Marine fishing practices and coastal aquaculture technologies in India

Among the countries bordering the Indian Ocean, India, endowed with 2.02 million sq. km of EEZ along a coastline of8129 km and 0.5 million sq. km of continental shelf with a catchable annual marine fishery potential of 3.93 million tonncs occupies a unique position. Besides, there are vast brackishwater spread areas along the coastline which offer ideal sites for seafamling and coastal mariculture

Biology of the Bluepuller, Chromis caeruleus (Cuvier), From Minicoy atoll

Chromis caeruleus, a resident reef fish on live ramose corals forming a dominant component in lagoons through-out Laskhadweep, is an important livebait for tuna. The species is diurnal in habit and is an active zooplankton feeder. Analysis of the gut contents reveals little selectivity in feeding

A critique on the relationship of surface area of live coral with total number of fishes as well as the biomass of fish in a coexisting system of Chromis caeruleus and Dascyllus aruanus (Pomacentridae) at Minicoy atoll

The pomacentrid fishes Chromis caeruleus (Cuvier) and Dascyllus aruanus (Linn.) coexist on ramose live corals without apparently displaying aggressive reactions. The population in a coral colony is of many size groups, an obvious result of continual s ettlement of postlarvae of fishes from plankton, probably a strategy in nature to prevent in breeding in resident fishes. The relationship between the total number of fishes residing on a coral and the upper surface area of the habitat (coral colony) can be expressed as : Y - 0.2117 — 0.000064 X, where Y is the number of fishes per unit area of the coral and X the upper surface area of the coral sampled ; the correlation coefficient (r) being — 0.486. The relationship between the fish biomass and the upper surface area of the habitat can be expressed as : Y = 0.07888 - 0.00005225 X, where Y is the wei^t of fish per unit area of the coral sampled and X is the upper surface area of the coral; the correlation coefficient (r) being —0.99. As indicated by these correlation coefficients, there exists a closer relationship (inverse) between the biomass of fish and the surface area of the microhabitat (live isolate coral) than between the total number of fish and the surface area at a time in a coexisting system of resident reef fishes. The ratio of the fish biomass and the upper surface area of the coral (an index of density of fish) is also found to vary in different samples, within a range of 380.3 to 934.25 cm' of the coral and a fish biomass of 22.42 to 30.87 gm weight of fish sampled. The total length of the fishes ranged from 7 mm to 40 mm in the samples. The ptesratt study also indicates that neither a numerical nor biomass consistency of fishes can be anticipated in a microhabitat over a prolonged time. Both these factors are ever changing as also the area of the living habitat viz. the live coral colony. This is due to the interplay of many natural and artificial factors, such as, continual recruitment of postlarvae, growth of fish at sites, migration and mortality of fishes as well as the partial death or growth of corals that cause a dwindling or expansion of living space for resident fishes. The above factors in nature control the density of fish population in a coral live isolate. The maximum carrying capacity of the habitat perhaps is never allowed to reach so that coexistence is made possible without the fishes displaying apparent agonistic reaction.. However, the present data did not clearly indicate the maximum carrying capacity of unit area of Acropora corymbosa sampled; the systems analysed were in different stages of density level

Observations on the lobsters of Minicoy atoll

The rock-lobsters Panulirus penicillatus, P. homariis and P. versicolor occur in Minicoy. P. versicolor, now the most common, is possibly a recent arrival as this species has not been previously recorded from here. The spatial distribution, social behaviour, local migration on the reef flats, specific habitat selection and juvenile recruitment of the species in the atoll are discussed. P. versicolor, though present all over the reefs in the atoll, shows a marked prefereence to the leeward side. The species is the most common during November- January, when it seems to migrate on to the upper reef flats. The dominant length range then is 160-180 mm. From the length-frequency distribution during this period, it is estimated that the species has a growth rate of about 6 mm TL per month for the first three years, after which there is an apparent retardation of the rate of growth to 4-3 mm per month. It is estimated by extrapolation that P. versicolor may take 10 to 11 years to attain a length of 460 mm, the maximum the species is known to reach

Survey Among Medical Students During COVID-19 Lockdown: The Online Class Dilemma

Background: In view of COVID-19 lockdown in India, many colleges started online classes. This study aimed to evaluate the attitudes of, and the factors affecting, medical students attending online classes during lockdown. Methods: We designed an online questionnaire with open-ended, close-ended, and Likert scale questions. Links to the questionnaires were shared with the medical students who have attended at least one online class during the COVID-19 lockdown period. Respondents were 1061 participants from 30 medical colleges from the states of Kerala and Tamil Nadu in India. Results: The majority of students – 94% (955/1016) – used smartphones to attend online classes. ZOOM/ Skype – by 57.1% (580/1016) – and Google platforms – by 54.4% (553/1016) – were commonly used. Learning at leisure – 44.5% (452/1016) – was the top reason why students liked online classes, whereas network problems – 85.8% (872/1016) – was the top reason why students disliked them. Lack of sufficient interaction – 61.1% (621/1016) was another reason why students disliked online learning. More than half the participants – 51.7% (526/1016) – did not want to continue online classes after COVID-19 lockdown. More students – 55% (558/1016) – favored regular classes than online classes. Conclusion: Students in our survey did not seem favorably disposed to online classes. Network problems experienced by students should be addressed. Furthermore, teachers should try to make the classes more interactive and educational institutions should address the problems pointed out by the students in order to make online classes more effective in the future

Exploited and potential resources of tunas of Lakshadweep

Oceanic species of tunas such as skipjack (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) constitute the major tuna resources taken from the Lakshadweep waters. They are being exploited from these islands by pole and line fishery. The paper detailed about the potential of tuna resources of Lakshadweep including the Strategies for future development

Quantitative changes in bottom trawl landings at Kasimedu, Chennai during 1998-2007

During the period 1998-2007, an annual average of 20,898 t of marine resources was landed by trawlers at Kasimedu, Chennai, by expending a mean annual effort of 35,608 units. The annual catch during 1998-2007 showed fluctuations between 12182 t in 2005 and 35,838 t in 2002. The mean annual effort of 13.21 lakh h in 1998 dropped down to 5.08 lakh h in 2007; mean annual catch declined from 36,364 t in 1998 to 17,293 in 2007. Catch per hour (CPH) increased from 27.51 kg in 1998 to 33.98 kg in 2007, in spite of reduction in both. Multiday trawl units which formed only about 8% of the annual operational units during 1989-’91, accounted for 39% and 31% of the operational units in 1998 and 2006, respectively. Seasonal abundance of catch indicated that maximum catch was landed during the third and fourth quarters of the year, which contributed to 34.2% and 25.1% of the annual average catch during 1998- 2007. Demersal finfish resources contributed maximum (38.1%) to the annual average catch during the period 1998-2007 followed by pelagic finfish resources (25.4%), crustacean resources (15.1%) and cephalopods (5.6%). Miscellaneous finfishes and shellfishes accounted for about 15.8% of the catch. The resources that regularly contributed to the bulk of the catch were elasmobranchs, carangids, threadfin breams, silverbellies, ribbonfishes, tunas, goatfishes, lizardfishes, croakers, barracudas, clupeids, whitebaits, snappers, shrimps, crabs and cephalopods

Population dynamics of tunas : stock assessment

Crafts and gears employed in the fishery and the system of collection of data at different centres along the west and east coasts in the mainland of India and from Minicoy Is. were dealt with earlier. In the manner described, the following informations were collected : — Numbers landed by fishing gear ; — Estimated total tunas landed by weight by fishing gear; — Estimated weight of sampled landings ; — Species composition of sampled landings, and — length and weight of tunas in sampled landing