Subject: abstract - cetaceans and trawls (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Thu, 30 Apr 1998 09:58:23 -0400 (EDT) 

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---------- Forwarded message ----------
Date: Tue, 28 Apr 1998 12:29:22 -0400
From: Dagmar Fertl <Dagmar_Fertl@mms.gov>
Reply-To: Marine Mammals Research and Conservation Discussion
     <MARMAM@UVVM.UVIC.CA>
To: MARMAM@UVVM.UVIC.CA
Subject: abstract - cetaceans and trawls

     Fertl, D.* and S. Leatherwood. 1997.  Cetacean interactions with
     trawls: a preliminary review.  _Journal of Northwest Atlantic Fishery
     Science_ 22: 219-248.

     *mailing address:  Minerals Management Service, U.S. Dept of Interior,
     1201 Elmwood Park Blvd, New Orleans, LA 70123, USA

     Cetaceans interact with trawls to an undetermined extent.  A
     preliminary review of global data indicates that individuals of 25
     cetacean species (two mysticete, 23 odontocete) have been documented
     to have died in working trawls or discarded trawling gear.  Cetacean
     interactions with trawls are complex, in part because both fishermen
     and cetaceans are drawn to areas of high prey density.  Furthermore,
     within such areas, cetaceans are probably often attracted to trawling
     activities because they make it easier for the animals to exploit a
     concentrated food source.  Individuals of 15 (possibly 16) cetacean
     species (13 odontocete, and one or even two mysticete) have been
     reported to feed in association with trawls.  Animals follow working
     nets (feeding on stirred-up organisms or fish gilled in mesh) and also
     feed on discarded bycatch.  Damage to gear as a result of feeding
     interactions or entanglement has been reported.  Such damage results
     in (1) harm to the animals, (2) creation of negative opinions of
     cetaceans by fishermen (regardless of whether a cetacean or a shark
     is, in fact, responsible for the damage in question), and (3) loss of
     time and money for repair and replacement of gear.  The relationships
     of cetaceans with trawls need to be further studied to determine what
     effects the trawl fisheries have on the ecology and population status
     of the whales and dolphins involved.