Upali S. Amarasinghe

University of Kelaniya · Department of Zoology and Environmental Management

Aquaculture is seen as an alternative to meeting the widening gap in global rising demand and decreasing supply for aquatic food products. Asia, the epicenter of the global aquaculture industry, accounts for over 90% of the global aquaculture production quantity and about 80% of the value. Asian aquaculture, as with global aquaculture, is dependent...

As in most artisanal fisheries, assessment of fishing effort is crucial to the management of the artisanal fishery of Parakrama Samudra, an ancient man-made tropical lake in Sri Lanka. Since there were few similarities between alternative ways of expressing effort for the gill-net cichlid fishery is the lake, this study aimed to find the most effec...

The conference ‘Fish Stock Assessment Methods for Lakes and Reservoirs: Towards the True Picture of Fish Stock’ (FSAMLR) was held in September 2007 in Ceske Budejovice, Czech Republic. A total of 110 participants from 34 countries attended the meeting and 93 lectures were presented. Great advances were reported in fish surveys using hydroacoustics...

There is a growing recognition of the need to conserve biodiversity that has been conceptualised in the Convention of Biological Diversity. Maintenance of fish species richness is particularly important, because habitat degradation in inland waters continues to accelerate on a global scale. Here we develop empirical models for predicting fish speci...

A collaborative international project funded by the European Union's INCO-DC programme is undertaking limnological, fish biological, environmental and socio-economic research in five tropical lakes and reservoirs in Sri Lanka, Thailand and the Philippines over the period 1998–2001. The aim is to determine their trophic structure and their capacity...

Recent trends in the pelagic fish landings of multi-day fishing fleets operated from Sri Lanka indicated significant declines in many fish species. Therefore, the present preliminary analysis investigates the perceptions of fishers on recent declining trends of pelagic fish landings from offshore areas of the Indian Ocean and further investigates w...

The intensive utilization of tropical inland water bodies for multiple and sometimes competing activities underlines the necessity for their integrated and holistic co-management. This paper presents our synthesis on lake and reservoir fisheries in South and Southeast Asia as social-ecological systems, based on a synopsis of our research findings f...

The challenge of promoting sustainable development has highlighted the limitations of traditional, compartmentalised scientifi c research into complex human-environmental systems. This landmark book integrates limnology, fi sh and fi sheries ecology, fi sh population dynamics, trophic modelling and socio-economics in a comparative study of fi ve tr...

https://www.sciencedirect.com/science/article/abs/pii/S2352485523003584?via%3Dihub

This paper describes the distribution, abundance and seasonal variation in blue whales (BWs) on the south coast of Sri Lanka, off Mirissa, where they are faced with anthropogenic threats. Data collection encompassed opportunistic sightings by whale-watching (WW) operations. This study revealed that large aggregations of BWs consistently overlapped...

In the Trincomalee bay of Sri Lanka, two species of squids, Uroteuthis duvaucelii and U. singhalensis, support profitable small-scale fisheries. The present study is an attempt to assess the fisheries of these two squid species using length-based stock assessment methodologies. Length frequency data collected from the landings of two species, colle...

As part of monitoring, control and surveillance of marine fisheries, a logbook monitoring and vessel monitoring system (VMS) were introduced for multi-day fishing. The present study investigates the possibility of using VMS data to validate logbook records of fishing locations of multi-day fishing vessels. The data from 1,424 multiday vessels were...

The introduction of high economic value species like giant freshwater prawn (GFWP) makes culture‐based fisheries (CBF) a substantial source of income and simultaneously supports the livelihood development of rural fishers in Sri Lanka. However, this CBF strategy has been implemented without any scientific basis, and therefore, this paper evaluated...

Gill surface area (S) and respiration (R) in juvenile and adult crustaceans scale with their body weight (W) such that S ∝ R ∝ Wd, with d ranging mostly between 0.6 and 0.9, but always <1, as in other water-breathing ectotherms (WBE). The growth of adult crustaceans therefore approaches an asymptote, whether or not seasonal growth oscillations are...

Globally, inland fisheries make a significant contribution to sustainable development across dimensions of food security, livelihoods, economic value and biodiversity. Nevertheless, aquaculture is generally considered to be environmentally unfriendly. As such, environmentally friendly approaches of increasing fish production such as fisheries enhan...

Even though small-scale fisheries throughout the globe are based on local ecological knowledge (LEK), it is often not involved in the decision-making process. An attempt is made to review the potential of using LEK of traditional coastal fisher communities in Sri Lanka and self-governing institutions in managing fisheries commons sustainably. Fishe...

Abstract In the fisheries sector, fisheries enhancement through culture-based fisheries (CBF) has been recognized as an environmentally friendly approach, which is bound to contribute to increasing food fish production, especially in developing countries. Through concerted efforts, Sri Lanka achieved considerable success in CBF development in small...

Abstract In this study, the variation of aquatic molluscan diversity concerning seasonal water level fluctuations (WLF) and sediment texture was investigated in some perennial irrigation reservoirs and the associated head headwater streams in the Kala Oya river basin in Sri Lanka. Altogether 11,752 molluscan specimens belonging to 10 gastropod taxa...

Water-level fluctuations are reported to be key processes influencing ecosystem structure and functions in lentic aquatic ecosystems such as reservoirs. The plankton community structure in reservoirs, being useful monitoring tools as reservoir trophic status indicators, are influenced by water quality parameters and water-level fluctuations. The pr...

Seasonal water-level fluctuations (WLFs) in reservoirs influence ecological processes, in turn affecting their benthic macroinvertebrate communities. The present study was carried out in 10 irrigation reservoirs of Sri Lanka to investigate the effects of seasonal WLFs on the benthic macroinvertebrate fauna. The study period was divided into two dis...

Seasonal water-level fluctuations (WLFs) in reservoirs influence ecological processes, in turn affecting their benthic macroinvertebrate communities. The present study was carried out in 10 irrigation reservoirs of Sri Lanka to investigate the effects of seasonal WLFs on the benthic macroinvertebrate fauna. The study period was divided into two dis...

Fish generally mature of a smaller fraction of their maximum sizes than birds and mammals. In farmed tilapia (Family Cichlidae), which can tolerate very adverse conditions, the stunting caused by these conditions also cause them to spawn at very small sizes. Such spawning at small sizes (or 'early spawning') is usually perceived as a unique feature...

Culture‐based fisheries (CBF) are increasingly accepted as strategies for enhancing inland fisheries, especially in tropical Asia. In Sri Lanka, CBF development in irrigation reservoirs has gained momentum due to concerted efforts of government fisheries authorities for inland fisheries enhancement. In the present study, production trends of five i...

As in many tropical countries, reservoir fishery of Sri Lanka is dominated by the exotic cichlid, Oreochromis niloticus (Linnaeus, 1758). Oreochromis niloticus populations in irrigation reservoirs are expected to be under the influence of various disturbances such as changes in hydrological regimes, trophic conditions and fishing pressure. In the p...

Abstract In Sri Lankan reservoirs, small, indigenous fish species (SIS) are abundant and can be differentially exploited using small mesh (15-38 mm stretched mesh sizes) gillnets without any detrimental effects on the cichlid fisheries. However, in the recent past a paradigm shift in the reservoir fisheries of Sri Lanka is observed from total depen...

Many of the seasonal water bodies in Sri Lanka harbour substantial numbers of aquatic birds. Local aggregation of water fowl during communal roosting and colonial breeding results in substantial inputs of nutrients into aquatic systems and can alter fresh water aquatic systems. The present study calculated the density and species richness of true a...

Institutional Robustness of Culture- based Fisheries in Perennial Reservoirs of Sri Lanka K.B.C. PUSHPALATHA1, MOHOTTALA G. KULARATNE2, U.S. AMARASINGHE3,* 1National Aquaculture Development Authority of Sri Lanka, 41/1, Parliament Road, Pelawatta, Battaramulla, Colombo, Sri Lanka 2Department of Economics, University of Kelaniya, Kelaniya, Sri La...

We were profoundly saddened to learn the demise of Professor Sena S. De Silva who passed away in Melbourne, Australia, on 6 May, 2020. Sena was respected and admired for his enduring commitment and outstanding contributions to the fisheries and aquaculture sector. His profound enthusiasm and dedication over the last 40 years merited him with a repu...

Ehirava fluviatilis is a marine origin clupeid found in Southern India and Sri Lanka, also found in two freshwater lakes, namely Parakarama Samudraya and Rajanaganaya reservoir, and that places are identified as secondarily colonizedhabitats. The objectives of this study were carried toinvestigate the fatty acid (FA) profile in the flesh of E.fluvi...

Many reservoirs provide multiple benefits to people around the world, in addition to primary uses such as irrigation. Thus, reservoir management should address their multiple uses. The water quality of ten irrigation reservoirs in Sri Lanka was examined in the present study with the objective of better understanding the effects of hydrological regi...

Most tropical rivers especially in the Asian region, are severely impacted by various human perturbations, and the diverse habitats in streams support rich invertebrate and vertebrate communities. It is hypothesized that the fish assemblages and their dietary structure in two tropical streams differ because they flow through different terrains and...

Importance of participatory approaches in the management of small-scale fisheries is being increasingly highlighted today throughout the world. Brush park fishery in Negombo estuary, Sri Lanka is a small-scale fishery where traditional ecological knowledge (TEK) accumulated over generations is utilized to optimize the harvests. In the present study...

Management of reservoir water quality is a global challenge due to the natural process of eutrophication and anthropogenic aggravation. In Sri Lanka, irrigation reservoirs support several secondary uses such as fish production, livestock farming, and many communal uses including drinking water supply. In the present study, basic limnological parame...

As fisheries production in reservoirs of most countries is a secondary use, challenges for improved management of fisheries should be addressed by building partnership between fisheries and other interested groups such as agriculture concerned with water management. Attempts were therefore made to develop empirical fish yield predictive models in t...

Background: Comprehensive understanding of risk factors related to socio-economic and demographic status and knowledge, attitudes and practices (KAP) of local communities play a key role in the design and implementation of community-based vector management programmes, along with the identification of gaps in existing control activities. Methods:...

The reproductive biological characteristics of Oreochromis niloticus (Linnaeus 1758) were investigated in relation to fishing pressure and water level fluctuation in 10 irrigation reservoirs of Sri Lanka. It was found that matured larger sized male fish made larger and deeper nests. The negative relationship between gonado-somatic index (GSI) and s...

This study investigated whether allochthonous inputs generated by cattle and water buffaloes grazing in the catchment or wading in the water in small village reservoirs of Sri Lanka can make a significant effect on yields from culture-based fisheries of those reservoirs. The analysis is based on limnological data of 37 randomly selected reservoirs....

Life history information on six endemic fish species namely Belontia signata, Pethiya cumingii, P. nigrofasciata, Puntius titteya, Rasboroides vaterifloris and Garra ceylonensis inhabiting the Kalu Ganga and Kelani Ganga river basins in Sri Lanka was evaluated. The growth constant of the fish species showed a positive relationship with the river or...

Background Socio-economic, demographic factors and Knowledge Attitude Practices (KAPs) have been recognized as critical factors that influence the incidence and transmission of dengue epidemics. However, studies that characterize above features of a risk free or low risk population are rare. Therefore, the present study was conducted to characteriz...

The nesting sites of Oreochromis niloticus (Linnaeus 1758) were studied in 10 irrigation reservoirs of Sri Lanka from April 2014 to April 2016 to understand the influencing factors. The optimal nesting depth and nest diameter varied across reservoirs. Nest density (ND) was negatively related to slope of the littoral area (in degrees) according to N...

Brush park fishery in Negombo estuary, Sri Lanka is a traditional fishing practice which relies on fishes attracted to artificial woody fish aggregation devices. This study investigates whether constituent species in these brush parks exhibit morphological variations in relation to their dietary habits. Fishes caught in brush parks were sampled fro...

Background. Gillnets of mesh sizes (6.9 to 12.7 cm) are used in individual boats in Sri Lankan reservoirs targeting exotic cichlid species, Oreochromis mossambicus (Peters, 1852) and Oreochromis niloticus (Linnaeus, 1758), which dominate the fisheries. The mesh composition of gillnets varies from boat to boat and from season to season making catch...

The benthic macroinvertebrate fauna and main abiotic parameters were studied to understand the patterns of diversity and structure along the temporal and longitudinal gradients in two tropical lotic ecosystems in the wet and dry zones of Sri Lanka. Invertebrate abundance (annual means) was in the same magnitude in the two streams (2,520 ind. m⁻² in...

As in many tropical reservoir fisheries, the major fishing gear in the reservoirs of Sri Lanka is gillnet. Gillnets of a wide range of stretched mesh sizes (6.9 - 11.4 cm) are used in individual boats in Sri Lankan reservoirs targeting mainly two exotic cichlid species, Oreochromis mossambicus and O. niloticus, which dominate the fisheries accounti...

Discharge-mediated seasonal patterns of food web interactions were investigated in two streams in Sri Lanka; Eswathu Oya (a perennial wet-zone stream) and Yan Oya (a seasonal dry-zone stream). Based on volumetric proportions of diet composition, relative abundance of fish species and their daily food rations, the mean cumulative consumption of each...

As in many tropical reservoir fisheries, the major fishing gear in the reservoirs of Sri Lanka is gillnet. Gillnets of a wide range of stretched mesh sizes (6.9-11.4 cm) are used in individual boats in Sri Lankan reservoirs targeting mainly two exotic cichlid species, Oreochromis mossambicus and O. niloticus, which dominate the fisheries accounting...

As in many developing countries, small-scale fisheries including beach seining contribute significantly livelihoods and food security of coastal communities. Beach seining in Sri Lanka is seasonal mainly during calm season deprived of strong monsoonal winds, and essentially a multi-species fishery. Knowledge about the seasonal occurrence of pelagic...

Many fisheries authorities in the world have been compelled to accept community-based management as an invaluable means to formulate fisheries management due to failures of small-scale fisheries exclusively managed by centralized units. Beach seine fishing practices in Sri Lanka are known to be institutionalized by traditional community-based coast...

An extra 30–40 million tonnes of food fish will be required by 2050 to meet the increasing need for a growing population. In the wake of plateauing of the traditional food fish supplies from marine capture fisheries, the gap in the supplies will have to be met from aquaculture and other plausible strategies, including increased inland fish producti...

Most of the fish stocks in the world, including European fish stocks, are threatened by overfishing and/or degraded environmental conditions. Although the Common Fisheries Policy (CFP) is the main policy instrument managing fish stocks in Europe, there is continued concern as to whether commercial fish stocks will achieve Good Environmental Status...

Local knowledge of fishers is considered to be useful in establishing effective dialogue between fishers and fishery managers to foster the sharing of power and responsibility between the government and local resource users. However, fishers' local knowledge is often considered anecdotal and consequently, these knowledge bases are largely underutil...

Local knowledge of fishers is considered to be useful in establishing effective dialogue between fishers and fishery managers to foster the sharing of power and responsibility between the government and local resource users. However, fishers' local knowledge is often considered anecdotal and consequently, these knowledge bases are largely underutil...

Testing the pertinence of Indigenous knowledge in fisheries management

In Sri Lanka, small non-perennial reservoirs (mostly < 50 ha) are numerous in the dry zone receiving less than 185 cm annual precipitation. These are irrigational and are not traditionally used for inland fisheries, due to inadequate natural recruitment, but has the potential for utilization for the development of culture-based fisheries (CBF), a f...

Stilt fishing is a unique fish catching method confined only to southern coast of Sri Lanka from Galle to Matara. Stilt fishermen sitting on a cross bar called “Petta” tied to vertical pole planted in the reef and carrying out rod and line fishing are a Sri Lankan icon that attracts local and foreign tourists’ attention. This small-scale, seasonal...

Most small-scale fisheries throughout the world are based primarily on fisher knowledge, which is essentially experiential knowledge consisting of a replicable, verbally transmitted set of skills. Even though fisher knowledge is well documented for some fisheries, there are only a few studies that explain how it actually works as a management syste...

Seasonal water level fluctuation, habitat alteration and colonization of marginal benthic fauna in irrigation reservoirs in the Kala Oya River basin in Sri Lanka. Sampath N. Weerakoon1, Withanage.U.Chandrasekara, Upali.S.Amarasinghe Department of Zoology & Environmental Management, University of Kelaniya, Sri Lanka. 1 Corresponding Author: sn...

Small scale coastal fisheries accounts for nearly 40% of world fish catches and provide direct employment for more than 90% of the world fishers employed in capture fisheries. Subsequent recognition of the failures of centralized fisheries management led the governments to accept community-based management as an invaluable means to formulate fisher...

Mass aggregation of waterfowls for breeding, results in allochthonous nutrient inputs into aquatic systems. This study evaluated accumulation of bird droppings as allochthonus nutrient input and its fluctuations in Anavilundawa International Ramsar Sanctuary in Sri Lanka where Asian openbill (Anastomus oscitans) mass breeding occurs annually. Reser...

In tropical Asia, there is a general paucity of natural lakes that are mainly located in the island states of the Philippines and Indonesia. Reservoir construction is extensive in the region primarily for irrigation, flood control and hydroelectricity generation, and fish production is essentially a secondary use of these reservoirs. Although the d...

Dengue has been recognized to be one of the major threats on the public health of many tropical countries including Sri Lanka. Controlling of the high rate of mortality caused by dengue, which remains without being altered regardless of the immense efforts and control strategies of the relevant authorities, has remained as a major challenge for the...

The quantification of species diversity is essential in several aspects of ecology, including conservation biology, and as an indicator of the well-being of ecological systems. However, species diversity of the wetland birds in the seasonal reservoirs in the dry zone of Sri Lanka has received very little attention. In the present study, an attempt...