Evidence of endocrine disruption of common carp at Willow Beach: Do we have an answer?

Michael R. Rosen1, Reynaldo Patiño2, David Alvarez3, Steven Goodbred4, and Kathy Echols3

U.S. Geological Survey, 1Water Science Field Team, NV; 2 Texas Cooperative Fish & Wildlife Research Unit; 3Columbia Environmental Research Center;

4Emeritus, North Carolina

Why are we concerned with Willow Beach?One female Common Carp taken in 2003 showed signs of intersex with spermatozoa visible in ovarian tissue and poor development of testicular tissues in male carp (Hinck et al., 2006; 2007)

In 2007/2008 Additional sampling at Willow Beach confirmed intersex in female fish and 3 of 5 male fish had possibly malignant testicular tumors (seminoma)

OocytesSpermatozoa

Seminoma

Testes from Willow Beach male carp

Fish Tissue and sediment samples collected in 2005 suggested organic chemicals (PCBs) may be an issue

South Cove

Overton

Sentinel

Las Vegas Bay

Willow Beach

0

50

100

150

200

250

300

350

Tot

al c

onta

min

ants

in s

edim

ent

(ng/

g)

PCBs

Las Vegas Bay Willow Beach Overton Arm South Cove 0

50

100

150

200

250

300

350

400

Tot

al P

CB

s (n

g/g

wet

wei

ght)

Carp composite (n = 5 - 10 per site)

Male Female

Fish Tissue 2007 - 2008mean concentration (n = 6 – 20 fish per site)

March 2007 July 2007 November 2007 March 20080

200

400

Male Carp

PC

Bs

(ng/

g w

et w

eigh

t) Las Vegas Wash Las Vegas Bay Willow Beach Overton Arm

• Summary of field-based studies on Common Carp

The reproductive and endocrine condition of male carp in LMNRA differed among sampling sites and can be classified from higher to lower as follows:

OA > LVB > LBW > WB.

Especially notable were The weak seasonality in the reproductive physiology

of male fish from LVW and WB;

The poor condition of fish from WB including the incidence of gonadal tumors and other reproductive organ anomalies.

Endocrine Disruption in Lake Mead

What is the reason(s) for these endocrine issues in carp from Willow Beach

Several possibilities exist:

1. Effluent from wastewater plant at Hoover Dam2. Effluent from wastewater from the Fish Hatchery3. PCBs from leaking transformers at the Dam4. Contaminants transported down from Lake Mead5. Environmental factors such as cold water released

from Hoover Dam, low food or nutrient supplies, erosion of naturally occurring toxic minerals into the lake

6. Old population of carp

Current study

In order to assess some of these possible sources:

Sediment, attached algae, and water (SPMD/POCIS) were collected at sites above and below the Fish Hatchery (5 sites total)

Fish were collected for histopathology all around these sites

Food, caulk, and rubber were sampled at the Fish Hatchery.

Sampling sites along

Willow Beach

Total distance is about 5 miles from

site 1 to site 5

Google Earth Image 2 miles

Fish Hatchery

Hoover Dam

Lake Mohave

Results

Fish Hatchery materials and feed

B-9 R

acew

ay C

aulk/

Gapfill

er

C-5 R

acew

ay ca

ulk

2:3

mm

trou

t fee

d

1:3

mm

razo

rbac

k fee

d

A-10

Racew

ay g

apfill

er

Racew

ay R

ubbe

r

0

10

20

30

40

50

60

70

80

90

PC

Bs

(ng/

g)

Algae and sediment

Site 1 Site 2 Site 3 Site 4 Site 5 0

1

2

3

4

5

6P

CB

s (n

g/g)

Sediment Algae

SPMD/POCIS Samples

No PCBs found in water samples

(not surprising) Concentrations of DDT metabolites, PAHs

hexachlorobenzene (HCB), heptachlor, heptachlor epoxide, dieldrin, PBDE-47 and -99, triclosan and methyl triclosan are all higher than at Overton Arm, but not as high as Las Vegas Bay

Other chemicals are present however, but at low concentrations: no greater than Overton Arm: However….

Site 1 Site 2 Site 3 Site 4 Site 5 0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5Y

ES

Ass

ay (

Est

roge

nici

ty)

Examples of other constituents in the water at Willow Beach

Site 1 Site 2 Site 3 Site 4 Site 5 Overton Arm0

20

40

60

80

100

120

140

160

150020002500300035004000

Con

tam

inan

t co

ncen

trat

ions

(pg

/L)

Site 1 Site 2 Site 3 Site 4 Site 5 Overton Arm0

20

40

60

80

150020002500300035004000

Total contaminants PDBEs Triclosan HCB PCA DDE

Water Temperature and Seasonality

Temperature of Hoover Dam outlet water is generally cold: 52 – 55 oF (11 – 13 oC)

Temperature doesn’t change much seasonally

Carp spawn from May to June at 64 – 86°F (18 – 30°C) with optimum of 73°F (23°C)

Therefore, cold temperatures and lack of seasonality may contribute to poor fish health

Seasonality in Fish

• Within a site, columns with same letter are not different• Asterisk - different from corresponding date in reference site (OA)

Highlights:

1. E2/KT levels generally lower in OA than other sites, except WB.

2. Seasonality absent in LVW and WB.

0.0

0.1

0.2

0.3

0.4

0.5

Overton ArmLas Vegas Bay

Las Vegas WashWillow Beach

abab b

c

a a

baa a

a a

a

a

a

a

**

*

*E2/

KT

rat

io

• E2/KT Ratio

Fish Histopathology 2010

GSI (%)

Testes MA area (%)

Intestitia Thickness (mm)

Conclusions

There isn’t any smoking gun Fish Hatchery materials appear to have some

PCBs in them and perhaps had more in the past Estrogenic chemicals were detected in the water

near the Hatchery PCBs and other contaminants occur at low

concentrations upstream of the Hatchery Low temperature of the water and lack of

seasonality can’t be discounted as a contributing factor

Thanks to NPS and FWS for access to sites on Lake Mohave and the Fish Hatchery

Funding was from the USGS-NPS collaborative

Water Quality Partnership Program

Questions?