Pinto Lake Water Quality

Pinto Lake Was Formed By Tectonic

Activity Around The End Of The Pleistocene Era, 10,000 Years Ago.

Pinto Lake Bathymetry

Pinto Lake Watershed is Approximately 5.8 Square Miles.

Residential Areas Adjacent to Lake

1

2

3

Sampling Locations

Carlson, R.E. 1977. A trophic state index for lakes. Limnol. Oceangr. 22:361-369.

Carlson Trophic State Index

pH and Chlorophyll-a at Pinto lake Site 3 surface

5.56

6.57

7.58

8.59

9.510

6/10/2005 7/10/2005 8/10/2005 9/10/2005

pH

050100150200250300350400450

Chlo

roph

yll a

(mg/

m3)

pH

Chl-a

Near-bottom

Mid-Depth

Surface

6/10/2005

7/5/2005

8/1/2005

9/6/2005

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Phosphate (mg/L)

Phosphate Depth Profile at Pinto Lake Site 2

Near-bottom

Mid-Depth

Surface

6/10/2005

7/5/2005

8/1/2005

9/6/2005

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Nitrate (mg/L)

Nitrate Depth Profile at Pinto Lake Site 2

Nitrogen Limited?

Near-bottom

Mid-Depth

Surface

6/10/2005

7/5/2005

8/1/2005

9/6/2005

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

Ammonia (mg/L)

Ammonia Depth Profile at Pinto Lake Site 2

48 hr NH3 LC 50 (mg/L)

Bluegill 0.024Rainbow Trout 0.008

Dissolved Oxygen Depth Profile at Pinto Lake Site 2

0

2

4

6

8

10

12

14

16

181 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Depth (ft.)

O2

(mg/

L)

6/10/2005

7/5/2005

8/1/2005

9/6/2005

Temperature Depth Profile at Pinto Lake Site 2

10

12

14

16

18

20

22

24

261 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Depth (ft.)

Tem

pera

ture

(°C)

6/10/2005

7/5/2005

8/1/2005

9/6/2005

So What Does This Tell Us?

The Habitable Zone of Pinto Lake is Restricted to the Upper 6 Feet

Pinto Lake Is Hypereutrophic.

D.O levels tend to drop significantly below two meters.

Ammonia Levels are at Toxic Levels for Trout and Bluegill through much of the water column.

Summary of Conditions Found

So What Makes Pinto’s Water So Lovely and Green?

Microcystis

Anabaena

Aphanizomenon

Microcystin contamination in fish from the Jacarepagua Lagoon (Rio de Janeiro, Brazil): ecological implication and human health risk.

Magalhaes VF, Soares RM, Azevedo SM.

Universidade Federal do Rio de Janeiro-CCS-NPPN-Laboratorio de Ecofisiologia e Toxicologia de Cianobacterias, cep: 21941-590, Rio de Janeiro, Brazil. valeria@nppn.ufrj.br

Chronic and subchronic toxicity from exposure to microcystins, cyclic peptide liver toxins from certain cyanobacteria, poses an important hazard, which has received little study. No in vivo information exists on accumulation and transfer of microcystin from the food chain to humans. This paper present results of a 3-year study that demonstrates bioaccumulation of microcystins by fish and potential rates of microcystin ingestion by humans. The study was carried out in a shallow coastal lagoon in the city of Rio de Janeiro (Jacarepagua Lagoon). Fish (Tilapia rendalli) were collected every 2 weeks from August 1996 to November 1999. Microcystins were analyzed by HPLC in phytoplankton, fish liver and viscera while fish muscle tissue was analyzed by enzyme linked immunosorbant assay (ELISA). Phytoplankton samples, dominated by the genus Microcystis, were confirmed to contain microcystins as were fish livers, viscera and muscle tissue. During the entire study period, including times of low water bloom densities, fish muscle tissue contained concentrations of microcystins close to or above the recommended limit for human consumption (0.04 microg x kg(-1) day). Our findings demonstrate that microcystins can accumulate in fish tissue used for human consumption. Rates of ingestion routinely exceed the TDI guidelines as set by the WHO for drinking water. Appropriate epidemiology and risk assessment should be undertaken so that an acceptable TDI and appropriate risk management decisions can be made for human consumption of fish which are harvested from cyanobacterial blooms that contain cyanotoxins.

Clinical and pathologic findings of blue-green algae (Microcystis aeruginosa) intoxication in a dog.

DeVries SE, Galey FD, Namikoshi M, Woo JC.

Veterinary Medical Teaching Hospital, Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616.

A healthy dog developed signs of lethargy and vomiting after ingesting water from a tide pool containing blue-green algae. Fulminant hepatic failure occurred, and the dog was euthanized 52 hours later. At necropsy, the liver was large, friable, and discolored a dark red. Histopathology showed hepatocyte dissociation, degeneration, and necrosis. The alga was identified as Microcystis aeruginosa, a known hepatotoxin. The intraperitoneal administration of lyophilized cell material from the bloom caused hepatic necrosis in mice.

Anticholinesterase poisonings in dogs from a cyanobacterial (blue-green algae) bloom dominated by Anabaena flos-aquae.

Mahmood NA, Carmichael WW, Pfahler D.

Department of Biological Sciences, Wright State University, Dayton, OH 45435.

Cyanobacteria (blue-green algae) implicated in the deaths of 9 dogs at Richmond Lake, SD, on Aug 26, 1985, were analyzed. The dominant cyanobacterial species from the water sample was Anabaena flos-aquae. The lyophilized bloom material or the high-performance liquid chromatography purified toxin peak, when administered to mice IP, induced clinical signs of salivation, lacrimation, urinary incontinence, defecation, convulsion, fasciculation, and respiratory arrest. Further comparison of the semipurified bloom toxin with an irreversible anticholinesterase anatoxin-a(s), produced by A flos-aquae strain NRC-525-17, revealed the bloom toxin and anatoxin-a(s) had similar properties on high-performance liquid chromatography and on the inhibition of electric eel acetylcholinesterase (EC 3.1.1.7).

Some Questions.

•Who cares?

•Who has control over water quality in the watershed?

•How do lake discharges affect the receiving waters?

• What risks are there to for recreational uses of the lake?

•What are the benefits of improving the water quality?

•What happens year round?

•Are nutrients released from the sediments readily available for algal growth at all times?

•What nutrient control methods are available?

•What algal control methods are available?

•What source control methods are available?

•What is a reasonable water quality to expect?

•Who has the $ (grants) to do anything?