Transcript Risk of Extinction of Marine Fishes

RISK OF
EXTINCTION OF
MARINE FISHES
CHRISTINE HUNG
ERNEST TSUI
QUINCY LAM
OUTLINE
 Causes of extinction risk
 Endangered species assessment organizations
 Major themes and ideas of the paper
 Criteria for extinction
 Management/Implementation
 Critiques
WHAT IS
EXTINCTION?
MAJOR CAUSES OF EXTINCTION:
OVEREXPLOITATION
 Overfishing
(Hutchings 2005)
 By-catch
(Polidoro et al. 2008)
 Tourist industry
(Taylor et al. 2014)
(IUCN 2008)
http://en.wikipedia.org/wiki/Parrotfish
http://wwf.panda.org/what_we_do/endangered_species/cod/
MAJOR CAUSES OF EXTINCTION:
HABITAT LOSS/DEGRADATION
 Natural causes
 Human-induced causes
 Anthropogenic effects
(Dulvy et al. 2003)
Example: Coral reefs faced with “Triple Jeopardy”
(Olden et al. 2007)
Source:http://climate.nasa.gov/system/news_items/main_images/13_newsPage-13.jpg
MINOR THREATS OF
EXTINCTION
 Invasive species
 Climate change
 Pollution
 Disease
(Dulvy et al. 2003)
LIFE HISTORY &
VULNERABILITY
 Vulnerability to capture
versus vulnerability to
overexploitation
(Taylor et al. 2014)
 Large body size
 Small geographical range
 Habitat specialization
(Dulvy et al. 2003)
(Dulvy et al. 2003)
COSEWIC – MARINE FISHES SPECIES
SPECIALIST SUBCOMMITTEE (SSC)
Legislative mandate to assess risk of extinction status of
marine fish species
Use 5 non-mutually exclusive groups of marine fish
1) Anadromous species
2) Elasmosbranchs
3) Species of high maximum age
4) Species of large maximum size
5) Species that have undergone substantial declines
(Powles 2011)
IUCN
41, 500 terrestrial plants and
animals assessed, only 1, 500
marine species
6 major marine species
groups assessed
 Sharks and rays
 Groupers
 Reef-building corals
 Seabirds
 Marine mammals
 Marine turtles
(IUCN 2008)
(Polidoro et al. 2008)
REYNOLDS ET AL.
SUMMARY/REVIEW
 Current Status
 Causes of declines and threatened status
 Correlates of vulnerability
 Relevance to extinction risk assessment
CURRENT
STATUS
 Only 6% of the world’s fish have
been examined
 Logistically difficult to record
and maintain detailed
information on things that live
underwater
 Census of marine life project
who oversaw some of the most
recent biological explorations of
the sea discovered around 6000
potential new species in 10
years
(http://www.coml.org)
CURRENT STATUS
(Reynolds et al. 2005)
CAUSES OF CURRENT
STATUS
 Documentation on species deemed threatened are often
lacking
 Focus of assessments are biased
Focus is on groups of species that are considered a
priori to be under the greatest threat
IUCN focusses on Elasmobranchs, groupers and
wrasses
 Most assessments occurred near shores
(Reynolds et al. 2005)
DECLINE STATISTICS
 As of 2001, marine fish has
declined an average of 65%,
29% of that by more than 80%
 Estimates of more than 97%
of biomass of large fishes (466kg) has been removed from
the North Sea
(Reynolds et al. 2005)
CAUSE OF DECLINE AND
THREATENED STATUS
 Many disappearances were not noticed until long after
they happened
 Most extinctions have been detected retrospectively using
indirect methods
 Our best population census techniques often have little
power
(Dulvy et al. 2003)
 Major cause of decline is
exploitation
 Efforts to reduce fishing
has not been adequate
(Dinmore et al. 2003)
OVEREXPLOITATION &
HABITAT LOSS
Overexploitation
 Perceived as the main cause of declines
 A biased viewpoint
Habitat Loss
 Restricted habitat = restricted population size
 Habitat loss from human activities = large impact (Hawkins et al.
2000)
e.g. coral reefs
(Reynolds et al. 2005)
CORRELATES OF
VULNERABILITY
 Dependent on interaction between extrinsic threats and
intrinsic ability of population to adapt to changes
 Large bodied fish heavily fished
(Jennings et al. 2001)
IMPORTANCE OF LIFE
HISTORY
Life history
Growth rate
Natural mortality rates
Maximum life span
Age at maturity
Reproductive output
(Charnov 1993)
LARGE-BODIED FISH
 High fecundity
 Repeated breeding
 Large number of eggs
Reality of Large-Bodied Fish
 Age at maturity and adult survival determines growth rate
(Caswell 2001)
 Low growth rate at small population size
 Much lower reproductive rate than expected
(Reynolds et al. 2005)
LIFE HISTORY
(Reynolds et al. 2005)
RELEVANCE TO EXTINCTION
RISK ASSESSMENT
 High Fecundity: a changing paradigm
 High population fluctuation is not the norm
 Current IUCN criteria inefficient
(Dulvy et al. in press)
NEW SPECIES
ASSESSMENT METHODS
 New search parameters:
Body size + Geographic range
Fuzzy logic computation
 New assessment parameters
(Dulvey & Reynolds 2002)
(Cheung et al. 2005)
Life history + IUCN criteria (COSEWIC)
Life history dominant (AFS and CITES)
CATEGORIES OF
EXTINCTION RISK
 Distinct Population Segment (DPS) and Evolutionarily
Significant Unit (ESU)
 Vulnerable
 Threatened
 Endangered
 Special Concern
 Conservation Dependent
(Musick 2011)
(Musick 2011)
MAIN APPROACHES TO
MEASURING EXTINCTION
RISK
 Life Histories and general trends
 Time Series
 Demographic analysis
(Dulvy et al. 2004)
GENERAL TRENDS
 Species have been found to have different responses to
extinction risks (Musick 2011)
 Extinction risks vary between species groups and among
different body sizes (Musick 2011)
 Fecundity, water temperature, competition, and habitat
vulnerability are some factors that may influence survival
rates (Musick 2011)
BIOLOGICAL REFERENCE
POINTS (BRP)
 Reference points have been developed to find potential
risks
 Production Models (Dulvy et al. 2004)
 Yield Per Recruit (Musick 2011;Dulvy et al. 2004)
 Stock-Recruitment (Musick 2011)
 Spawning Stock Biomass per recruitment (Musick 2011;Dulvy et
al. 2004)
AFS RISK CRITERIA FOR
DETERMINING SPECIES
AT RISK
 Identify DPS at risk at an early stage to avoid listing it as
threatened or endangered
 Reduce the probability of under or overestimating
extinction
 Use best existing knowledge of stock dynamics and apply
them to low populations
 Allow experts to discuss about life history and
conservation status to reduce risk of extinction
(Musick 2011)
ADDITIONAL CONSIDERATION
FOR EXTINCTION RISK MODELS
 Geographical range that should be considered for a unit
 Ecological specialization
 Minimum viable population size
 Comparability of threat criteria
(Dulvy et al. 2004)
EXAMPLE STUDY:
CORAL REEFS
Carpenter et al. 2004`s paper “One-Third of Reef-Building
Corals Face Elevated Extinction Risk from Climate Change
and Local Impacts”
Coral Reef Background
 Coral Reef Systems contributes to marine biodiversity
Facing threats at a global and local scale
SPECIES SPECIFIC
RISK
 231 coral reef species were listed under threatened
categories in IUCN
 40% of the 704 species are reef-restricted 303 of 704
species are highly susceptible to bleaching
 Susceptible to general anthropogenic disturbances
(Carpenter et al. 2008)
GENERAL STATE OF
CORAL REEF SYSTEM
 Eastern tropical pacific reef systems affected by warming
effects
 Slow recovery in remote regions
 1998 Indian Ocean mass bleaching affected coral reef
systems and reducing structure
 Cascading effect on fish populations
(Carpenter et al. 2008)
CORAL REEF MANAGEMENT
AND IMPLICATIONS
 Possibility of going extinct,
depending on its ability to adapt to
climate change (Carpenter et al. 2008)
 Funding has been implemented to
protect marine areas from
overfishing, controlling tourism
and coral reef damage but may not
be effective in protecting coral reef
systems (Goreau et al. 2001)
Global Scale Management:
Autonomous Reef
Monitoring Structures
(ARMS)
 Need to address root causes of
mortality in order for proper
protection (Goreau et al. 2001)
http://www.pifsc.noaa.gov/cred/survey_methods/a
rms/overview.php
MORE CRITIQUES
 COSEWIC (Polidoro 2011)
 IUCN (Dulvy et al. 2004)
 Problems with models? Makes too many assumptions
(Dulvy et al. 2004)
 Size-based effects on extinction risk may be irrelevant
with life histories (Olden et al. 2007)
QUESTIONS?
DISCUSSION QUESTIONS
1.
Even if we gain a greater understanding of marine fish
species, will the ongoing effects of climate change affect
our ability to conserve species at risk?
2.
How should IUCN better refine their criteria for evaluating
marine fish species at risk?
3.
What alternatives, beside hatchery stocking, can be
implemented towards managing threatened fish species?
4.
With the cost and difficulty of conducting identification and
stock assessment of fish species, should we continue the
same practices, even though we currently don’t have an
effective method of conserving threatened species?
5.
Once a prominent commercial viable fish has gone extinct,
will fisheries begin to decrease exploitation decrease?
LITERATURE CITED
Baillie, J. E. M., Hilton-Taylor, C. & Stuart, S. N. (eds) 2004 2004 IUCN red list of threatened species. A global assessment. Gland,
Switzerland/Cambridge: IUCN.
Caswell, H. 2001 Matrix population models, 2nd edn. Sunderland: Sinauer.
Carpenter K.E., A. Muhammad, G. Aeby, R.B. Aronson, S. Banks, A. Bruckner, A. Chiriboga, J. Cortes, J.C. Delbeek, L. DeVantier,
G.J. Edgar, A.J. Edwards, D.
Fenner, H.M. Guzman, B.W. Hoeksema, G. Hodgson, O. Johan, W.Y. Licuanan,
S.R. Livingstone, E.R. Lovell, J.A. Moore, Clarissa Reboton,
Z.T. Richmonds, A.D. Rogers, J. Sanciangco, A.
Sheppard, C. Sheppard, J. Smith, S. Stuart, E. Turak, J.E.N. Veron, C. Wallace, E. Weil, and E. Wood. 2008. Onethird of reef-building coral face elevated extinction risk from climate change and local impacts. Science 25: 560-563.
Coˆ te´, I. M. & Reynolds, J. D. (eds) In press. Coral reef conservation. Cambridge: Cambridge University Press.\
Dulvy, N. K., Jennings, S., Goodwin, N. B, Grant, A. & Reynolds, J. D. In press. Comparison of threat and exploitation in status in
North-East Atlantic marine populations. J. Appl. Ecol.
Dulvy, N. K., Metcalfe, J. D., Glanville, J., Pawson, M. K. & Reynolds, J. D. 2000 Fishery stability, local extinctions, and shifts in
community structure in skates. Conserv. Biol. 14, 283–293.
Dulvy, N.K., Sadovy, Y., and J.D., Reynolds. 2003. Extinction vulnerability in marine populations. Fish and Fisheries 4:25-64.
Dulvy, N.K., J.R. Ellis, N.B. Goodwin, A. Grant, J.D. Reynolds, and S. Jennings. 2004. Methods of assessing extinction risk in marine
fishes. Fish and Fisheries, 5: 255-276
Goodwin, N. B., Grant, A., Perry, A., Dulvy, N. K. & Reynolds, J. D. In press. Life history correlates of density dependent recruitment
in marine fishes. Can. J. Fish. Aquat. Sci.
Goreau, T., T. McClanahan, R. Hayes, and A. Strong. 2001. Conservation of coral reefs after the 1998 global bleaching event.
Conservation Biology 14: 5-15.
Hawkins, J. P.,Roberts,C.M. & Clark,V. 2000 The threatened status of restricted-range coral reef fish species. Anim. Conserv. 3: 81–
99.
Hutchings, J.A. 2005. Life history consequences of overexploitation to population recovery in Northwest Atlantic cod (Gadus norhua).
Canadian Journal of Fisheries and Aquatic Sciences 62:824-832.
Hutchings, J. A. & Baum, J. K. 2005 Measuring marine fish biodiversity: temporal changes in abundance, life history and
demography. Phil. Trans. R. Soc. B 360: 315–338.
Jennings, S. & Blanchard, J. L. 2004 Fish abundance with no fishing: predictions based on macroecological theory. J. Anim. Ecol. 73:
632–642.
Jennings, S., Kaiser, M. J. & Reynolds, J. D. 2001. Marine fisheries ecology. Oxford: Blackwell Science.
Jennings, S., Reynolds, J. D. & Mills, S. C. 1998 Life history correlates of responses to fisheries exploitation. Proc. R. Soc. B 265:
33–339.
Musick, J.A., 2011. Criteria to define extinction risk in marine fishes: The American Fisheries Society Initiative, Fisheries, 24: 6-14.
NMFS 2004 Annual report to Congress on the State of U.S. Fisheries—2003, U.S. Dept. Commerce, NOAA. Silver Spring, MD:
National Marine Fisheries Service.
Olden, J.D., Hogan, Z.S., and M.J.V., Zanden. 2007. Small fish, big fish, red fish, blue fish: size-biased extinction risk of the world’s
freshwater and marine fishes. Global Ecology and Biogeography 16:694-701.
Polidoro, B.A., Livingstone, S.R., Carpenter, K.E., Hutchinson, B., Mast, R.B., Pilcher, N., Sadovy de Mitcheson, Y. and Valenti, S.
2008. Status of the world’s marine species. In: J.-C. Vié, C., Hilton-Taylor, and S.N. Stuart (eds.).The 2008
Review of The IUCN Red List of Threatened Species. IUCN, Gland. Switzerland.
Powles, H. 2011. Assessing risk of extinction of marine fishes in Canada – the COSEWIC experience. Fisheries 36:231-246.
Reist, J.D. 1997 The Canadian perspective on issues in Arctic fisheries management and research. In Fish ecology in Arctic North
America (ed. J. B. Reynolds), pp. 4–12. Bethesda, MD: American Fisheries Society.
Reynolds, J.D., Dulvy, N.K., Goodwin, N.B., and J.A., Hutchings. 2005. Biology of extinction risk in marine fishes. Proceedings of the
Royal Society B: Biological Sciences 272:2337-2344.
Taylor, B.M., Houk, P., Russ, G.R., and J.H, Choat. 2014. Life histories predict vulnerability to overexploitation in parrotfishes. Coral
Reefs 33:869-878.
http://www.coml.org