated in the presence of inadequately-treated pollutants (detergents from industries and homes, heavy metals like cadmium and mercury from dry docks, pesticides from agriculture practices, etc) brought in by river discharge, which eventually enters the coastal water and destroys the juvenile fish. Research papers have also reported high levels of heavy metals including methylmercury, between 100 to 400 meters depth of the sea, which is rises to near surface during upwelling. This toxin induces neurological, endocrine, and olfactory dysfunction causing alterations to fish behaviour and morality of larvae. This and other toxicants (both organic and inorganic) are eventually assimilated in the tissues, which affects their physiological functions including impaired gonadal or thyroid hormone levels, thereby altering the fish population structure and their migratory behaviour. The toxins eventually enter human body leading to serious ailments. There are other climate change related factors that can affect fish population. Indian Ocean Dipole which affects sea surface temperature, strengthening wind intensity due to global warming, enhanced discharged of fresh water that lowers sea water salinity, frequent high-intensity cyclones in Arabian Sea that churns the upper ocean facilitating subsurface nutrients to reach the photic zone are some important nature-induced factors which could affect fish migratory behaviour and ultimately its catch. Assessing the effects of climate change on marine fisheries is one of the challenges for sustainable management of marine ecosystems. Man-made factors like overharvesting using advanced fishing gears like baits and nets, and creating artificial luminescence of different intensities on the sea surface to attract fish during night-time fishing using LEDs are some grey areas that needs to be researched. Strict monitoring mechanisms should be put in place to check overfishing (specially juvenile fish), discharge of untreated effluents and plastic waste in water bodies. In conclusion, the fall in the fish catch landing in Goa will be a matter of concern to the fishing industry and common men if the negative trend continues.