Decadal scale linkages between climate dynamics & fish production in Chesapeake Bay and beyond Co-authors: Ed Martino, Xinsheng Zhang, Jackie Johnson NOAA/NOS/NCCOS/Cooperative Oxford Lab Co-authors: Jackie Johnson, Ed Martino, Xinsheng Zhang Bob Wood bob.wood@noaa.gov
Approach Examining bio-physical linkages affecting fish production Working backwards forcing Northern Hemisphere teleconnections 4 regional weather patterns habitat 3 PC1 scores estuarine hydrography 4 2 0-2 -4 exploration/confirmation 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 Years Wood & Austin (2009) CJFAS 66/3 1988 1990 MDNR seine VIMS seine VIMS trawl Patuxent trawl spring plankton community dynamics 2 1 1992 1994 fisheries recruitment (CBASS) 1996 1998 2000 5 2002 2004 utility fisheries landings
Fish production in Chesapeake Bay young-of-the-year (YOY) recruitment scatter plots (1965-2004) The CBASS recruitment pattern (+) correlation among anadromous fishes striped bass white perch blueback herring alewife spot Young-of-the-year abundance Atlantic menhaden menhaden (+) correlation among shelf-spawners (-) correlation between anadromous & coastal spawners
A simpler CBASS index the CBASS ratio-based-index (CBASS rbi ) CBASS rbi = Log 10 (menhaden JAI / striped bass JAI) Juvenile abundance indices (JAI) publicly available: www.dnr.state.md.us/fisheries/juvindex/index.html extends CBASS index to 2009 correlation w/ pca-based CBASS index = 0.89 ratio is normally distributed Striped bass YOY Menhaden YOY
A the starting oligohaline-mesohaline point CBASS species transition groups zone have (OMTZ) striped bass Common nursery areas menhaden Potomac R.
And different life history strategies Spawning Estuarine nursery area Estuarine fresh-saltwater boundary late April Retention within oligohaline-mesohaline transition zone (OMTZ) Peak Mid-Atlantic coastal spawning Dec-Feb Up-estuary migration to OMTZ Feb-June (latepostlarvae to early juveniles) First feeding YOY prey (Mar-Jun) Oligohaline, winter-spring zooplankton species (May-Jun) First-feeding larvae: zooplankton YOY to juveniles: phytoplankton
Is the Bay s plankton community responsive to the same signal? PCA used to isolate strongest spring plankton dynamics exploration/confirmation Chesapeake Bay Program s plankton survey (1985-2001): Northern Bay stations only 1.longest fish recruitment survey monitors only MD waters 2.collection differences between north & south Bay inhibit comparability spring plankton community dynamics? 1 fisheries recruitment (CBASS)
Plankton data (for PCA) Mean monthly plankton counts: March-June aggregated across the northern Bay s oligohaline-mesohaline transition zones (OMTZ) Mean Spring Salinity, 1985-2001 Patuxent R. Potomac R. RET2.2 Upper Bay TF1.7 LE1.1 LE2.2 CB2.2 CB3.3 ET5.2 ET5.1 Northern Bay Choptank R. Note: OMTZ spans the nursery grounds for striped bass & menhaden YOY Atlantic Ocean
Plankton community PCA results Eigenvalues 10 8 6 4 2 Eigenvalue scree plot 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 PC # 44 Plankton PC # Eigenvalue Plankton data set s proportion of variance Cumulative variance % Correlation with CBASS rbi 1 14.5 0.26 26% 0.88 2 8.01 0.14 40% 0.34 3 6.9 0.12 52% 0.07 4 5.2 0.09 61% 0.19 5 4.7 0.08 69% 0.04 *p<0.0001
PC1-species correlations phytoplankton zooplankton Taxa March April May June Chlorophytes 0.67 0.60 0.12 0.26 Cryptophytes 0.47 0.71 0.84 0.50 Cyanophytes Phytoplankton 0.29 filter -0.19feeding -0.25 Diatoms 0.79 0.51 0.09-0.28 Dinoflagellates -0.23 0.32 0.65-0.37 Acartia sp. 0.36 0.57-0.67-0.50 Cladocera -0.02-0.42-0.53-0.60 Copepod nauplii 0.39-0.13-0.56-0.73 spawning Cyclopoida -0.25-0.70-0.65-0.69 Eurytemora -0.07 Zooplankton predation -0.57-0.68-0.78 Harpacticoida -0.5-0.58-0.54-0.40 Ctenophora -0.26
Habitat Investigate: Habitat-hydrographical variability as a likely force behind the coupled CBASS-plankton dynamics habitat estuarine hydrography 2
Hydrographical data Temporal resolution: monthly March-June Spatial resolution: Mean conditions aggregated across all stations bounding the oligohaline-mesohaline transition zone (aka the OMTZ) Bay Spring Salinity, 1985-2001 Northern Chesapeake RET2.2 TF1.7 LE1.1 LE2.2 USGS Bay flow Transect B CB2.2 CB3.3 Southern Bay (Virginia waters) ET5.1 ET5.2
Correlation: Spring hydrography & plankton PC1 scores Environmental variable Plankton PC1 CBASS rbi water temp. March 0.16-0.04 water temp. April 0.20-0.02 water temp. May -0.21-0.36 water temp. June 0.32 0.09 salinity March 0.51* 0.21 salinity April 0.76** 0.51* salinity May 0.81** 0.68** salinity June 0.61** 0.41 Salinity March-June 0.76** 0.51* *p<0.05 **p<0.01
CBASS& plankton PC1 Scores Salinity & flow Correspondence among hydrographic conditions, CBASS rbi, & plankton PC1 Mean spring salinity spring Bay flow(-1x) Plankton PC1 CBASS -6-4 -2 0 2 4 6-1.5-1.0-0.5 0.0 0.5 1.0 10 15 20 25 550000cfs 450000cfs 350000cfs 1985 1987 1989 1991 1993 1995 1997 1999 2001
dry year -1985 1996 wet year 6*10^6 4*10^6 2*10^6 0 800 600 400 200 0 15 10 5 0 8 6 4 2 0 March-June Surface Salinity
Climate Forcing regional weather patterns 3 exploration/confirmation spring plankton habitat community estuarine hydrography 2 dynamics 1 fisheries recruitment (CBASS)
US climate division weather correlations with CBASS rbi Winter-Spring precipitation (Dec-Jun) Plankton PC1 scores (-) (-) r value -0.6-0.3 0.0 0.3 0.6 + Spring temperature (March-May) +
Spring sea level pressure anomalies during very strong fish production years (1 st quartile) Atlantic menhaden dry & warm striped bass wet & cool Coastal storm cyclogenesis (high Bay flow) High pressure anomalies over Labrador & NE of Great Lake Pressure gradient drives cold air to the Chesapeake from the northeast (colder) Prevailing storm track to the north of the Chesapeake (low Bay flow) High pressure anomalies in the Gulf of Mexico & south of Bermuda Pressured gradient drives warm air to the Chesapeake from the GOM (warmer)
Correlation between East Coast Winter Storms (Nor Nor easters easters) & the striped bass JAI (MD DNR) 24 24 20 20 16 16 12 12 8 8 4 4 1.0 1.0 Striped bass bass juvenile abundance log10 log10 (MD (MD DNR DNR JAI) JAI) 0.5 0.5 0.0 0.0 East East Coast Coast Winters Storm Storm Count Count (Dec-Apr) 0 0 1955 1965 1975 1985 1995 2005 1955 1965 1975 1985 1995 2005
Role of teleconnections? fisheries recruitment (CBASS) spring plankton community dynamics 1 exploration/confirmation fisheries recruitment (CBASS) spring plankton community dynamics 1 exploration/confirmation estuarine hydrography habitat 2 estuarine hydrography habitat 2 fisheries recruitment (CBASS) 3 Northern Hemisphere teleconnections 4 forcing Northern Hemisphere teleconnections 4 forcing regional weather patterns 3 regional weather patterns 3
Teleconnections that affect the mid-atlantic US: correlations with fish & plankton dynamics telecon xn indices CBASS ratio r = Plankton PC1 r = AMO Dec-Jun ***-0.51 *0.44 AMO Mar-Jun **-0.43 0.36 NAO Dec-Jun 0.03-0.24 NAO Mar-Jun 0.00-0.28 PDO Dec-Jun 0.07-0.08 PDO Mar-Jun 0.04 0.21 SOI Dec-Jun 0.03-0.06 SOI Mar-Jun 0.07-0.15 PNA Dec-Jun -0.03 0.17 PNA Mar-Jun -0.07 0.17 p-value key: ***0.001 ; **0.005; *0.1;
The linkage between SLP correlation w/cbass the AMO & CBASS SST-AMO correlation SLP-AMO correlation
Management utility does this mean anything for fishery landings? exploration/confirmation forcing Northern Hemisphere teleconnections 4 regional weather patterns habitat estuarine hydrography spring plankton community dynamics 2 1 fisheries recruitment (CBASS) 5 utility fisheries landings
Striped bass landings and the AMO
Atlantic menhaden landings & the AMO
take-homes The Chesapeake ecosystem is highly responsive to climate variability, especially with respect to the winter-spring transition The Chesapeake appears to have been responding strongly to the AMO for over a century These fluctuations seem to be driving production & commercial landings within and beyond the Chesapeake for economically and ecologically valuable fishes The stable nature of the AMO s ~65-year periodicity may help prevent collapses by allowing managers to anticipate persistent recruitment declines
The Atlantic Multidecadal Oscillation Precipitation correlation AMO correlation maps Surface air temperature http://www.aoml.noaa.gov/phod/faq_fig1.php (Enfiield et al., 2001) +AMO = wet/cool = -CBASS -AMO = dry/warm = +CBASS