Valuing mangrove benefits: contribution of mangrove forests to local livelihoods in Bhitarkanika Conservation Area,East Coast of India

The consumptive benefits of mangrove forests to subsistence economy receive little recognition. This paper quantifies the value of provisioning services of mangrove forests to local livelihoods in terms of forestry and fishery products. To examine the use of mangrove products, 324 households from 36 villages in the Bhitarkanika Conservation Area located in East Coast of India were surveyed using structured questionnaires. For estimating the contribution of mangrove forests to fish productivity, fish production was evaluated in three stages—inshore fishery, offshore fishery and the role of mangrove forests as nursery ground for fish and shellfish. The findings revealed that 14.2% of the fuel need of each household was being met by the forests. Other forestry products used were timber, honey and thatch grass. During the study, 14 species of fish and three of shellfish were recorded. The total catch for inshore fishery was estimated as 3.77 kg h⁻¹ having market price of US2.25. In offshore fishery the number of species caught as well as income from the catch was higher in areas with mangroves (US 2.25. In offshore fishery the number of species caught as well as income from the catch was higher in areas with mangroves (US 44.61 h⁻¹) than in those without mangroves (US$ 2.62 h⁻¹). The market price of the forestry and fishery products used by the people was estimated as US$ 2.62 h⁻¹). The market price of the forestry and fishery products used by the people was estimated as US 107 household⁻¹ annum⁻¹. The resources extracted from mangrove forests contributed to more than 14.5% of the total income of the household. This was around 30% for the households residing in the immediate vicinity of the forests. This study suggests that provisioning services provided by the mangrove forests are of significant importance to the coastal communities as they increase the resilience and sustainability of the local economy.     

Estimating historical commercial rock lobster (Jasus edwardsii) catch inside Australian State territorial waters for marine protected area assessment: the binomial likelihood method

The rock lobster (Jasus edwardsii) fishery of South Australia is the State’s most valuable fisheries resource with an export value exceeding ~AU$100 million. The fishery operates primarily inshore (<60 m), and overlaps with a series of marine protected areas (MPAs) currently proposed for State territorial waters. As a result, the need to quantify the impact of proposed MPAs on commercial landings of rock lobster within territorial waters is an integral part of the MPA assessment process. Removing fishing effort displaced by MPAs prevents a corresponding increase in exploitation outside protected zones. We describe a binomial likelihood method that utilises historical commercial catch data to estimate catch totals of rock lobster inside South Australian State waters. Lobster catches per km² showed a high level of spatial variation with estimated historical lobster catch in State waters spanning approximately three orders of magnitude. The method identified key areas where high lobster catch (up to 500 kg/km²) overlapped with State waters. Binomial likelihood outputs have particular application to the estimation of net catch loss in situations where fishery buy-back or financial compensation are a considered option as part of the MPA implementation process.     

Predation Risk within Fishing Gear and Implications for South Australian Rock Lobster Fisheries

Depredation of southern rock lobster (Jasus edwardsii) within fishing gear by the Maori octopus (Pinnoctopus cordiformis) has economic and ecological impacts on valuable fisheries in South Australia. In addition, depredation rates can be highly variable resulting in uncertainties for the fishery. We examined how in-pot lobster predation was influenced by factors such as lobster size and sex, season, fishing zone, and catch rate. Using mixed modelling techniques, we found that in-pot predation risk increased with lobster size and was higher for male lobsters. In addition, the effect of catch rate of lobsters on predation risk by octopus differed among fishing zones. There was both a seasonal and a spatial component to octopus predation, with an increased risk within discrete fishing grounds in South Australia at certain times of the year. Information about predation within lobster gear can assist fishery management decision-making, potentially leading to significant reduction in economic losses to the fishery.     

Estimation of overall fishing intensity of tuna longline fishery-yellowfin tuna (Thunnus albacares) fishery in the indian ocean as a case study

According to the FAO catch statistics, the total catch of yellowfin tuna (Thunnus albacares) from the Indian Ocean is characterised by decline in the longline fishery and rapid increase in the surface fishery. In the present communication, an attempt has been made to estimate the overall effective fishing intensity of longline fishery for yellowfin tuna by the Japanese longliners during the years 1973–1975. The results on areas and seasons of effective effort expended are presented, along with estimates of tuna availability, effective fishing intensity and the relative gear efficiency.     

Translocation of marbled African lungfish,Protopterus aethiopicus (Telostei: Protopteridae), and its fishery in Lake Baringo,Kenya

The translocation of the marbled African lungfish Protopterus aethiopicus into Lake Baringo created a new fishery for the local community, who capture them primarily in a bottom-set long line fishery. Its introduction, development and current fishery status in the lake are documented. Annual catch data were obtained from the District Fisheries Office, while catch and effort data of the long line fishery were recorded at one active fish-landing site between February and October 2001. Lungfish comprise a significant component of commercial landings, sometimes exceeding catches of the Baringo tilapia Oreochromis niloticus baringoensis as the most landed species by weight. Daily catch rates and effort varied considerably, ranging from 5.51–15.18kg day^?1 and from 50–590 baited hooks day^?1, respectively. Daily catch per fisher ranged from 0–35.72kg, while the overall mean catch per unit effort (CPUE) was only 0.003kg per hook-hour. This study provides the only baseline CPUE data for a lungfish long line fishery that the authors are aware of, for comparison with future studies in this or other lakes where lungfish are similarly exploited. Recommendations for improved management and the maintenance of a viable lungfish long line fishery in Lake Baringo are presented.     

Gargoor trap fishery in Kuwait,catch rate and species composition

Kuwait's fisheries include shrimp trawlers, gill nets, intertidal stake nets, and demersal fish traps, known locally as gargoor. The gargoor fishery used to be the nation's most important in terms of value and landings volume, but declines in catch rates have reduced its ranking. This paper describes the status of the gargoor artisanal fishery. The main landings place was sampled for catch and effort, and fish length‐frequency data from May 2003 to December 2005. The catch rate, monthly average number of boats operating, and the number of gargoor cleared were estimated for dhow boats fishing in Kuwait's waters and international waters, and speed boats operating in Kuwait waters only. Over the duration of the study period, the speedboat catch rates were higher than those of dhow boats, i.e., 3.7 kg/trap‐pull vs. 2.6 and 2.5 kg/trap‐pull for dhows fishing in Kuwait's territorial waters and international waters, respectively. The grouper, Epinephelus coicodes, was the main species captured, contributing 19.3% and 17.8% to the dhow catch in Kuwait waters and international waters, respectively. The catch rates by dhow boats declined from an average of 4.7 kg/trap‐pull in 2003 to 2.7 kg/trap‐pull in 2005 representing a 41% decrease. If this decreasing catch rate trend continues, then fishing effort should be reduced to allow stock recovery. It is recommended that the number of gargoor fished in Kuwaiti waters should be limited and that several no‐fishing zones be established to ensure the minimum spawning stock biomass and preserve biodiversity for all fisheries.     

The role of discounting and dynamics in determining the economic efficiency of time-area closures for managing fishery bycatch

Time-area closures are commonly used to manage fisheries bycatch and involve temporarily closing an area of the ocean to particular fishing gears. We examine conditions in which implementing a time-area closure would increase the economic value of fisheries, focusing on a case study application in the Gulf of Mexico. Pelagic longline fishermen catch the highly valued Atlantic bluefin tuna (Thunnus thynnus, Scombridae) on their Gulf of Mexico spawning grounds while fishing for Atlantic yellowfin tuna (Thunnus albacares). We analyze a multispecies, multifishery bioeconomic model that includes information on migratory patterns from electronic tagged bluefin tuna. We use dynamic optimization to identify management strategies that would maximize the net present value of tuna fisheries, allowing for discounting of future benefits and costs relative to the present. If past fishing mortality rates continue in Atlantic bluefin tuna fisheries, implementing a time-area closure in the Gulf of Mexico incurs economic costs. However, the net present value of the fisheries is increased by implementing a time-area closure as part of a broader commitment to rebuild the heavily depleted bluefin population, provided the discount rate and the costs of such a closure in forgone fishing opportunities are not too large. The increase in economic value offered by a time-area closure is small relative to the overall economic value of rebuilding itself and it may be economically optimal only to implement a closure once sufficient rebuilding has already taken place.     

The artisanal fishery of Metangula,Lake Malawi/Niassa,East Africa

The artisanal fishery of Metangula, on the remote Mozambique coast of Lake Malawi/Niassa, was studied for four months during the rainy season from December 1998 to March 1999. Catch, catch composition and fishing effort were determined for the most important gear types. The different gears exploited different stocks of fish. Copadichromis spp. were caught mostly in deep-water seine (chirimila) nets and accounted for >50% of the total catch. Oreochromis spp. were the major catch in the beach seine fishery. Labeo mesops and Opsaridium microcephalus were the most important catches in gill nets. The catfishes Bathyclarias spp. and Bagrus meridionalis dominated the long line fishery. Since 1983 there has been a considerable increase in fishing effort. The number of beach seines, chirimila nets and long lines increased 2.8 times, 2.9 times and 2.5 times, respectively, and there was a fourfold increase in the number of gear owners and fishing assistants. Comparison with data for Chembe Village in Malawi indicates that the fish populations at Metangula are not yet as impacted as they are on the populous and accessible Malawi coast. Some constraints on the fishery include the lack of management and financial support, poor gear and infrastructure, and the lack of access to markets.     

Artisanal Green Turtle,Chelonia mydas,Fishery of Caribbean Nicaragua: I. Catch Rates and Trends, 1991–2011

This is the first assessment of catch rates for the legal, artisanal green turtle, Chelonia mydas, fishery in Caribbean Nicaragua. Data were collected by community members, monitoring up to 14 landing sites from 1991 to 2011. We examined take levels, and temporal and spatial variability in catch rates for the overall fishery, by region, and community using General Additive Mixed Models (GAMMs). More than 171,556 green turtles were killed during the period, with a mean estimated minimum 8,169±2,182 annually. There was a statistically significant decline in catch rates overall. Catch rates peaked in 1997 and 2002, followed by a downward trend, particularly from mid-2008 to the end of the study period. Similar downward trends were evident in both study regions. Community specific catch rate trends also indicated declines with decreases ranging from 21% to 90%. Decrease in catch rates in Nicaragua is cause for concern even though the principal source rookery at Tortuguero, Costa Rica, shows an increase in nesting activity. Explanations for the apparent discrepancy between the increasing trend at Tortuguero and decreasing catch rate trends in Nicaragua include: i) an increase in reproductive output, ii) insufficient time has passed to observe the impact of the fishery on the rookery due to a time lag, iii) changes in other segments of the population have not been detected since only nesting activity is monitored, iv) the expansive northern Nicaragua foraging ground may provide a refuge for a sufficient portion of the Tortuguero rookery, and/or v) a larger than expected contribution of non-Tortuguero rookeries occurring in Nicaragua turtle fishing areas. Our results highlight the need for close monitoring of rookeries and in-water aggregations in the Caribbean. Where consumptive use still occurs, nations sharing this resource should implement scientifically based limits on exploitation to ensure sustainability and mitigate impacts to regional population diversity.     

Recruitment dynamics and fishery characteristics of juvenile goatfishes Mulloidichthys spp. in Hawai‘i

The most common goatfishes in Hawai‘i, Mulloidichthys flavolineatus and M. vanicolensis, comprise a unique resource due to their cultural, ecological and biological significance. These species exhibit pulse-type recruitment to nearshore areas during the summer months. Such pulses of juvenile fishes provide prey for pelagic and nearshore fishes and support a popular directed fishery. However, limited scientific information exists on juvenile stages of these fishes, known locally as oama, despite their contribution to coastal ecology and the extensive nearshore fisheries. Here we resolve growth rates, habitat preferences, hatching dates, size and age structure, as well as fishing catch rates based on new recruits in 2014 and 2015. We sampled 257 M. flavolineatus and 204 M. vanicolensis to compare ecological and fisheries characteristics between species and years. Both show strong habitat segregation, with M. vanicolensis found almost exclusively on hard and M. flavolineatus on soft substrates. Oama recruited in anomalously high numbers in 2014, a trend reflected in a higher catch per unit effort. In contrast, 2015 recruits grew faster, were heavier on average and hatched later than during 2014. Both species have calculated hatch dates in March to July, with M. vanicolensis hatching earlier, recruiting earlier and being consistently larger than M. flavolineatus. This baseline information regarding recruitment and early life-history characteristics can enhance management for other data-limited species that comprise a substantial component of nearshore fisheries in Hawai‘i.     

西北太平洋柔鱼渔业生物经济模型及其管理策略

西北太平洋柔鱼是中国大陆、日本及中国台湾鱿钓船队共同开发的主要经济头足类之一,如何兼顾鱿钓船队的渔业利益,并综合考虑生态效益、经济效益和社会效益,科学制定渔业管理目标是确保柔鱼资源可持续利用的重要研究内容。根据中国大陆、日本及中国台湾鱿钓船队的渔获统计数据及相关经济参数,构建基于多船队的生物经济模型,模拟了50年内(1997—2047年)各捕捞船队开发柔鱼资源过程中的动态变化,并探讨了在10种不同的管理方案下各船队捕捞努力量、柔鱼资源量、渔获产量及其渔业利润随时间的动态变化。结果表明,在所有设计方案下,随着捕捞努力量的动态变化,资源量在前10a均呈急剧下降趋势,随后经长期波动后逐渐趋于稳定并维持在较低水平。从长期效益来看,方案9(提高中国台湾船队捕捞系数)的累计产量及累计利润中等,但能兼顾各国或地区船队间的经济利益和社会效益,可建议以方案9作为柔鱼渔业的参考管理目标;从柔鱼资源保护角度来看,方案4(提高中国大陆船队作业成本)的资源量保持最好,可以对方案4进行适当的优化作为参考管理目标,即提高中国大陆船队作业成本,同时适当降低日本船队的可捕系数,可确保柔鱼资源量保持在更高的水平上。     

In situ video monitoring of by-catch interactions within commercial rock lobster (Jasus edwardsii) fishing traps

The incidental capture of non-target and undersized target species during commercial fishing operations has been identified as a major issue and ongoing challenge for fisheries management. In the Northern Zone rock lobster (Jasus edwardsii) fishery (NZRLF) of South Australia, escape gaps have been mandatory in all commercial fishing traps since 2002 to reduce non-target species (by-catch) catch rates and juvenile lobster mortality. This study used in situ video monitoring of by-catch species in traps with and without escape gaps to understand how by-catch species interact within commercial fishing traps. Twenty-two different by-catch species were observed entering commercial rock lobster traps, 20 of which were temperate reef finfish. Overall, on-board by-catch rates were significantly higher in hauled traps without escape gaps and were dominated by reef-dwelling finfish species, particularly Meuschenia hippocrepis and Notolabrus tetricus. However, in situ video monitoring within traps showed no difference in the maximum number of finfish by-catch (MaxN) in traps with or without escape gaps. We suggest that the difference in by-catch rates between hauled traps with and without escape gaps may be driven by species-specific behavioural interactions within traps prior to hauling. Overall, this study shows that the implementation of escape gaps in the NZRLF has considerably reduced fishery by-catch rates. Furthermore, the use of in situ video monitoring has provided a better understanding of by-catch behavioural interactions within traps, not previously identified in on-board sampling research, which may partly explain the mechanisms underpinning escape gap effectiveness.     

Bio‐economic analysis of the Mar Menor (Murcia,SE Spain) small‐scale lagoon fishery

An integrated fisheries management tool based on a bio‐economic model was applied to the demersal fishery in the Mar Menor coastal lagoon in SE Spain, with the objective of exploring solutions to ensure the sustainability of this activity. The hypothesis is that excess harvesting in recent years by fishers trying to offset growing production costs has led to the inefficient use of lagoon fishery resources. The authors established the basic bio‐economic conditions of the fishery in 2012 by means of field sampling and personal interviews with producers, and analyzed the response of several biological and economic indicators (target species biomass and yield, fleet profits) to a management scenario based on limiting the fishing season of one of the main types of fishing gear (fish traps, locally known as ‘paranzas’). Results show that a reduction in fishing mortality of two overexploited species (Sparus aurata and Lithognathus mormyrus) will help recover the biomass of these stocks by more than 40% as well as increase the economic value of the fishery, with profits increasing by 17% over a 4‐year period.     

Farmacoeconomía del tratamiento de las candidiasis invasoras

BackgroundInvasive candidiasis episodes have increased during last years and they have been related with high rates of crude mortality. Invasive candidiasis-related deaths have not diminished significantly with the introduction of antifungals in the past decade. Finantial managers are worried about extra costs from acquisition of new antifungal agents.AimThis review includes the main studies age-stratified to assess different variables related to the economic burden of invasive candidiasis.MethodsSystematic review of biomedic databases including Medline, PubMed and EMBASE.ResultsThe studies show hospital stay as the main variable related with higher impact in the increase of invasive candidiasis costs. Acquisition costs of antifungals have a very low impact in the invasive candidiasis costs.ConclusionsPharmacoeconomics applied in candidiasis invasive therapy must avoid assessing acquisition costs of antifungals exclusively, needing to include both direct and indirect costs associated with this fungal infection. The cost of antifungal acquisition represents a low impact in the overall economic burden of this fungal infection. Further pharmacoeconomics evaluations should be performed including similar definitions to decrease the possible bias in results interpretation.     

Estimating the most effective and economical pheromone for monitoring the European spruce bark beetle

In recent decades, there have been an increasing number of outbreaks of Ips typographus in Europe. A large amount of sanitary felling has taken place, with significant economic and ecological consequences. In order to anticipate such large-scale outbreaks, an effective monitoring system should be set up. One important aspect of monitoring is deciding which pheromone to use. Therefore, we decided to test five different commercially available pheromone lures under different disturbance conditions: Pheroprax®, IT Ecolure Extra®, Ipstyp®, Ipsowit® and Typosan®. We investigated the ability of the pheromones to distinguish between disturbed and undisturbed locations, their cost-efficiency ratio, and side effects such as bycatch abundance and composition. We set 50 traps in two areas with sites that were disturbed and undisturbed by windstorms. We collected the catch from traps every 1–2 weeks from the end of March until the end of September in 2019. We found that IT Ecolure Extra®, Ipsowit® and ® Pheroprax® caught the most I. typographus and best showed changes in the trap catch of I. typographus throughout the whole season. There was a low amount of bycatch (<6% of the total catch) and a low number of predators (a few specimens), but some groups seem to prefer certain pheromones. The cost of the pheromones increased with their effectiveness. However, pheromone costs are low relative to the personnel costs involved in setting traps and collecting the catch. Based on all of the gathered data, we created an index which helps to assess the cost-efficiency of the five chosen commercially available pheromones. We also present guidelines on how to make such an index to assist other researchers in choosing the right pheromone for monitoring populations of I. typographus or other bark beetle species.     

Elasmobranch species richness,fisheries, abundance and size composition in the Azores archipelago (NE Atlantic)

ABSTRACT

Elasmobranchs are a vulnerable resource, more susceptible to overfishing than most teleosts, and their assessment is complicated due to a general lack of information about their fisheries, biology and ecology. This study aimed to analyse all fishery and survey data available for elasmobranchs caught over the past c. 25 years around the Azores (NE Atlantic) to provide a baseline information, which can be used to inform stock assessment and management strategies. Elasmobranch species covered pelagic, benthopelagic and demersal habitats, from shallow to deep-water strata in areas around the islands and seamounts. These species are taken accidentally as by-catch of three main fisheries: swordfish fishery, black scabbardfish fishery and demersal bottom longline fishery. The latter represents one of the most important fishing activities in the Azores, and frequent elasmobranch by-catches include Raja clavata, Galeorhinus galeus, Deania calcea, D. profundorum, Etmopterus pusillus and E. spinax. A slight reduction in the abundance indices of these species was observed, despite the implemented technical measures (e.g. minimum size, zero catch). Little is known about resource dynamics for the Azorean region and no analytical assessments have been conducted. This study highlights the vulnerability to overfishing of these resources and the urgent need to develop management strategies.     

A comparative study on socio-economic indicators and viability in small-scale fisheries of six districts along the Turkish coast

The study evaluates the status of small-scale fishermen and fishing operations, using socio-economic indicators and economic viability estimates in six selected fishing areas of Turkey during the 2002–2003 fishing season. Fifty-six percent of all small-scale fishing boats investigated achieved a positive net profit, fully recovering their operational and investment costs. Considering the viability of the fishery, 56% can be considered as economically viable. Percentages of negative gross cash flow (GCF) for each of the vessels in the district was 56% in Foça, 57% in Karaburun, 15% in Mordoğan, 16% in Akyaka, 65% in Akçapınar, and 44% in Marmaris. On the other hand, when sustainability is defined with more than an economic performance ratio of 10%, only 41% of the small-scale fishing vessels seem to have shown favourable results. Criteria such as comparatively higher catch, smaller crew size and lower labour costs, structure of the fishery or misreporting might have had a slight role in affecting the overall results which indicate that livelihood and economic viability are threatened by irregular and relatively low income levels in the small-scale fisheries sector. Given the economic conditions of small-scale fishing communities, it is suggested that all persons concerned at the community, industry and government levels should take a fresh look at the problem of sustainability. As such, more attention needs to be paid to the fishery management option by looking at performance data and having long-term monitoring of the socio-economic indicators.     

Determinants of temporal trends in size in vessel-based reporting in the USA Illex illecebrosus fishery

The Illex illecebrosus fishery in the northwestern Atlantic Ocean is a trawl‐based fishery. Illex illecebrosus normally lives <1 year, thus managing the fishery using a standard stock assessment approach is difficult. Real‐time management is an attractive option. The purpose of this study was to investigate the utility of data on size composition reported by commercial vessels for application in real‐time management in the I. illecebrosus fishery. Observations were collected from fish processors for 1996–98 and from fishing vessels directly reporting in 1999–2001. Mean size of I. illecebrosus increased more or less steadily through the fishing season in each year. Apparent growth rates, determined by evaluating the change in mean size in the catch, varied considerably between years. Apparent growth rates appear to be reasonable expressions of true growth rates because either the bulk of the squid entered the fishery at the beginning of the fishery and remained with the fishery for the duration of the season, or the squid on the outer shelf, available to the fishery, represented an emigrated portion of a larger coherent offshore population. Depth exerted only a minor influence on the size of squid caught, whereas the size–frequency varied significantly with latitude. Largest squid were caught at the southern and northern extremes of the study domain. Refrigerated seawater (RSW) trawlers consistently caught smaller squid than did freezer trawlers. The complexity of I. illecebrosus size structure revealed by this study indicates the necessity of obtaining a dispersed data set, in space, with a degree of temporal detail to elucidate trends. Such a data set is conceivably obtainable from fishing vessels reporting information as they fish providing that the sampling design addresses issues concerning the dispersion of vessels across latitude, the appropriate composition of the reporting fleet, and the collection of sufficient observations per tow to adequately resolve the range in size as well as the mean.     

The use of angler diary surveys to evaluate long-term changes in muskellunge populations on Lake of the Woods, Ontario

Reported improvements in the muskellunge angling fishery on Lake of the Woods, Ontario over the last two decades have paralleled an increase in the practice of catch and release angling, and an increase in minimum size regulations for this species. The overall status of muskellunge populations in this large, complex lake has proven difficult to monitor using standard assessment methods. A volunteer muskellunge angler diary program, established in 1988, has provided a cost effective method of gathering a large amount of information with which to track this fishery and associated populations. Results from angling diaries indicated increased angling effort, catch and success rates for muskellunge on Lake of the Woods since the early 1990s. Although the month of July accounted for the majority of angling effort and catch, angling success rates and sizes of fish reported in diaries improved monthly into the late fall. Angling success rates were consistently higher in angling diaries than from creel surveys, but both survey types showed similar long-term trends in the fishery. Angler diary data, incorporating both the numbers of fish caught and/or seen by anglers, were used to calculate catch equality indices which proved to be sensitive to changes in population abundance. Increased minimum length regulations for muskellunge during 1987–2001 have been largely responsible for a decline in harvest rates from an estimated 36% in 1986 to 0% since 1999. Although higher size limits have yet to produce more quality-sized fish in angler catches, diary survey data, supported by recent improvements in catch rates from assessment gill nets, would indicate that muskellunge recruitment has increased. This article concludes with a brief review of how muskellunge angler diary data has been used in the past, including recommendations to minimize biases associated with this survey method.     

ASPECTS OF THE FISHERIES OF LAKE LIAMBEZI,CAPRIVI

SUMMARY

Lake Liambezi, situated in the Linyanti Swamp, Caprivi, is inhabited by 43 fish species. Population estimates with seine nets, rotenone and explosives gave values of 74 to 157 kg ha^?1. The composition of seine net catches differed markedly from gill net catches where non-Cichlids form a majority. Results of a fleet of gill nets show that best catches of 25 kg 50 m^?1 net night^?1 can be made with 60 mm mesh nets, catching predominantly non-Cichlids (Marcusenius macrolepidotus, Schilbe mystus, Synodontis spp.). A small commercial fishery is established on the lake, with 60 active fishermen using large mesh (100–150 mm) gill nets. Their catch consists mainly of cichlids (Sarotherodon andersoni and S. macrochir) and Clarias spp. Production figures dropped from 637 ton in 1973–74 to 115 ton in 1975–76. This drop is ascribed to reduced effort as well as a reduction in catch per unit effort. Recommendations are made to utilise the fishery potential of Lake Liambezi in a more balanced way by introducing small mesh gill nets to harvest non-Cichlid populations.