%0 Journal Article
%T Density-Dependent Effect Occurs Regardless of Density
%A Kazumi Sakuramoto
%J Open Access Library Journal
%V 3
%N 11
%P 1-11
%@ 2333-9721
%D 2016
%I Open Access Library
%R 10.4236/oalib.1103112
%X <div style="text-align:justify;">
	<span style="line-height:1.5;">Maximum sustainable yield (MSY) is the most
important concept in fisheries resource management. MSY can be established
based on the concept of the density-dependent effect. However, the concept that a density-dependent effect controls
the fluctuation of the population living in the ocean is controversial. This
paper discusses the validity of the density-dependent effect focusing on the
stock-recruitment relationship (SRR). In many cases, the SRR shows a clockwise
or ant-clockwise loop. If we try to explain the population fluctuations using
the density-dependent effect, the clockwise or anti-clockwise loop observed in
SRR cannot be explained. However, the mechanism proposed here can well
reproduce the phenomena observed in many SRR including the clockwise or
anti-clockwise loop. In other words, the most important relationship between
stock and recruitment is likely to be the interspecific relationship and/or environmental
conditions, not the density-dependent effect. If the density-dependent effect
observed in SRR is not real, then the MSY theory is not valid, and all the
management procedures based on MSY would also not be valid.</span> 
</div>
%K Stock-Recruitment Relationship
%K Density-Dependent Effect
%K MSY
%K Pink Salmon
%U http://www.oalib.com/paper/5275534