I would have answered that question with "most" or "all."
Even if there were no substantial efforts at population recovery or
enforcement, the very "listing" of a species ensures some benefits.
Environmental impact studies, necessary for any private development or civil
works projects, address status and protection of any threatened or endangered
species ("TES") and frequently influence engineering alternatives of a
project (with less "practical" but more "benign" alternatives being
implemented for the conservation of the local TES). Also, "listing" makes a
species more attractive for funding and for research (with substantially
greater efforts directed towards a species AFTER they are listed as a TES).
Species benefit when they are better-studied and better-understood.
If you do not believe that the ESA helps TES then you should read this paper:
Miller, R.R., J.D. Willliams, and J.E. Williams. 1989. Extinctions of North
American fishes during the past century. Fisheries 14(6): 22-38. Unless my
math is off, it shows that the overwhelming majority (80%) of the fish
species that have gone extinct in North America did so prior to the ESA. I
do not know exactly how many listed fishes have gone extinct since 1973 but I
know that its not very many.
Also - do a literature search on the TES of your choice and see how many
species-level studies were conducted before and after their date of listing.
I know that for Topeka shiner and pallid sturgeon, there were a paucity of
field studies before their listings and a flurry of work immediately prior to
and afterwards.
- Jan Hoover
Vicksburg, MS
-
/-----------------------------------------------------------------------
/ This is the discussion list of the North American Native Fishes
/ Association (NANFA). Comments made on this list do not necessarily
/ reflect the beliefs or goals of NANFA. For more information about NANFA,
/ visit http://www.nanfa.org Please make sure all posts to nanfa-l are
/ consistent with the guidelines as per
/ http://www.nanfa.org/guidelines.shtml To subscribe, unsubscribe, or get
/ help, visit the NANFA email list home page and archive at
/ http://www.nanfa.org/email.shtml