by K. Hansen, Feb 22, 2022 in WUWT

There have been a couple of mentions of the decline effect over the past month, mostly prompted by a recent paper that appeared in  PLOS BIOLOGY  authored by Jeff Clements, Josefin Sundin, Timothy Clark, and Fredrik Jutfelt titled “Meta-analysis reveals an extreme “decline effect” in the impacts of ocean acidification on fish behavior”.

The subject matter of the paper, examining the decline effect in the field of Ocean Acidification (OA), particularly in studies on the effects of OA on fish behavior, is itself interesting.  I have written about OA and OA science many times here at WUWT.

There are two parts to this story about the decline effect.  1)  The specific case of the decline effect in OA studies claimed in the Clements et al. paper.   2)  The general case of the hypothesized causes of the decline effect in the sciences.

This essay will address the first issue:  the decline effect in OA studies.

The decline effect in OA science:

As for the specific OA case,  part of that story, featured in the Clements et al. paper,  has been well-covered by Steve Milloy at JunkScience in his article “Climate fish scare turns out to be just a fish story”.

There are several obvious potential causes of a decline effect in a field. They are: publication bias, citation bias, methodological bias, and investigator effects. 

As part of the review process of the new Clement et al. paper, each of those potential causes was investigated – and all but one were eliminated as a major cause.  It is that last cause that I write about today.

The missing parts in Steve Milloy’s coverage are something that I have written about before and is left under-said Clements et al. (2022):

First, you may recall that Timothy Clark (one of the co-authors of Clements (2022)) and others wrote a paper bluntly titled: “Ocean acidification does not impair the behaviour of coral reef fishes” published Nature in January 2020.

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