Drought is a major limiting abiotic stress influencing wheat production in
many parts of the world. The erratic nature of water deficits makes breeding
and selection for drought resistance deficient. In environments with late
season drought stress, yield losses are usually associated with kernel abortion
or reduction in kernel growth....
Genetic resistance is the most appropriate way to control diseases in crop plants.
Resistance can be described as qualitative (involving a gene-for-gene system) or
quantitative (with continuous distribution of disease levels). The relationships
between different types of resistance remain obscure, as does the genetics of
quantitative traits. The use of...
Samples of weathervane scallops taken on Oregon Department of
Fish and Wildlife cruises off Oregon waters during 1981-1982 were
analyzed for a comparative growth study. No evidence of internal
growth marks were found in the shell structure when analyzed by the
acetate peel technique. Internal growth lines formed in the...
The evolution of oceanographic conditions in the upwelling region off northern Chile
(18°–24°S) between 1996 and 1998 (including the 1997–1998 El Niño) is presented using
hydrographic measurements acquired on quarterly cruises of the Chilean Fisheries Institute, with
sea surface temperature (SST), sea level, and wind speeds from Arica (18.5°S), Iquique...
We present the evolution of oceanographic conditions off the western coast of South America between 1996 and 1999, including the cold periods of 1996 and 1998–1999 and the 1997–1998 El Niño, using satellite observations of sea level, winds, sea surface temperature (SST), and chlorophyll concentration. Following a period of cold...
To date, the use of oceanographic data in fisheries management has been limited by
the scarcity and the difficulty of accessing complete oceanographic datasets.
Consequently, fish stocks are managed with limited knowledge about the habitat where
fish live and incomplete understanding of what oceanographic conditions affect their
populations. With the...
Until the 1930s, flows of the Colorado River maintained approximately
781,060 hectares of wetlands in its delta. These wetlands provided important feeding
and nesting grounds for resident and migratory birds as well as spawning and
protection habitat for many fish and other invertebrate species. However, the Delta's
wetlands started to...
Setting aside the traditional simplistic “tragedy of the commons” notion, fisheries crises observed in the Northern Atlantic may be seen as the result of “mismatches” in the decision making process. The collapse of two fisheries, Atlantic Cod (Gadus morhua) in Canada and European Hake (Merluccius merluccius) in Europe, illustrate the...