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commfish / seak_sablefish

NSEI sablefish stock assessment
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Ecosystem discussion in the assessment report #21

Closed jysullivan closed 5 years ago

jysullivan commented 5 years ago

It remains unclear how we should treat ecosystem data and discussion in the assessment report.

While environmental data are not explicitly used in the assessment model for sablefish, an understanding of ocean conditions can help guide management decisions, especially in the case of buffering abundance estimates to account for uncertaintly in recruitment. Evidence points to above average water temperatures that persisted in the Gulf of Alaska from 2014 to 2016, nicknamed the Blob, as the leading cause the spike in sablefish recruitment (Hanselman et al. 2017). Preliminary results from laboratory studies indicate that the optimal thermal environment for age-0 sablefish is around 16 deg C, which is consistent with water temperatures observed during the Blob years (A. Sreenivasan, NOAA, May 20, 2018, pers. comm). Sea surface temperature forecasts from the North American Multi-Model Ensemble (NMME) show continued warm conditions in the Gulf of Alaska through the2019 spring and summer seasons (Kirtman et al. 2014; https://www.cpc.ncep.noaa.gov/products/NMME/seasanom.shtml). It remains unclear if these year strong year classes will thrive under continued warming conditions and tracking body condition may provide clues to overall health and survival of these year classes.

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Forecasted sea surface temperature (SST) anomalies from the North American Multi-Model Ensemble (NMME) for April, May, and June (AMJ, 2 month lead), May, June, and July (MJJ, 3 month lead), and June, July, and August (JJA, 4 month lead). Figure adapted from the three-month spatial anomalies of global SSTs at https://www.cpc.ncep.noaa.gov/products/NMME/seasanom.shtml. Data accessed March 1, 2019.

jysullivan commented 5 years ago

@ben-williams @apolson8 Please see the commit related to this issue and changes to the text.