Methods for assessing the vulnerability of African fisheries resources to climate change

Abstract

Because of the dietary and financial importance of fisheries resources in many African countries, concerns have been expressed regarding the potential for adverse impacts to fisheries resources from clunate change, and a need has been ~dentified for assessment tools that can evaluate the potential for impacts in a timely and cost-effective manner. This paper presents a framework and set of methods for assessing the potential effects of climate change on fisheries resources in Africa. The framework identifies the need to first link predicted climate changes to changes in the aquatic environment, and only then can potential impacts to aquatic resources be evaluated. The approach developed for Africa was constrained by several factors, including availability of existing data and assessment technologies, and the need for a rapid evaluation of potential climate impacts. The assessment approach employs a variety of methods including empirical models which predict changes in mortality, maximum sustainable yield, and yearly catch, a bioenergetics model, and a habitat suitability model. Previously developed or newly derived site-specific empirical models can be used to compare mortality, yield, and annual catch estimates among historic, current, and predicted climate conditions. Similarly, bioenergetics modeling can be used to compare growth rates and biomass production among different climate conditions. Habitat suitability models can be developed for current climate conditions, and the effects of changes in climate-driven habitat variables such as water depth, temperature, and current veloc~ty on habitat suitability can be evaluated for different climate conditions. Use of these approaches is recommended because they can utilize existing ecological data and do not require extensive new data collection activities, they are not technologically complex, and they can provide evaluations of potential climate change impacts in a timely and cost-effect~ve manner.

Trophometric index: a predictor for fish density, biomass and production in Mediterranean reservoirs in Spain

“…Fishery production indices proved to be very useful tools for the management of fisheries in a large number of aquatic environments. However, they have not only proved useful in fisheries but also in studies related to the growth of species (Wilde & Muoneke 2001) or climate change (Schlesinger & Regier 1982; Schlesinger & Regier 1982; Hlohowskyj, Brody & Lackey 1996). In the case of the Spanish reservoirs, there are no fisheries associated with these systems, as, for socio‐cultural and historical reasons, they have no economic value, unlike fisheries of marine species.…”

Climate change and freshwater fisheries

“…The implications of climate change for fisheries has been examined particularly thoroughly in marine systems, and this is reflected in a strong bias to marine fisheries in the climate change literature (Hennessy et al, 2007). There is a large and growing literature, however, on the probable impacts of climate change on freshwater ecosystems (George, 2010;Kernan et al, 2010;Goldman et al, 2013) and fishes, with numerous reviews (Magnuson & Destasio, 1997;Ficke et al, 2007; focusing on a range of different geographical locations (McDowall, 1992;Hlohowskyj et al, 1996;Meyer et al, 1999;Schindler, 2001;Mooij et al, 2005;Graham & Harrod, 2009;Thieme et al, 2010;Bell et al, 2011;Koehn et al, 2011;Pratchett et al, 2011;Goldman et al, 2013), habitat types (Carpenter et al, 1992;Xenopoulos et al, 2005;Caissie, 2006;Jeppesen et al, 2010a;Schneider & Hook, 2010;Dell et al, 2013;Dokulil, 2013), biomes (Filipe et al, 2012;Reist et al, 2006a, b) or particular life history strategies, e.g. diadromous taxa (Bryant, 2009;Lassalle & Rochard, 2009).…”

“…As generally seen in the literature (Kundzewicz et al, 2007), there is an extreme bias towards studies from temperate North America and Europe Vincent et al, 2013). There are very few reliable data from the southern hemisphere (Welcomme et al, 2010; or the productive and speciose tropics (Hlohowskyj et al, 1996).…”

“…Climate change and its impacts on freshwater fishes and fisheries have been discussed by fish biologists for almost four decades (Meisner et al, 1987;DeAngelis & Cushman, 1990;Magnuson et al, 1990;Meisner, 1990;Shuter & Post, 1990;Tonn, 1990;Maitland, 1991;McDowall, 1992;Hlohowskyj et al, 1996). Its importance is officially recognized: statutory agencies across the world include climate change as a principal area of concern, while international and national funding agencies increasingly support research into climate change.…”

Ecosystem vulnerability to climate change: a literature review

“…Consequently, a large number of studies have attempted to quantify ecosystem vulnerability, in a wide range of ecological settings and using a wide range of different methodologies (e.g. Hlohowskyj et al, 1996;Strzepek et al, 1996;Hurd et al, 1999;Lassiter et al, 2000;Johnson et al, 2005). Many studies have also provided qualitative evaluations of vulnerability to climate change (e.g.…”