Managing for Overall Value - Ecosystem Based Management March 7, 2014 Southwest Alaska Municipal Conference Anchorage, AK The recommendations and general content presented do not necessarily represent the views or official position of the Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service
Why Ecosystem Science? • Built into the Magnuson – Stevens fishery conservation and management act • Sec. 406 FISHERIES SYSTEM RESEARCH (f) REGIONAL ECOSYSTEM RESEARCH • STUDY. – “…the Secretary (Dept. of Commerce), in consultation with the Councils, shall undertake and complete a study on the state of the science for advancing the concepts and integration of ecosystem considerations in regional fishery management. The study should build upon the recommendations of the advisory panel and include” – • “Recommendations for scientific data, information and technology requirements for understanding ecosystem processes,…” • “…stakeholder participation” • “…recommendations for ..understanding ecosystem processes .. to account for effects of environmental variation on fish stocks and fisheries” • “describe…Council efforts to implement ecosystem approaches…”
Report RecommendationHighlights • Maintain current stock assessment surveys. • Sablefish example • Seek to account for the effects of environmental variation on fish stocks and fisheries. • Ecosystem Chapter provided to Council • Sustain ecosystem observations, process oriented research, and integrative modeling. • Bering Sea Walleye Pollock Example
NOAA Fisheries Ecosystem Science Jason Link, Ph.D Senior Scientist Ecosystem Management Ihde, T, and H. Townsend. 2013. Interview with Jason Link: champion for ecosystem science and management. Fisheries 38(8):363 - 369
Stock assessments by region (2013) Alaska 31 11 3 Northwest Northeast 6 4 Pacific Islands 5 Southwest 8 Southeast and Caribbean
What is stock assessment? Biomass = Birth + Growth - Catch - Death We collect data from the fishery and from surveys to determine: Birth (recruitment), growth, and death (natural mortality) from which we get an optimum level of catch (fishing mortality) Optimum catch is based on Maximum Sustainable Yield (MSY) Assessment and management’s job is to determine the level of risk we are willing to take to maximize the return from the fishery A high growth stock produces a high rate of return, with high volatility A low growth stock produces a low rate of return, with low volatility Dana Hanselman
Stock Assessments Sablefish Walleye Pollock
Stock Assessment and Fishery Evaluation Reports Gulf of Alaska Sablefish http://www.afsc.noaa.gov/refm/stocks/assessments.htm
2000 2008 1997 Recruitment
Seek to account for the effects of environmental variation on fish stocks and fisheries. http://www.afsc.noaa.gov/REFM/Docs/2013/ecosystem.pdf Pg. 148
Ecosystem indicators and sablefish recruitment Modeling age-2 sablefish abundance Shared rearing habitat for juvenile salmon and age-0 and age-1 sablefish Indicators: age-0 sablefish stage August chlorophyll a (+) August sea temperature (+) Juvenile pink salmon abundance (+) 2nd order autoregressive (+) Figure 5. Joint linear regression and time series error model describing age-2 sablefish abundance as a function of chlorophyll a and sea temperature during the age-0 phase, juvenile pink salmon estimated from adult returns, and a 2nd order autoregression process (R2 = 0.97, F = 50.5, P-value = 0.00008, BIC = 73). Yasumiishi, Shotwell, Hanselman, Orsi, Fergusson in prep
Sustain ecosystem observations, process oriented research, and integrative modeling At what life history stage does climate have the greatest impact on fish recruitment?
Hypotheses Climate and Ecosystem Productivity Hypothesis H1: Climate change and variability have predictable affects on the bottom-up and top-down mechanisms which regulate fish recruitment. Critical size and period Hypothesis H2: The effects of climate and ecosystem function on fish recruitment are most evident during 2 critical periods: early to juvenile stage when mortality is a function of growth rate; the first winter when mortality is a function of size and energetic status obtained during previous summer and fall.
Fisheries – Oceanographic Surveys Northern Bering Sea and Chukchi Sea Assessment Gulf of Alaska Assessment 18° Latitude Southern Bering Sea Assessment 40° Longitude
Bering SeaSea Surface Temperature Anomaly Poor Recruitment Better Recruitment
Zooplankton (Fish Food) Large Copepods Small Copepods Euphausiids
Age 0 Pollock Diet Coyle et al. 2011
Relationship to Recruitment Age 1 Age 0
Oscillating Control Hypothesis Bering Sea Walleye Pollock Bottom up Climate connection to ecosystem Top down Ecosystem connection to fish recruitment Hunt et al. 2011
Integrated Model Goal: Understand the impact of climate variability and change on ocean conditions and birth, growth, and death of commercial fish.
Climate Scenario Example From IPCC climate models
Bering Sea Project underscores commitment to research supporting the ecosystem approach to fisheries management • $52 M funding • 24,205 person-days of fieldwork completed • 100 principal investigators • 2007 – 2010 Field Work • 2011 – 2013 Synthesis • 119 publications to date bsierp.nprb.org BEST-BSIERP Bering Sea Project bsierp.nprb.org
Ecosystem Indicator: Average Summer Sea Temperature Coyle et al. 2011
What is stock assessment? Example 1: The dividend stock Rougheye rockfish: Maximum age: ~200 years Maximum sustainable harvest rate: 3% Change in annual quota: +-2% Example 2: The growth stock Walleye pollock: Maximum age: ~ 20 years Maximum sustainable harvest rate: ~30% Change in annual quota: +/- 20% Optimum catch is termed Maximum Sustainable Yield (MSY) Assessment and management’s job is to determine the level of risk we are willing to take to maximize our return A high growth stock produces a high rate of return, with high volatility A low growth stock produces a low rate of return, with low volatility Dana Hanselman