Centre for Ecological and Evolutionary Synthesis

Sea fisheries- and integrated marine environment management

Geir Ottersen

Bio4150-9150 15/4-2013

I’ll be talking about • Traditional fisheries management • Fisheries management within the precautionary principle • Ecosystem based fisheries management • Examples of failed and successful fisheries management • Integrated management plans for the North, Norwegian, and Barents Seas • The Arctic Ocean

Maximum sustainable yield Principle: catch = population growth surplus MSY is, theoretically, the largest catch that can be taken from a stock over an indefinite period. MSY aims to maintain the population size at the point of maximum growth rate by harvesting the individuals that would normally be added to the population, allowing the population to continue to be productive indefinitely.

MSY assumes logistic growth

dN = dt

K-N K N·R

maximum growth rate

reduction due to competition,

density-dependence

carrying capacity

K-N K N·R·

N K/2 K 0

Pop. growth (”production”)

Decrease in production because of dd effects

Small production because of few fish

Max catch= max production= MSY

MSY was a leading fisheries management strategy until well into the 1980s, is still used, but has a number of serious weaknesses: - The concept is often difficult to apply in practice, ignores uncertainty - Purely single species, no consideration of trophic interactions - Tends to treat all individuals in the population as identical, ignoring size and age structure - Doesn’t take into account that productivity varies with environmental conditions - Doesn’t account for spatial variability in productivity - Ignores the issue of bycatch

Biological reference points – the precautionary principle I

Biological reference points represent either a level of fish mortality or a level of the spawning stock.

Since 1998, ICES has defined precautionary-principle reference points and attempted to quantify these for most stocks.

overfished and overfishing

overfished

overfishing

Blim - a bottom limit for the spawning stock of a species If the spawning stock falls under that limit, there is great chance of poor recruitment Flim - an upper limit for fishing mortality If this limit is exceeded over a long period, there is a high probability that the stock will fall below Blim

The precautionary approach implies that the stock should be kept well above Blim and so a precautionary level (Bpa) is set at a higher level which gives reasonable certainty that the stock will stay above Blim Precautionary fishing mortality Fpa < Flim

Biological reference points – the precautionary principle II

Management strategies: Quotas • Three main strategies for the setting of quotas:

1. Constant quotas + : economical/societal benefits of stable catch - : unstable – a small stock may be fished out not economically optimum yield for large stocks

2. Constant harvest rate (constant % of biomass caught) + : catch every year - : not economically optimum yield

3. Constant escape (constant biomass escapes catch) + : economically optimum yield - : economical/societal drawback of unstable catch levels (some years no catch at all)

• Additional strategy to quotas: Some areas with no fishing/catch

• Best suited for demersal fish and evertebrates with relatively small migration (flatfishes, lobster, scallops)

• Not well suited for highly migratory fish (mackerel, herring..) (with different habitats according to life stage and season)

Management strategies: Marine reserves/protected areas

Four small reserves established in 2006

• Already in 2010 clear trend towards many more lobsters in the areas

• Significant increase in mean size/length

• No increase in lobster numbers in control areas with lobster fishing

Management strategies: Marine reserves/protected areas Example: Lobster reserves around the Norwegian Skagerrak coast:

Traditional fisheries legislation only regulates the relation between fishers and ressource

A move from single species to ecosystem based management

Graphics from WWF

Modern fisheries legislation ”Havressursloven” regulates the relation between fishers and the whole ecosystem

Graphics from WWF

Example of failed management 1: Labrador-Newfoundland cod

• The fishery was of great economical, societal and political importance from the 1500s

• Dramatic collapse of the stock around 1990-1991

• The fishery was stopped in July 1992 and there is still no indication of a full-scale reopening

• 35000 Canadians lost their jobs

• Reasons for the collapse:

1. Stock estimates based upon ”catch per unit effort” (CPUE). Fish concentrated in large shoals as numbers dropped → stock size overestimated

2. High unaccounted mortality due to bycatch and dumping of too small/unwanted fish

3. Simultaneously the climate changed towards colder unfavourable conditions

4. Rebuilding of the stock is extremely slow – has the ecosystem switched to an alternative stable state with more shrimps, crabs and marine mammals?

Example of failed management 1: Labrador-Newfoundland cod

• Huge stock during the 1950s

• Long lived → a few good year classes is enough to give a large stock over a prolonged period (e.g., 1950s)

• Stock more or less wiped out by the late 1960s/early 1970s

Example of failed management 2: NSS herring in the 1960s

WHY? Catch efficiency increased during the 60s (sonar, power block, synthetic nets) Dense schools also at low numbers (catchability still high) Catch (too) high as late as 1969 Cold unfavourable conditions

• Herring and cod normally produce many recruits in warmer years

• 1983: Warm year, good year class of herring and cod at early stages → researchers and managers predicted good cod fishery in the late 1980s

Example of failed management 3: The Barents Sea in the 1980s

What happened: Predation by cod and herring and fishery caused the capelin stock to collapse → crisis in the cod fishery in the late 1980s → - 100 000 harp seals ”grønlandssel” seeking food towards the coast drowned in nets - 200 000 sea birds died

BUT One did not take into consideration that 1-2 year old herring eat capelin larvae Capelin is the key prey for cod (rich in fat)

Common factors behind mismanagement examples

1. Overestimated stock size (Newfoundland cod, NSS herring) – typically based upon catch-per-unit-effort

2. Underestimated mortality due to bycatch (Newfoundland cod) or predation by other species (Barents Sea capelin)

3. Environmental shifts changes the sustainable catch level (Newfoundland cod, NSS herring)

4. Ignorance of trophic interactions (Barents Sea, lack of rebuilding of Newfoundland cod)

The stock is doing well! Total stock estimate: 3.5 million tonnes Expected spawning stock 2013: 2.2 million tonnes Blim: 220 000 tonnes Bpa : 460 000 tonnes Catch 2011: 720 000 tonnes Norwegian catch 2011: 332 000 tonnes Norwegian catch 2011 value: 3.9 billion NOK Agreed quota for 2013: 1 million tonnes

Examples of successfull management: Barents Sea cod now I

Examples of successfull management: Barents Sea cod now II

Why are we doing well now?

Better management practices • HCR implemented • IUU fishing reduced

Luck (favourable climate)

IMR’s SURVEY ON SPAWNING COD - ”SKREI”

2013 Late March 2013: Enormous amount of spawning cod – new record!

Integrated management plans ”Meldinger til Stortinget” White papers to the Parliament

Norwegian Sea 2009 Barents Sea 2006 revised and updated 2011

North Sea 2013, being finalized now

The Norwegian Sea

Status reports by sector

Report on societal issues

Vulnerability of

areas of particular biological value

Integrated management plan for the Norwegian Sea ” Melding til Stortinget”

Environmental impact assessment by sector

Indicators, reference values

and action thresholds

Maritime transport Fisheries External

pressures

Assessment of cumulative effects Conflicts Needs for further Cumulative of interest knowledge effects

Petroleum/ energy

Description of the environment including areas of particular biological value

The North Sea

Human impact on the North Sea

Report on vulnerability of particularly valuable areas

The North Sea Area report including environmental and ressource description

Identification of areas of particular biological value

With areas of particular biological value we mean: - Areas that are important for biological production - Areas that are important for biodiversity

Within these two main criteria are a wide range of sub-criteria

The North Sea

1 - Bremanger to Ytre Sula 2 - Korsfjorden 3 - Karmøyfeltet 4 - Boknafjorden/Jærstrendene 5 - Listastrendene 6 - Siragrunnen, 7 - Transekt Skagerrak, 8 - Ytre Oslofjord 9 - Skagerrak 10 - sandeel grounds 11 - sandeel grounds 12 - mackerel grounds + coastal zone

North Sea: Areas of particular biological value

North Sea: Areas of particular biological value

1 - Bremanger to Ytre Sula 2 - Korsfjorden 3 - Karmøyfeltet 4 - Boknafjorden/Jærstrendene 5 - Listastrendene 6 - Siragrunnen, 7 - Transekt Skagerrak, 8 - Ytre Oslofjord 9 - Skagerrak 10 - sandeel grounds 11 - sandeel grounds 12 - mackerel grounds + coastal zone

Example: Area 7 - Transect Skagerrak

The aim is to protect the sub-surface landscape with its plant and animal life, representative of Skagerrak with the broad range of nature types present. The area spans from waters sheltered between islands and skerries to strongly exposed offshore regions.

From National plan for marine protected areas

Example: Areas 10-11: Sandeel ”tobis” spawning/wintering areas

Sandeel is an ecologicaly and commercially important fish species in the North Sea

Vulnerability of the biologically valuable areas

Vulnerability is here a measure of how and how much an activity influences the identified valuable area

The vulnerability of each of the biologically particularly valuable areas was assessed in terms of the resilience of species and habitats to anthropogenic pressures.

Pressures include fisheries, maritime transport, petroleum activities and long-range transboundary pollution.

Area of especial value

Value Vulnerability

Present activity level Possible future activity level

Normal activity Acute

accidents

SVO 10: Vikingbanken

Spawning and habitat area for sandeel, feeding area for whale

Impacted by fisheries, toxic substances, marine waste Vulnerable to heavy fishing of sandeel, environmentally hazardeous substances and marine waste

Vulnerable to oil pollution from accidents with oil spills from ships or platforms

Vulnerable to heavy fishing, oil pollution and area use by petroleum activities

Vulnerability evaluation (example)

The Barents Sea revised and updated report

Fisheries activity 2009 (vessels > 21 m)

Ship traffic 2nd half of 2010

Prospects for petroleum extraction mapped 2007-2009

Areas of particular biological value and vulnerability (in green)

Nature types of particular biological value and vulnerability Lofoten-Vesterålen-Troms

Examples of red-listed species in the area

A new ocean opening for human use – how to manage it?

Minimum in 1979

MINIMUM ICE COVERAGE

Suggested by IMR for Norwegian part: A baseline study: - Planning of a joint survey in the Arctic Ocean (using the new ice-going vessel) scheduled for autumn 2016 Scientific research includes - Evaluate the impact of changes in productivity and possible restructuring of the Arctic marine ecosystem - Investigate the interplay between the Arctic Ocean and the shallow shelves - Evaluate environmental risks of human activities

ARCTIC OCEAN: - Mostly international waters – makes management complex - Arctic council will play an important role (Nordic countries, USA, Canada, Russia)

Do we expect expansion of Barents Sea fish populations into the Arctic?

“Atlantic cod have a low potential to establish spawning grounds in the Arctic….demersal shelf species”

Hollowed et al. Fish. Oceanogr. 2012

COD Distribution autumn 2012

Do we expect expansion of Barents Sea fish populations into the Arctic?

“Capelin potentially could expand in the Arctic if prey concentrations were sufficient to sustain increased populations”

Hollowed et al. Fish. Oceanogr. 2012

CAPELIN (LODDE) Distribution autumn 2012

That’s all, thanks for your attention