Marine fisheries conservation: insights
from an ecological approach
Francis Juanes
Department of Biology
University of Victoria
Centre for Coastal Science and Management, May 1, 2012
Worldwide marine fisheries declines
Myers & Worm 2003
Abundance (Millions of mature individuals)
Predatory fish
Hutchings & Reynolds 2004
NMFS 2000
Assessing Conservation status
• Usually based on:
– temporal abundance estimates
– age-specific metrics from commercial catches
– geographical distribution limits
• When stocks are healthy and catches high,
these data are often sufficient
Assessing Conservation status
• When stocks decline main questions asked of
fisheries science concern:
– life history
– behaviour
– ecology
– genetics
– habitat use
– environmental effects or overfishing?
• We are often in an empirical ‘vacuum’, i.e not
enough data!
Metric tons (thousands)
Gulf of
Maine
Gulf of
Maine
Georges
Bank
Georges
Bank
Year
Mayo, R., and L. O’Brien.
2000
Only data
come from
1880, n=6
Cod fecundity in US waters
Bottom trawler Lisa Anne II
Nikolai Klibansky with a 127cm female cod caught in the Gulf of Maine
DAULS deployed within fishing gear
• I have focused on questions pertaining to
various ecology/genetics/life history aspects in a
variety of commercially (and ecologically)
important fish (and shellfish) species
• These studies cannot be completed without
taking an interdisciplinary approach and with the
help of students, collaborators, fishers
• Today I will give you a (very) brief overview of
some of those studies I hope to begin in British
Columbia
Chinook salmon catches are declining
Figure 1. Historical catches of Chinook salmon in Northern BC, Central BC, off the west coast of Vancouver Island (WCVI), and Strait of Georgia/Fraser River/Jonstone Strait (SOG/FR/JST). Catches are expressed relative to the historical maximum for each region. Data from Chinook Technical Committee (2012). Chinook salmon in coastal waters
Mortality rates
NEPTUNE Canada
Subsea Instruments
Hydrophones
Listening to the Earth,
monitoring seismic activity
Gravimeter
Seismometer
Piezometer Bottom
Pressure
Recorder
Folger Passage: observations in a rockfish conservation area
Biological sound zonation
Biological sound zonation
Neritic province
Depth (m)
0
Oceanic province
Sea level
Epipelagic zone
Unknown?
Widespread
Continental
shelf
Not expected?
200
1000
Upper continental
slope
Ba
th
ya
lz
on
e
Lower continental
slope
4000
Abyssal plain
6000
Canyons and trenches
Expected
Mesopelagic zone
Bathypelagic zone
Abyssal zone
Hadal zone
Sound production in a
noisy environment
Conclusions
•  Ecology, genetics and life history
studies can provide important insights
for fisheries conservation
•  Insights can direct management/
recovery strategies
•  These studies need to be done before
stocks collapse!