Tropical river fisheries valuation: background papers to a global synthesis

This report is a compilation of five regional reviews that document the global status of tropical rivers and inland fisheries in three continents: Latin America, Africa and Asia. It explores the role of ‘valuation’ methods and their contribution to policy-making and river fishery management. From the compilation, the best estimate of the global value of inland fisheries for those three continents is US$ 5.58 billion (gross market value), which is equivalent to 19 percent of the current value of annual fish exports from developing countries (US$ 29 billion) for 2004. The compilation shows that there is a general shortage of information on inland fisheries, especially derived from conventional economic valuation methods, though information from economic impact assessment methods and socio-economic and livelihood analysis methods is more widely available. The status of knowledge about the impact of changes in river management on the value of tropical river fisheries is weak and patchy. Although the impacts of large dams on the hydrology, ecology and livelihood support attributes of tropical rivers are well-recognized, there have been only few valuation studies of these issues. The document highlights the need for further valuation studies of tropical river and inland fisheries in developing countries. It underlines how vital it is for policy-makers and other stakeholders to understand the importance of these natural resources in order to make appropriate decisions concerning their role in development policy and illustrates why capacity building in valuation should become a major priority for agencies concerned with fisheries management and policy-making.

Review of river fisheries valuation in tropical Asia

This study attempts to estimate the economic value of riverine fisheries in tropical Asia and quantify the economic impacts of any changes to the environment that affects rivers and hence fisheries. The value of riverine fisheries has been considered in the following two ways: firstly, through a compilation and summary of the results of existing studies on this topic; secondly, by estimating the direct use value of riverine and floodplain fishing by country using quantities and freshwater fish prices derived from various sources. Furthermore, a review of the characteristics of the fisheries is presented. These fisheries have been shown to be valuable (i.e., economically or socially important) in at least two specific ways: as a generator of commercially marketable output, and as a source of income and employment in relatively impoverished communities.

The valuation of riparian fisheries in Southern and Eastern Africa

This paper reviews the published and gray literature concerning economic valuations of river fisheries in eastern and southern Africa, extracting the best available information on their direct economic values and on the impacts of changes in water management on this value. It then assesses the methods used and makes recommendations regarding approaches to be used in future. The review concentrates on rivers with their associated floodplains and major deltas. The values and issues associated with estuaries and lakes are not considered.

Review of river fisheries valuation in West and Central Africa

This paper provides a review of the valuation of river fisheries in West and Central Africa. It is the general perception that, compared to the biological and ecological aspects of river fisheries, this particular subject area has received relatively little attention. Economic valuation is concerned with finding expression for what is important in life for human society. It should, therefore, be a central and integral part of government decision-making and policy. The review started with concepts and methods for valuation. Three main types of valuation techniques were identified: conventional economic valuations, economic impact assessments and socioeconomic investigations, and livelihood analysis. On the basis of a literature review, valuation information was then synthesized for the major regional river basins and large lakes, and also used to develop a series of national fisheries profiles. To supplement this broad perspective, a series of case studies are also presented, which focus in particular on the impact of changes in water management regime. Finally, the paper presents an assessment of the three main types of valuation methodology and a set of conclusions and recommendations for future valuation studies.

Review of river fisheries valuation in Central and South America

Unlike Africa and Asia, where a large part of the population are heavily dependent upon fishing for their livelihoods, fishing for a living in the interior of Central and South America (CSA) remains a marginal occupation for all but the most isolated of families. As such, the economics and management of fisheries on the continent have received little attention from within the continent and the rest of the world. This study shows that while a number of studies have been carried out on fishing in the region, they tend to be limited in their geographical focus and time scale. Although fishing of freshwater species may appear to be comparatively insignificant in the region, the rivers of CSA are very important. This report attempts to analyze the literature available on CSA river fisheries and attempts to draw out an economic value of these fisheries. It is divided into a number of sections. First, the authors describe the major river basins on the continent, characterize their fisheries, and place freshwater fisheries in CSA into a global context. Second, the authors provide a review of valuation techniques for fisheries and use this analytical framework to review the principal literature on freshwater fisheries in the region. Then they turn their attention to the economic impact of dams and water abstraction schemes, reviewing the available literature to ascertain how/if economic values are computed for the impact on fisheries. Finally, they offer some conclusions and recommendations on the direction for future studies of freshwater fisheries in CSA.

Recreational anglers' valuation of near-shore marine fisheries in Florida

This report describes and summarizes the results from a state-wide survey of Florida resident saltwater anglers. The survey was designed to provide estimates of the economic value anglers place on marginal changes in management of selected near-shore marine species. The Contingent valuation method was used to elicit angler willingness to pay for changes in management for redfish, seatrout , mullet, sheepshead, pompano. and king mackerel. Contingent valuation is a process in which respondents are presented with a detailed scenario that describes an opportunity to express their willingness to pay for a proposed change in current conditions. The process consists of three parts. First. the change in current conditions, or the "good" to be valued is described. Second, the payment method is described. The payment method is usually closely related to typical methods of buying goods similar to the one to be valued. Finally. the respondent is asked how much they would pay for the good described in the scenario. A special saltwater fishing license stamp that would allow the holder to take advantage of the described management change was used as a payment mechanism. (PDF contains 147 pages.)

Coastal resource planning system: Integrating evaluation of ecological integrity and ecosystem services valuation

Efficient and effective coastal management decisions rely on knowledge of the impact of human activities on ecosystem integrity, vulnerable species, and valued ecosystem services—collectively, human impact on environmental quality (EQ). Ecosystem-based management (EBM) is an emerging approach to address the dynamics and complexities of coupled social-ecological systems. EBM “is intended to directly address the long-term sustainable delivery of ecosystem services and the resilience of marine ecosystems to perturbations” (Rosenberg and Sandifer, 2009). The lack of a tool that integrates human choices with the ecological connections between contributing watersheds and nearshore areas, and that incorporates valuation of ecosystem services, is a critical missing piece needed for effective and efficient coastal management. To address the need for an integrative tool for evaluation of human impacts on ecosystems and their services, Battelle developed the EcoVal™ Environmental Quality Evaluation System. The EcoVal system is an updated (2009) version of the EQ Evaluation System for Water Resources developed by Battelle for the U.S. Bureau of Reclamation (Dee et al., 1972). The Battelle EQ evaluation system has a thirty-year history of providing a standard approach to evaluate watershed EQ. This paper describes the conceptual approach and methodology of the updated EcoVal system and its potential application to coastal ecosystems. (PDF contains 4 pages)

Burrowing behaviour of signal crayfish, Pacifastacus leniusculus (Dana), in the River Great Ouse, England

Observations were made on crayfish burrows in five locations on the Great Ouse River. The burrow densities and the relative abundance of crayfish were observed. Also, laboratory experiments were carried out in order to study the characteristics and mechanisms of burrowing.

Observations on the behaviour of Polyphemus pediculus and functions of its extremities in the process of feeding. [Translation of: Materialy po biologii i gidrologii Volzhskikh vodokhranilishch, pp. 13-16. Moscow, 1965]

The author summarises observations on the behaviour of Polyphemus pediculus and functions of its extremities in the process of feeding. The crustacean Polyphemus pediculus seizes its prey, kills it and pulverises its food with the help of its extremities. Therefore for a study of its feeding method was necessary not only to have been acquainted in detail with the structure of its extremities, but also to have observed their interaction for the accomplishment of the stated functions.

Behaviour and mechanism of feeding of Lathonura rectirostris (Cladocera, Macrothricidae). [Translation from: Zoologicheskie Zhurnal 50, 1002-1010, 1971.]

The behaviour in the feeding process and the functional morphology of Lathonura rectirostris O.F. Muller - one of the widely distributed species of macrothricids - is studied. The current work is an attempt at morpho-functional analysis of the apparatus of the trunk appendages of Lathonura rectirostris O.F. Muller. This highly specialized species, the method of feeding of which basically comes to the mechanical scraping-off and collection of epiphytic single-celled algae and particles deposited on the surface of aquatic plants.

Some data on the predacious behaviour of tendipidae larvae [Translation from: C. R. Acad. Sci. U.R.S.S. 111, 466-4, 1956]

A study has been made primarily of the food of the chironomid Procladius nigriventris: this includes Alona affinis, Bosmina coregoni, Camptocercus, Eucyclops serrulatus, Paracyclops fimbriatus, Acanthocyclops viridis, Harpacticoida, Diaptomus graciloides, Ostracods, Chironomus sp, Polypedilum sp and Tanytarsus sp. Chironomus larvae usually found in the gut are in their 1st or 2nd instars , though occasional 3rd instars are present. The study summarises other findings on the feeding behaviour of Procladius nigriventris.

Some observations on the behaviour of plankton in waters discharged by the lakes [Translation from: Ost.bot.Zeit 103(1), 98-109, 1955]

This information is based on the limnological observations of the very interesting and remarkable discharge of the Lunzer Obersee, (1117m). On journeying towards the Mittersee, the Lunzer Obersee discharge takes on all the characteristics of spring-water; it was found to be of interest to take note of the change of the composition of the water on those stretches of the course where it flows shows the ground. For this purpose it was necessary to take temperature-recordings, chemical examination of the water and a quantitative determination of the plankton. Samples were taken in 1954 of zooplankton at different times of the year at the discharge of the lake and analysed. The significant loss of organisms in the way of discharge is discussed.

Évaluation de la production primaire et de la chlorophylle à partir des données hydrologiques. Application au Golfe de Guinée

Quantitative relationships between nitrate distribution, chlorophyll and primary integrated values have been used to evaluate the phytoplankton abundance in the Gulf of Guinea. Data of Guinee I cruise (May-July 1968) of the R.V. Jean Charcot have been used. They show a large oligotrophic convergence area (< 250 mg C/m2/J). A relationship previously found between the depth of the nitracline (first level where the nitrate appears) and the depth of the thermal maximum gradient is confirmed. From a practical point of view, this relationship is very useful since it allows, when the biological or chemical data are not available, a rough estimation of phytoplankton integrated biomass and production in the water column, from a temperature profile.

Résultats du groupe de travail FAO/COPACE sur l'évaluation des stocks démerseaux côtiers du secteur Côte d'Ivoire - Congo

The exploitation rate of demersal stocks in the Côte d'Ivoire-Congo area is in most cases below the level permitting maximum sustainable yield. Any increase in total catch would be achieved through an increase in catch per effort which implies bigger mesh sizes than those in use now (40-45 mm). A first step would be to fix the minimum legal mesh size to 60 mm. New, probably limited resources (crab, squids, benthic sharks) are to be sought along the continental slope.