Biodiversity of Fishes on the Boreal Shield in Ontario

Biodiversity of Fishes on the Boreal Shield

in Ontario

Class 10Presentation 1

Thanks to

Nicholas E. MandrakResearch Scientist

Great Lakes Laboratory forFisheries and Aquatic Sciences

Department of Fisheries and OceansBurlington, ON

Outline

Defines some of the biological diversity of fresh water fishes in Ontario

What are the threats to fish biodiversity?

Biodiversity Includes

Species Subspecies Populations / Evolutionary Significant

Units (ESUs) Morphotypes Assemblages / Communities

Species

128 native, 19 introduced fish species in Ontario.

Of the 128 species in 24 families, 5 were endemic to the Great Lakes

No species endemic solely to Ontario. Greatest fish species richness south of the

Shield.

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

0 5 10 15 20 25 30 35 40

No. of Spp.

Paddlefishes

Trout-perches

Sturgeons

Smelts

Silversides

Mudminnows

Eels

Drums

Cods

Bowfin

Topminnows

Temperate Basses

Mooneyes

Gobies

Pikes

Herrings

Gars

Sticklebacks

Lampreys

Sculpins

Catfishes

Sunfishes

Suckers

Perches

Salmons and Trouts

Minnows

Native

Introduced

Great Lakes CiscoesW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Freshwater Fish RichnessW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Species

Greatest fish species richness south of the Shield. Why?

Combination of what happened following the last Ice Age, current climate and water chemistry.

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

postglacial dispersal, climate, water chemistry

morphometry, water chemistry

biotic interactions

modified from Tonn 1990

North America~600 spp.

NorthernNorth America

~130 spp.

Shield~60 spp.

Shield Lakes<30 spp.

evolutionary processes

Postglacial DispersalW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Postglacial DispersalW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Mandrak and Crossman 1992

Some genes from fish that survived in Beringia refugia

Mean Annual Air TemperatureW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

ProductivityW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Species

Few species found in northern Ontario that are not found in south.

Few exceptionsWha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

1 cm

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Subspecies

No longer used by ichthyologists. None listed in official names list by

American Fisheries Society.Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Populations / ESUs Population - group of individuals of single

species inhabiting specific area, limited gene flow with other populations. Many populations restricted to single lakes (e.g.

headwater lakes). Evolutionary Significant Units (ESU) –

population, or group of populations, that is substantially reproductively isolated and represents an important component in the evolutionary legacy of the species.

Populations/ESUs of only a few species in Ontario identified, none comprehensively.

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Distributions of mtDNA lineages among lake trout populations

Wilson and Hubert (1996)

Morphotypes Individuals of a species may exhibit

variation in physical characteristics = phenotypic variation.

May be result of: adaptation to:

different habitats (e.g. sunfishes) different prey to minimize competition (e.g. ciscoes

developing different gill rakers depending on food source)

predation (e.g. sticklebacks with different plates on their backs)

genetic drift caused by: isolation (founder effect) (e.g. Aurora trout isolated in

5 lakes) limited gene flow (e.g. lake trout, little migration)

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

Algonquin CiscoesW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Aurora troutW

hat

is B

iodi

vers

ity?

Wha

t is

Bio

dive

rsity

?

Aurora trout

Brook trout

Communities

Communities – group of interacting species living in a specific area, or all species living in a given area.

Assemblages – limited to specific taxon (e.g. fishes)

Fish assemblages on Shieldsimpler than south of Shield fewer warmwater predators (e.g. basses)

Wha

t is

Bio

dive

rsity

?W

hat

is B

iodi

vers

ity?

What are the threats to fish biodiversity?

1. Habitat alteration, loss

2. Overexploitation

3. Introduced species

4. Atmospheric pollution

1. Habitat alteration and loss Habitat is the physical, chemical and biological

components in a species’ environment required for survival.

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

1. Habitat alteration and loss In southern Ontario, agriculture and urbanization

e.g. habitat loss, runoff effects physical (turbidity) and chemical (nutrients) quality of water.

In northern Ontario, direct and indirect effects of resource extraction.e.g. logging directly affects water supply, physical

(turbidity) and chemical (nutrients) quality of water; logging roads have perched culverts, increased access leads to spread of overexploitation, introduced species.

e.g. mining tailings directly pollute water, smelting can lead to acid precipitation.

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

1. Habitat alteration and lossT

hrea

ts t

o B

iodi

vers

ityT

hrea

ts t

o B

iodi

vers

ity

Perched culverts

Mine tailings

Turbidity

2. Overexploitation

Overfishing exceeds natural mortality of population, or targets spawning stock (typically larger individuals).

Commercial fishing in larger lakes. Recreational fishing in smaller lakes.

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

2. OverexploitationT

hrea

ts t

o B

iodi

vers

ityT

hrea

ts t

o B

iodi

vers

ity 1930s saw demise of commercial catch in L Huron due to over fishing. Sea lamprey may have had an effct as well

1950s saw demise of ciscoes due to over fishing. Ciscoes not affected by lamprey

Great Lakes Ciscoes

Extinct

ExtinctExtirpated in GL

Extirpated in GL*

Extirpated in GL*

* Except Superior

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

3. Introduced Species Species not native to an ecosystem,

introduced deliberately or accidentally. Deliberately through:

authorized stocking (outdated process) illegally to establish “glory hole” for sport or bait

fishes (seeding lakes) releasing unused bait or unwanted aquarium fishes.

Accidentally by ballast water, bait bucket water, boats, movement through canals.

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Smallmouth Bass

Introduced

Source: Checklist of Ontario Freshwater Fishes Annotated with Distribution Maps

(Mandrak and Crossman 1992)

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

May have been in L Ontario spread to upper Gt Lakes after Welland Canal built

3. Introduced Species

Potential impacts on native species: Habitat alteration or destruction (e.g. carp

uproot aquatic plants) Competition with, predation on, native

species. (e.g. lamprey, ruffe) Introduction of diseases and parasites

(e.g. whirling disease in trout)

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

ruffe

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Vanden Zanden et al. 1999

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Using C13/12 ratio gives us idea of trophic position of fish. Higher ratio higher trophic position

Atmospheric Pollution

Anthropogenic contributions to atmosphere can have far-reaching (e.g. global) effects on aquatic environments.

Acid precipitation, climate change.

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Acid Precipitation Direct effects: loss of fish populations Numerous indirect effects.

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Change in Mean Annual Temperature1990-2050

+2°C to 5°C

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Change in Mean Annual Temperature1990-2080

+5°C to 8°C

Thr

eats

to

Bio

dive

rsity

Thr

eats

to

Bio

dive

rsity

Climate ChangeT

hrea

ts t

o B

iodi

vers

ityT

hrea

ts t

o B

iodi

vers

ity

Potential Effects Colonization of Shield by warmwater

introduced species and associated impacts (N.B. requires human assistance).

Negative impacts on cool- and cold- water fishes resulting local and regional decline in condition, abundance and range.

Conclusions

Biodiversity at sub-specific levels largely Biodiversity at sub-specific levels largely unknown.unknown.

Threats: habitat degradation/loss; Threats: habitat degradation/loss; overexploitation; introduced species; overexploitation; introduced species; atmospheric pollution.atmospheric pollution.

Synergistic interaction of threats likely to Synergistic interaction of threats likely to be exacerbated by climate change.be exacerbated by climate change.

Conclusions

Science NeedsScience Needs Identify biodiversity at sub-specific levels.Identify biodiversity at sub-specific levels. Identify limiting factors and threats.Identify limiting factors and threats. Identify mitigation and adaptation strategies.Identify mitigation and adaptation strategies.

Protection and Recovery NeedsProtection and Recovery Needs Identify gaps in protection .Identify gaps in protection . Identify and undertake recovery activities.Identify and undertake recovery activities.