Status of Multi-Geared Small Scale Fishery Operated in Koggala Lagoon and Adjacent Coastal Area

Management of multi-species and multi-geared fisheries is challenging due to conflicts and competitions of fishers. However, such a complex fishery exists for the last 100 years in Koggala lagoon, which extends only for 727 ha area, in southern Sri Lanka. This study evaluated the fish catch and income sharing mechanisms which enable to survive these fisheries in highly dynamic biological and socio-economical environments. Eight landing sites at the lagoon body, lagoon mouth and adjacent coast were weekly visited from April to August 2015 in drawing random samples to determine gear-based catch per unit effort (CPUE), species diversity and income levels. Questionnaires and discussions among fishers were used to identify potentials and threats for the fishery. Dominant 25 fish species and 6 shrimp species were observed in the catches of 11 fishing methods including snares, a fish trap which was not recorded from Koggala lagoon. During the study period high variations of CPUE were observed within and among fishing methods. Hierarchical cluster analysis based on present-absent data showed two clearly separated clusters (P<0.05). Though the educational level and years of experience significantly differed between lagoon and coastal fishers (P<0.05), the respective income was not significantly different. Targeting different species and different life history stages by different types of gear seems to be the key in sustaining multi-geared fisheries in the lagoon for last 100 years. Though school education does not have any effect on selecting fishing location, fishing experience seems to be important in operating some specific gear. Species aggregation and their susceptibility for different gear reveled in this study must be important in developing fishery management strategies for the lagoon. Despite to the effective catch sharing mechanism, the sand bar formation, which is the most concerned issue by both lagoon and coastal fishers, will determine whether Koggala lagoon fisheries will survived for another 100 years due to its effects on altering species diversity.Keywords: Artisanal fisheries, Catch composition, Socio-economic statu

How Artisanal Stake-seine Fishery Survived for Last 300 Years in the Dynamic and Competitive Environment?

Despite to the high fishing pressure; use of illegal fishing methods; deforestation, manufacturing, tourism and even the dynamic market environment, an artisanal stake-net fishery, which operates for shrimps, has been able to survive since 1721 in Negombo lagoon in the western Sri Lanka. The key strength of the stake-net fishery is its community-based management systems which closely related with the ecosystem. But sustainable-utilisation is practically difficult in developing countries because assessing resources, setting limits on their utilisation, monitoring and enforcing complex regulations is not easy where government agencies do not have sufficient capacity for collecting data. Therefore, the present status of stake-net fishery management system in present competitive environment was evaluated. The Rapid Appraisal method was used, in gathering information on the community-based management system, by contacting active fishermen; community leaders; fish collectors; and auctioneers from 2011-2013. The equitability of sharing resources by a rotational lots drawing system for distributing access rights to fishing sites among members was identified as the key feature in limiting the fishing pressure resulting low conflicts and sustainable resource usage. Access right is tightly restricted to "culturally-homogeneous" eligible members. Loyalty of fishermen to uphold the Stake-net fishery management system remains strong. Loss of fishing sites due to siltation dramatically increased over the last 4-5 years. However, there is no guarantee that the cumulative past experience of a society will necessarily fit them to solve new problems & threats. Anyhow, successful community-based stake-net fishery management provides a useful blueprint upon which the management of other fisheries might be based.Keywords: Management: Community and Co-management, Fisheries Management, Fisheries Economic

Pleustonic colonies of cnidarians (Physalia physalis, Porpita porpita and Velella velella) found along the coastal belt of Sri Lanka

Three species of the free-floating, colonial hydrozoans namely Physalia physalis L., Porpita porpita L. and Velella velella L., found along the coastal belt of Sri Lanka are reported here with their morphological descriptions and respective abundance. The study was conducted from March 2017 to April 2018, implementing monthly coastal surveys at 26 sampling stations along the coastal belt of Sri Lanka. The abundance of stranded colonies of those species was assessed using line transects and the specimens were identified taxonomically. Of the porpitids found in this study, V. velella was reported for the first time in Sri Lankan waters while P. porpita was re-reported trustworthy as its initial record was just a sighting. The siphonophore P. physalis was also re-reported and it always represented the lowest abundance among the stranded colonies of the three species. The highest abundance of all the species was from May to August on the southwest coast of Sri Lanka, and from November to February on the northeast coast. There was a significant size difference in colonies of each species between the two coasts

In vitro models for the study of osteoarthritis

AbstractOsteoarthritis (OA) is a prevalent disease of most mammalian species and is a significant cause of welfare and economic morbidity in affected individuals and populations. In vitro models of osteoarthritis are vital to advance research into the causes of the disease, and the subsequent design and testing of potential therapeutics. However, a plethora of in vitro models have been used by researchers but with no consensus on the most appropriate model. Models attempt to mimic factors and conditions which initiate OA, or dissect the pathways active in the disease. Underlying uncertainty as to the cause of OA and the different attributes of isolated cells and tissues used mean that similar models may produce differing results and can differ from the naturally occurring disease.This review article assesses a selection of the in vitro models currently used in OA research, and considers the merits of each. Particular focus is placed on the more prevalent cytokine stimulation and load-based models. A brief review of the mechanism of these models is given, with their relevance to the naturally occurring disease. Most in vitro models have used supraphysiological loads or cytokine concentrations (compared with the natural disease) in order to impart a timely response from the cells or tissue assessed. Whilst models inducing OA-like pathology with a single stimulus can answer important biological questions about the behaviour of cells and tissues, the development of combinatorial models encompassing different physiological and molecular aspects of the disease should more accurately reflect the pathogenesis of the naturally occurring disease

Immediate Need of Managing Blue Swimmer Crab Resource off Northern Sri Lanka for a Sustainable Industry

After 2008, in the post-war context of northern Sri Lanka, the Blue swimming crab (BSC), Portunus pelagicus, fishery is U68blooming and becoming an export-oriented industry. Presently the major concern of BSC industry is how long this resource could sustainably utilized, if fishery continuous with current increasing exploitation rates. Hence, present status of BSC resource and fishery were evaluated. Biological data were collected drawing weekly random samples from commercial catches from November 2014 to December 2015. Catch records from 2005 to 2015 were collected from fish-collectors' log-books. Threats and issues on the BSC industry were analysed through personal interviews; semi-structured questionnaires; direct-observations and group-discussions by covering 90% of randomly selected stakeholders: fishers; processers; collectors, exporters, scientist etc. Catchers obtained from many fishing grounds in the region consist of significantly higher amount of small carbs (<100g). During January-March very small individuals, which are smaller than the estimated length at 50% maturity (L50), 7.68cm carapace width (62g in weight), were dominated in catchers. The open-access and common-property rights have triggered ~70-times increased fishing effort during last 10-years mainly leading to growth overfishing. Moreover, poaching by fishermen of neighbouring countries impose high pressure on both the resource and the industry leading to wrong estimates of fishing effort and subsequently maximum-sustainable yield. Fishery needs to be managed immediately prioritising threats and issues identified in this study. The correct choice of management may require co-management and community-based management recognition or implementation of locally based fishing rights, which is common in Sri Lankan coastal fisheries.Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, held July 11-15, 2016 at Aberdeen Exhibition and Conference Center (AECC), Aberdeen, Scotland, UK

Wind tunnel simulations of the atmospheric boundary layer

The velocity profile shape and boundary layer thickness of an equilibrium boundary layer grown over a long fetch of roughness are closely matched with those of a boundary layer artificially thickened using spires (by adjusting the shape and height of the spires). Other turbulent characteristics of these two wind tunnel simula tions of the atmospheric wind are then compared. At the same time, more information on rough wall boundary layers is obtained to allow for a rational choice of the shape and spacing of roughness elements required to produce a particular simulation of the full scale boundary layer. A technique for calculating the shape of boundary layers in exact equilibrium with the roughness beneath, using a data correlation for the wall stress associated with very rough boundaries and a semi-empirical calculation method, is examined experimentally. Wall shear stress, measured directly from a drag plate, i combined with boundary layer integral properties to show that the shear stress formula is reasonably accurate and that the boundary layer grown over a long fetch of roughness is close to equilibrium after passing over a streamwise distance equal to about 350 times the roughness element height. The boundary layer quickly generated using spires proved to be a fair approximation to that grown over a long fetch of roughness, but did not accurately represent the longitudinal turbulence intensity of the full scale atmospheric wind or the naturally grown boundary layer. The boundary layer produced here by spires showed little change in gross characteristics after travelling about eight spire heights downstream of the spires. A distance of six or seven such heights has been advised by other workers in the past.Applied Science, Faculty ofMechanical Engineering, Department ofGraduat