Not to be cited without Ne pas citer sans permission of the authors' autorisation des auteurs ' DFO Atlantic Fisheries MPO Pêches de l'Atlantique Research Document 96/126 Document de recherche 96/126

Status of Atlantic salmon in Salmon Fishing Area 21 , in 1995, with emphasis on the upper LaHave River, Lunenburg Co ., Nova Scoti a

by

,Peter G. Amiro, Eric M. Jefferson and Carolyn J . Harvie Science Branch Department of Fisheries and Oceans P.O. Box 550 Halifax, N.S. B3J 2S7

'This series documents the scientific basis 'La présente série documente les bases for the evaluation of fisheries resources in scientifiques des évaluations des ressources Atlantic . As such, it addresses the halieutiques sur la côte atlantique du issues of the day in the time frames Canada. Elle traite des problèmes courants required and the documents it contains are selon les échéanciers dictés. Les not intended as definitive statements on the documents qu'elle contient ne doivent pas subjects addressed but rather as progress être considérés comme des énoncés reports on ongoing investigations. définitifs sur les sujets traités, mais plutôt comme des rapports d'étape sur les études en cours . Research documents are produced in the official language in which they are provided Les Documents de recherche sont publiés to the secretariat . dans la langue officielle utilisée dans le manuscrit envoyé au secrétariat . 2

TABLE OF CONTENTS ABSTRACT 3 SUMMARY SHEET 4 INTRODUCTION 5

Stocking programs ...... 6 CONSERVATION REQUIREMENTS 6 Above Morgan Falls ...... 6 Other rivers in SFA 21 ...... 6 Conservation requirements for the LaHave River derived from survey data ...... 6 LaHave River above Morgan Falls derived by simulation modeling ...... 7 LaHave River above Morgan Falls derived by stock and recruitment ...... 7 DESCRIPTION OF FISHERIES AND HARVESTS 8 First Nation fisheries ...... 8 Aboriginal Peoples' fishery ...... 8 Angling fishery ...... 8 Commercial fisheries ...... 9 RESEARCH DATA 9 ASSESSMENT METHODOLOGY 10 In-season assessments ...... 10 LaHave River salmon population based on counts at Morgan Falls ...... 10 Egg depositions...... 11 Hatchery-origin smolt return rates ...... 11 Forecasts of counts to Morgan Falls and returns to LaHave River in 1996 ...... 1 1 ASSESSMENT RESULTS 12 In-season assessments above Morgan Falls ...... 12 Estimates of the 1995 total LaHave salmon population calibrated to the 1983 basin-wide population estimate ...... 12 Estimates of returns and spawners to eleven other rivers in SFA 21 ...... 12 Estimated escapement and egg deposition above Morgan Falls in 1995 ...... 13 Estimated egg deposition to LaHave River in 1995 ...... 1 3 HATCHERY-ORIGIN SMOLT RETURN RATES 13 FORECAST COUNTS AT MORGAN FALLS FOR 1996 13 CONCERNS OF ADVISORY COMMITTE E 14 SOURCES OF UNCERTAINTY IN THE ASSESSMENT 15 ECOLOGICAL CONSIDERATIONS 16 LITERATURE CITED 18 3

Abstract

The status of Atlantic salmon spawning escapements for the LaHave River above Morgan Falls relative to conservation objectives, descriptions of fisheries, forecasts for 1996, trends in marine survival of hatchery-origin fish and issues of the Zone 21 Management Advisory Committee are presented. The status of stocks in other rivers of SFA 21 is inferred from reports of recreational catch statistics and a distribution of probable angling exploitation rates estimated for the LaHave River. Conservation requirements for LaHave River above Morgan Falls and the entire catchment basin are reviewed using remote-sensed estimates of habitat, published estimates of habitat, stock and recruitment analysis and the results of a life history process model for the river.

Egp deposition above Morgan Falls in 1995 was 76% of the 1995 conservation objective of 1 .96x10 . The modal deposition for the entire LaHave River basin was 104% of the 1995 basin-wide required conservation deposition of 3 .86x106 eggs . The most probable pre-fishery abundance for eleven other rivers of