Bugs re­veal poor river health

Shepparton News - Country News - - COBRAM HORSE TRIALS -

A snap­shot of river health in the north cen­tral catch­ment re­gion has found a num­ber of rivers and streams are in poor eco­log­i­cal health.

About 50 volunteers mea­sured the con­di­tion of the Lit­tle Mur­ray River, Lod­don River, Gun­bower Creek and Box-Pyra­mid Creek, cre­at­ing a base­line snap­shot of the health of the wa­ter­ways.

The com­pre­hen­sive wide-scale cit­i­zen science mon­i­tor­ing pro­ject mea­sured the health of the four wa­ter­ways by mea­sur­ing the kind of wa­ter­bugs present.

North Cen­tral Catch­ment Man­age­ment Au­thor­ity pro­ject man­ager Ni­cole Bullen said the type of wa­ter­bugs in a river told us a lot about its health.

‘‘If there is a large di­ver­sity of wa­ter­bugs, the river is gen­er­ally in bet­ter shape,’’ Ms Bullen said.

‘‘Low num­bers of cer­tain wa­ter­bugs can in­di­cate an eco­log­i­cal dis­tur­bance, and we can also get an in­di­ca­tion of pol­lu­tion lev­els by what sort of bugs are present.’’

Nine sites were mon­i­tored in the lower Lod­don River and over­all scores in­di­cated the sys­tem did not meet agreed stan­dards for eco­log­i­cal health.

Macroin­ver­te­brate com­mu­ni­ties in the lower Lod­don River have likely been af­fected by a highly al­tered flow regime, de­creased over-bank flood­ing, poor wa­ter qual­ity (such as high tur­bid­ity and low dis­solved oxy­gen lev­els), de­graded habi­tat from in­fill­ing of pools with sed­i­ment, and poor ri­par­ian con­di­tion through past clear­ing and stock ac­cess.

Though in-stream woody habi­tat den­si­ties up­stream of Kerang Weir are near nat­u­ral lev­els, there are ar­eas down­stream of the weir that have been chan­nelised and desnagged in the past.

Where ri­par­ian im­prove­ments have been de­liv­ered in the Lod­don sys­tem, the wa­ter qual­ity and macroin­ver­te­brates may take time to re­cover to a good con­di­tion.

Ms Bullen said Water­watch volunteers, as well as recre­ational an­glers, took part in the mon­i­tor­ing.

‘‘The data pro­vides a base­line assess­ment of river health with fish in mind,’’ she said.

‘‘Healthy rivers mean healthy bugs, which leads to healthy and abun­dant na­tive fish, and we know a cen­tury of reg­u­la­tion has changed fish num­bers dra­mat­i­cally.

‘‘We know that years ago peo­ple were ask­ing which kind of na­tive fish their fam­ily would like for din­ner be­fore they went fish­ing and the Mur­ray River Fish­ing Com­pany was pulling tonnes of fish out of the river ev­ery week.

‘‘Things have changed, and this snap­shot has shown that these wa­ter­ways are in poor health, with all but one record­ing a unan­i­mous se­verely im­pacted rat­ing.’’

Ms Bullen said the snap­shot will now be used as base­line data to mea­sure the im­pact of the North Cen­tral CMA’s Na­tive Fish Re­cov­ery Plan, a plan to re­store the qual­ity of the wa­ter­ways and their na­tive fish pop­u­la­tions.

Ms Bullen said it was im­por­tant the lo­cal community con­tin­ued to be in­volved in mon­i­tor­ing the sites.

‘‘We want to hear from any­one keen to help out and be­come volunteers. We will pro­vide them with train­ing and all the equip­ment they need,’’ she said.

‘‘They will help us make a big dif­fer­ence to the qual­ity of their lo­cal creeks and rivers.’’ ■ To vol­un­teer, phone 5448 7124 or email: info@nc­cma.vic.gov.au

Help needed . . . North Cen­tral Catch­ment Man­age­ment Au­thor­ity is look­ing for volunteers to as­sist in mon­i­tor­ing river health in the re­gion.

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