NRSC 4100 Final

L8 Fish Hatcheries

100

Methods for broodstock collection (4)

• Trap net 

• angling 

• electrofishing 

• seining (e.g., in rivers)

200

Explain how egg fertilization occurs for Male and Female fish 

• females ready to spawn when belly soft, and egg mass slips down body due to gravity 

• kill female, bleed her (at gills), cut open to get eggs 

• males anaesthetized, squeezed to get sperm

 • usually use 1 male, then a second male, per female, to ensure good sperm (for some rainbows, use 2 and 3 )

 • add a bit of water, starts sperm swimming! 

• wash off milt

300

Following the above process, If non-reproductive stock desired

heat or pressure treat eggs at this stage to create 3N (triploid)

400

Explain the process of rearing 

• Rearing in hatcheries typically starts off in the incubation room with trays of eggs 

• Once the eggs have hatched the fry are “ponded” (at the alevin-fry stage, placed into a trough or larger pond with flow through water systems)

• Fish reared in metal or concrete or plastic raceways or tanks, either indoors (e.g., kokanee), semi-indoors (roofed), or totally outdoors

500

Rearing in incubation rooms consist of 

• Eggs placed in vertically stacked incubation trays (5,000 - 10,000 eggs/tray) 

• Water runs continuously through trays in such a way that there are no areas of dead water (eggs here would die) 

• Water is usually well water that is aerated in a tower

600

Explain egg development implications  in the incubation room 

- dead eggs turn white (orange to pink normally) and must be removed 

• Disease prevention (Biosecurity protocols in place) Development 

• Eggs require a certain number of degree days (thermal units) to reach each stage • e.g., 20 days to eyed stage

700

Explain the Methods of Marking & Tagging Fish 

• use coded wire nose tags, 

• adipose fin clipped to identify fish as having a nose tag 39 Tagging  Most hatcheries “mass-mark” (clip all adipose fins) to identify as hatchery fish  

• tagging machine operator places fish head into machine 

• wire tag is injected into the nose cartilage of the fish through a hollow needle

- tag is magnetized at front end of machine • fish goes down shoot, a second magnet pushes "good" fish (with tag) into recovery bin

800

What information can you obtain from a CWT?

laser coded to identify species, year hatched, hatchery, original waters stock taken from, and where released

900

Explain how fish are transported for release from hatcheries 

- fish released via truck, or for remote lakes plane and helicopter

 • truck has oxygen supply and O2 levels are monitored from cab 

• At Clearwater, fish not anaesthetized, but are starved for two days prior to transport

L9 Aquatic Invasives

100

Describe the ecological and economic threat posed by the introduction of invasive fish species in BC

Invasive fish can have detrimental impacts on native fish populations that provide revenue through sport and commercial fisheries

Conflicts arise when bass lobbyists try and compare bass fishery income implications etc...

200

Name the 6 species of invasives covered in lecture

1. Smallmouth bass 

2. Largemouth bass 

3. Yellow perch 

4. Walleye 

5. Northern pike 

6. Goldfish

300

Problems with bass (4)

-efficient carnivores that eat invertebrates (reducing food for native fishes), and are piscivorous (at age 2), eating our local fish 

-e.g., smallmouth bass are estimated to eat 35% of outmigrating juvenile salmon in some areas of the Pacific Northwest 

-concern that bass may affect listed fish such as the Umatilla Dace 

-there is a conflict between the desire to have bass as sportfish (lots of active bass clubs in BC), and the desire to reduce bass numbers to reduce the loss of salmonids

400

Problems with Yellow perch (3)

-efficient carnivores that eat invertebrates (reducing food for native fishes), and piscivorous, eating our local fish 

-spines on fins and operculum (gill covers) makes them difficult for other fish to eat perch 

-as well, these fish are also popular with some anglers (we see a wide range in attitude in the Okanagan…)

500

Problems with Walleye (3)

- these fish are very efficient carnivores that are highly piscivorous, eating our local fish

- walleye appear to have caused a decline in densities of Rainbow Trout and Mountain Whitefish in the Columbia River

- sturgeon stocking in walleye waters now uses larger fish to deal with walleye predation

600

Problems with Northern pike (4)

1. Predation (consuming large numbers of fish daily with preference for soft-bodied fish such as rainbow trout) 

2. Introduction of a wide variety of parasites and diseases (e.g., Triaenophorus tapeworm is a high risk, not native to the Columbia system, and significantly affects table quality of salmonids) 

3. Competition with other species for common food resources (reducing growth and survival) 

4. Potential to impact opportunities to recover SARA listed species such as white sturgeon and shorthead sculpin in the Columbia River

700

Largemouth bass

Ecol. Consequence Small Water Bodies 

Ecol. Consequence Large Water Bodies

Small water body = very high 

Large water body = moderate 

Very high risk = Extirpation of native populations likely

800

Smallmouth bass

Ecol. Consequence Small Water Bodies 

Ecol. Consequence Large Water Bodies

Small water body = very high 

Large water body = high

Very high risk = Extirpation of native populations likely

900

Yellow perch

Ecol. Consequence Small Water Bodies 

Ecol. Consequence Large Water Bodies

 

Small water bodies  = Very High 

Large water bodies = Medium

Very high risk = Extirpation of native populations likely

1000

Northern Pike 

Ecol. Consequence Small Water Bodies 

Ecol. Consequence Large Water Bodies

 

Small water bodies = Very High 

Large water bodies = Very High 

Very high risk = Extirpation of native populations likely

1100

Potential problems with goldfish (4)

1. Competition with salmonids for invertebrate food

2. Increased turbidity due to “pick-and-spit” feeding

(affects plant growth, trout foraging)

3. Predation on fish eggs/fry, and small amphibians

4. Introduction of parasites that can affect salmon

1200

Solutions to invasive fish problems in BC (6) 

1. in small lakes, use rotenone to kill all fish (but also kills local fish) 

2. Smallmouth bass: kill bass on nests (Alex Prud’homme’s research suggests spearfishing males on nest, electrofish juveniles) 

3. in larger system: don’t let anglers put them there in the first place (public education crucial)

4. Yellow perch: artificial spawning substrates can be used to remove egg masses 

5. Northern pike in the Columbia River: gill netting to reduce population size 

6. Close a water body to fishing if invasive fish are found (e.g., Fussee Lake and New Lake in the East Kootenays closed to sport fishing due to the illegal introduction of invasive fish species (largemouth bass in Fussee, yellow perch in New) July 2017

1300

2 main conclusions of invasive fishes 

1. Once invasive fishes are established in a large watershed population reduction, rather than eradication, is the only option 

2. The best management option is to stop invasive fishes at national and provincial borders, educate anglers to not move fish, and to enforce an aggressive boat inspection program (for fish, invertebrates and plants)

1400

Explain the impacts of Zebra and quagga mussels (2)

- These mussel settle on any solid surface and grow in big clusters attached to each other overgrow and clog water intake pipes of power stations, municipal water supplies and agricultural raw-water intakes

- Can lead to paralysis in water-fowl through biomagnification of, from anoxia to fish to fowl

1500

How to prevent the spread of zebra quagga mussels (3)

- Clean-Drain-Dry all boats and trailers 

- Mandatory inspection for boats and trailers entering BC from the USA or Alberta/Yukon 

- Educate the boating & fishing public

L9 Aquatic Invasives/ L10: Effects of dams and reservoirs

100

Explain what whirling disease is (2): 

-a parasite (Myxobolus cerebralis) that infects young trout and salmon introduced to North America from Europe over 50 years ago 

- causes young fish to swim in a corkscrew-like pattern (the “swirling”), which makes it difficult for the fish to eat, and to evade predators Whirling disease -parasite causes skeletal deformation and neurological damage (e.g., black tail), and those fish that do survive are deformed

 

200

How would you prevent whirling disease (4)

- Clean your fishing gear between trips 

- Never transport fish from one water body to another 

- After cleaning your catch, do not throw bones or entrails into the water (spores from the carcass will enter the water)

- Do not use felt soled wading boots, which can hold spores and spread them from river to river. If you do, soak the boots in 10% chlorine bleach and water for at least 15 minutes, and then rinse well

300

Positive effects of dams (4)

 •Store water 

•Modify magnitude and timing of flows for better human use 

•Allows control of hydroelectric power, fisheries, water for irrigation, domestic use, recreation, removal/dilution of pollution, denitrification, trap sediments, better navigation, flood control 

•In BC, generates income for province (but note that water conservation not used to save water, but to generate increased power sales…)

400

Negative effects of dams: (11)

•Flooding: upstream wetlands, riparian areas, agricultural land, human communities 

•Flooded areas form reservoirs of disease vectors 

•Deeper parts of reservoirs can go anoxic:

 -accumulation of toxins 

-convert metals to toxic forms 

-release phosphorus, causing algal blooms downstream 

•Downstream river, floodplain and wetlands deprived of water and sediments (remember the Flood Pulse Concept), resulting in decreased productivity and biodiversity 

•River downstream of a dam is artificially colder or warmer, depending on whether the release is hypolimnetic or epilimnetic, respectively 

•Natural hydrograph of river is modified; fish are adapted to the natural regime (e.g., for migration) and not the new, artificial regime 

•Impoundments increase evaporative water loss by up to 33% compared to the river and surrounding land pre-flooding 7

- Evaporative losses have increased salinity of water and surrounding land, harming agriculture and stressing fishes 

•Habitat changes alter competition and predation among fish species, and promotes hybridization (genetic problems, and can endanger small populations) 

•Interrupted migrations splits apart metapopulations 

•Dams threaten endemic species and specialists (adapted to the previously present river conditions), and favours generalists and invading (or introduced) species (reservoirs are often managed for an introduced species fishery)

500

Two solutions have been tried to reduce the impact of dams on fish populations

1. Artificial spawning channels, have only marginally increased Kokanee reproduction

2. Restoration effort in the arrow lakes, fertilization program

600

Two new technologies to help with fish passage

1. New turbine designs that reduce fish mortality 

2. SALMON CANNON to transport fish from below to above dams

700

Negative effects of large dam removal (3)

1. Permits upstream access for invasive species 

2. Loss of most reservoir populations

3. Potential for catastrophic sediment movement 

800

Why would loss of most reservoir populations be a problem (3)

- Lentic species completely removed 

- Riparian and littoral habitats isolated 

- Nutrient rich substrate prime for invasive plants

900

What would the implications of catastrophic sediment movement? (3)

• High intensity – short frequency 

• Low intensity – high frequency 

• Release of sediment-bound pollutants

1000

What is Run of River? (5)

•Unlike traditional hydroelectric facilities, run of river projects do not require (major) damming of water. 

•Water is diverted from a river and sent into a pipe called a penstock. The penstock feeds the water downhill to a generating station. 

•The natural force of gravity creates energy required to spin the turbines that generate electricity.

 •Water leaves the generating station and returns to the river without altering existing flow or water levels (downstream).

 •BC is arguably the most attractive region in Canada for development of ROR projects due to mountainous terrain and rainy climate

1100

Effects of Run-of-River Power (4) 

- Some studies show that small hydro projects can release fine sediment and reduce benthic algae diversity, but not significantly affect benthic invertebrates  

- One study found that reduced flows caused an increased rate of drift of Baetis mayflies, while another found in their review that reduced flows produced varying effects on invertebrate abundance, but regularly reduced benthic invertebrate taxa richness. 

- ROR can affect salmonids by reducing flows, blocking migration with low-head dams, and flow fluctuations (Gibeau et al. 2017):

 -  the effects of small hydro operations in British Columbia need further study, especially cumulative effects (see next slide).

1200

Describe how vertical sluice floodgates allow salmon access to wetlands

Vertical sluice gate style of floodgate allows salmon access (only closes during floods)(vs. top mounted flood gate) 

L11: Fish-forestry interactions

100

Describe nine negative effects of logging on streams

1. Increased landslide frequency 

2. Increased sediment generation and movement

3. Altered streamflow (hydrological regime) and channel morphology

4. Decreased riparian function

5. Introduction of logging debris (e.g., fine slash), and removal of stable debris (i.e., LWD), with subsequent channel alteration 

6. Altered water quality 

7. Blocking of migration pathways 

8. Altered recruitment of suitable spawning materials

9. Altered ground water flow 

200

Increased sediment generation and movement

•Due to accelerated erosion rates (e.g., from road surface area) and mass soil movement (e.g., slumps and earth-flows, debris movements) 

Main causes: 

• poor road placement / inadequate road maintenance 

• insufficient culvert sizes 

• steep hill-slope gradient 

• placement or side-cast of excess materials 

• removal of slope support by undercutting 7 

• alteration of slope drainage by interception and concentration of surface and subsurface water 

• surface erosion from exposed/disturbed soil

300

Altered streamflow (hydrological regimes) and channel morphology

- due to changing input of water and sediments, and physical footprint 

• includes dewatering and widening of channel 

• wider, shallower streams tend to also be warmer

400

Riparian zone functions

• Stabilize banks 

• Shade to keep water cool 

• Filter pollution/excess nutrients

 • Contribute CPOM (coarse particulate organic matter, for shredders)

• Contribute terrestrial insects that fall in (food for fish) 

• Contribute LWD (large woody debris) (more on that later)

500

Altered water quality 

• recent concern is UV radiation (resulting in death of algae, invertebrates, harms fish) 

•DOC (dissolved organic carbon) acts as a “sunscreen” for rivers, absorbing UV

 • clearcut logging can affect production of DOC to streams

600

Function of LWD (4)

- Provides structure to stream channel - stabilizes gravel bars, and forms waterfalls and pools

• Removal of LWD results in sediment release (bad for fish!) 

• Logging of riparian zones of small streams can lead to a reduction of LWD in the long term = channel instability 

• Retention of coarse particulate organic matter (CPOM), which is eaten by invertebrate shredders

700

Describe a “good”  cut block (3)

1. Ideally sufficient riparian vegetation is left on the cutblock to maintain bank stability, and provide CPOM and shade 

2. If trees removed to the edge of the stream, then fine slash should be kept out of the stream channel to prevent redistribution of flow, or accumulation of silt 

3. Best management practices call for 5% retention of windfirm codominants in a proportion of streams

800

Describe the major findings of the Carnation Creek project (5)

The Carnation Creek Experimental Watershed Project provided critical insights into the effects of forest harvesting on aquatic ecosystems, particularly salmon and trout populations,

1. Habitat Alterations: Increased bank erosion, loss of large woody debris, and sediment movement disrupted stream stability and spawning material availability.

2. Fish Habitat and Population Declines: Elevated sedimentation halved chum and coho egg survival; chum spawner returns dropped 3.5-fold.

3. Temperature Increases: Clear-cutting raised stream temperatures by up to 4°C, altering fish development and reducing chum fry survival.

4. Trophic Shifts: Riparian canopy removal shifted nutrient inputs and reduced invertebrate populations.

5. Landslides and Debris Torrents: Over 80 landslides caused lasting habitat changes.

 

900

Forestry Activities regulated by the Forest Planning and 

Practices Regulations (FPPR)

Division 3 – Riparian Areas (most important for fish!) 

• Classifies streams, lakes & wetlands

 • Defines riparian management areas (RMA’s) and restrictions within those

 • General protection of fish and fish habitat (stream crossings, temperature sensitive streams, barriers to migration etc.)

1000

Explain how stream class is applied to riparian reserve zones 

1100

Why are headwater streams important (4)

Provides 

- Dissolved organic matter (sunscreen)

- CPOM and FPOM

- Invertebrates (both aquatic and terrestrial)

- Cool, well oxygenated water

1200

How does the federal fisheries act apply to logging as well as FRPA?

- Cannot reduce productive habitat, which fish depend directly or indirectly to carry out their life processes 

1300

Discuss the cumulative effect of logging in the province

Logging was recently proven to negatively affect salmon in BC 

C baileys study - “increases in the cumulative area of logging activity in their study watershed were associated with 97% or greater reductions in the freshwater productivity of steelhead, coho salmon, and coastal cutthroat trout.

L12: Fish Range Interactions/

100

 Describe how range use is regulated in BC on crown land

FRPA management objectives (6) for range use are similar to other forest practices in BC (RPPR)

And Water Sustainability act for water use 

FRPA (Division 3 – Riparian and Upland Areas) 

 Protection of fish (section 32) (1) A range agreement holder who carries out a range practice must ensure that the range practice is conducted at a time and in a manner that is unlikely to: 

(a) harm fish, 

(b) have a material adverse effect on fish passage, or 

(c) destroy, damage or harmfully alter fish habitat. 

(2) If satisfied that it is not practicable, given the circumstances or conditions applicable to a particular area, the minister may exempt a range agreement holder, in relation to that area

200

Describe how range use is regulated in BC on private land

• FRPA does not apply… 

• Water Sustainability Act (replaces the Water Act)

 • Fisheries Act 

• Land Act (leases, farm planning)

300

Describe eight major impacts of cattle grazing on fish habitat

1. Removal of riparian (and other) vegetation

2. Alteration of runoff

3. Increased sediment generation and introduction (from upslope)

4. Destabilization of stream banks and altered channel morphology

5. Instream disturbances (especially for drinking but also for passage) - stirring up sediment and crushing eggs/redds

6. Chemicals (pesticides/fertilizers) or excess nutrient additions 

7. Removal of water for irrigation purposes 

8. Entrapment of fish in irrigation canals

400

Describe eight management actions to reduce the negative impacts of cattle grazing on fish habitat

1. Rotational grazing to reduce impact 

2. Use of riparian pasture *have to move the cattle out quickly

3. Exclude cows from riparian areas using fencing 

4. Restrict access and/or armor the areas they do use (modify substrate)

5. Keep feedlots away from streams

6. Screen ditches and water intakes (LAW)

7. Provide off-channel watering 

8. Careful ditching, tilling and dirt road maintenance to reduce sediment transport.  

500

the federal Fisheries Act

Fish and fish habitat are protected under this Act  “Fish” includes all life stages of fin-fish, shellfish, crustaceans, and marine mammals 

- A key concept concerning fish habitat is that works cannot cause a HADD = Harmful Alteration Disturbance or Destruction Harmful = Any change in the physical, biological, or chemical attributes of habitat which adversely affect their ability to provide the basic life requisites 

- “No net loss of productive capacity of habitats” the maximum natural capability of habitat to produce healthy fish, safe for human consumption, or to support or produce aquatic organisms upon which fish depend

- Can compensate replacement of natural habitat, increase in the productive capacity of existing habitat  

600

the federal Fisheries Act definition of habitat includes 

• Spawning grounds 

• nursery 

• rearing 

• food supply 

• migration areas 

• on which fish depend directly or indirectly to carry out their life processes 

• “Ecologically linked” 9 

May include: 

• wetlands 

• ponds 

• swampy areas 

• small streams 

• ditches

 • side channels

700

The Water Sustainability Act (3)

- Governs the extraction and use of water 

• Requires permission for projects that cause changes in and about a stream 

• Governs use of fresh water

800

Fish Protection Act (FPA)

Riparian Areas Regulation 

(Enacted under Section 12)

 “calls on local governments to protect riparian areas during residential, commercial, and industrial development by ensuring that proposed activities are subject to a science based assessment conducted by a Qualified Environmental Professional (QEP)”

900

Describe Recreational Fisheries Regulations examples(7) 

No fishing areas 

Allowable methods

Gear restrictions

Quotas

Size limits 

Temporary (environmental) restrictions 

Boating restrictions 

1000

No fishing areas (3)

- within 23 m of lower entrance to an obstacle or leap 

-within 100 m radius of any gov’t facility for counting, passing or rearing fish (e.g., fishway, hatchery, aerator)

 -special cases n.b. these areas are not always posted no fishing!

1100

Allowable methods (5) 

-angle 

-down-rig

 -ice fishing 

- spearing (non-game fish, & burbot in certain areas) 

-set line (must be marked with your name, etc.)

1200

Gear restrictions (5)

-single hook 

-single barbless hook

-artificial flies (float & sinker allowed) 

-fly fishing only (float & sinker not allowed) 

-bait ban = bait, fin fish, roe, aquatic invertebrates, chumming

1300

Quotas (4)

-daily 

-possession quota 

-monthly 

-annual

1400

Daily vs Possession limits 

Daily limit –the maximum number of a species a person may retain in one day 

Possession limit –the number of a species that a fisher may have in his/her possession at any given time, except at place of normal residence (normally 2x daily limit for that species)

1500

Example of when a total ban of fishing may be imposed 

Used to detour the movement of fish from one water body to another 

“It is illegal to fish for bass or perch in the Thompson-Nicola Region. This measure is part of B.C.’s management approach to illegal fish introductions.

L13: Fisheries Policy/L14: Climate change

100

Limits (3)

- minimum size 

- maximum size 

- slot limits

200

Temporary (environmental) restrictions

-river fishing in BC can be restricted if water temperatures exceed 20°C

 -this is due to added stress of angling on the fish (the warm water speeds up the fish’s metabolism, and warm water contains less oxygen than cold water)

 -common in Rocky Mountain states as well1; e.g., Wyoming, Montana impose “hoot owl” restrictions (i.e., no fishing 2 p.m. until sunrise during hot summer weather) (owls are active in early morning…)

300

Boating restrictions (6)

- no angling from boats 

- no angling from power boats 

- no power boats

 - electric motors only 

- engine power restrictions 

- speed restrictions

400

Describe the changes in temperature and oxygen expected to take place due to climate change

Temperature is expected to increase therefore reduce oxygen

Ultimately can stress fish and reduce overall size

500

How is total catch projected to shift?

Total catch remains the same, but there is an increase at higher latitudes  and a decrease in the tropics of up to (which tend to be the most vulnerable, socioeconomically) 

Implications for global food security 

600

How will fish populations shift in Canada?

2017 

- Canada will see a net gain in marine species, but many areas will see a high turnover of species (i.e., see both losses and gains of species)

2019 

Marine catches in Canada will decrease, after all

700

Globally how is climate change going to affect fish stocks? (2) 

-climate change will reduce the average size of fish caught  

- climate change (warming) will not drastically change the amount of fish for harvest but change the distribution putting the tropics at a disadvantage

800

Explain the effects of climate change on interior, Freshwater fish communities (6)

• Elevated temperatures stress trout and salmon -When temperatures go above 20°C sport fishing is halted 

• Reduced water levels stress fish, block passage 

• Drought increases competition between e.g., irrigation water use and use of water by fish (e.g., kokanee in Upper Nicola River) for spawning 

• Increased temperatures stress migrating salmon migrating back to interior streams, and cause death (depletion of energy reserves, as they don’t feed), or increased death rate from parasites (death rate varies from 10-90% of returning sockeye in Adams River run) 

• Changes in ocean productivity produced by changes in ocean currents and upwelling make returning salmon smaller, and fewer in number

 • Lake chemistry is changing, with small, productive lakes getting higher in pH, which kills trout when above ~9

L15: Fish habitat

100

Restoration

return of ecosystem to original, undisturbed state

200

Rehabilitation

repair or improve certain components or functions (but not restored)

300

Reclamation

return an area to a habitat state prior to disturbance, function not always returned

400

Mitigation

Alleviate habitat problems influenced by human activities

500

Enhancement

Improve habitat through manipulation

600

Common habitat improvement techniques in 

Rivers & streams (4)

1. Bank stabilization 

2. In-stream structures 

3. Artificial spawning and rearing channels 

4. Road crossings

700

Bank stabilization

•stabilization will stop process of erosion, actual technique used will depend on water velocities, bank slope, and amount of suspended material in the water

800

Three major techniques for bank stabilization

1) Rock (hard)

2) Vegetated (soft) 

3) Integrated

900

Rock (hard) methods

boulders or rip rap to armour bank or redirect flows away from bank 

-includes groynes, rock revetments, turning rocks

1000

Vegetated (soft) methods

use plants or plant cuttings 

-includes herbaceous ground cover, rooted stock, live cuttings, fascines, brush mattress, brush layers

1100

Integrated methods

use variety of materials including rock, timber, soil or plants, landscape fabrics -includes vegetated geogrids, tree revetments

1200

What is and when would you use gabions?

 

- Gabions = baskets made of metal, which contain rock arranged to form a wall on the bank parallel to the stream channel. Can be arranged offset (terraced) or flat.

Used when streams with banks too steep for rip-rap 

1300

Rip-rap (rock-armour)

•pieces of rock used to line bank 

•rocks should be angular and hard, particle size depends on current velocity

1400

When should you use rip-rap?

At locations of critical infrastructure, bridges, roads, pipelines.

1500

Best type of rip-rap 

Vegetated

L15: Fish habitat

100

Riparian planting and it's pros (2)

• plant vegetation so that roots will consolidate bank soils, filter runoff, and provide cover for salmonids 

• typical species are willow, red osier dogwood, and cottonwood (try to plant native species!) 

• Often combined with brush barrier or mattress

Pros

• Can be done without heavy equipment 

- Achieve more natural and functional bank  

200

What is this?

Live fascine – can be quick fix & low cost!

300

What is this? 

Brush mattresses

400

What is this?

Vegetated geogrid

500

Instream structures

Large woody debris (LWD), undercut banks and cover structures (e.g., boulders)

600

What do instream structures provide? (5)

- juvenile salmonids rarely leave the protection of large organic debris, boulders, undercut banks and overhead vegetation 

• cover, particularly for rearing juvenile salmonids, is critical 

• pools provide refugia from: drought, ice, and elevated water temperatures in summer 16 

• LWD is important in providing cover and habitat heterogeneity (e.g., variation in stream velocity and depth), and acts as a substrate for invertebrates (food for fishes) 

• needed when riparian trees are removed

700

Examples of instream structures (3)

- root wads 

- tree revetments 

- Wisconsin cover log

800

Artificial spawning and rearing channels

• Built adjacent to rivers (and lakes) to create additional spawning or rearing habitat (cut off from lake after spawning if simply want to avoid egg-bound diploid females) 

900

What do Artificial spawning and rearing channels provide?

- provides refugia for all life stages during spate/flood events 

1000

Road crossings – restoring access

- Important component of any watershed restoration project is identifying and repairing improper culvert installation and road crossings 

1100

What is being done about road crossings? 

In general restoring fish passage in BC is happening at a very slow rate

2012

Status of fish passage in BC: 

  with 320,000 crossings on fish streams in BC • Based on culvert assessments done to date in BC, as many as 70%, or about 224,000 of these crossings are expected to be closed-bottom culverts, and 60-90%, (up to 200,000) of these closed-bottom culverts are likely to impede fish passage. 

• So far…over 10,000 have been assessed, 93 restored through this program

Fish passage in BC 2022

- Since the Fish Passage program's inception in 2007, more than 150 stream crossings have been remediated up to 2022, providing renewed access to more than 750 km of fish habitat.*  

1200

Common habitat improvement techniques in 

Lakes (2)

1. Aeration & other water chemistry manipulations 2. Spawning channels

1300

Aeration & other water chemistry manipulations

• Eutrophication, shoreline development, watershed activities and removal of water all play roles in habitat loss in lakes 

• Manipulations may include many techniques to either slow eutrophication (aeration, cattle management, etc.) or even increase nutrients (fertilization or “enrichment”)

1400

Examples of Lake restoration techniques

• Algicides 

• Destratification 

• Dilutional flushing

• Diversion 

• Dredging 

• Biomanipulation of food web (top down, or bottom up)

• Hypolimnetic aeration 

• P inactivation (e.g., alum, iron, etc.) 

• Sediment oxidation 

• Sound waves to destroy nuisance algae 

• Better watershed practices to address non-point sources of nutrient

1500

Inactivation of phosphorus

Alum  

Add aluminum salts to form aluminum hydroxide floc that settles to lake bottom to form a barrier to further phosphorus release 

Alum addition to bind phosphorus Widely used, removes P from water column

L15: Fish habitat/ L17 Jim arner

100

Inactivation of phosphorus

Iron 

(e.g., Orihel et al. 2016 for use of iron compounds for algal control in Alberta)

200

•Common habitat improvement techniques in:

Marine (2)

1. Marine protected areas 

2. Artificial reefs

300

Marine Protected Areas

Leaving it alone to restore itself

400

Artificial reefs

Provide habitat complexity and cover for fish (can range from sunken ships to more natural looking artificial reef systems)

500

What region does the Provincial Fisheries Thompson-Nicola manage?

Over 1,200 recreational fishing lakes and streams in the Thompson-Nicola Region

600

How many lakes are stocked in the Thompson-Nicola Region for angling?

Approximately 200 lakes are stocked, with the rest being wild stocks or naturalized populations.

700

What are the primary species targeted in the Thompson-Nicola Region fisheries?

Rainbow trout, kokanee, bull trout, lake trout, burbot, whitefish, and white sturgeon

800

What are the three objectives of the Provincial Freshwater Fisheries Program?

1. Conservation of wild stocks and their habitats.

2. Protect First Nations food, social, and ceremonial use.

3. Optimize recreational fishing opportunities.

900

What species was historically world-renowned in the Thompson River?

The Interior Fraser Thompson River Steelhead

1000

Why was the steelhead fishery in the Thompson River closed in 2018?

Due to a decline in steelhead numbers, now considered an endangered species under provincial concern.

1100

What are the key objectives of the Nicola Watershed Bull Trout project?

1. Monitor water temperatures during migration and spawning.

2. Assess spawning numbers and habitats.

3. Compare current data to historical records for changes.

1200

What preliminary observations were made about Nicola Bull Trout populations?

Few spawners and redds were observed, with some systems exceeding migration temperature thresholds.

1300

What management techniques are used to address small lake winterkill issues?

Aeration systems like Hypolimnetic Oxygen Injection and Sprinkler Aerators.

1400

What challenges face the fisheries in the Thompson-Nicola Region?

1. Limited team capacity.

2. Climate change impacts.

3. Threats from invasive species and diseases.

1500

What is Whirling Disease, and why is it a concern?

A disease affecting juvenile salmonids caused by a parasite, confirmed in BC in 2023, with no current effective treatment.