Aquatic Final Flashcards by Pippa McMahon

List the five main salmonid spawning habitat variables

depth

velocity

substrate

cover

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In which time(s) of year do most salmonid production bottlenecks occur in Pacific Northwest streams and rivers, and by which mechanism do they occur(s)?

Summer:

lack of cover
increased predation

Winter:

lack of overwintering habitat
lack of food sources

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Fish that spawn once and die are biologically known as ? while those fish that can spawn more than once are known as ? (provide an example of each)

Semelparous

sockeye salmon

iteroparous

sturgeon

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List two fluvial conditions where it would not be appropriate to place boulders in a stream as a salmonid habitat restoration technique

icy

high velocity

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At what concentrations does DIN become limiting in streams?

< 20 micrograms/L

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What are three components of nutrient spiralling in streams, and which component usually dominates the overall spiralling distance?

uptake

transport (dominates overall SP)

release

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Does off-channel habitat provide critical habitat during winter in coastal streams?

Yes

It provides important shelter from high flows

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What lifestage of fish should be considered when designing for fish passage?

Adult spawning and Juveniles

Adults are usually focussed on, but consider juveniles as they are often more limited

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What determines quality of rearing habitat?

Depth

Velocity

Substrate

Cover and structure

Temperature

Nutrients

Dissolved oxygen

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Precipitation Projections for climate change

70-74 mm per year of increase of precipitation

By 2100, we will have an increase of like 90 mm/year

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What are biostandards

Indices of habitat suitability

Preferred suite of habitat conditions for a particular life stage of a species

Quantitative prediction of the suitability of a particular environment for the organism

Preference ~ Suitability>Occurance

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Which two key salmonid life history characteristics must you know before undertaking any stream restoration project?

anadromous or resident

salmonid species

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What is (a) the optimal temperature range, and (b) upper lethal temperature limit for adult sockeye salmon?

optimal temperature range: 12-14C

upper lethal temperature limit: ~25C

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A general rule of thumb is that an area ? times the size of the redd would be a reasonable estimate of territory size for spawning salmonids.

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List three factors that can influence marine survival of salmonids

upwelling/downwelling

temperature (El Nina, PDO)

predation

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What are the three general categories of swimming speeds for fish that are important to know when you are restoring fish access?

prolonged

sustained

burst

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For adult salmonid migration, the average water velocity should not exceed ? for culverts shorter than 25 m and ? for culverts longer than ?

2 m/sec for culverts shorter than 25 m

0. 9 m/sec for culverts longer than 25 m

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How far (in cm) below the natural grade line of the stream bed should new culverts be placed?

Trick question!

20 to 40 % of the diameter below the natural grade line of the stream to allow for natural substrates to line the culvert bottom, and control natural erosion downstream of the culvert

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Fish that travel between fresh and saltwater (provide two examples)

Diadromous

Pacific salmon

Atlantic salmon

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Adult fish that live in saltwater and reproduce in freshwater (provide two examples)

Anadromous

Pink salmon

sockeye salmon

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Adult fish that live in freshwater and reproduce in saltwater (provide one example)

Catadromous

American eel

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Fish that migrate within freshwater only

Potamodromous

Bull trout

Dolly Varden

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Identify three sensory cues that anadromous salmon are thought to use when navigating during their migration from the open ocean to their natal stream/lake, and indicate which stage of their life history they would use this sensory cue

Olfactory- juveniles

magnetoreception- adults

sun angle as compass- adults

List three benefits that large boulders may provide to in stream biota

Stabilize spawning gravel

Create localized scour and eddy features

Increase turbulence, providing cover from predators

Provide micro habitat diversity

Provide fish holding and feeding areas in fast water

Increase substrate for benthic invertebrates

Where should boulders be placed in a suitable gradient boulder deficient stream to restore fish habitat?

Placed toward the middle of the stream, BUT not in a pool, the deepest ⅓ of a stream Middle or tail of riffles Upper, middle or lower sections of runs Head or tail of pools Deepest ⅓ of channel

Individual boulder spacing within a boulder cluster should be what distance apart? Boulder clusters should be spaced what distance apart?

1 -2 m apart 3 m apart

What are the three basic design concepts for off-channel habitat and the 4th design type?

Wall-base Surface water flow Groundwater Alcoves/ponds

Which general order of streams have (a) the most frequent disturbance regimes, and (b) the greatest habitat complexity and hence reliance on LWD for habitat complexity?

(a) mid order | (b) mid order

Does off-channel habitat provide critical winter habitat in interior streams?

Depends. Usually these channels tend to freeze over in the winter because they are too shallow and slow moving But if the mainstream is too cold and the off-channel is groundwater, then they will move into off-channel for winter

List four nutrient assessment methods used to determine macronutrient limitation in streams and rivers

low-level chemistry analysis synoptic surveys bioessays slippery feel

At what concentration does (a) SRP become limiting in streams, and (b) what laboratory filter size is used to measure SRP

(a) < 1 microgram/L | (b) 0.45 u

What nitrogen molecules are included in the laboratory analysis for DIN?

NO2 NO3 NH3

What are the BC guidelines (in mg/m2) for CHl in streams for (a) aesthetics and (b) for aquatic life?

50 mg/m2 100 mg/m2

On a bag of fertilizer, what do the three numbers indicate?

1st number = % weight of nitrogen NO2-H, NO3-H, NH3-H 2nd number = % weight of P2O5 3rd number = % weight of K2O

If a 10 kg bag of fertilizer contained 10-40-5, what is the weight of P in the bag?

10 kg * (40/2.29)

On an atomic weight basis, when is the N:P ratio in a stream considered to be (a) N limited, (b) N and P co-limited, and (c) P limited?

(a) <10:1 (b) 10:1 to 20:1 (c) >20:1

10:1 N:P atomic weight ratio is equivalent to a ? N:P weight: weight ratio, what about 20:1 N:P

4.5:1 N:P weight to weight ratio, 9:1

20:1 N:P atomic weight ratio is equivalent to a ? N:P weight:weight ratio

9:1 N:P weight to weight ratio

Explain Bottleneck in terms of salmonids

Environmental condition of limiting factor Or event that limits or prevents population growth Example: Rock slide blocking access. Or lack of suitable freshwater rearing habitat For salmon, its at the Parr Stage for the FRESHWATER REARING SALMON only

For salmon that rear in freshwater, what two types of habitat are often most limiting?

Summer rearing habitat (need refuge from temperature too warm! Over-wintering habitat

Name of the zone immediately below stream bed? List three Functions/processes

Hyporheic Zone I. Critical role in egg incubation Ii. Moderate flow and temperature Iii. exchange of nutrients iV. De-nitrifying microbes and biofilms V. Directly affected by an measures to mitigate spawning habitat

Describe two restoration/mitigation strategies to address spawning gravel degradation in streams?

Gravel cleaning and Gravel Augmentation

When considering boulder placement, a tractive force calculation is needed to determine the minimum boulder size that will be stable and remain in place. This is calculated as:

Boulder diameter (cm) = 1500 x D x S Where value represented by D: Bankful depth (m) Where value represented by S: Slope of the river (m/m)

What two species of salmonid are most often associated with off-channel habitats?

Coho Chum

What is the ongoing issue on the Seymour River as it pertains to fish passage and describe the restoration method?

The rockslide that blocked access for fish. They used low velocity explosives to chip away at the rock.

Describe a solution to eliminate supercritical flow in a culver that cannot be replaced, with the intent of decreasing water velocity and increasing water depth within the culvert

Install baffles. Install roughness elements such as boulders or baffles in the culvert, which reduce water velocities, increase water depth, retain substrate, and provide resting areas for migrating fish. Install weirs(notched or unnotched) at several points in the culvert that create sllower and deeper impounded sections.

What is the concentration (microg/L) cutoff for Phosphorus Limitation?

<1 microgram/L

What is the concentration (microg/L) cutoff for Nitrogen Limitation?

<20 microgram/L

What is the most BIOAVAILABLE form of phosphoru

Soluble REACTIVE Phosphorus

Why are streams oligotrophic?

Dams Logging right up to the banks (removing vegetaion/LWD) Overfishing/Depleted fish stocks Loss of wetlands/flood plain access

Why do fish migrate?

Reproduction Feeding Avoiding predators

How do fish migrate?

Most salmon smolts use passive drift at night to migrate tail first down the river estuary Detect magnetic fields Detect the sun

How is site fidelity important to ER?

the tendency to return to a previously occupied location, Has resulted in reproductive isolation. Led to specialized adaptations of distinct populations in their natal habitat. Developed genetically unique, discrete stocks within given species.

What is the most important goal for restoring fish habitat?

Restoring fish passage to allow fish to migrate is one of the most important restoration goals

Life cycle of 3 fish

``` Pacific salmon life cycle Fertilized eggs Fry Parr Estuary smolts Marine adults Spawning adults ``` ``` Pink salmon Short life span (2 years) Transient in estuaries Spend little time in freshwater Fry have no parr marks Spawning males have large humps ``` Chum salmon 4 year life cycle Widest distribution of salmon in BC Can't jump high, prefer shallow and calm waters Juveniles spend minimal time in freshwater Associated with off channel habitat Coho salmon 3-4 year life cycle Interior fraser stocks are endangered Very colorful fry with white streaks on fins Associated with complex habitat and off channels ``` Chinook salmon Highly variable life cycle Long residency in estuaries Ocean going chinooks are smaller and spend more time the estuary Not associated with off channels ```