Unusual fish mortality in Minicoy Lagoon

The article reports that except atherinids, all fishes other fishes were affected due to low oxygen level

Shrinking seagrass meadows observations from four Lagoons of Lakshadweep Archipelago

Seagrass meadows worldwide are declining fast, taking with them many species which depend on these underwater prairies as their habitat and feeding as well as breeding grounds. Our results obtained on the biomass and density of seagrass vegetation in the reef and lagoons of Agatti, Chetlat, Kavaratti and Kiltan Islands of U.T. Lakshadweep, indicated gradual but steady shrinking of seagrass meadows. The percentage reduction in density of seagrass meadows since December 2011 to November 2015 was estimated at 88.5% in Agatti, 88.7% in Chetlat, 78.4% in Kavaratti and 81.3% in Kiltan. Wet biomass of parts below the sediment were always higher than the epigeal parts comprising leaves, stem and bracts. The possible reason behind this decline in seagrass biomass might be grazing, deterioration of water quality due to increased anthropogenic activities and climate change. This situation calls for urgent steps to monitor the ecology and physico-chemical parameters of water and sediment in the existing meadows and to undertake immediate habitat restoration programmes

Observations on the Food and Feeding Habits of the Skipjack Tuna, Katsuwonus pelamis (Linnaeus) from Minicoy, Lakshadweep

The food and feeding habits of the skipjack tuna based on the data for the period 1993-96 is given here. Fishes, Cephalopod and crustaceans formed the main food items. Among fishes. Der.u/~lerri.ss p. is the dominant species found almost throughout the year. Cephalopod is fully comprised by squid. In prawns, Thula.s.socari.s sp. was seen during June-August and Lrl,tochela sp. during October-December. But in general empty condition dominated. The feeding habits in relation to the catch is discussed in addition to the comparison of the present observation with the earlier studies from here

Simple and portable seawater filtering device using pipette filler

Filtration of seawater from the intertidal and coastal areas for separating chlorophyll pigments or particulate organic matter (POM) requires vacuum and for creating vacuum, a suction pump operated using AC/DC is essential. From the field or sea, large quantities of water samples have to be saved, brought to the laboratory and preserved by freezing until the filtration. Seawater filtration in remote areas with no power supply or portable suction pump is difficult but can be made possible by deploying a simple device involving filtering flask, a rubber hose and a safety pipette filler

Plastic pollution in the islands of Laccadive Archipelago and its possible impact on the atoll ecosystem

All the islands of Laccadive Archipelago including the inhabited ones are known comparatively less impacted from anthropogenic means as they are far and free from polluting industries. However, it is estimated that beach debris in ten of the inhabited islands show mean quantity of 10.567 g/m2 which includes PET and glass bottles, plastic carry bags, HDPE and nylon ropes, cement bags, net pieces, footwear and insulators like PUF, styrofoam and thermocol pieces when observed quarterly for one year period during October 2013 to September 2014. Minicoy Island accounted for maximum quantity (31.73 g/m2 ) and Kiltan Island accounted for minimum value (4.53 g/m2 ) of beach debris. Plastic thin carry bags and containers of household products account for 40% among the beach litter which is much higher than the national average of 14% reported for the entire coastline. The quantity of beach debris in the islands was proportional to the number of island population, except for Kavarathi Island which registered the maximum per capita share of 17.5 kg/head and the lowest (2.19 kg/head) by Kiltan Island. Thin carry bags and sheets smother over seagrass and seaweed beds and choke the macrophytes while damage the biota beneath. Upon photolysis over a period of time, these plastic bags can be fragmented and become microplastics. These tiny particles of plastics can enter into the food chain of fragile atoll ecosystem as well as can settle on the coral polyps which may lead to their mortality. The Island Administration can enforce strict legislation to discard plastics after use in designated places only and to encourage reuse, reduce and recycle the plastic materials

On the fishery and some aspects of the biology of dogtooth tuna, Gymnosarda unicolor (Ruppell) from Minicoy, Lakshadweep

The results of a study, on the fishery and biology of dogtooth tuna, Gymnosarda unicolor (Ruppell), conducted at Minicoy during 1995 to 1999 are presented. The resource is exploited from around the reef areas during July-August or September for sustenance when the usual fishing activities like pole and line and trolling are suspended. The total catch in a season varied from 56 to 481 kg. The size ranged from 44 to 126 cm fork length with the modal group at 58 and 62 cm. The length-weight relationship was found to be Log W = -4.5337 + 2.77 Log L. Fish below 70 cm size was found to be immature

Note on a stranded Humpback dolphin

On 17th September, 2015, a dead dolphin was found at Beypore beach, Kozhikode. On enquiry with local fishermen, it was reported to be washed ashore eight days before. It was identified as Indo-Pacific Humpback dolphin Sousa chinensis (Osbeck, 1765) with the help of external characters especially the number of teeth. It had a stocky, robust body with a well-defined beak set off from the rounded melon. The specimen was a male measuring 107 cm in length and weighing about 18 kg

Seagrass meadows in India and their certain ecosystem services

Seagrass meadows also known as marine prairies have attained tremendous significance and their services as ecosystem are greatly valued for food, feed, shelter, refuge marine biodiversity hotspots and nursery grounds to many marine vertebrates and invertebrates of commercial and ecological importance, besides their highest primary production and their role in checking ocean acidification and global warming impacts through their excellent carbon sequestration potential. Ecosystem services of certain seagrass meadows available in Indian coasts within the four categories such as cultural, provisioning, regulating and supporting are discussed in this communication. While exploiting the services offered by the seagrass meadows, their conservation should assign top priorit

Seagrass restoration trials in Kavaratti Lagoon, Lakshadweep: Growth patterns of transplants and their impact on overgrazing

It is essential to restore degraded seagrass habitats as they are among the major blue carbon ecosystems undergoing degradation at alarming proportions throughout the globe. As our earlier attempts at seagrass transplanting trials ended up in grazing by herbivores, fresh trials in enclosed rafts were initiated which resulted in an 80% survival rate. The results indicated the magnitude of overgrazing on seagrass shoots and the height of transplants after 37 days in the enclosed rafts was 105 mm registering a net height of 71.05±9.1mm, while in the exposed rafts the leaves of the transplants were found grazed and the final mean height was only 13.3 mm registering a net height of shoots far below its initial height. Any initiative to restore seagrass meadows in the degraded areas must be taken up under protected mode or the existing seagrass meadows should be allowed to recover on their own by preventing overgrazing and checking man-made interferences

Turtle herbivory of seagrass ecosystems in the Lakshadweep atolls: concerns and need for conservation measures

Green turtles and turtle grass are interdependent in the atoll ecosystems of Lakshadweep as green turtles are herbivores and the latter are being consumed by the turtles. Since the herbivore is being protected by legislation, their herbivory on turtle grass is uncontrolled and had resulted in near total wiping of seagrass meadows. This case study was made from Agatti atoll in detail and the status of seagrass meadows in three neighboring atolls. The present communication stresses the need for the earliest restoration and to conserve the seagrass meadows from being destroyed by the increasing population of green turtles which is essential for the very existence of turtles itself in Lakshadweep Sea