Change in Ocean Surface Thermal Habitat in a Continental Shelf

Marine Ecosystem and Its Affect on Lower Trophic Level Organisms

Kevin Friedland, Joe Kane, Janet Nye, Jon Hare, John Manderson, Michael Fogarty

From: “Long-term trends and regime shifts in sea surface temperature on the continental shelf of the northeast United States” Friedland and Hare, 2007

ERSST Cells Representing the Northeast Shelf

1860 1880 1900 1920 1940 1960 1980 2000

11

12

13

14

Sea

sur

face

tem

pera

ture

, °C

Year

Average SST for the Northeast Shelf, 1854-2011

1860 1880 1900 1920 1940 1960 1980 2000

1

2

3

4

5

Minima Maxima

Year

SS

T M

imim

a, °

C

22

23

24

25

26

27

SS

T M

axima, °C

Minima and Maxima SST for the Northeast Shelf, 1854-2011

Thermal HabitatArea of the ocean surface within a temperature range

Extraction Region for Thermal Habitat Analysis

-1 4 9 14 19 24 291

51

101

151

201

251

301

351

Day

of t

he y

ear

Thermal habitat, °C

1.3

2.0

2.8

3.5

4.2

4.9

logarea

Annual Distribution of Thermal Habitats for the Northeast Shelf

-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1

234

5

6

78

9 101112

1314

15

16

17

181920

21

222324

25 2627

Fac

tor

2

Factor 1

Principal Components of Thermal Habitats

-2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 280

5

10

15

20

The

rmal

hab

itat,

km2 1

03

Thermal habitat SST, °C

Frequency Distribution of Thermal Habitats

Time Series of Thermal Habitats by PC Groupings

Mann-Kendall Test of Time Series Trend

ThermalHabitat Tested

Range (°C) Trend p1-4 Upward 0.093

5-10 Downward 0.00611-15 Downward 0.00516-20 Upward 0.08221-27 Upward 0.001

16

20

24

28

32

88

92

96

54

56

58

60

62

38

40

42

1985 1990 1995 2000 2005 201018

20

22

24

(a) 1-4°C

(b) 5-10°C

(c) 11-15°C

The

rmal

hab

iat,

km2 1

03

(d) 16-20°C

(e) 21-27°C

Northeast Shelf Plankton Surveys

Spatial Distribution of Plankton Samples (binned by 0.1°)

J F M A M J J A S O N D

1000

1500

2000

2500

3000

3500

Stations SST

Month

Sta

tions

4

6

8

10

12

14

16

18

20

22S

ea surface temperature, °C

Temporal Distribution of Plankton Samples and SST

Calanus finmarchicus

Pseudocalanus spp

Centropages typicus

Temora longicornis

Metridia lucens

Centropages hamatus

0 5 10 15 20 25 30 35

Catch per tow, 103 100m3

Spring Fall

Principal Zooplankton Species

Pseudocalanus spp: P. moultoni and P. newmani

Mean Latitudinal Catch Trends for Principal Zooplankton SpeciesSpring Fall

Spring, Pseudocalanus sppFall, Centropages typicus

Fall, Centropages hamatus

35 36 37 38 39 40 41 42 43 44

-1

0

1

Spring Calanus finmarchicus Pseudocalanus spp Centropages typicus Temora longicornis Metridia lucens Centropages hamatus

Z

Latitude, °N

36 37 38 39 40 41 42 43 44 45

-1

0

1

Fall Calanus finmarchicus Pseudocalanus spp Centropages typicus Temora longicornis Metridia lucens Centropages hamatus

ZLatitude, °N

Catch Weighted Latitude of Seasonal DistributionsUsing data for Feb-April (36-43°N) as indicative of spring and September-November

(37-44°N) as fall, calculate the CPUE by latitudinal bins, including zero tows, then calculate the CPUE weighted latitude of the distribution. Difference between the

spring and fall meant to represent the annual distributional excursion.

Realized Habitats of Seasonal DistributionsUsing data post-stratified by 1° bins for Feb-April (bins with 28 of 31 years of data and year with at least 27 bins) as indicative of spring and September-November

(same except at least 26 bins) as fall, calculate the bin CPUE, if CPUE>0.1 of season mean CPUE, sum the bin area.

Seasonal Stratified Area Weighted Catch Per Unit EffortUsing data post-stratified by 1° bins for Feb-April (bins with 28 of 31 years of data and year with at least 27 bins) as indicative of spring and September-November

(same except at least 26 bins) as fall, calculate the bin size-weighted CPUE, including zero tows, then log transform and take Z-score.

Realized Habitats of Seasonal

Distributions

Catch Weighted Latitude of Seasonal

Distributions

Seasonal Stratified Area Weighted Catch

Per Unit Effort

1980 1985 1990 1995 2000 2005 201050

100

150

200

250

300Calanus finmarchicus

Spring Fall

Rea

lized

hab

itat,

km2

Year

1980 1985 1990 1995 2000 2005 201036

37

38

39

40

41

42

43

44Calanus finmarchicus

Spring Fall

Latit

ude,

°N

Year

1980 1985 1990 1995 2000 2005 2010-3

-2

-1

0

1

2

3Calanus finmarchicus

Spring Fall

Abu

ndan

ce, Z

log

Year

Realized Habitats of Seasonal

Distributions

Catch Weighted Latitude of Seasonal

Distributions

Seasonal Stratified Area Weighted Catch

Per Unit Effort

1980 1985 1990 1995 2000 2005 201050

100

150

200

250

300Metridia lucens

Spring Fall

Rea

lized

hab

itat,

km2

Year

1980 1985 1990 1995 2000 2005 201036

37

38

39

40

41

42

43

44Metridia lucens

Spring Fall

Latit

ude,

°N

Year

1980 1985 1990 1995 2000 2005 2010-3

-2

-1

0

1

2

3Metridia lucens

Spring Fall

Abu

ndan

ce, Z

log

Year

Realized Habitats of Seasonal

Distributions

Catch Weighted Latitude of Seasonal

Distributions

Seasonal Stratified Area Weighted Catch

Per Unit Effort

1980 1985 1990 1995 2000 2005 201050

100

150

200

250

300Temora longicornis

Spring Fall

Rea

lized

hab

itat,

km2

Year

1980 1985 1990 1995 2000 2005 201036

37

38

39

40

41

42

43

44Temora longicornis

Spring Fall

Latit

ude,

°N

Year

1980 1985 1990 1995 2000 2005 2010-3

-2

-1

0

1

2

3Temora longicornis

Spring Fall

Abu

ndan

ce, Z

log

Year

Realized Habitats of Seasonal

Distributions

Catch Weighted Latitude of Seasonal

Distributions

Seasonal Stratified Area Weighted Catch

Per Unit Effort

1980 1985 1990 1995 2000 2005 201050

100

150

200

250

300Centropages hamatus

Spring Fall

Rea

lized

hab

itat,

km2

Year

1980 1985 1990 1995 2000 2005 201036

37

38

39

40

41

42

43

44Centropages hamatus

Spring Fall

Latit

ude,

°N

Year

1980 1985 1990 1995 2000 2005 2010-3

-2

-1

0

1

2

3Centropages hamatus

Spring Fall

Abu

ndan

ce, Z

log

Year

Realized Habitats of Seasonal

Distributions

Catch Weighted Latitude of Seasonal

Distributions

Seasonal Stratified Area Weighted Catch

Per Unit Effort

1980 1985 1990 1995 2000 2005 201050

100

150

200

250

300Centropages typicus

Spring Fall

Rea

lized

hab

itat,

km2

Year

1980 1985 1990 1995 2000 2005 201036

37

38

39

40

41

42

43

44Centropages typicus

Spring Fall

Latit

ude,

°N

Year

1980 1985 1990 1995 2000 2005 2010-3

-2

-1

0

1

2

3Centropages typicus

Spring Fall

Abu

ndan

ce, Z

log

Year

Realized Habitats of Seasonal

Distributions

Catch Weighted Latitude of Seasonal

Distributions

Seasonal Stratified Area Weighted Catch

Per Unit Effort

1980 1985 1990 1995 2000 2005 2010-3

-2

-1

0

1

2

3Pseudocalanus spp

Spring Fall

Abu

ndan

ce, Z

log

Year

1980 1985 1990 1995 2000 2005 201036

37

38

39

40

41

42

43

44Pseudocalanus spp

Spring Fall

Latit

ude,

°N

Year

1980 1985 1990 1995 2000 2005 201050

100

150

200

250

300Pseudocalanus spp

Spring Fall

Rea

lized

hab

itat,

km2

Year

“The U.S. GLOBEC Georges Bank Program [1994-1999] is a large multi- disciplinary multi-year oceanographic effort. The proximate goal is to understand the population dynamics of key species on the Bank - Cod, Haddock, and two species of zooplankton (Calanus finmarchicus and Pseudocalanus) - in terms of their coupling to the physical environment and in terms of their predators and prey. The ultimate goal is to be able to predict changes in the distribution and abundance of these species as a result of changes in their physical and biotic environment as well as to anticipate how their populations might respond to climate change.”

From: “A synthesis of large-scale patterns in the planktonic prey of larval and juvenile cod (Gadus morhua)” Heath and Lough 2007

1975 1980 1985 1990 1995 2000 2005 2010 20150.0

0.4

0.8

1.2

2.8

3.2 Georges Bank Gulf of Maine Preliminary values

Rec

ruits

to S

SB

rat

io

Year

Cod Recruits to SSB Ratio

Cod Recruits versus SSB

0 20 40 60 80 1000

10

20

30

40

50Data from 2000

Age

1 R

ecru

its, 1

06

SSB, 103 mt

Georges Bank

0 5 10 15 20 250

10

20

30

40Gulf of Maine

Data from 2000

Age

1 R

ecru

its, 1

06

SSB, 103 mt

Spatial Distribution of Cod (from GMRI)

Four Index Areas to Characterize Cod, Pseudocalanus spp, and C. finmarchicus CPUE

Georges Bank (GB), Northern GOM (NGOM),Southern GOM (SGOM), Southern New England (SNE)

78°W

76°W

74°W

72°W

70°W

68°W

66°W

64°W

62°W

34°N

36°N

38°N

40°N

42°N

44°N

46°N

Normalized spring cod, Pseudocalanus spp, and C. finmarchicus CPUE

-1.0

-0.5

0.0

0.5

1.0

-1.0

-0.5

0.0

0.5

1.0

1976 1980 1984 1988 1992 1996 2000 2004 2008

-1.0

-0.5

0.0

0.5

1.0

GB NGOM SGOM SNE

Cod

Pse

udoc

alan

us s

ppC

. fin

mar

chic

us

Year

Z-score of CPUE

Summary

There has been a condensation of the principal thermal habitats (5-15°C) of the Northeast Shelf ecosystem, and an expansion of the warm water thermal

habitats (16-27°C). The condensation of principal habitats has been intensified by the maintenance of cold water habitats (1-4°C) in the system.

Lower trophic level organisms, comprising species that are the principal prey of the early life forms of upper trophic level organisms, have responded to the

change in thermal habitat. Moist notably, the copepod Pseudocalanus spp has declined in abundance commensurate with a reduction of their thermal habitat.

Pseudocalanus spp along with Calanus finmarchicus are the principal prey of larval cod. The recruit/SSB ratio for cod has declined for the Gulf of Maine stock

and is difficult to interpret for the Georges Bank stock. A finer scale spatial analysis suggests that where Pseudocalanus spp has declined cod has not responded to management measures and where Pseudocalanus spp has

remained abundant, cod has recovered to higher stock levels.