Terms of Reference

Assessment of Arctic Char in the Darnley Bay area of the Northwest Territories

Regional Peer Review – Central and Arctic Region

February 6-7, 2014
Winnipeg, MB

Chairperson: Margaret Treble

Context

Anadromous Arctic Char (Salvelinus alpinus) are an important subsistence resource for the residents of Paulatuk, NT, with the majority of the harvest occurring in the marine waters along the eastern shores of Darnley Bay during the summer. Arctic Char from the Hornaday River are the most important stock for Paulatuk harvesters, and harvests traditionally occurred at the mouth of the river during the char’s upstream migration in August. A decline in the char harvests in this area prompted the establishment of the Hornaday River Char Monitoring Program in 1990. Two harvesters from Paulatuk collect harvest, catch-effort and biological data from the fishery during August. The program has occurred annually since its inception and the data are used to examine evaluate stock status and trends, including relative abundance and population demographics. The last formal stock assessment was conducted in 1999, incorporating monitoring and research data available up to and including 1998. That assessment indicated improvements in population metrics relative to the late 1980s, a time of diminishing subsistence and commercial catches, and reduced size of individual fish. The Paulatuk Char Management Plan, ratified in 1998, recommended the total annual harvest of 1,700 Arctic Char from the Hornaday River which has remained unchanged since.

In recent years, residents of Paulatuk have been shifting more of their fishing effort for Arctic Char north-eastward in Darnley Bay to a coastal area at the mouth of Lasard Creek, near the mouth of the Brock River. This system also supports a smaller putative stock of anadromous Arctic Char. The extent of mixing between char from the Hornaday and the Brock systems is not known, although a tag return in 1996 did confirm movement of fish between the two systems. In 2011, monitoring efforts were expanded to include this area as well. Although Arctic Char are still harvested at the mouth of the Hornaday River in summer and in the river itself in fall/winter it is unclear to what extent the shift in harvest location alters the harvest rate of Arctic Char originating from both rivers. This uncertainty is compounded by the lack of information on the discreteness of these stocks, the degree of mixing between them, and the possible contribution of any other stocks to the harvest. To inform management of Arctic Char, an updated population assessment of the Hornaday will need to consider the change in fishing areas and potential for a mixing of stocks in the fishery.

Currently, the Paulatuk Hunters and Trappers Committee and Paulatuk Char Working Group have requested an increase in harvest to meet the subsistence needs of the community. As a result, Fisheries and Oceans Canada Resource Management has requested Science advice on the current stock status and sustainable harvest level of Arctic Char from the Hornaday River, and information on the contribution of putative stocks to the harvests at important fishing locations during the summer.

Objectives

The objectives of this  meeting is to undertake a science-based peer review of all available information relevant to providing advice on the sustainable harvest level for Arctic Char from the Hornaday River. Specifically the meeting will address the following objectives:

1. examine trends in the catch-effort and biological data collected at the mouth of the Hornaday River between 1990 and 2013 by the Hornaday Char Monitoring Program;
2. compare the results from the Hornaday Monitoring Program with the recently established monitoring program at Lasard Creek;
3. determine whether Arctic Char from the Hornaday and Brock rivers are separate stocks and examine their current contribution to the harvest at the Hornaday and Lasard Creek coastal fishing locations;
4. incorporate total harvest, catch-effort and biological time-series data from the Hornaday River for a surplus production modelling exercise to estimate the population abundance and sustainable harvest level, and associated risk levels, for Arctic Char from the Hornaday River;
5. present baseline genetic information on the contribution of Arctic Char that may not originate from either Hornaday or Brock rivers to the harvest in Darnley Bay (i.e., “Blue Char”); and
6. discuss future research needs and current monitoring plans for Arctic Char in Darnley Bay.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Documents

Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, and Ecosystems and Fisheries Management sectors)
• Fisheries Joint Management Committee
• Academics
• Paulatuk Hunters and Trappers Committee
• Other invited experts.