Return-Path: <WHE_WILLIAM@flo.org> Received: from flo.org by VMSVAX.SIMMONS.EDU (MX V3.1C) with SMTP; Tue, 24 May 1994 08:21:04 EDT Date: Tue, 24 May 1994 8:24:50 -0400 (EDT) From: WHE_WILLIAM@flo.org To: email@example.com Message-ID: <firstname.lastname@example.org> Subject: Minke population in No. Atlantic From: SMTP%"MARMAM@UVVM.BITNET" 23-MAY-1994 18:48:53.75 To: WHE_WILLIAM CC: Subj: Minke Whale population Date: Mon, 23 May 1994 20:40:59 BST Reply-To: Marine Mammals Research and Conservation Discussion <MARMAM@UVVM.BITNET> Sender: Marine Mammals Research and Conservation Discussion <MARMAM@UVVM.BITNET> Comments: Warning -- original Sender: tag was rbaird@SOL.UVIC.CA From: Michael Halford <email@example.com> Subject: Minke Whale population X-To: firstname.lastname@example.org X-cc: email@example.com To: Multiple recipients of list MARMAM <MARMAM@UVVM.BITNET> IFAW Technical Briefing 94:8 May 1994 How Many Minke Whales in the Northeast Atlantic? SUMMARY Dr Justin Cooke has presented to the Scientific Committee a re-analysis of some of the Northeast Atlantic minke whale sightings data obtained by Norwegian scientists. If Cooke is right there are about 53,000 minke whales in the Northeast Atlantic, not 87,000 as claimed by Norwegian scientists. Calculation of a catch limit from each of these numbers leads to very different results; about 250 animals from the Norwegian estimate close to zero from Cooke's. Cooke has calculated a new value for g(0), a critical number used in the calculations which lead to population estimates. g(0) is a measure of the chance that a whale on the track of the survey vessel will be seen. It can range from zero to one. If all whales present are seen then g(0) = 1. If g(0) is 0.5 then the raw estimate is doubled. Cooke's best estimate is 0.59, compared with the earlier Norwegian estimate of 0.36. The difference between the estimates of g(0) arises mainly from differences in numbers of whales identified as duplicates [ie the same whale seen by different observers] in the data from experiments carried out especially to estimate g(0). Discrepancies arise from a combination of poor specification of criteria for such identifications, subjective judgements that cannot be reproduced, inadequate specification of their methods by Norwegian scientists. It seems that the Norwegian scientists were careless in their analyses of their own data in that they missed many duplicates. It also seems that the majority of the Scientific Committee acted irresponsibly in uncritically 'accepting' the Norwegian analyses in 1992, and in not attempting to verify them in 1993. While the RMP itself may be a finely tuned and exhaustively tested instrument, the casual approach that the Scientific Committee appears to have taken in advising how it might be implemented (should the Commission so decide) clearly leaves much to be desired.