More than 80% of Australians are located within 50 km of the coast with more than half the nation living within the coastal fringe from Brisbane to Melbourne. The major problems for this coastline are urbanisation, water quality, freshwater supply, severe storms and beach erosion. The socio-economic issues of relevance to the NSW-IMOS Node are:
Future climate change will have wide ranging effects on the coastal and marine environment of NSW. The East Australian Current (EAC) is predicted to both strengthen and warm significantly which will have many diverse effects from changing weather patterns to shifts in marine species distribution. The intensification of the EAC, under climate change, suggests that productive continental shelves may be vulnerable to the risk of changed productivity and altered fisheries yields
The NSW coastal zone receives freshwater inputs from rivers and stormwater, as well as licensed municipal and industrial discharges. Apparent increases in the frequency of phytoplankton blooms (red tides) have been linked to oceanographic events such as upwellings, downstream of the EAC separation zone and periods of declining rainfall that have resulted in Sydney’s storage being as low as 33% capacity are of intense concern in the region.
In recent years severe storm events generated by East Coast Lows (ECLs), have caused fatalities, severe flooding and erosion and caused hazards for shipping, but are also source of significant amount of needed rainfall (10-20% of coastal rainfall in NSW). A recent example of the damaged caused by ECLs are the events in June 2007, which caused nearly $1000M in damage and were the cause of 10 deaths. Most ECLs occur in winter and are associated with warm SST anomalies.
Waves and beaches
Prevailing sediment transport along the NSW coast is from south to north despite the prevailing EAC being in the opposite direction. Along-shore sediment transport occurs because of the dominant south-easterly incident direction of the wave climate. Given that the NSW coast has many substantial shoreline erosion hotspots, more monitoring data is essential to give insight into the role of offshore processes in nearshore beach form, sand volumes and configuration. To date, a significant proportion of NSW’s beaches and nearshore subtidal areas remain unmapped. An improved understanding of the long-term dynamics across the shelf is critical.
Our largest marine industry is marine tourism, the second largest of all states contributing 22% of the national marine industry ($27 billion in value added during 2002-03). The value of the marine industry (i.e. all recreational and light commercial vessels) in NSW has been valued at over $2 billion pa and employs over 11,000 – both figures are almost equivalent to all other states combined. Commercial tourism businesses operating in coastal NSW include beach equipment hire, boat hire, charter fishing, general charters, dive operators, marine mammal watching, ferry services, filming, photography, houseboat hire, jetski hire, kayaking, parasailing, surf schools.
Recreational fishing brings approximately $2.5 billion dollars to the Australian economy each year and engages some 3.4 million Australians. In NSW approximately 17% of the NSW population fish at least once a year. In NSW the recreational catch has in the past constituted about 30% of the commercial catch, but for 6 major species the recreational catch is actually greater than the commercial. Target species that are especially relevant to recreational fishing, tourism and IMOS are bream, flathead, mulloway, prawns, kingfish, dolphin fish, Australian salmon, grey nurse shark, bullshark and white shark.
In 2011-12 gross commercial fisheries production for NSW reached $136 million per year. Commercial fishing is not a large contributor to the economy across the Temperate East Marine Planning region. Temporal variation in phytoplankton due to upwelling, EAC strengthening and sea-surface warming (with an associated increase in ECL’s), and their significance to fisheries have yet to be investigated. Changes in phytoplankton availability as a natural food source for in-situ aquaculture farming due to increasing sea-surface temperatures may also require investigation.
There have been 244 shark attacks in NSW waters since 1791, of which 68 were fatal, 121 had non-fatal injuries, and 55 instances where people were uninjured. The presence of sharks in Sydney Harbour in 2013 surprised the public and resulted in a decline in beach attendance. This period was distinguished by strong, wind-induced upwelling which reduced local water temperatures at the warmest time of the year from 25ºC to as low as 15ºC.
Marine protected areas for NSW are located at Cape Byron, Solitary Islands, Lord Howe Island, Jervis Bay, Port Stephens-Great Lakes and Bateman’s Bay regions and cover a total area of ~3,500 km2 of state waters (to 3 nm). The NSW Marine Parks Authority (MPA), now the Marine Estate Management Authority (MEMA) established and managed this system of multiple-use marine estates to conserve marine biodiversity, maintain ecological processes and provide for ecologically-sustainable use, public appreciation and education of the marine environment. An important factor requiring consideration during marine park zoning is the extent of connectivity among populations of key species, although it is recognised that this is a feature of marine populations about which we know relatively little.
Other industries of importance for the NSW-IMOS region are shipping and defence, with one of the two major Royal Australian Navy (RAN) centres based in Sydney-Garden Island, with additional bases at Jervis Bay (HMAS Creswell; HMAS Albatross). The RAN’s primary need from IMOS is supporting data to improve operational ocean forecasts (BLUElink), especially wave and sonar impact forecasts.