Mercury in fish — Lake Eildon (south) and the Upper

January 2015

This advice relates to environmental mercury around Lake Eildon and what its presence means for people who catch and eat fish, or use water from these waterways.

Some varieties of fish (commercially sold or caught recreationally) may contain high levels of mercury. Eating fish is important for a healthy diet, however, pregnant women and women planning pregnancy, and parents or carers of infants and young children should limit the number of servings of fish containing high levels of mercury. This is because the developing brain of the unborn child and young children is sensitive to mercury exposure.

Where is mercury found?

Mercury occurs naturally and in very low levels in rocks and soils. It may also occur in some soils and waterways from historical gold mining activities where it was used to recover gold from the mined, crushed rock.

The upper Goulburn River (above Lake Eildon), Big River and Howqua River catchments have been associated with historical gold mining. Mercury has been found in river bed sediments and some fish in these locations as a result.

As these rivers flow into the southern parts of Lake Eildon, it is likely that the bottom sediments and some long- lived fish species contain mercury.

Mercury in fish

Fish are high in protein and other essential nutrients, low in saturated fat and contain omega-3 fatty acids. As part of a healthy diet, everyone is encouraged to eat two to three serves of fish per week.

People take in small amounts of mercury in their diet from eating fish. In most fish, the levels are very low however some varieties contain high levels of mercury due to their feeding habits or surrounding environment.

Commercially sold fish that may contain high levels of mercury include shark (flake), ray, swordfish, barramundi, gemfish, orange roughy, ling and southern bluefin tuna.

In freshwater environments containing mercury, some species of fish may contain high levels of mercury. This is more likely in fish that are predatory (eat other fish) and also live a long time in this environment.

Who should limit their intake of fish containing high levels of mercury?

The developing brain is sensitive to the effects of high mercury exposure.

It is therefore important that pregnant women, women planning pregnancy and young children (up to six years of age) limit their weekly intake of fish varieties known to contain high levels of mercury.

Food Standards & New Zealand provides advice on the number of serves of different types of commercially-sold fish (shark (flake), ray, swordfish, barramundi, gemfish, orange roughy, ling and southern bluefin tuna) that can be safely consumed. This information is available at www.foodstandards.gov.au.

The following advice applies to recreational fishing in Lake Eildon (south) and the Upper Goulburn River, and mercury in fish.

Page 1 Department of Health and Human Services Which fish in Lake Eildon and surrounding rivers contain high levels of mercury?

Fish from Lake Eildon and the rivers that flow into it are periodically tested for contaminants such as mercury. The greatest information is available for mercury levels in brown trout as well as in redfin.

Brown trout: Large brown trout (more than 40 cms fork length1), caught in the following locations are likely to contain high levels of mercury: • Lake Eildon - south east lower region and the central region, up to Brier Cove and Point Robertson, including the arms of the Goulburn River; Big River and Howqua River.

Redfin: Redfin are a predatory species that can live for a long time. Redfin caught in the following parts of Lake Eildon are likely to contain high levels of mercury:

• Lake Eildon - south east lower region and central region, up to Brier Cove and Point Robertson, including the arms of the Goulburn River, Big River and Howqua River.

Brown trout Redfin

1 Fork length of a fish as measured from the tip of the snout to the fork of the caudal fin. Often used for angling species. [Glossary of fish terms – Australian Museum http://australianmuseum.net.au/Glossary-of-fish-terms]

Page 2 Department of Health and Human Services These areas are marked on the following map of Lake Eildon:

Basemap : Indicative map of the areas of Lake Eildon covered by this advisory.

Page 3 Department of Health and Human Services How much of these fish can be eaten from these locations?

Advice for: Number of serves Redfin or large brown trout ( > 40 cm), caught from:

Pregnant women, women planning pregnancy Limit to one per fortnight South east lower region of Lake and young children (less than six years old) Eildon and the central region of Lake Eildon, up to Brier Cove and Rest of the population Limit to one per week Point Robertson, including the arms of the Goulburn River; Big River and Howqua River

One serve: Adult is 150 grams (eg two frozen crumbed fish fillets) Child under 6 years is 75 grams (eg three fish fingers)

Can I still use this area for water activities?

Mercury is not very water soluble and settles in the sediments of streams, rivers or the bottom of some parts of Lake Eildon. Testing of surface waters at various depths and locations in Lake Eildon found low levels of mercury, all within the acceptable level for recreational use, including swimming. This is also true for waters in the upper Goulburn River.

Like all water activities, commonsense safety rules apply to prevent drowning.

Can I drink the water in the Upper Goulburn River (above Lake Eildon)?

Untreated river water can contain a range of contaminants, including micro-organisms that may cause illness. It is therefore not recommended that people drink untreated river water, regardless of its source.

For people living along rivers where a town drinking water supply is not available, rainwater collected from the roof is recognised as the most reliable and safest way to source drinking water.

Bush campers should carry in water for drinking. Alternatively, untreated river water needs to be boiled before drinking or using for cooking.

Is it safe to drink tap water supplied by the local water authority?

Goulburn Valley Water Corporation provides drinking water supplies for human consumption. Samples of this drinking water supply are regularly tested with all mercury levels well below the health-based Australian Drinking Water Guideline value.

Water samples from Molesworth and Woods Point (near Gaffney’s Creek) are also tested for mercury. These locations are called ‘regulated water supplies’, which means that they are available for a number of uses but not human consumption. Mercury levels in all of these samples were low.

For further information:

Fishing in : Department of Environment, Land, Water and Planning: www.depi.vic.gov.au

Mercury in fish and eating fish during pregnancy:

Food Standards Australia & New Zealand at: www.foodstandards.gov.au Better Health Channel at: www.betterhealth.vic.gov.au NSW Food Authority at: www.foodauthority.nsw.gov.au

Mercury and your health:

See you local doctor if you or a member of your family have health concerns.

For general information about drinking water quality or the potential health effects of chemicals contact the Environmental Health Unit (Department of Health) on 1300 761 874.

The Department of Environment Land Water and Planning and Environment Protection Authority Victoria have contributed to the development of this advice. Page 4 Department of Health and Human Services