Base de données de recherche des TNO

Régions: Gwich'in Settlement Area

étiquettes: biology, fisheries assessment

Objectif(s): The objective of this project is to assess the fish population of Travaillant Lake. Once in the summer and again during the fall, field crews will use experimental gill nets with varying mesh sizes to capture a representative sample of species and sizes within species in Travaillant Lake and at two locations in the Travaillant River.

Description du projet: The objective of this project is to assess the fish population of Travaillant Lake. Once in the summer and again during the fall, field crews will use experimental gill nets with varying mesh sizes to capture a representative sample of species and sizes within species in Travaillant Lake and at two locations in the Travaillant River. The lake sampling site will be located on the southwest shore of Travaillant Lake, and the river sampling sites will be located north of Travaillant Lake in the Travaillant River, and in the Travaillant River south of the lake between Travaillant Lake and Andrew Lake. The Travaillant Lake system, located entirely within the Gwich’in Settlement Area (GSA) is one of the most culturally and traditionally important areas within this region. In recent years, in light of proposed industrial development and exploration that may threaten the aquatic environment within this system, Travaillant Lake has become a focus of fisheries related studies which have attempted to collect information on biological characteristics, vital rates and document life history traits of important subsistence fish species within this system. The main objectives of this study are to determine baseline population status and develop reliable indicators of population abundance and mortality rates of key harvested fish species (lake whitefish and broad whitefish) in the Travaillant Lake system and to identify and determine the relative abundance and species composition of other species within the lake system. With future monitoring, such information will allow us to detect subsequent changes that may occur from changes in harvest levels and environmental disturbance in relation to proposed pipeline development in this region of the north. This study was initiated in 2004 and is proposed to be carried out over a minimum of 3 years in order to obtain reliable estimates of population abundance and mortality. Field crews will be transported to Travaillant Lake and/or the Travaillant River via float plane (July) and helicopter (October). For stock assessment purposes, experimental gill nets with varying mesh sizes (1-inch to 5.5-inches) will be used to capture a representative sample of species and sizes within species within Travaillant Lake and at two locations in the Travaillant River. Captured fish will be sampled and the following biological characteristics will be recorded: fork length (±1 mm), round weight (± 50 g), gonad weight (± 0.1 g), sex and maturity. In addition, tissue samples will be removed and archived for contaminant and or genetic analysis. Data will be analyzed to determine age and length frequencies, age at maturity, size at maturity, growth, mortality and fecundity. When fishing, sampling effort (soak time of experimental gill nets) will be recorded in order to estimate relative abundance through the calculation of catch per unit effort (CPUE). In total, the following sample sizes can be expected: broad whitefish (Coregonus nasus) – 750 specimens; lake whitefish (Coregonus nasus) – 750 specimens; cisco species (Coregonus spp.) – 200 specimens; northern pike (Esox lucius) – 45 specimens; lake trout (Salvelinus namaycush) – 50 specimens; inconnu (Stenodus leucichthys) – 5 specimens. Reports will be prepared and distributed to the RRCs (Gwich'in). Results will also be communicated at RRC meetings and GRRB board meetings. Fieldwork will be conducted from July 6 to August 15, 2007 on the southwest shore of Travaillant Lake; north of Travaillant Lake in the Travaillant River, and in the Travaillant River south of the lake between Travaillant Lake and Andrew Lake.