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Sustaining Canada’s Marine Biodiversity: Responding to the Challenges Posed by Climate Change, Fisheries, and Aquaculture Jeffrey Hutchings Dept Biology, Dalhousie University

Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

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Page 1: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Sustaining Canada’s Marine Biodiversity: Responding to the

Challenges Posed by Climate Change,Fisheries, and Aquaculture

Jeffrey HutchingsDept Biology, Dalhousie University

Page 2: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

“Of…major fish stocks supporting Canada’s fisheries… overall fish population sizes have declined by 50 per cent, according to a recent Royal Society of Canada Expert Panel.” Oceana Canada, Sept 2015

Among the top 15 papers ever read at the website of Environmental Reviews:(Hutchings et al. 2012. Climate change, fisheries, and aquaculture: trends and consequences for Canadian marine biodiversity. Env. Rev. 20: 220-311.)

Presentations: • MPs/Senators on Parliament Hill • Canada Oceans Lecture (Vancouver)• Universities (Calgary, Victoria, Queens,

Dalhousie, Tasmania); • Public Lectures (e.g. Orillia, ON; Halifax)

The Report’s recommendations were sent one week ago to several

high-level Liberal Members of Parliament from British Columbia.

Page 3: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Elements of Precaution: Recommendations for the Regulation of Food Biotechnology

in Canada (2001)

Royal Society of CanadaExpert Panel Report (2001)

Spencer Barrett, U. TorontoJoyce Beare-Rogers, OttawaConrad Brunk, U. WaterlooTimothy Caulfield, U. AlbertaBrian Ellis, UBCMarc Fortin, McGillAnthony Ham Pong, OttawaJeffrey Hutchings, DalhousieJohn Kennelly, U. AlbertaJeremy McNeil, LavalLeonard Ritter, GuelphKarin Wittenberg, U. ManitobaCampbell Wyndham, CarletonRickey Yada, Guelph

Communication of science to

decision-makers

Ideal situation occurs when

decision-makers

solicit Expert Panel advice

Page 4: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Objectives:• Document trends in marine biodiversity• Describe trends in key biodiversity stressors and

predict their consequences for sustaining biodiversity• Audit Canada’s performance in meeting national and

international obligations to sustain biodiversity

(2012)

Page 5: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Territorial Seas(Exclusive Economic Zone)

-------------------------Canada: 2,687,667 km2

EU: 1,008,904 km2

US: 796,441 km2

Longest coastline in the world (~230,000 km)

8 of 10 provinces and all 3 territories (86% of the population) border salt water

Canada: An Ocean Nation?

Page 6: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Canada’s Immense Ocean Geography Comes WithChallenging Ocean Stewardship Responsibilities

Haida Gwaii, BC

Johnstone Strait, BC Battle Harbour, Labrador

Cape Race, NewfoundlandAxel Heiberg Island, Nunavut

RecommendationThat the Government of Canada identify international

leadership in oceans stewardshipas a top government priority.

Page 7: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Oceans: Some Global Considerations

Habitat for 1-2 million species

1 in 3 humans depend on fish as their primarysource of protein

90% of all ocean fisheries are coastal

45% of humans work within 100 km from a coast,generating ~61% of the world’s total Gross NationalProduct (GNP)

Page 8: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Ocean Ecosystem Services

Secure access to wild, low-fat, highly nutritious food

Carbon sequestration

Source of oxygen (> 50% of what we breathe)

Socio-economic well-being of coastal communities

Recreation, tourism, transportation

What is the monetary value of ocean ecosystem services?

Page 9: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

What is the Monetary Value ofCanada’s Ocean Ecosystem Services?

Canada’s Boreal Forest: $703 billion annually

Southern Ontario’s Greenbelt: $2.6 billion annually

Mediterranean Sea: €26 billion annually

Secure access to wild, low-fat, highly nutritious food

Page 10: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Whichspecies?

Which fishpopulations?

How were the ‘zone’ categories scientifically determined?

Status of Major Fish Stocks in Canada (Environment Canada, 2015)

www.ec.gc.ca/indicateurs-indicators/default.asp?lang=en&n=1BCD421B-1

For species in the ‘cautious’ and ‘healthy’ zones…

Page 11: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

B BMSY

0.2

Canada

Current fish biomass compared tobiomass at maximum sustainable yield

TheTarget

Canada’s marine fishes are atabout 0.3 of, or 70% lower than, the target.

Hutchings et al. 2012. Expert panel report on Sustaining Canadian Marine Biodiversity. Royal Society of Canada.

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0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

B BMSY

0.2

US Argentina Australia

EU

Canada

International

Western Pacific

International

New Zealand South Africa

Current fish biomass compared tobiomass at maximum sustainable yield

Protected Areas?

TheTarget

Canada’s marine fishes are atabout 0.3 of, or 70% lower than, the target.

Hutchings et al. 2012. Expert panel report on Sustaining Canadian Marine Biodiversity. Royal Society of Canada.

Page 13: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

0.8% of Canada’s oceans are in Marine Protected Areas (MPAs)

0.11% of Canada’s oceans are closed to extractive use (CPAWS 2015)

10.5% of Canada’s land (3 times size of Germany) is protected2020Percentage of area protected

Terrestrial

Marine

Page 14: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

“Increase the proportion of Canada’s marine and coastal areas that are protected to five percent by 2017, and ten percent by 2020.”

Page 15: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Canada’s Marine Biodiversity ObligationsExamples of National and International Biodiversity ObligationsProtect biodiversity Adopt precautionary approach; adopt ecosystem approachProtect and recover species at riskProtect marine environment from land-based activitiesIntegrated management plans for coastal & marine watersMaintain sustainable fisheries & sustainable aquacultureEstablish a network of Marine Protected Areas (MPAs)Protect vulnerable, rare & fragile ecosystems

VanderZwaag et al. (2012) Environmental Reviews

“As determined by the Royal Society of Canada in 2012,

Canada has failed to protect its aquatic biodiversity,

despite having the legal and policy framework to do so.”

(Ecology Action Centre, October 2015)

Page 16: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

RecommendationThat Fisheries & Oceans Canada

rapidly increase its rate of statutory and policy implementation.

Page 17: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

RecommendationThat Canada implement statutory renewal

to fulfill national and internationalcommitments to sustain marine biodiversity.

USA

Magnuson-StevensFishery Conservation and Management Act (1976)

Australia

Environment Protectionand BiodiversityConservation Act (1999)

Norway

Nature Diversity Act (2009)

Page 18: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

What is biodiversity?Variability, or differences, among living organisms

(e.g., species, populations, genes).

Page 19: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Marine taxonomic group

Estimated no.species:

CANADA

Estimated no.species:

GLOBAL

Microbes (Arctic) 9,500-54,000 Not estimatedPhytoplankton 1,657 ~5,000Macroalgae 860-979 ~9,300Cold-water corals 104 ~700Sponges 265 5,000-10,000Zooplankton 900 Not estimatedBenthic infauna 2,127 Not estimatedFish: sharks,

skates, rays61 ~1,100

Fish: other (bony) 831-971 ~14,200Seabirds 38-64 383-475Mammals 52 125Hydrothermal vents 66 592

Trend dataavailable

Canada’s Marine Species RichnessCanada’s Marine Species Richness (Expert Panel, 2012)

Page 20: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Ogac Lake, Frobisher Bay (620 )

West Coast of Ellesmere Island (810 )

The Arctic

© J Hutchings

© J Hutchings

Phytoplankton

Phytoplankton

Page 21: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Many marine mammals areincreasing in abundance

Trends in Marine Biodiversity

Page 23: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

COSEWIC Species at Risk(April 1978-Nov 2015)

(Extinct 15)Extirpated 23Endangered 316Threatened 167Special Concern 205

711

17% of species at risk are marine

Page 24: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Group Wildlife Species at Risk(Extirpated, Endangered,

Threatened, Special Concern)Fishes 74Mammals 34Birds 9Molluscs 3Reptiles 4Total 123

Canadian Marine Wildlife Speciesassessed by COSEWIC as being at risk

Trends in Marine Biodiversity

Page 25: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

NE Pacific OffshoreThreatened

(2008)

West Coast TransientThreatened

(2008)

Northern ResidentThreatened

(2008)

Southern ResidentEndangered

(2008)

Killer Whale

2008

DietsResidents: salmonTransients: seals

Page 26: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Northern Right WhaleEndangered

Northern Bottlenose WhaleEndangered

Page 27: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Group Wildlife Species at Risk(Extirpated, Endangered,

Threatened, Special Concern)Fishes 74Mammals 34Birds 9Molluscs 3Reptiles 4Total 123

Canadian Marine Wildlife Speciesassessed by COSEWIC as being at risk

Trends in Marine Biodiversity

Page 28: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Ivory Gull(Endangered)

But, Northern Gannetshave been increasing

1986-2006: 80% decline

Page 29: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Group Wildlife Species at Risk(Extirpated, Endangered,

Threatened, Special Concern)Fishes 74Mammals 34Birds 9Molluscs 3Reptiles 4Total 123

Canadian Marine Wildlife Speciesassessed by COSEWIC as being at risk

Trends in Marine Biodiversity

Page 30: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Porbeagle (Atlantic)89% decline since 1961

American Plaice(Atlantic)

Newfoundland andLabrador: 95%

decline since 1960

© Canadian SharkResearch Lab

Fishes

Basking Shark(Pacific)

>90% sincemid 20th century

Page 31: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

British Columbia’s Rockfishes

Bocaccio

Threatened (2007): 80-96%

Canary Rockfish Longspine ThornyheadSpecial Concern

(2007)

Endangered (2013): 95-99%Rougheye Rockfish

Special Concern(2007)

Page 32: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Ogac Lake

Depletion of Canadian

Atlantic cod

A loss of 2 billion breeding individuals

By weight, loss of ~27 million adult humans

Hutchings & Rangeley (2011) Can. J. Zool.

90% decline

Page 33: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Trends in BiodiversityTrends in Biodiversity Stressors

Page 34: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

LabradorCurrent

Gulf Stream

Trends in Physical and ChemicalOceanographyTemperature

Salinity (salt content)Ocean stratification (layering)

Acidity (pH)Oxygen content

OttawaMarseille

Iqaluit Bergen

Page 35: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Axel Heiberg Island (780N, 890W)15 August 2005

Global climate change(IPCC, 2013)

• Since 1960, the oceans’ net heat uptake has been 30 times greater than that of the atmosphere

Since 1971, 90% of theglobal heat uptake

has been borneby the oceans;> 30% of CO2 is

absorbed by the oceans

Increased CO2leads to

more carbonic acid(ocean acidification)

and lesscalcium carbonate

(vital for manyinvertebrates)

Page 36: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Gulf ofSt. Lawrence

Page 37: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

(surface air temperatures strongly correlated with sea surface water temperatures)

Gulf of St. Lawrence is warming • sea surface temperature increased ~2oC since mid-1980s• 2 warmest years in the last century occurred in the last 16yrs

Page 38: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Gulf of St. Lawrence is experiencing reducedoxygen levels in deep (295m) waters

• deep waters briefly hypoxic in early 1960s (<30% O2 saturation)• hypoxic conditions have existed since 1984

British Columbia: all time series of at least 25 years in durationshow declining trends in O2 at depths between 100 and 400m(greatest reductions at 200-300m)

Page 39: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Sea Ice: Arctic…and Atlantic

Page 40: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

~14% per decade

Decline in Gulf of St. Lawrence ice extent: ~14% in past 30 years

Page 41: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Lower St. Lawrence

Estuary

200-320m

Dufour et al. (2010)

Increase in acidity since

1930spH

Page 42: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Trends in Multi-species

FishingMortality

(blue lines)

Pacific and Atlantic

Pacific

AtlanticFish

ing

mor

talit

y (F

) rel

ativ

e to

FM

SY

Overfishing: when BLUE line is above RED line

Globally, over-fishing results in losses of:• $50 billion

annually; • $2 trillion in past

30 years (World Bank)

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1985 1990 1995 2000 2005 2010 2015

0

50000

100000

150000

200000A

quac

ultu

re P

rodu

ctio

n (to

nnes

) Total

Finfish (mainly salmon)

Shellfish (mainly mussels & oysters)

Canada

Value of Canadian aquaculture (1986-2013) peaked in 2006

(~ $1billion, in 2011 $)

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OverviewTrends in Biodiversity & Its StressorsEffects of Stressors on Biodiversity

The Expert Panel Report

Page 45: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

• spatial shifts in species distributions

Consequences of Climate Changeto Marine Biodiversity

• structural and functional changes tomarine ecosystems (e.g., food webs)

• alteration or loss of habitat• temporal/spatial changes in productivity

What will this mean for populations?

Page 46: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

ArcticOceanArctic cod

Capelin

Thick-billed murre

Page 47: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Fisheries-inducedalterations to

marine food websand marineecosystems:

Northwest Atlantic

Page 48: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

1975 1985 1995 2005 20150

5001000150020002500

Land

ed V

alue

(x10

00, i

n 20

11 d

olla

rs)

All fisheries

Atlantic

Pacific

1990 1998 2006 20140

100200300400500600 Groundfish (bottom) fisheries

1990 1998 2006 20140

40

80

120

160 Pelagic/Other finfish fisheries

1990 1998 2006 20140

100200300400500 Diadromous fisheries (e.g. salmon)

1990 1998 2006 20140

500

1000

1500

2000Invertebrate fisheries

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Elvers (young American eel)American eel is a Threatened species

As much as C$7,300(€5,100) per kilogram in 2015!

Elvers,in parking lot,

Bangor, Maine,…in the rain

(20 Nov. 2015)

Page 50: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Warmer

Fresher

Warmer

Fresher

Pacific Ocean

1920 1940 1960 1980 2000

1920 1940 1960 1980 2000

Tem

pera

ture

Salin

ityTe

mpe

ratu

reSa

linity

Dominant species of zooplankton (Neocalanusplumchrus) in Strait of Georgia is: decreasing in abundance blooming earlier (by 50 days, compared to 1970s)

What are the consequences of such phenological change

for marine species(birds, fishes)?

British Columbia’s waters have becomeincreasingly warmer and fresher

Page 51: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Cod Reproductive (Parental) Population Size

Pershing et al. (2015) Science

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Pershing et al. (2015) Science

Cod Reproductive (Parental) Population Size

Small population size

Small populations are more vulnerable to stochasticity than large populations.

Page 53: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Population Productivity

(per capitapopulation growth rate; ora population’s‘compound rate of interest’)

Abundance

Population Threshold?

A Tipping Point?

The dome-shaped curve is indicative of an Allee Effect(or depensation).

Page 54: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Populationsshowing recoveryafter fishing stopped(black lines)

Populationsshowing little or norecovery after fishing stopped (red lines)

Hutchings (2015)Proc. R. Soc. B

Population sizeas a proportion of

maximumobserved size,

Nmax

Page 55: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Population Productivity

(per capitapopulation growth rate; ora population’s‘compound rate of interest’)

Abundance

Population Threshold?

A Tipping Point?

~10% of maximum

Caveat: There are unlikely to be ‘tipping points’ per se

More important?

The time period that abundance

remains low.

Page 56: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Median numberof years below

10% of Nmax

Recovered/Rebuiltpopulations: 0 yr

Populations exhibitinglittle or no recovery: 8.5 yr

Population sizeas a proportion of

maximumobserved size,

Nmax

Hutchings (2015)Proc. R. Soc. B

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The greater the depletion and the longer the period of depletion: the longer the recovery period the more uncertain the recovery

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Kuparinen, Keith & Hutchings (2014) Conserv. Biol.

Allee effect greatly increases

the time to recovery and the

uncertainty of recovery

(2014)

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rmax

0 20 40 60 80 100

Recruits perSpawnerPer capitaPopulationgrowth rate

(r)

Nat

ural

Mor

talit

y (M

)

Spawning Stock Biomass(parental population size)

Fisheries Science:Implicit assumption is

that death due to natural causes does not change with abundance.

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Biomass

NaturalMortality

Fishing (F)

Swain and Benôit (2015) Mar Ecol Prog Ser

Natural mortality increasing as abundance

declines.

Recruitment

Page 62: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Many depleted fishes show little or no recovery, despite

massive reductions in fishing mortality.

Atlantic cod

Porbeagle

White hake

Northern wolffish

Cusk

Winter skate

Bocaccio

Page 63: Sustaining Canada’s Marine Biodiversity: Responding to the Challenges … ·  · 2017-05-29Sustaining Canada’s Marine . Biodiversity: Responding to the. Challenges Posed by Climate

Northern Cod

Forecasting recovery

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2007 2012

Former CanadianFisheries Minister

John Crosbie

99% decline

Canadian NorthernCod Stock

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2007 2012

Northern cod today

Currently at 26% of thelimit reference point (Blim)

DFO (2015) CSAS Science Response 2015/018

Currently at ~5% of thestock size in early 1960s

(Canadian Journal of Fisheries & Aquatic Sciences; October 2015)

There are still no recovery targets or

harvest control rules for northern cod

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RecommendationThat the Government of Canada resolveregulatory conflicts of interest affecting

Canada’s progress in fulfillingobligations to sustain marine biodiversity.

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RecommendationThat the Government of Canada reduce the

discretionary power in fisheries managementdecisions exercised by the

Minister of Fisheries and Oceans.

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The simplest and best strategy: protect existing diversity rebuild depleted populations and species to restore

natural diversity.

“Such a strategy will restore the natural resilience of Canada’s ocean ecosystems to adapt in response to the challenges posed by climate change and other anthropogenic activities.”

Expert Panel’s Over-arching Conclusion