NATIVE FISH POPULATIONS POSSIBLY THREATENED BY HANCOCK OPERATIONS
Some of the native fish species possibly threatened by Hancock's operations throughout Victoria include; Australian Grayling* (Prototroctes maraena), Barred Galaxias* (Galaxias fuscus), Blackfish (Gadopsis marmoratus), Broadfinned Galaxias (Galaxias brevipinnis), Catfish* (Tandanus tandanus), Dwarf Galaxias* (Galaxiella pusilla), Ewens Pygmy Perch* (Nannoperca variegata), Macquarie Perch* (Macquarie australasica), Mountain Galaxias (Galaxias olidus), Murray Cod* (Maccullochella australasica), Spotted Galaxias (Galaxias truttaceus), Trout Cod* (Maccullochella macquariensis), Tupong (Pseudaphritis urvillii), Yarra Pygmy Perch* (Edelia obscura) and Yellow Belly (Macquaria ambigua).
Please note that many of these species are listed under the Flora and Fauna Guarantee Act and are threatened in Victoria. (Marked with * - see above).
October 2003 Strzelecki Ranges.
Cable logging of pine plantation located near Mount Joy in the Merrimans
Creek catchment. This area has an annual rainfall of 1200mm. What happens
to the exposed soil after heavy rain?
"The major single cause throughout the world of the extinctions of populations of fish (and indeed most other species of both plants and animals) is the destruction of habitat". Dr Peter Maitland.
FOR IMPACTS OF HERBICIDES ON DOMESTIC WATER SUPPLY CATCHMENTS CLICK HERE
A stream is completely dependent on the surrounding land and vegetation in its catchment and is consequently subjected to the effects of actions carried out there. A stream is a system of habitats linked together in a continuous one-way flow of water, so the actions on a stream at one point can also affect areas downstream.
The basic causes or streamside zone degradation include;
Sediment (particles of material suspended in the water column or deposited in the stream bed) is a natural component of rivers and streams. Natural erosion and decay processes constantly deliver sediment to streams, so that all waterways carry some level of sediment. This is normally low in upland streams, but can be relatively higher in lowland rivers. Artificially increased loads of sediment, resulting from human activity, can have adverse effects on both the physical form of the river, and aquatic flora and fauna.
"The most common environmental change caused by land use activities in the catchments is an increase in sediment input to rivers and streams. Increased levels of sediment can adversely affect all aspects of freshwater ecosystems by reducing water quality and degrading or destroying habitat. Increased turbidity or suspended sediment can have adverse physical, physiological and behavioural effects on stream-dwelling flora and fauna". Page 200 Gippsland - Comprehensive Regional Assessment - September 1999. Published by the joint Commonwealth and Victorian Regional Forest Agreement (RFA) Steering Committee.
Increased levels of sediment can adversely affect all aspects of freshwater ecosystems and fish by: reducing light penetration, increasing loads of soluble nutrients and toxic substances attached to sediment particles, clogging gills and causing asphyxiation, causing illness and reduced growth rates or death through ingestion, reduced visibility, filling spaces in the river bed and destroying important habitat, working its way into the stream bed, interfering with feeding by organisms that filter food from the water column, destroying attachment sites for animals and eggs, smothering plants.
June 2001: Morwell River running very turbid, downstream from Hancock logging operations in the Strzelecki Ranges. Eventually this sediment will end up in the Gippsland Lakes.
The major effect of sedimentation is the blanketing of the stream bed (substratum) and the filling of pools and scour holes. Clogging of the stream bed removes spaces between particles which are used as rearing and habitat areas by juvenile fish, small species and stream invertebrates. The eggs of species such as Macquarie Perch (Macquaria australasica) which are deposited in gravel substrate are liable to smothering by sediment. Silt clogs mayfly gills and smothers the bed of the river and kills algae growing on rocks. Deposited silt can suffocate and kill Blackfish eggs. High turbidity levels can be lethal to blackfish larvae and juveniles. Even adults have been observed dying in highly turbid river water, their gills clogged up with fine sediment. Heavy siltation can also smother habitat, spawning grounds and food sources and can move into estuaries, smothering fish breeding grounds, particulary after periods of high rainfall.
Adult blackfish live in submerged hollow logs or amongst a clump of logs/branches (called snags) or submerged tree roots. Hollow logs are used for breeding which occurs in early summer. A female and a male pair up, the female laying several hundred sticky eggs which attach in layers to the bottom of the inside of the log. Only about 500 eggs nearly 4mm in diameter are laid by a 300mm female. The eggs are then guarded by the male (not the female), who also fans away any silt which may settle on the eggs. Depositing eggs in less suitable areas such as sediment covered logs will lead to reduced egg and larvae survival.
Other endangered fish species are also severely impacted by sedimentation of streams. For example the Australian Grayling lay their eggs in the interstices of the gravel bottom, Catfish prefer gravel to mud where the eggs are passed down between the gravel. Murray Cod deposit their eggs on firm substrates. Spawning is not confined to hollow logs and the Murray Cod require a silt free surface to accept adhesive eggs. This is probably similar to the trout cod.
May 2003: Mount Robertson Plantations(LEGL93-69). - King Parrot Creek catchment. Even during low rainfall events, roads can contribute large amounts of sediment into waterways.
There are an enourmous number of invertebrates (animals without backbones) that live in streams. These include Mayflies, stoneflies, caddisflies, alderflies, craneflies, blackflies, dragonflies, aquatic worms, snails, small spiders (called watermites), crustacea such as yabbies, nematodes, flatworms, freshwater sponges and freshwater crabs. Many invertebrates such as mayflies hatch from eggs in the water. The invertebrates are found mainly attached to and amongst snags, leaf packs and rocks. Leaves falling into the stream are eaten directly by invertebrates known as "shredders", such as some stonefly and caddisfly larvae, which shred or bite the softer parts of the plant material. Material not consumed by the shredders is colonised by microorganisms such as aquatic fungi and bacteria and broken down to progressively smaller sizes. Freshwater algae also colonise the leaves and twigs. Invertebrates known as "scrapers", such as some mayflies and snails feed directly on the fungi and algae. As the organic material is broken down, the resultant finer material then serves as a food source for other invertebrates which filter material from the water (filter-feeders), or collect deposited material on stream beds (detritus-feeders).
As freshwater ecosystems get silted up, there is a decrease in diversity of macroinvertebrates, often decreasing to just populations of worms which can survive in the silt bed. Problem fish such as European Carp are best suited for seeking out these worms as Carp have a bottom grubbing feeding style.
Indigenous vegetation is vital for healthy waterways. It influences the quality and quantity of surface run-off, as well as intercepting rainfall, promoting infiltration, which in turn decreases surface run-off. In regards to flooding, well vegetated stream beds rarely erode away during flooding, whereas cleared riverbanks are often "blown-out" completely (eg East Gippsland floods 1998). The root systems of riverside vegetation and the stream side snags they create, also protect riverbed and riverbank stability. This prevents erosion, high turbidity levels and increased siltation.
A forest is more than just trees. It is an incredibly diverse series of ecosystems connected by a countless array of complex interactions. And one fact often overlooked by the timber industry and conservationists alike is that forests are vital for the long term health of our water resources. Poorly planned plantation and native forest harvesting can have serious impacts on our waterways.
"In comparison with harvesting in native forests, the environmental
impact of softwood and eucalypt plantation forestry is potentially more
severe, as the rotation periods are considerably less (between 20 and
40 years for pines . . . ). Silvicultural tending also involves more frequent
and intensive interventions, and growing pines appear to make a larger
impact on water yield that do regenerating eucalypts. Overall, this impact
on the aquatic environment is characterised by:
Timber harvesting is one human activity that increases sediment levels in river and streams. Depending on soil types, alot of sediment can be washed into rivers and streams during periods of high rainfall when overland flow is generated. The Cooperative Research Centre for Catchment Hydrology (CRCCH) has recently concluded that the main source of sediment from timber harvesting is i) unsealed roads, ii) snig tracks, iii) log landings, iv) general harvesting areas.
In regards to roads and tracks "more than 80% of the rain that falls onto these surfaces is converted to runoff. These large volumes of water transport sediments through the landscape".
May 2003: Mount Robertson Plantation (LEGL93-69). Logging trail on unnamed tributary of King Parrot Creek.
The following quotes from the recent Otways Forest Hydrology Project state;
p42 "In plantation forests, the density of roading is considerably greater and the effects of this have been reflected in the magnitude of sediment production reported in some studies. Increased streamwater suspended sediment and turbidity have been associated in particular with the establishment of P.radiata plantations (Cornish 1989). Factors reponsible for this include a high roading density, the frequent occurrence of streamside roading networks and a reliance on downhill snigging (Cornish, 1989b).
p42 "Grayson et al (1993) found that annual sediment production from forest roads was in the range of 50-90 tonnes of sediment per hectare of road surface per year"
p48 "Davies and Nelson (1993) recently illustrated that fine sediment input to these ephemeral, first order streams, such as those formed due to gullying at road outlets, is significantly enhanced by logging on steep slopes, by factors of two to three times the median values for unlogged streams".
p52 "Davies and Nelson (1994) examined the impacts of forest logging on instream habitat, fish and macroinvertebrate populations in Tasmania and related the observed impacts to the width of the riparian buffer strip at each site. Their results are among the first in Australia to quantify changes in water quality due to altered buffer widths. Their conclusions state clearly that "all impacts of logging were significant only at buffer widths of less than 30m"
Otways Forest Hydrology Project
The CRCCH also found that "*Sediment concentrations in road runoff were between 5 and 8 times higher on well-used roads than abandoned ones. *Roads with higher intensity traffic have greater volumes of loose material available at the surface. This is replenished after each rainfall event by continuing vehicle usage. *Roads used infrequently or abandoned have little available sediment and, in the absence of traffic are minor sources of sediment." It could be argued that heavy machinery, log trucks etc cause far more compaction, gullying and sediment run-off than normal private use vehicles.
The key is to minimise the impact of sediment delivery pathways. For instance the CRCCH found that the Cuttagee Creek Catchment in NSW "has an additional 10km of stream channels or gullies due to gully inititiation at road drainage outlets and because of these new channels, some 31% of the natural stream network now receives runoff and associated pollutants from road drainage outlets. 83% of gully initiation occurred at relief culverts draining cut-and-fill roads and that the combination of large contributing road length and steep hillslope gradient results in erosion and gully formation at the road-drainage outlet". According to the CRCCH "best management practices have to be applied in every logged forest to manage these sources and pathways.
These practices include:
May 2003: The insidious creep of sediment into an unnamed tributary of King Parrot Creek in the Mount Robertson plantation (LEGL93-69). Sediment at this location managed to flow through 10 metres of buffer vegetation and still managed to enter the waterway. Only light rain had been falling at the time. In the case of heavy rainfall, large torrents of sediment laden water will enter local waterways.
The woodchip/timber industry in Victoria often operates in the headwaters of our catchments. In order to log the best of what's left of our forests, where slopes are often steep, soils often shallow based and highly erodable (once disturbed) generating considerable sediment mobilisation into river systems with high rainfall events that these areas are often subject to. Furthermore many plantations in Victoria were established without full consideration to protecting streams and waterways from the impacts of sedimentation. In many of these plantations, buffer and filter strips are non-existant. This is an unsustainable outcome for many of our rivers and streams. This fundamental flaw can be ended by plantation companies establishing buffer zones and filter strips of at least 30 metres in areas that do not have them at present and properly maintaining present buffer zones.
Also, the Code of Forest Practices, the legal document supposedly regulating timber harvesting is much more lax on private land than it is on public lands. For instance in regards to hardwood and softwood plantations it states (p41);
*where buffer and filter strips are currently without a cover of intact
native vegetation they may be used for tree planting and subsequent
harvest, subject to conditions set out in Section 18.104.22.168 (Site Preparation)
and Section 3.2.3 (Timber Harvesting-Water Quality Protection);
Site preparation by non-mechanical means (eg spot herbicide treatment) should be considered for plantable buffer and filter strips to protect soil values; . . . "
September 2002: Recent plantation clearfelling on Traralgon Creek (a Class 1 stream) in the Strzelecki Ranges. How much sediment will wash off this site in the event of heavy rain? Note disintergrating creek crossing in foreground.
Furthermore the code states;
"Streams should be classified as follows:
Class 1: Rivers and streams having a variable catchment area, but which flow on average greater than 90% of the year (Permanent Streams).
Class 2: Temporary streams that display a defined stream-bed, obvious inclusion and usually distinctive riparian vegetation, and carry water at wetter times of the year.
Class 3: Drainage lines with evidence of the action of periodically flowing water and/or a channel of more than 30cm depth with clearly defined bed and banks carrying water only during, or immediately after periods or heavy rainfall. Riparian vegetation may or may not be present.
Class 4: Permanent spring, swampy ground, wetlands, or other bodies of standing water.
Table 2. Minimum width (m) for buffer strips (B) and filter strips (F) to be applied to various stream categories.
In regards to timber operations within buffer strips in plantations, the Code states p48;
"*plantation trees may be harvested either mechanically or manually from areas classified as buffer strips, but care must be taken during felling to direct them out of the buffer. Activities associated with harvesting in the buffers should result in minimal disturbance to the soil or its protective cover;
*buffers containing intact native vegetation must be protected from damage caused by trees felled in adjacent areas. Trees accidently felled into these buffers should be carefully removed with minimal disturbance to the soil or its protective cover;
*machinery may also enter a buffer strip for the construction and use of specified stream crossings of for plantation site preparation purposes.
Otway Ranges June 2002: Logging debris bulldozed into creek headwaters and torched. This occurred in Lardners Creek headwaters which flows into the Gellibrand River. We have concerns about sediment and phosphorous entering waterway from such poor practice. The Gellibrand River is argueably Australia's best Blackfish stream.
Operations within filter strips in plantations:
*plantation trees located in filter strips may be harvested either mechanically or manually . . . Slash accumulation in the filter strip should be minimised.
*filter strips comprising intact native vegetation should be protected from damage caused by trees felled in adjacent areas. Trees accidently felled into these filters should be carefully removed with minimal disturbance to the soil or its protective cover.
*machine entry into filter strips for the purposes of crossing drainage lines or temporary streams is permitted only at specified crossing points, and soil disturbance must be minimised;
*where log culverts are used they should be removed immediately following completion of harvesting (or any subsequent re-establishment work for which they are required) using a technique which minimises soil disturbance"
Minimum width (m) for buffer strips B and filter strips (F) to be applied to various stream categories for different slope classes on soils which have low permeability and high potential for overland flow.
It should also be pointed out that local councils are the authority responsible for monitoring logging operations on private land. All of Hancock's operations are on land classed as private under the Code of Forest Practices;
(p65 Code of Forest Practices - Private land- For the purposes of this Code, Private Land comprises:
. . . c) land vested or leased by the Victorian Plantation Corporation or its successor in law . . . "
Many local councils have neither the will nor the resources to adequately monitor private land logging. There are some exceptions to this rule, however in general Hancock Watch have found many local councils unaware of their responsibilities in monitoring compliance with the Code of Forest Practice.
We strongly urge Hancock Victorian Plantations to establish buffer zones on all drainage lines, permanent streams, wetlands and temporary streams that do not have them at present. It is crucial that the impacts of sediments/herbicides/fungicides etc are reduced from entering waterways by increasing buffer zones.
It is clear that in too many Hancock plantations, the company is re-establishing their buffer zones with pine trees, meaning that when the plantations are harvested almost no protection will be granted to our waterways. This in turn threatens the long term viability of many of Victoria's fish populations. On the other hand it is encouraging that we have heard reports that Hancock is establishing buffers on creeks in some areas. We at this stage have not been able to validate whether this is correct or not.
Various shonky roading photos. The photo on the left and right was taken in the Albert River catchment in the Strzelecki Ranges. Note sediment potential from heavily eroding logging road and poor silt traps supposed to control sediment from entering local Albert River. Photo in centre was taken in the King Parrot Creek catchment and shows busted up culverts. Another prime location for the entry of sediment into waterway.
At present there is little information on the effects of disturbances such as timber harvesting on the long term population levels. Several studies have shown that forestry activities can be deleterious to stream biota by increasing siltation, turbidity, salinity and stream habitat integrity (see review by Campbell & Doeg 1989, Growns & Davis 1994). Buffer zones are an established method used extensively in forestry management to protect streams. Davies & Nelson (1994) investigated the effectiveness of buffer zones on stream fauna and determined that the impacts of logging are directly dependent on buffer widths. The authors found that a minimum buffer width of 30m was required to reduce logging impacts on streams and that buffer zones of between 30-100m appear to provide protection from short term logging impacts. Similarly, Barton &Davies (1993) found 30m buffer strips were effective in reducing the effects of pesticide concentrations in streams within plantations of Eucalyptus nitens in Tasmania. Larger buffer widths of 100m have been shown to reduce changes in stream fauna at least 8 years after logging ceased (Gowans & Davis 1991).
While these studies relate specifically to the instream fauna, the effects of timber harvesting on the fauna which inhabit stream margins remains largely unknown. Horwitz (1990b) suggests that forestry activities may pose direct and indirect threats to the crayfish through habitat destruction from creation or use of logging roads and removal of vegetation. Any activity leading to an alteration in the nature of the streamside water table or drainage patterns could affect the species survival. Variation in stream flows and water table levels occur when forest vegetation is cleared and when regrowth forest is planted. This is due to decreased transpiration rates after tree felling followed by increased transpiration rates in regrowth. Any activity which damages stream bank intergrity and alters water tables and drainage lines could be potentially harmful.
Doran & Richards (1996) investigated the management requirements of the Mt Arthur burrowing crayfish, Engaeus orramakuna, found in north-east Tasmania. They examined populations in logged and unlogged areas and found the species to be in high abundance in logged areas with healthy, fertile populations present throughout sites where E. phyllocercus was collected. In the current survey, these species were never found to be sympatric with E. phyllocercus, although their ranges obviously overlap. Therefore it is possible the species may occur if wet forest is located within the region or that the presence of E. quadrimanicus/cunicularius excludes E. phllocercus in this part of the species range.
Mt Worth, an area of 1040ha, is the only State Park from which the species is located. The number of specimens of E. phyllocercus collected from Mt Worth was low, but this was most likely a result of sampling difficulties rather than a true reflection of crayfish distribution. The crayfish is probably wide spread throughout the flood-beds of streams in the park, particularly those dominated by Mountain Ash and closed fern communities.
It is evident from some of the locations from which the crayfish were collected, that they can tolerate some level of disturbance. However, it is uncertain as to whether crayfish occur at the same density at these sites or whether their long term survival is secure.
The Strzelecki burrowing crayfish does not appear to occur extensively outside the 30km2 range estimated by Horwitz (1990). However, like the Narracan crayfish, it is widespread througout its range occurring in flood beds and creek banks of streams, particularly the smaller stream tributaries. It is also common in very wet gullies and seepage areas with underground springs.
Much of the land within the species range appears to be occupied by suitable habitat, although its distribution within pine plantations needs clarification. Most sites from which E. rostrogaleatus was collected occur within land utilized for softwood and hardwood plantation owned by Hancocks and Australian Paper Plantations. The 1230ha within Tarra-Bulga National Park represents the only area of protected habitat within the species range.
E. rostrogaleatus most likely found in the following Hancock plantations;