Manly Lagoon Dredging Project - Manly Council - NSW Government

Manly Lagoon Dredging Project – Review of Environmental FactorsPrepared for Manly and Warringah Councils(Section 5.3.1). The Water Quality Monitoring Program to be implemented during dredgingworks will monitor TSS levels.Immediately prior to installation of the silt curtains, fish will be captured and removed fromthe area to be isolated. Towing the silt curtain into place using 2 boats at either bank, orother means of achieving this aim should be considered by the contractor.If, despite efforts to remove them, distressed fish are observed within the work area the onsiteenvironmental officer will make attempts to remove them and relocate them downstreamfrom the dredging activity. This activity would be recorded, including date and time ofincident, number and species of fish involved. Should ten or more distressed fish beobserved in a ten minute period, work will be stopped until the situation has been fullyevaluated, Council and I&I NSW have been notified, and mitigation measures and workmethod statements have been appropriately amended. In the event that any fish are founddead within the lagoon area, these will be promptly removed and held on ice. Offsite, anydead fish would be identified, counted and measured, with copies of records supplied toManly and Warringah Councils and I& I NSW.Submerged rocks, logs and woody snags can provide important habitat for fish and othermarine species by providing shelter, substrate for food and breeding sites (NSW Fisheries,1999). If the works require the removal or relocation of snags (in particular fallen trees orlogs) I&I NSW (Fisheries) will need to be notified prior to removal and reinstatement orrelocation, as required under the Fish Habitat Protection Plan No. 1.Protected BirdsIn order to mitigate impacts on any identified protected breeding birds at Manly Lagoon anumber of mitigation measures are proposed as described below. There will be no directdisturbance of the habitat or trees in which viable nests have been established.Identified nests will be monitored during dredging works to determine the presence of anyeggs or chicks. Where these are found to be present, works will be scheduled such thatapproach to the nest sites is avoided as far as practical during these times.Considering the breeding, incubation and fledgling periods of the Little Pied Cormorant(Phalacrocorax melanoleucos), it is expected that the breeding activities identified inNovember 2009 at Manly Lagoon will be complete by the time the works commence.However, monitoring of the nesting sites, as mentioned above, would be needed to confirmthe nesting activities, i.e. the presence of any eggs or chicks, of these two colonies. Ifnesting activity is apparent closer to commencement of works then dredging activities shouldbe scheduled to avoid active nest sites as far as possible.All contractors will be made aware of the presence and location of any identified nestingbirds, and shall maintain the maximum practical distance from the nest sites whilst dredgingnearby sections of the lagoon.2 July 2010 Cardno (NSW/ACT) Pty Ltd 95H:\Doc\2010\Reports.2010\Rep2580v4.doc