Document ID: chunk:federal_register_of_legislation:F2016L00300:body:0:p16
Version: federal_register_of_legislation:F2016L00300
Segment Type: other
Provision Reference: 
Character Range: 44138–47250

from exposure of the gills to dissolved or colloidal metals include disruptions and/or alterations to gas exchange, ammonia excretion, ion regulation and osmotic regulation (Newman, 2003) as well as structural lesions and other functional disturbances (Jezierska & Witeska, 2006).
Due to their distribution in shallow coastal habitats in close proximity to urban and industrial areas handfish, particularly spotted handfish, are exposed to numerous impacts from anthropogenic activities (DEP, 2013). Impacts to handfish populations from coastal developments can arise as a result of increased top soil runoff and sedimentation in surrounding waterways, while impacts from marine developments can occur due to the loss or modification of habitat (DEP, 2013).
In recent decades considerable effort has been put into improving water quality in the Derwent Estuary, including site works to reduce heavy metal discharge at the zinc smelter, expansion of the wastewater treatment plant at the paper mill, introduction of effluent reuse schemes for sewage from metropolitan Hobart and improvements to storm water management (Whitehead et al., 2013). Sediment samples taken in 2011 indicate that concentrations of heavy metals have decreased at some sites in the Derwent since 2000, however levels vary across the estuary and copper, arsenic, zinc and cadmium concentrations increased in some spotted handfish locations (Whitehead et al., 2013). Nevertheless, within the past decade overall discharges of heavy metal were reduced by more than 60 percent, discharges of organic matter were reduced by more than 90 percent, discharges of sewage-derived nutrients were reduced by 10-20 percent and considerable improvements were made in stormwater treatment (DEP, 2014).
At the time of writing this plan there continues to be substantial collaborative effort focussed on improving the condition of the Derwent. The best example of this is the Derwent Estuary Program (DEP), a regional partnership between Tasmanian State Government, local governments, commercial and industrial enterprises, and community-based groups focussed on progressively improving the health of the Derwent Estuary and protecting the important ecosystems and iconic species it supports, including spotted handfish (DEP, 2014). Key areas for action identified by DEP include managing and reducing heavy metal contamination, preventing eutrophication, promoting water sensitive urban design, conserving iconic habitats and species and education and interpretation (DEP, 2014).

4.2.3 Traditional boat moorings
Traditional block and chain swing moorings can have significant localised impacts on benthic habitat in sensitive areas (SEQ Catchments, 2014). In the Derwent Estuary a large number of traditional boat moorings are located in known, historic or potential spotted handfish habitats due to the deliberate positioning of moorings in shallow and sheltered estuarine embayments (Green, pers comm., 2014). Traditional moorings consist of a concrete block (or other dump weight) with a heavy chain attached and are designed to allow boats to move in