NE Regional Cod Tagging Program - Why we need your tags.....

The primary scientific goal of the Northeast Regional Cod Tagging Program was to tag and release 100,000 Atlantic cod throughout the Gulf of Maine and neighbouring Canadian and New England waters, with the aim of improving our understanding of cod movements in the region.

The first part of this goal has been achieved! Through the hard work of over 250 fishermen working with ~25 scientists, we have exceeded our milestone by tagging >114,000 cod. However, the ultimate ability of this Program to provide reliable information on the movement patterns of cod is solely dependant on the continued support of the region’s fishermen by continuing to report recaptures of these tagged fish.

Tag returns from this Program, though low, have risen steadily over the months. These returns are already providing us with valuable information, but the more returns that are reported, the more accurate future analysis and conclusions will be.

At present, there is considerable variation in the number of tags reported from each region and this variation does not necessarily reflect cod abundance or fishing effort for these areas. As such, the current data could mis-represent the movement which is actually occurring. For example, the number of tags released by our Canadian partners for this Program is ~5,600, which is ~5.6% of the total tag releases. However, Canadian fishermen and processors have reported ~15% of the total number of tag returns and their information shows a strong movement of cod from Georges Bank into the Bay of Fundy and other Maritime waters. In contrast, fewer tag returns to date show a southerly movement into American waters. While this data could reflect the true primary direction of movement, it may also be an artefact of greater willingness of Canadians to report tags (and/or less willingness of Americans to report tags). It is important for fishermen who are sceptical about this Program and how its data will be used, to understand that skewed data will only compromise the accuracy of the final result, which in the long run, will not best serve the fishery.

• This data is not intended to estimate stock abundance, but it will provide valuable information on how the cod stocks move, mix and grow.

• The higher the number of tags reported, the more representative and accurate, the data.

• Certain biological data collected through this Program (e.g. growth information) can supplement the data used in current cod biological assessments, and should help verify or improve the accuracy of these calculations.

• Skewed data, due to reluctance to return tags from different fishing regions and gear types, could jeopardize the integrity of the data obtained, and could lead to mis-representative conclusions.

• Around 250 fishermen have worked on this highly collaborative Program, and it would be rewarding for them to see good results and science come out of their efforts.

• Many fishermen have expressed an interest in seeing more advanced tagging techniques (e.g. acoustic and data storage tags) being used. However, unless we begin to see an increase in tag-return rate, it would be difficult to justify funding such a study, since these techniques are more expensive and often require the fish to be recovered for data-download. If tagged fish are not returned, this data is lost.

We thank those of you who have diligently returned tags for the duration of this Program - your input has been greatly appreciated. We hope that you will continue to report recapture information, and please also encourage your colleagues to do so. We look forward to receiving tagged cod returns during 2006 and beyond.