22 research outputs found
Sonneratia ovata (Sonneratiaceae)я╝НA New Distributional Record for India from Andaman and Nicobar Islands
Sonneratia ovata Backer was found from Havelock, Andaman and Nicobar Islands, representing a new addition to
the mangrove flora of India. This species lacks petals and is characterized by the finely warty calyx, the lobes of which are red on the
inner side and by the adpressed calyx lobes in fruit. Since S. ovata is considered rare as a whole, conservation measures are
imperative for managing the mangrove diversity of the Islands with special reference to this species
Fishery and Exploitation of Malabar Grouper, Epinephelus malabaricus (Bloch & Schneider 1801) from Andaman Islands
The fishery and population dynamics of groupers from Andaman Islands were studied from Jan 2010 to Dec
2011 with a special emphasis on Malabar grouper, Epinephelus malabaricus (Bloch & Schneider 1801). The average
annual catch of Malabar grouper was 1,296 tonnes contributing to 21.6% of annual grouper landings. Length-weight
relationship of Malabar grouper showed that growth was allometric (b=2.96) and relative condition factor (Kn) was 1
and the growth parameters viz., LтИЮ, K and t0 were 124.60 cm, 0.80 and -0.05 respectively. The recruitment pattern was
unimodal with one major peak during April to July throughout the study period. The natural mortality (M), fishing
mortality (F) and total mortality (Z) were 1.05, 1.48 and 2.53 respectively and exploitation rate (E) was 0.58. The M/K
ratio (1.31) was found to be well within the normal range of 1to 2.5. Catch per unit effort varied from 4 to16.5 kg.h-1.
The maximum sustainable yield (MSY) was 1,107 tonnes which was lower than the average annual catch (1,296 tonnes),
indicating over exploitation. The current study calls for further research in identifying the grouper fishing and spawning
aggregation grounds and introduce measures for reducing fishing efforts with input and output controls to sustain the
Malabar grouper fishery in Andaman waters
Validation of Potential Fishing Zone (PFZ) forecasts from Andaman and Nicobar Islands
The annual exploitable fisheries of Andaman and
Nicobar Islands are estimated to be 1.48 lakh t of
which a meagre 22% is harvested currently. Potential
Fishing Zone (PFZ) forecasts based on remotelysensed
chlorophyll concentration and sea surface
temperature were applied for harvesting the
unexploited marine fishery resources. Simultaneous
validation experiments (n = 87) synchronizing with
PFZ forecasts within (PFZs) and outside (non-PFZs)
the demarcated zones employing different vessel
categories viz., gillnetters (n = 50), trawlers (n = 22)
and longliners (n = 15) were carried out. Significant
disparity in fish catch was observed within and
outside PFZs. Fish catch from gillnetters composed
of carangids, clupeids, scombrids with Megalaspis
cordyla being dominant at PFZ. Carangids,
sphyraenids, serranids, lutjanids, lethrinids and
carcharhinids were reported from trawlers with
significantly higher CPUE from PFZs except
nemipterids. Fish catch from longliners constituted
mainly of carcharhinids and serranids, where the
catch of former was found to be significantly higher
at PFZs
Tropical storm off Myanmar coast sweeps reefs in RitchieтАЩs Archipelago, Andaman
The reefs in some islands of Andaman and
Nicobar suffered severe damage following a tropical
storm in the Bay of Bengal off Myanmar coast during
13тАУ17 March 2011. Surveys were conducted at eight
sites in Andaman, of which five were located in the
RitchieтАЩs Archipelago where maximum wind speeds
of 11 ms-1 was observed; and three around Port Blair
which lay on the leeward side of the storm and had not
experienced wind speeds of more than 9 ms-1. Corals
in the shallow inshore reefs were broken and dislodged
by the thrust of the waves. Significant damage
in the deeper regions and offshore reefs were caused
by the settlement of debris and sand brought down
from the shallower regions. The fragile branching
corals (Acropora sp.) were reduced to rubbles and
the larger boulder corals (Porites sp.) were toppled
over or scarred by falling debris. The reefs on the
windward side and directly in the path of the storm
winds were the worst affected. The investigation exposes
the vulnerability of the reefs in Andaman to the
oceanographic features which generally remain unnoticed
unless the damage is caused to the coastal
habitats
Influence of mesoscale eddies on a commercial fishery in the coastal waters of the Andaman and Nicobar Islands, India
Mesoscale eddies enhance the productivity in a stratified coastal environment by upwelling. The seas around the Andaman and Nicobar Islands have been found to have frequent mesoscale eddy activity. Commercial fishing grounds coincide with upwelling areas associated with cyclonic and anticyclonic eddies and also with areas between two adjacent eddies. There are different eddy zones supporting different types of fishing gears and fish. The current study aims at identifying the different zones of mesoscale eddies in the Andaman Sea and compares the productivity and fishing activity in each of them. Data collected from 454 commercial fishing trips in the Andaman Sea along with maps of sea level anomaly and Moderate Resolution Imaging Spectroradiometer (MODIS) global level 3 mapped thermal infrared (IR) daytime sea surface temperature (SST) from the Aqua and Terra satellites were used for the study. Known upwelling areas such as the periphery of anticyclonic and the core of cyclonic eddies showed higher catches in longlines, ring seines among the fishing gears, and among all the fish species groups. Downwelling areas such as the periphery of cyclonic and the core of anticyclonic eddies showed lower catches with ring seines and the fish species groups. Areas in between adjacent eddies were explored in this study and the fish captures in such areas were found to be different with types of fishing and the target fish group. The study shows results that link eddy activity with the performance of a fishery
Halgerda dalanghita Fahey & Gosliner, 1999 (Gastropoda: Nudibranchia: Discodorididae) - a new record for India from the Andaman Islands
Halgerda dalanghita Fahey & Gosliner, 1999, a discodoridid nudibranch was reported from Havelock Island of RitchieтАЩs Archipelago representing a new addition to the Opisthobranch fauna of India. This species is characterized by a firm, bright orange coloured mantle with a network of angular ridges on the dorsum that is ornate with white lines and dots; rhinophores with 17 brown lamellae on a translucent white stalk; highly pinnate gills with eight branchial leaves. The present record extends the known geographical distribution of H. dalanghita and this is the sixth species representing the genus in India.┬а</div
Not Available
Not AvailableOpisthobranchia (Phylum:Mollusca) are one of the least studied groups in India, and very little is known from remotely located islands like Nicobar. Recent marine faunistic surveys conducted at Nicobar Group of Islands in the intertidal and subtidal zones revealed the presence of four opisthobranchs.Not Availabl
Not Available
Not AvailableSonneratia ovata Backer was found from Havelock, Andaman and Nicobar Islands, representing a new addition to
the mangrove flora of India. This species lacks petals and is characterized by the finely warty calyx, the lobes of which are red on the
inner side and by the adpressed calyx lobes in fruit. Since S. ovata is considered rare as a whole, conservation measures are
imperative for managing the mangrove diversity of the Islands with special reference to this species.Not Availabl
Not Available
Not AvailableAndaman and Nicobar Islands (ANI) have an estimated fisheries potential of 2.4 lakh tonnes/annum (John et al., 2005). But, the fish harvest has always been far below the maximum sustainable yield (MSY) with an average harvest of around 30,000 tonnes for the last decade (Roy and George, 2010). The islands have witnessed an array of extreme events and inclement weather prevails during incessant rains rendering fishing vulnerable to occupational hazards. Infrastructure and accessibility within the islands are inadequate, resulting in poor fishing operations.Not Availabl
Integrated Potential Fishing Zone Forecasts: A Promising Information and Communication Technology Tool for Promotion of Green Fishing in the Islands
Andaman and Nicobar Islands (ANI) have an estimated fisheries potential of 2.4 lakh tonnes/annum (John et al., 2005). But, the fish harvest has always been far below the maximum sustainable yield (MSY) with an average harvest of around 30,000 tonnes for the last decade (Roy and George, 2010). The islands have witnessed an array of extreme events and inclement weather prevails during incessant rains rendering fishing vulnerable to occupational hazards. Infrastructure and accessibility within the islands are inadequate, resulting in poor fishing operations