A method for detecting and identifying the lethal environmental factor on a dominant macrobenthos and its application to Lake Shinji, Japan

Abstract

Abstract.A new method to single out the environmental factor limiting the life of any macrobenthic animal under stressed condition is proposed. The method is based on the assumption that the influence of each environmental factor on the life of a species can be expressed by an S-shaped function having lethal, limiting and non-limiting ranges, and the combined effect of several environmental factors is expressed by a multiple of these functions. To single out a lethal factor, we used the cumulative curve of abundance arranged in the order of each environmental factor. Comparison of these curves enables us to identify the most effective environmental factor limiting the life of a particular species and determine its effective range. Determination can be made from a single field observation without recourse to specially prepared experimental data if a sufficiently extensive survey was made in a field observation.

Analysis of the dynamic characteristics of seawater intrusion using partial wavelet coherence: a case study at Nakaura Watergate, Japan

“…The Hii River at the west end of Lake Shinji supplies this coupled brackish lake system with most of its fresh water. Lake Shinji is a oligohaline lake with average salinity between 1 and 6 psu (Yamamuro et al 1990). Lake Nakaumi has a strongly differentiated twolayer system, salinity of the surface water is 14-20 psu and that of the bottom layer is 25-30 psu.…”

Experimental exclusion of the burrowing crab Macrophthalmus japonicus from an intertidal mud flat: effects on macro-infauna abundance

“…The spatial distribution of the estuarine macrozoobenthos is considered to respond to environmental variables such as salinity (Sanders et al 1965, Yamamuro et al 1990, Teske & Wooldridge 2003, sediment grain size (Yamamuro et al 1990, Teske & Wooldridge 2003, and sediment redox conditions (Gamenick et al 1996, Kanaya & Kikuchi 2008. Peterson (1977) showed that interspecific interactions, too, are important factors, and trophic relations (including competition for food and predator-prey relationships), are among the most important (Gray & Elliot 2009a).…”