Search bioRxiv⌕ Search

Biology subjects

Leisher, C.

Publications and source records attributed to Leisher, C..

2 recordsLinked to original sources

Ranking the direct threats to biodiversity in sub-Saharan Africa

Sub-Saharan Africa benefits from large investments in biodiversity conservation, yet there is no prioritization of the many direct threats to biodiversity available to inform organizations developing sub-Saharan or sub-regional conservation strategies. Consequently, regional investments by funders of biodiversity conservation such as international conservation organizations, foundations, and bilateral and multilateral donors may be suboptimal. To identify the priority threats to biodiversity in sub-Saharan Africa, we classified the direct threats to biodiversity using standardized threats categories and triangulated data from a Delphi consensus of sub-Saharan Africa biodiversity experts, known threats to IUCN Red-listed sub-Saharan African species, and National Biodiversity Strategy and Action Plans from 47 sub-Saharan African countries. After ranking the threats from each source and averaging the rankings, we find that the highest threats are: annual and perennial crops (non-timber); logging and wood harvesting (natural forests); fishing and harvesting aquatic resources (marine and freshwater); and hunting and collecting terrestrial animals. Within the sub-regions of sub-Saharan Africa there is considerable variation. The highest ranked threat in Central Africa is hunting. In East Africa, it is agriculture. In Southern Africa, it is invasive non-native/alien species, and in West Africa, agriculture and logging are tied as the highest threats. There are known ways to address all of these threats, and concentrating investments on these threats while accounting for unique socio-ecological contexts across sub-Saharan Africa is essential for the sustained conservation of biodiversity.

ecology↗

Adoption and consequences of new light-fishing technology (LEDs) on Lake Tanganyika, East Africa

Maintaining sustainable fisheries requires understanding the influence of technological advances on catch efficiency. Fisheries using light sources for attraction could be widely impacted by the shift to light emitting diode (LED) light systems. We studied the transition from kerosene lanterns to LED lamps in Lake Tanganyika, East Africa, examining factors that led to adoption as well as the impact of the new light sources on fish catch and composition. We used a combination of field experiments with catch assessments, fisher surveys, underwater light spectra measurements, and cost assessments to evaluate the impact of switching from kerosene to LED lamps. Overall, we found a very rapid rate of adoption of homemade outdoor LED light systems in Lake Tanganyika. Most of the batteries used to power these lamps were charged from the city power grid, rather than photovoltaic cells. The LED light spectra was distinct from the kerosene light and penetrated much deeper into the water column. Regardless of light type, most of the fish caught within the two dominant species were below maturity, indicating that current fishery is not sustainable. Although the LED lamps were associated with a slight increase in catch, environmental factors, particularly distance offshore, were generally more important in determining fish catch size and composition. The main advantages of the LED lamps were the lower operating costs and their robustness in bad weather. Overall, the use of battery-powered LED lighting systems to attract fish in Lake Tanganyika appears to reduce economic costs but not contribute new impacts on the fishery.

scientific communication and education↗