Quiz 5

Management Objectives

greater emphasis on habitat restoration, greater emphasis on recreation and C&R, changing values regarding native fish conservation, better understanding of ecosystem (watershed) influences on fisheries production, and realization of problems created by past management activities

Disturbance ecology

Management programs have evolved in response to perturbations in rivers and streams

Pulse (Disturbance Ecology)

Abrupt Δ, dissipation thru time - storms, fire - typical recovery or pre-disturbance conditions at various time scales

Press (disturbance ecology)

Abrupt Δ, maintained thru time - dams, roads, deforestations - fish and macroinvertebrate responses depend on type, magnitude, and duration - persistence of biota doesn’t equal healthy, species replaces by tolerant taxa likely

Ramp (disturbance ecology)

Increases thru space and time - urbanizations, climate change - alterations of watersheds may increase through time, and environmental   factors may interact to increase disturbance levels; consider the effects of   increased temperatures, reduced rainfall, and decreased fire intervals on a   trout stream through time; add in anthropogenic changes in the watershed,   disturbance levels continue to climb

Successful management will need to increasingly focus on __________, not on sportfishes/imperiled species

maintaining the structure and function of lotic communitites

Habitat degradation due to diversions, dams, grazing, mineral extraction, timber harvesting, and agriculture has been particularly evident in coldwater streams. Some reasons for habitat degradations

migration barriers
dam-related reductions in flow, flow variability, and altered timing
erosion and streambank instability in riparian zone
organic and inorganic pollution and sediment deposition

altered timing

when streams flood or the flow quickens. when altered from its original timing, it can be harmful because it can overlap with when species breed or migrate

Goals of habitat restoration

identify limiting factors, identify and remove anthropogenic stressors in the watershed, monitor project success

identify and remove anthropogenic stressors in the watershed

restoration activities undertaken with a full understanding of how it will affect the stream: land use, erosion, temperature, rainfall, eutrophication

Effective monitoring of project success

10% of 37,000 projects reviewed by Bernhardt et al. (2005,2007) had been monitored.

Stream degradation often occurs because of alterations to riparian zone vegetation, hence restoration activities need to start outside the stream. _______, ______, and ________ can restore the integrity of the riparian zone, increase bank stability, reduce erosion, and decrease stream temp.

Bank contouring, revegetation, and tree planting

Bank contouring, revegetation, and tree planting

can help restore the integrity of the riparian zone, increase bank stability, reduce erosion, and decrease stream temp

Root wads

reduce flow, accumulate sediment (good for cover), protect banks, and can provide habitat complexity in the form of cover and altered depth profiles.

Vanes

lines of boulders that direct flows away from banks and to the center of the channel. protects shorelines, create habitat complexity (increased depth and flow variability), shallow pools, and cover for macroinvertebrates and fish

Sills

like vanes. structures that create small waterfalls tied into the banks. create plunge pools below and shallow impoundments above. ARE NOT movement barriers

Deflectors

rock/LWD structures (oriented downstream) that direct flows from banks; water flows around, not through. directing flow from one bank to the other will necessarily increase erosive forces unless the bank is naturally or artificially armored. can be used to increase flow and remove sediment from gravel beds for nesting salmonids/centrarchids

Another thing that has been used to improve spawning for nesting species

providing and/or cleaning gravel

Some stream habitat projects

large-scale riparian zone restoration, channel realignment, instream hydrologic manipulation. also reconnecting streams with lentic/wetland habitats - good for nursery areas for salomids

Flow disruption

culverts, impacts stream passage for anadromous, potamodromous fishes

Instream structure

provide cover for fishes and macroinvertebrates, and it contributes to microhabitat variability in flow

Instream structure should:

function at all water levels, large enough to withstand high stream power at elevated stages, and should not become a problem (flooding hazard)

disruption of _____, ______, and _____ of flow variation can impact reproduction and survival for many species

timing, duration, and magnitude

Culverts should be

passable at most flows (seasonality important), adequate depth for largest species, passable by all species (velocity), resting habitat in long spans

supplemental and maintenance stocking

programs used with lotic sportfishes, much less common than in the mid-1900s

Direct manipulations in managing stream biota

usually enhancement of fisheries productivity thru stocking or eradication/control of problem fish

why are fishes being stocked?

angler demand, degraded spawning conditions, translocations of imperiled   fishes (e.g., reintroductions to neighboring headwater streams)

What are the impacts of the stocking program on native fishes?

potential impacts of hatchery or non-native genomes on receiving pops
stocking densities, effects on other fish species
potential disease/parasite introductions
potential to achieve project goals/objectives

Invasion-isolation tradeoff

headwater populations being isolated to reduce predation, competition, or hybridization with non-native fishes. relies on low-head barriers to reduce/eliminate upstream movements of problem fishes

One issue with invasion-isolation tradeoff

genetic effects on the isolated upstream targets, like reduced genetic diversity or genetic drift

How could we help prevent the issue with invasion-isolation tradeoff?

continued stocking of downstream adults to the target population.

Rotenone

a piscicide that is sometimes used in streams after removing native species to kill all non-native fish.

PTRA

Propagation, translocation, reintroduction, augmentation

Rule 1 of PTRA

Determine if necessary. determine need for action within the historic range. Determine habitat viability, need for restoration. May preclude PTRA, but immediate threats may require establishment of an ark population

Rule 2 of PTRA

get approval and advice. regional approval, recovery plans, special permits, IACUC needed

IACUC

Institutional Animal Care and Use Committee

Rule 3 of PTRA

Carefully choose the source pop. genetic/morphological study important. biogeographic patterns of co-occuring species may be good if the species has been extirpated from historic range. make sure you have the right species

what happened with the 20-year captive breeding of Greenback Cutthroat trout?

they found out the hatchery fish were actually colorado river cutthroat trout, then they found out that a GRCT population was discovered on the western divide and propagation continued

What does the example of the Greenback Cutthroat trout tell us?

To make sure you know that the species you are doing PTRA with actually needs it, and to make sure you have the right species.

Rule 4 of PTRA

Naturalize the hatchery environment. No strain, diseases/parasites. good flow, substrate, cover, water quality. food should be appropriate and mimic natural foods. artificial predator stimuli. standardize.

Rule 5 of PTRA

Develop release protocols. Habitat surveys, mitigate factors causing extirpation. Tag individuals for future assessment. Screen for diseases/parasites

Rule 6 of PTRA

Evaluate and adapt. Monitor and modify based on survival, growth, genetic composition. meant reestablish viable pops.

Rule 7 of PTRA

inform the public. educate. conservation easements with landowners of riparian zones. have public recreational/commercial catch data

Water quality first step

identification of point and nonpoint pollution sources

Point-source pollution

any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack

Nonpoint source pollution

runoff from rain and snowmelt carries pollutants into waterways such as rivers, streams, lakes, wetlands, and even groundwater.

Primary nonpoint and point-source water pollutants

nutrients, silt/sediment, organic material, metals and toxic organics, pathogens

Streams can be

autotrophic or heterotrophic, and maintenance of natural canopy cover and allochthonous inputs (CPOM, WD) sustain trophic structure and energy flow in small streams

Perennial stream

flowing water year-round

Intermittent stream

flowing water only during certain times of year

Ephemeral streams

flow only after rainfall

What does ameliorating high flows do?

Reduces watershed impermeability for stream biota

What does enhancing low flows do?

Maintains groundwater for stream biota

Environmental flows

a measure of that water quantity and quality over time. maintaining and monitoring can provide significant benefits to resident fishes.

Common angler regulations

licenses/registration of anglers. stamps. closed areas (no take zones). recreational-only fishing areas (ROFAs). creel limits. possession limits. closed seasons. pollution advisories

Stamps

help reduce mortality and increase targeted funding

closed areas (no take zones)

protect anglers and fishes in habitats or during periods of high vulnerability

Recreational-Only Fishing Areas (ROFAs)

reduce commercial/recreational competition and improve survival

Creel limits

more effective at lower angler densities. limiting catch per angler

Possession limits

usually =creel or 2x creel limit. further reduce fish mortality

Closed seasons

used historically in some streams (put and take fisheries), but “opening day” phenomenon occurs and is problematic

Pollution advisories

warns anglers not to eat fish if the water is polluted.

Length limits

used in many systems. can be a minimum length or maximum length

What is minimum length used for?

ensure reproduction before harvest (but consider genetic selection)

What is maximum length used for?

limits best for protecting stock reproduction and trophy individuals

Slot limits

implemented to establish trophy fisheries. Example would be that you can only catch fish that are between 13-18”.

Gear limits

protects stocks from catch mortality. examples are artificial or single hook lures, fly-fishing only, barbless hooks.

Catch and Release

popular management technique. good if hooking mortality is low. gear (artificial or natural), hooking location, depth (gut/swim bladder is physoclistous fishes), time to release (how long it took you to release), and water temp (stress, metabolism, DO) need to be monitored.

Protected slot limits

foster growth thru the slot and develop “trophy” fisheries. Recruit density not a problem (must harvest below the slot)

Harvest slot limits

maximize densities of large reproducing adults (good for reducing survival bias) while also allowing C&R or minimal-harvest trophy fisheries. recruit density maintained, no harvest below slot.

Some stream fisheries have….

tightly controlled harvests. Ex. Salmon - change year-to-year based on catch quotas and can close quickly with quota is reached

Typical regulations for stream fisheries

Barbless hooks, Mark selective fishery in-season management

Mark Selective Fishery In-season Management

Marking fishes so anglers know its a fisheries fish and not a wild fish. Specific criteria such as legal sized encounters (harvested and released), which, if exceeded, may cause the fishery to be modified or closed to limit impacts on wild stocks.

Jack Salmon

younger and significantly smaller mature male salmon that return to rivers early.

Citizen science and angler data collection

becoming popular with social media. biased by avidity. can be used in analyses, but need to acknowledge the bias. still valuable for trends with similarly biases data. helpful for assessing angler values, knowledge of management regulations and success or failure.

Things that can minimize regulation effectiveness

release mortality, heterogenous catchability, quality-driven effort response

Maintaining groundwater inputs may be

critical to the discharge and thermal regimes of a stream

How is climate change interacting with groundwater availability to eliminate surface flow?

reduced recharge, increased withdrawals by agriculture, industry, municipalities. Doctrine of Prior Appropriation not helping much.