Transport trajectories and cross-shelf delivery of larval arrowtooth - PowerPoint PPT Presentation

Transport trajectories and cross-shelf delivery of larval arrowtooth flounder ( Atheresthes stomias ) to suitable nursery habitats in the Gulf of Alaska Esther Goldstein, Janet Duffy-Anderson, Jodi Pirtle, Matthew Wilson, William Stockhausen, Calvin Mordy International Flatfish Symposium November 2017

Management & ecology of marine fish populations Subpopulations

Management & ecology of marine fish populations Subpopulations Pelagic larvae Settle to obligate nursery habitats Population connectivity à management designations Recruitment à fisheries & ecological impacts

Recruitment controls Oceanographic transport of larvae & Delivery to suitable nursery habitats

Gulf of Alaska & arrowtooth flounder Arrowtooth flounder Important predator • High abundance in the past decade •

Gulf of Alaska & arrowtooth flounder Arrowtooth flounder Important predator • High abundance in the past decade • *adapted from Stabeno et al. (2014)

Recruitment controls 1) Oceanographic transport of larvae Individual-Based Biophysical Model + ROMs Arrowtooth flounder life-history Stockhausen et al. in revision http://west.rssoffice.com/pws_roms?variable=curr

Recruitment controls 1) Oceanographic transport of larvae Individual-Based Biophysical Model + ROMs Arrowtooth flounder life-history Stockhausen et al. in revision http://west.rssoffice.com/pws_roms?variable=curr

Recruitment controls 1) Oceanographic transport of larvae Individual-Based Biophysical Model + ROMs Arrowtooth flounder life-history Stockhausen et al. in revision http://west.rssoffice.com/pws_roms?variable=curr

Recruitment controls 1) Oceanographic transport of larvae Individual-Based Biophysical Model + ROMs Arrowtooth flounder life-history Stockhausen et al. in revision http://west.rssoffice.com/pws_roms?variable=curr

Recruitment controls 1) Oceanographic transport of larvae Individual-Based Biophysical Model + ROMs Arrowtooth flounder life-history Stockhausen et al. in revision http://west.rssoffice.com/pws_roms?variable=curr

Recruitment controls 2) Delivery to suitable nursery habitat Maximum entropy model • Presence of 40-80 mm arrowtooth flounder Depth, Bathymetric Position Index, Tidal Current Speed, Sand Substrate • Slope, Sea Whip Presence, Bottom Temperature (ROMs), Aspect Eastness, Aspect Northness Test AUC 0.78 •

Recruitment controls 2) Delivery to suitable nursery habitat Maximum entropy model Threshold value ≥.36 • Presence of 40-80 mm arrowtooth flounder Depth, Bathymetric Position Index, Tidal Current Speed, Sand Substrate • Slope, Sea Whip Presence, Bottom Temperature (ROMs), Aspect Eastness, Aspect Northness Test AUC 0.78 •

Recruitment controls 1) Oceanographic transport of larvae (2000-2011) 2) Delivery to nursery habitats (habitat suitability) à Particle tracking + habitat suitability à Settlement competency at ~ 8 months with 7 days window 2011 IBM output figure

Oceanographic transport & suitable nursery habitats Total Suitable habitat Suitable habitat Reduces total survivorship Mirrors inter-annual variability in total survivorship

Oceanographic transport & suitable nursery habitats Total Suitable habitat Suitable habitat Reduces total survivorship Mirrors inter-annual variability in total survivorship Transport routes à similar within-year mechanisms?

Oceanographic transport & suitable nursery habitats Spawn ~300-600 m deep

Oceanographic transport & suitable nursery habitats Spawn ~300-600 m deep Offshore advection vs shelf?

Oceanographic transport & suitable nursery habitats Spawn ~300-600 m deep Offshore advection vs shelf? Cross-shelf transport

Oceanographic transport & suitable nursery habitats Spawn ~300-600 m deep Offshore advection vs shelf? Cross-shelf transport à Canyons as conduits

Oceanographic transport & suitable nursery habitats Suitable habitat Offshore advection Cross-shelf transport Canyons as conduits • Bathymetric Position Index & Bathymetry

Oceanographic transport & suitable nursery habitats Total Suitable habitat Offshore Offshore & suitable habitat Offshore, Offshore, no Most individuals offshore •

Oceanographic transport & suitable nursery habitats Total Suitable habitat Offshore Offshore & suitable habitat Offshore, canyon, & suitable habitat Offshore, no canyon, & suitable habitat Most individuals offshore •

Oceanographic transport & suitable nursery habitats Total Suitable habitat Offshore Offshore & suitable habitat Offshore, canyon, & suitable habitat Offshore, no canyon, & suitable habitat Most individuals offshore • Canyons buffer inter-annual variability – persistent & reliable •

Transport & population connectivity Connectivity patterns from spawning à settlement

Transport & population connectivity 1 25 50

Transport & population connectivity - survivors Total 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Transport & population connectivity - survivors Total 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Transport & population connectivity – suitable habitats Total Suitable habitats 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Transport & population connectivity – canyons Total Suitable habitats Offshore, canyon, & suitable habitat 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Transport & population connectivity Total Suitable habitat Offshore, canyon, & suitable habitat Retention à high survivorship à patterns differ via canyon transport

Transport & population connectivity Total Suitable habitat Offshore, canyon, & suitable habitat Retention à high survivorship à patterns differ via canyon transport Mechanisms à dispersal & retention

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2000

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2001

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2002

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2003

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2004

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2005

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2006

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2007 2007

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2008

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2009

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2010

Trajectories: suitable habitats via canyons Suitable habitat Offshore, canyon, & suitable habitat 2011 2010

Trajectories: high quality habitats via canyons Total Suitable habitat Offshore, canyon, & suitable habitat Canyons buffer inter-annual fluctuations in survivorship despite transport variability

Trajectories: high quality habitats via canyons Total Suitable habitat Offshore, canyon, & suitable habitat Canyons buffer inter-annual fluctuations in survivorship despite transport variability Influence of eddies on canyon transport, survival, & retention?

Eddies: survival & retention Total Suitable habitat Offshore, canyon, & suitable habitat 2002

Eddies: survival & retention EKE

Eddies: survival & retention Survival & retention influenced by sub-regional EKE?

Eddies: survival & retention PC1 & PC2 ~70% Suitable habitat Canyons Total

Eddies: survival & retention Regional Westward: Higher settlement Suitable habitat Canyons Total

Eddies: survival & retention EKE + total settled Suitable habitat Canyons Total

Eddies: survival & retention EKE + total settled + retention Suitable habitat Canyons Total

Eddies: survival & retention EKE + total settled + retention canyons à EKE & retention coupled Suitable habitat Canyons Total

Arrowtooth flounder in the Gulf of Alaska E à W transport Eddies à high recruitment & survival Canyons à reliable routes to suitable habitats influenced by eddies

Arrowtooth flounder in the Gulf of Alaska E à W transport Eddies à high recruitment & survival Canyons à reliable routes to suitable habitats influenced by eddies Recruitment controls Oceanographic transport & suitable nursery habitats