health status of cod (gadus morhua) at dumpsites for ...chemsea.eu/admin/uploaded/bssc cod...

Part-financed by the European Union (European Regional Development Fund)

Health Status of Cod (Gadus morhua) at Dumpsites for Chemical Warfare Agents

in the Baltic Sea T. Lang1, N. Fricke1, M. Faber1, M. Brenner2, U. Bickmeyer2, K. Broeg2, K. Lehtonen3, R. Turja3,

J. Baršiene4

1Thünen Institute of Fisheries Ecology (DE) 2Alfred-Wegener-Institute of Polar and Marine Research (DE) 3Finnish Environment Institute, Marine Research Centre (FI)

4Nature Research Centre, Institute of Ecology (LT)


Aim of the study:

to assess the health status of cod at known and suspected chemical warfare agents (CWA) dumpsites and in reference areas of the Baltic Sea

by applying a batterie of physiological, pathological, cellular and subcellular health indicators

Cod health status at Baltic Sea CWA dumpsites


Some words about cod (G. morhua) in the Baltic Sea: Two cod stocks in the Baltic Sea:

– western stock – eastern stock

Borderline between stocks: ~ Bornholm

Eastern stock spawn in summer in the Bornholm Basin and in the Gotland basin (mainly because of favourable salinity)

Western stock spawns in early spring in the Arkona Sea and further west

Fishery: approx 70,000 t/year

Cod in the Baltic Sea


Cod sampling areas

Bornholm Basin CWA

Gdansk Deep CWA

Gotland Basin CWA

Little Belt CWA

western stock eastern stock

Main dumping site

Reference site


Sampling: Dec. 2011: Bornholm Basin/Gdansk Deep and reference areas

May 2012: Gotland Deep and reference areas

Dec. 2012: Gotland Deep, Bornholm Basin and reference areas

Sept. 2013: Bornholm Basin and reference areas

Fishing: pelagic and bottom trawling

Platform: FRV Walther Herwig III (DE)

Sampling of cod


Vertical distribution of cod: impact of hydrography (T, S, 02)

Fishing depth Dec. 2011

Water depth: 95 m Fishing: 40-60 m

Water depth: 105 m Fishing: 60-80 m Water depth: 60 m

Fishing: bottom

Bornholm Basin (B13) Gdansk Deep (B15) Gdansk (B09, ref.)


Health indicators:

Cod health indicators measured

Fitness • Condition factor (CF) • Liver somatic index (LSI) • Spleen somatic index (SSI) • Gonadosomatic index (GSI)

Disease & pathology • Gross diseases and parasites • Liver histopathology • Head kidney pathology • Lysosomal membrane

stability • Differential blood cell

counts

Cyto-/genotoxicity • Morphological alterations in

red blood cells

Oxidative stress • Antioxidant defence

enzymes (e.g., catalase, glutathione reductase)

Neurotoxicity • Acetylcholinesterase (AChE)

inhibition


Cod fitness indices

0.100.120.140.160.180.20

B01 B11 B10 B13 B09 B15 B14

mea

n SS

I +/-

95

% C

.I.

Sampling area

Spleen Somatic Index gutted weight

Dec. 2011

Dec. 2012

* *

3.00

5.00

7.00

9.00

B01 B11 B10 B13 B09 B15 B14mea

n LS

I +/-

95

% C

.I.

Sampling area

Liver Somatic Index gutted weight

Dec. 2011

Dec. 2012

* * * * *

0.002.004.006.008.00

10.00

B01 B11 B10 B13 B09 B15 B14

mea

n G

SI +

/- 9

5 %

C.I.

Sampling area

Gonadosomatic Index gutted weight

Dec. 2011

Dec. 2012

* * *

0.60

0.80

1.00

1.20

B01 B11 B10 B13 B09 B15 B14mea

n CF

+/-

95

% C

.I.

Sampling area

Condition Factor gutted weight

Dec. 2011

Dec. 2012*

* * *

Results: some significant differences between sampling years; CF higher in western cod (B01, B11, B10), GSI higher in eastern cod (B13, B09); no significant differences between CWA areas (B13, B14, B15) and reference area (B09)


Externally visible diseases of cod

Disease/parasite Aetiology

Skin ulcerations Bacterial

Skeletal deformities Multifactorial

Pseudobranchial swelling

Parasitic (Amoeba-like)

Fin rot/erosion Bacterial

Epidermal hyperplasia/ papilloma

Viral, skin

Cryptocotyle lingua Digenean trematode, skin

Loma branchialis (= morhua)

Microspora, gills

Lernaeocera branchialis Copepode, gill chamber

Examinations based on standardised methodologies for fish disease monitoring (ICES, BEAST project)


0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

B01 B11 B10 B13 B09 B15 B14

mFD

I +/-

95%

C.I.

Sampling area

Fish Disease Index (FDI)

Dec. 2011

Dec. 2012

*

Externally visible diseases of cod: Fish Disease Index

Results: some significant differences in the FDI between sampling years and between areas (only 2011); highest value in fish from the Bornholm CWA dumpsite (B13) in 2011 but not in 2012; overall, no clear indication of effects of CWA on the status of external diseases

Fish Disease Index (FDI) combines disease data into one numeric figure per fish and considers: • Presence/absence of all diseases

• Severity grades (1-3)

• Disease weights (based on known or suspected effects on affected hosts)

• Adjustment factors for effects of size, sex and season (derived from empirical long-term data)

FDI is an established ICES/OSPAR analysis and assessment tool and was adapted to Baltic cod

The maximum FDI value is 100; high FDI values indicate poor health


Liver diseases/histopathology in cod

Myxozoa Nematoda

Infiltration/ Regeneration

Macrovesicular Steatosis

Results: Non-specific liver lesions with no clear link to pollution are dominating, neoplastic lesions (tumours and pre-stages) are very rare

Examples of non-specific liver lesions


Liver diseases/histopathology in cod: Liver Disease Index

Results: some differences in LDI between areas and sampling years; no significant differences between CWA areas (B13, B14, B15) and reference area (B09)

5.00

6.00

7.00

8.00

9.00

10.00

11.00

12.00

B01 B11 B10 B13 B09 B15 B14

LDI +

/- 9

5 %

C.I.

Sampling area

Liver Disease Index

Dec. 2011

Dec. 2012

*

LDI combines data on the presence and severity of all liver lesion types into one numeric figure per fish


Lysosomal stability in head kidney of cod

Results LMS-Test: Differences of the reference site (B09) are significant for both peak 1 and 2 (Kruskal-Wallis-Test, p<0.05, n=60)

Tim

e of

des

tabi

lisat

ion

[min

]

peak 1 peak 2

Lysosomal Membrane Stability (LMS) – Head Kidney Dec. 2011


Head kidney pathology in cod

Results Dumping sites: Tissue less dense, haematopoietic cell (HC) cluster small with less number of cells and higher number of histopathological alterations Results reference area: Dense tissue, cluster of HC surrounding blood vessels, less alterations

Histopathological Alterations

1 Vacuolisation

Reference site

1

2

3

4

3

4 1

Exposed sites

2 Karyomegaly 3 Hypertrophy 4 Apoptotic bodies


Head kidney pathology of cod

Results: Significantly more alterations at dumping site B13 compared to reference site B09 (Kruskal-Wallis-ANOVA-Test, p<0,05, n=30).

*

Hist

opat

holo

gica

l alte

ratio

ns [n

]

Histopathological Alterations

Dec. 2011


Geno- and cytotoxicity in cod red blood cells

Genotoxicity

*

*

0.0

0.2

0.4

0.6

0.8

1.0

1.2

B01 B11 B10 B13 B09 B15 B14

Sampling area

MN

+NB

+BN

b/10

00 e

ryth

rocy

tes Dec. 2011

Dec. 2012

Results: significant differences in geno-/cytotoxicity levels between areas and sampling years; indication of elevated levels in CWA areas (B13, B14, B15) compared to the reference area (B09)

Cytotoxicity

***

00.2

0.40.60.8

11.21.4

1.61.8

B01 B11 B10 B13 B09 B15 B14

Sampling area

FA+B

N+8

/100

0 er

ythr

ocyt

es Dec. 2011Dec. 2012

Fragmented apoptosis, bi-nucleated cells, 8-shaped nuclei Micronuclei, nuclear buds, nucleoplasmic bridges

Micronucleus Apoptosis


Enzymatic biomarkers in cod: oxidative stress, neurotoxicity

Results: Some significant differences in GR activity between dumpsite (B13, B13 dump) and reference area (B09); no differences in GST, CAT and AChE (data from Dec. 2011)

0.00100.00200.00300.00400.00500.00

B13 B13 dump B09 B14

GST

(nm

ol m

in−

1 mg

prot

− 1 )

+

/- 9

5% C

.I.

Sampling area

Glutathione S-transferase

0.00

50.00

100.00

150.00

200.00

B13 B13 dump B09 B14CAT

(µm

ol m

in−

1 mg

prot

− 1 )

+/

- 95%

C.I.

Sampling area

Catalase

0.005.00

10.0015.0020.0025.0030.00

B13 B13 dump B09 B14GR

(µm

ol m

in−

1 mg

prot

− 1 )

+/

- 95%

C.I.

Sampling area

Glutathione reductase

* *

0.0020.0040.0060.0080.00

100.00

B13 B13 dump B09 B14AChE

(µm

ol m

in−

1 mg

prot

− 1 )

+/

- 95%

C.I.

Sampling area

Acetylcholinesterase


Fish Health Index A integrates 5 health parameters with 3 grades each:

a) Condition factor b) Liver somatic index c) External diseases d) Liver histopathology e) Lymphocyte ratio

Cod health: Fish Health Index

1.50

2.00

2.50

3.00

B01 B11 B10 B13 B09 B15 B14

mea

n FH

I +/-

95

% C

.I.

Sampling area

Fish Health Index A (5 parameters)

Dec. 2011

Dec. 2012

FHI = (a(1,2,3) +b(1,2,3) +c(1,2,3) +d(1,2,3) +e(1,2,3))*5-1

FHI range: 1 (good) – 3 (bad)

* * * *

Results: some significant differences in FHI-A values between cod from the reference area (B09) and other areas. However, no indication that health of cod from CWA areas (B13, B14, B15) is significantly affected.


Health status of cod in CWA areas: Conclusions (1)

Single health parameters measured in cod reveal differences between CWA dumpsites and reference areas.

Responses were stronger on tissue and cell level and less pronounced on individual or population level (early warning?)

However, when combining all health parameters into a simple Fish Health Index (FHI-A/FHI-B), the results do not indicate major differences in health status of cod from CWA dumpsites compared to cod from reference areas.

A possible reason for the inter-annual variability could be changes in hydrographic conditions between 2011 and 2012 (influx) that may have affected the general health status or the vertical distribution of cod.


Hydrography: 02 concentrations in the Bornholm Basin

Oxygen deficiency in Oct./Nov. 2011 But: Oxygen increase in Feb. 2012

(http://www.io-warnemuende.de/suboxische-und-anoxische-bereiche-im-tiefenwasser-der-ostsee.html)

(Cruise Report R/V "ALKOR" Cruise- No. AL-385B ( 06AK1202 ) 02.02 - 14.02 2012)

Fehmarn (>7 ml/L)

Bornholm Basin (>2 ml/L) Gotland Basin

(<1 ml/L)

Results: strong variations (seasonal/annual) in hydrographic conditions (e.g. O2 concentrations in deep water layers), largely depending on water influx from the west


Vertical distribution of cod: impact of T, S and 02

Horizontal and vertical distribution patterns of adult cod (Gadus morhua) along a hydroacoustic transect (15°45’00’’E) in the central Bornholm Basin in April (top panel), June (middle panel) and August (lower panel) 2007 and 2008. Black dots represent indi-vidual cod identified by hydroacoustic single-fish tracking. Dotted line, salinity 11 halo-cline; solid line, 1 mL L-1 oxycline (Schaber et al. 2012, Fish. Oceanogr. 21:1: 33–43.)

Results: Cod in the Bornholm Basin prefer salinities of >11 PSU and oxygen concentrations of > 1 ml/L. However, they can be found even in deep water layers < 1 ml/L O2 (e.g. June 2007 and 2008); if O2 concentrations are higher, fish aggregate at the bottom (e.g. April 2008).


Health status of cod in CWA areas: Conclusions (2)

There is evidence that cod prefers deep water layers even at low O2 concentrations and may, thus, get in direct contact with dumped munitions and CWA, increasing the risk of adverse health effects.

However, due to the inconsistent pattern and the marked inter-annual variability of responses measured so far, there is no clear picture yet regarding the extent of such effect.

Data on more parameters (biological and chemical) and over a longer period of time are required for a more conclusive assessment of acute and chronic CWA effects.

In a variable environment like the Baltic Sea, it cannot be excluded that health risks posed by CWA vary on the short and the long term and, thus, regular monitoring and assessment of CWA risks should be considered.


... the end

Thanks for your attention and

support!

health status of cod (gadus morhua) at dumpsites for ...chemsea.eu/admin/uploaded/bssc cod...

Documents