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Coral reefs at Casurina beach in the Karainagar Island of Jaffna peninsula, Sri Lanka are among the most heavily explored destinations for coastal tourism. We investigated the impact of algal overrunning and tourism on coral reefs over the last eight years. Coral reefs in Casurina beach are largely used by native fishermen for artisanal fishing, sea cucumber collection and for tourism. Baseline survey results indicated a vast competition and phase shift of corals to algal state. At present 52% of the coral reef area is covered with fleshy macroalgae and dead coral, which are more than one year old, and covered by turf or encrusting coralline algae. Increased number of tourist visits and boating act as chronic anthropogenic disturbances causing loss of coral cover, increased algal growth and degradation of ecosystem services in coral reefs.

A detailed investigation on length-weight relationship of four sea cucumber species, Holothuria spinifera, Bohadschia marmorata, Stichopus naso, and Holothuria atra found in the commercial catches of North-East coastal waters of Sri Lanka was conducted from May 2014 to September 2016. Minimum length and weight were recorded in S. naso while maximum size was recorded by B. marmorata. Length-weight relationship was carried out to investigate the correlation coefficient (r), exponent “b” value and condition factor (K). Calculated length-weight relationships obtained for H. spinifera, B. marmorata, S. naso and H. atra were W = -1.824 L1.887, W = 0.080 L1.108, W = 0.012 L1.021, and W = -0.110 L1.234, respectively. Correlation coefficient for length-weight relationship ranged from 0.696 to 0.774 and was significant at PH. spinifera (1.887), B. marmorata (1.108), S. naso (1.021) and H. atra (1.223) were significantly different (PH. spinifera (3.89±1.03), B. marmorata (4.12±2.21), S. naso (3.558±1.73) and H. atra (2.688±1.34) indicating the good nutritional condition in all four sea cucumbers species.

The present study was carried out in Navanthurai fishing village with the objective of identifying socio economic problems related to livelihood of crab fishers and marketers. Primary data were gathered using a pre-tested questionnaire from 48 families and personal interviews. Mean age of crab fishers, retailers, auctioneers and wholesalers were 43.3, 47.5, 33 and 35.6 years, respectively. Among them, 20% of crab fishers and 12.5% of retailers have received only primary education (Grade 1 to 5) and all the wholesalers and auctioneers have completed above junior secondary education. Only 20.8% of crab fishers had their own crafts. Ownership of craft and the level of education were found to be significantly related to the income of crab fishers (P

Present study was carried out at the landing sites at Challai, Puthumattalan and Peppearippiddy in Mullaitivu coastal region of Sri Lanka from May to September 2015. A total of 3 sea cucumber species belong to family Holothuridae and Stichopodidae were identified. Bohadschia marmorata was common in the catches and found in all three landing sites.. Holothurians were harvested through SCUBA diving. Holothuria spinifera and Stichopus naso were dominant in catches at Challai landing site while B. marmorata was dominant at Puthumattalan landing site. During the study period, the estimated highest number of individuals in catches was recorded in June in the three landing centers, Challai (84328), Puthumattalan (73457) and Peppearippiddy (36371), while the number of fishing efforts were 12-17 boats/day, 10-12 boats/day and 6-10 boats/day in the respective three locations. Nevertheless, there was no significant difference between the landing sites and species except for S. naso (P

Background. The doublespotted queenfish, Scomberoides lysan (Forsskål, 1775), is one of the most important and highly priced food fishes popular for dry fish production in Sri Lanka. Knowledge of spawning pattern and season are important for the management of S. lysan. The biology of S. lysan is poorly known, however, and no specific management regime is available for this species in Sri Lanka. The presently reported study is the first attempt to understand the reproductive characteristics of S. lysan with implications for its management. Materials and methods. Weekly samples, totalling 1429 specimens, were collected from Sri Lankan marine waters from January 2010 to December 2011, analyzed macroscopically, and their maturity stages identified. Sex ratio, size at maturity, length-class distribution, monthly distribution of maturity stages, fecundity, and the indices related to reproduction were examined. Statistical analyses were performed to determine relations between gonad weight, total length, fork length, and fecundity. Results. Females were categorized macroscopically into five maturity stages, males into four (males mature slightly earlier than females). Spawning and spent stages of females were only available during June and September and significant peaks in the gonadosomatic index of males and females were also noted from these two months. Conclusion. The spawning period of Scomberoides lysan in Sri Lankan waters shows two peaks, one in June and another in September. The present knowledge could be used in the formulation of management strategies intended to maintain the S. lysan stock at sustainable level. Such management measures could be limit the catches of S. lysan during spawning season, allowing limited number of boats, closure of spawning area during spawning months, and harvesting small fish under 55 cm of low consumer demand should be discouraged.

Sea cucumbers are fascinating and commercially valuable species belong to Class Holothuroidea. The present study was conducted with the aim of documenting the species composition and diversity of sea cucumber population in Point Pedro coastal area of Jaffna peninsula. The investigation was carried out from May 2014 to June 2015 at two study sites namely Viyaparimuli and Munnai. Sea cucumbers were collected within random transects areas of 4 m width and 100 m length. All the sea cucumbers were brought to the laboratory and identified up to species level based on the morphological characters and spicule preparation. Standard ecological parameters such as Simpson's Index (D), Shannon index (H) and Evenness index (J) were estimated. A total of four species belong to the Order Aspidochirotida and two each representing Family Holothuriidae and Family Stichopodidae were identified. Among them Holoturiaatra was the dominant species contributing 46.46% of the population followed by S. horrens, S. herrmanni, H. leucospilota representing 32.78%, 17.16% and 3.60%, respectively. The presence of S. horrens, S. herrmanni, H. leucospilota were recorded for the first time in Point Pedro area. According to diversity indices, maximum species diversity, richness and evenness were reported at Munnai site compared to Viyaparimoolai site. The information and observations in this study will be of use in formulating management policies for the sea cucumber fishery in the Point Pedro coastal area.

Crabs are economically important and a protein rich commodity in the coastal as well as offshore fisheries in Sri Lanka. Crabs are one of the potential aquaculture candidates and also form important commercial and recreational fishery. The present study was conducted with the aim of documenting the species composition and diversity of crabs inhabiting in the Navanthurai coastal area of Jaffna peninsula of Sri Lanka. The current investigation was carried out from November 2011 to October 2012 in Navanthurai coastal waters, which is a part of the Jaffna estuary situated between latitudes 9°36’– 9°50’North and longitudes 79° 40’– 80°40’ East. Specimens were collected using different types of nets; mainly driftnet, gill net, hoop net and ‘Sirahuvalai’. All crabs were brought to the laboratory and identified up to species level based on the morphological characters. Accordingly, five edible species of crabs namely; Scyllaserrata, Portunus pelagicus, Thalamita craneta, Charybdis notator and Portunus sanguinolentes, belong to four genera of the family Portunidae were recorded. . Among them P.pelagicus is the dominant species contributing 93.5% followed by T.craneta and S.serrata representing 5.5% and 1.5%, respectively. However, S.serrata is the most demanded species of crabs both for local and export markets. Only a few individuals of C.natator and P.sanginolentus were observed representing 0.37% and 0.13%, respectively of the harvest. The information and observations in this study will be of use in formulating management policies for the crab fishery off the Navanthurai coastal area.Tropical Agricultural Research Vol. 25 (4): 595 – 601 (2014)