2 Connectivity Status Assessment and Goals

Connectivity Status Assessment

The planning team identified two Key Ecological Attributes (KEAs) to assess the current connectivity status of the watershed for each focal species – Accessible Key Habitat and Accessible Overwintering Habitat (Table 2.1). KEAs are the key aspects of anadromous salmon habitat that are being targeted by this WCRP. For each KEA, an associated indicator was assigned to measure the status of that KEA. The connectivity status indicators were used to establish goals to improve key habitat connectivity over time and is the baseline against which progress is tracked over time.

The current connectivity status was estimated using three spatial models:

1. Accessibility model: Naturally accessible waterbodies are those that are considered likely accessible to focal species if no human-made barriers existed on the landscape. These were spatially delineated for each focal species using natural barriers (i.e., waterfalls, gradient barriers, or subsurface flows) that would naturally limit upstream movement (Table 1).

2. Habitat model: A subset of the naturally accessible waterbody layer was defined as key habitat, i.e., habitat likely to support spawning or rearing, rather than simply movement corridors. The habitat model identifies areas within waterbodies that have a higher potential to support key habitat based on stream channel gradient and discharge. The habitat model criteria can be found in Appendix C.

3. Connectivity model: A layer of known or modelled structures was overlaid on the key habitat results. Structures with unknown passability were treated as a full barrier until confirmed passable by either local knowledge, desktop review, or field assessment. Watershed connectivity was estimated by calculating the amount of key habitat that is connected to the ocean (i.e., not fragmented by human-made barriers). Key habitat with no structures or only passable structures downstream was considered connected. Key habitat upstream of full, partial, or potential barriers was considered disconnected. All connected habitat was summed and divided by the total amount of key habitat in the watershed to arrive at the KEA indicators. Detailed methods for the connectivity model can be found in Appendix C.

Table 2.1: Connectivity status assessment for spawning (a) and rearing (b) habitat in the Bulkley River watershed. The two KEAs - Accessible Spawning Habitat and Accessible Rearing Habitat - are evaluated by dividing the length of linear habitat (of each type) that is currently connected to focal species by the total length of all linear habitat (of each type) in the watershed.

Focal Species	KEA	Indicator	Poor	Fair	Good	Very Good
Andromous Salmon	Available Habitat	% of total linear habitat	<80%	-	81-90%	>90%
		Current Status:				92

Comments: Indicator rating definitions are based on the consensus decisions of the planning team, including the decision not to define Fair. The current status is based on the connectivity model output, which is current as of December 2024.

Focal Species	KEA	Indicator	Poor	Fair	Good	Very Good
Andromous Salmon	Available Overwintering Habitat	Total Area (m2) of overwintering habitat connected	?	?	?	?
		Current Status:

Comments: No baseline data exists on the extent of overwintering habitat in the watershed. A priority action is included in the Operational Plan (strategy 2.3) to develop a habitat layer, and this will be used to inform this connectivity status assessment in the future.

Goals

Table 2.2: Goals to improve (1) spawning and rearing and (2) overwintering habitat connectivity for focal species in the Horsefly River watershed over the lifespan of the WCRP (2021-2040). The goals were established through discussions with the planning team and represent the resulting desired state of connectivity in the watershed. The goals are subject to change as more information and data are collected over the course of the plan timeline (e.g., the current connectivity status is updated based on barrier field assessments).

Goal #	Goal
1	By 2040, the percent (%) of total linear habitat connected for anadromous salmon will increase from 92% to 96% within the Horsefly River watershed (i.e., reconnect at least 14.77 km of habitat).
2	By 2024, the total area of overwintering habitat connected for anadromous salmon will increase by 1,500 m² within the Horsefly River watershed.