Sustaining global capture fisheries production Ray Hilborn School of Aquatic and Fishery Sciences
Overview of the talk Status of fish stocks Understanding sustainability Impacts of bottom trawling Forage fish impacts CFOOD e-media
The end of the line
All fish gone by 2048 Science ,445 Citations
Source: Time magazine, November 2006
NCEAS working group: Finding common ground in marine conservation and management
The RAM Legacy Stock Assessment Database
Coverage in RAM Legacy 40% of world catch
Regional trends in biomass Source: Global Assessment Database (ramlegacy.org)
Regional trends in exploitation rate Source: Global Assessment Database (ramlegacy.org)
Yield lost by overfishing (red) and underfishing (yellow)
Science 2012
Assessed stocks stabilize, others decline Source: Costello et al. (2012) Science 338: ~35% ~65% +
Large stocks in good shape Average Catch in MT 1,000, ,000 10,000 1, U.S. definition of overfished
Defining sustainability
“Sustainability Science” William Clark editor of Sustainability Science for PNAS Our approach is grounded in a definition of sustainable development that focuses on the well being of people over the long run. In particular, it argues that the development of a social-environmental system is sustained over a period of time if over that period appropriately inclusive measures of well-being do not decline
The three pillars of sustainable development IUCN Adams 2006
Elements of sustainability Continued ability of the ecosystem to produce what we want Acceptable levels of environmental impact – Whose choice – Compared to what Social well being – Maintenance of fishing communities – Equity in income, gender – Human rights Economic performance
Ah ha: sustainability is a state, abundant is sustainable, overfished is not
Less by-catch but higher carbon footprint More by-catch but lower carbon footprint
Sustainability is a process The worst way to measure sustainability is B/BMSY Better is F/FMSY The best is to evaluate the management system – Monitor abundance changes – Adjust exploitation rate in relation to abundance – Effectively enforce regulations
A survey of fisheries governance Mike Melnychuk and Ray Hilborn 46 questions for 400 stocks Four areas: research, management, enforcement, socioeconomics … as examples Stock size and/or fishing mortality rate are reliably estimated Fishery management plan exists and strategies or tactics designed to meet objectives are specified Dockside monitoring and enforcement measures are sufficient for the fishery management system to effectively regulate fishing pressure
Fisheries governance
Evaluation of best practices for impacts of bottom trawling on benthic marine ecosystems A progress report
An independent assessment of the science of benthic impacts A scientific team of international experts to – Determine the footprint of bottom trawling in different areas How much area? What kind of habitat? What trend in trawl footprint? – Determine the impact of trawling on different benthic organisms By gear type, habitat type, type of organism – Determine the indirect impact of bottom trawling on target species – Evaluate a range of possible best practices Impact on catch Impact on benthic organisms
The Study Group
Collecting the data -Vessel Monitoring System -Logbook data -Effort timeseries
Trends in effort
High resolution mapping of trawling global footprint
Frequency of trawl coverage
Global footprint of trawling
Forage fish impacts on predators primarily marine birds and mammals Global policy conversation dominated by LENFEST report Many weaknesses in this report A 2 year project to review what is known about impacts Design management strategies
Impacts of MPAs on fisheries yields Working group organized in conjunction with FAO We have had one meeting -- looking for a major supporter to continue the activity
CFOOD e-media Web site to provide independent science Track false claims in media Twitter and Facebook feeds
The competing narratives Fishing continues to expand and empty the ocean … large areas of the ocean must be closed and many kinds of fishing banned Fishing provides a sustainable high quality food, and if properly managed protects the oceans and supports people
Conclusions Where fisheries are being actively managed sustainability and rebuilding are the outcome Many important fishing countries do not actively manage their fisheries All fishing has impacts but good science suggests fishing impacts are low compared to alternative foods, and can be further reduced
Thanks to NCEAS working group team – Especially Dan Ricard, Julia Baum, Coilin Minto, Olaf Jensen Trevor Branch and Boris Worm UCSB Dan Ovando and Chris Costello
These stocks constitute 90% of global catch reported to FAO
Pauly’s “status of fisheries” from catch data From Pauly 2007
FAO has a very different trend
Environmental impacts Measured in LCAs Energy consumption Greenhouse gasses Eutrophication Acidification Land Use Other Impacts Freshwater consumption Pesticides Antibiotics Soil Erosion
Energy Consumed
Greenhouse gases
Eutrophication potential
Summary of environmental impacts