Lynnath Beckley

The proliferation of informal access tracks enables unmanaged recreational activity in remote coastal areas and such tracks can directly and indirectly impact the coastal environment. With the aim of enhancing the capacity of conservation managers to address this problem, coastal access tracks in the western Kimberley region of northern Australia were mapped using recent, high resolution ALOS panchromatic satellite imagery. We mapped tracks within the 10 km buffer of the Mean High Water Mark and track density was evaluated in relation to proximity to settlements and main roads. Tracks accessing the shoreline were analysed per shoreline type. We mapped a total of 1,600 km of coastal tracks and nearly 1000 coastal access points. Significant differences were found between areas east and west of King Sound; only of tracks and 14 coastal access points were east of King Sound. There was also a large, significant difference in average track disturbance density between the study area to the east (9 m2/ha) and west (89 m2/ha) of King Sound. Track densities were examined for potential association with variables such as tenure, type of coast, distance from settlements and main roads. We found that land tenure classes that restrict human access, the relative attractiveness of geomorphology, and a travel impedance effect related to the proximity of formal roads and isolated human structures, are factors that significantly influence the spatial distribution and density of coastal access tracks. On the basis of these findings, we make several recommendations with respect to the management of coastal access tracks in the western Kimberley.

The tropical north-west of Australia boasts a marine environment with a diverse array of biota as well as highly dynamic oceanography because of large tidal fluctuations, seasonal monsoons, tropical cyclones and El Niño influences. Krill, as part of the holoplankton, are influenced by such oceanographic conditions. An investigation off the Kimberley coast during the austral autumn of 2010 revealed 20 species of krill, of which three, Euphausia fallax, Euphausia sibogae and Nematoscelis gracilis, were identified as new records for the region. Although the number of species increased from shelf to oceanic waters, concentrations of krill decreased. Pseudeuphausia latifrons was the most abundant species off the Kimberley coast, with concentrations highest in shelf waters sampled during the night (2.84 ± 1.95 m-3). This species was also the most abundant at the 100 m and 200 m isobaths, but Stylocheiron carinatum dominated in the deeper waters (500 m, 1000 m and 2000 m stations). In terms of environmental influences on the krill assemblages, together mean seawater density, zooplankton settled volume and depth provided the highest correlation with krill assemblages (r2=0.69, P=0.002). Mean seawater density was used as an indicator for water masses, and two distinct water masses were identified in the study area, a warmer (300°C), higher salinity (>34.7 psu) surface layer overlayed a cooler, less saline layer. The Kimberley coast is one of the least studied marine environments of Australia, particularly for zooplankton, and this study improves the understanding of oceanographic influences on krill diversity and distribution in this highly dynamic environment.

The Houtman Abrolhos Islands (280-290S, 1140E) are the most significant seabird breeding sites in the south-east Indian Ocean for large populations of lesser noddy (Anous tenuirostris), brown noddy (A. stolidus), sooty tern (Onychoprion fuscata) and wedge-tailed shearwater (Ardenna pacifica) during the spring/summer period. The availability of neustonic fishes and squid for prey is pivotal in seabird breeding success and juvenile survival. A large set of surface macro-zooplankton samples collected in August/September 2011 across three transects radiating out 300 km from the Abrolhos, as well as strategically targeted stations in meso-scale oceanographic features was available for study. The potential prey field was examined by distance from the island colonies and oceanographic features (e. g, Leeuwin Current, warm-core and cold-core eddies) which were present throughout the duration of sampling. CTD profiles and IMOS sea-surface temperature imagery indicated strong Leeuwin Current (activity near the shelf-edge and cooler, more saline, Sub-Tropical Surface Water e 17. 50C) in the south of the study area in which a complex eddy field was present. Settled volumes of macro-zooplankton obtained using a surface net with 1 mm mesh ranged from 40 — 377 ml/ 1000 m3. In total, 248 phyllosoma larvae of the Western Rock Lobster, 36 squid larvae and 1, 175 larval and post larval fishes were collected. The Myctophid Hygophurn hygomii was dominant in the samples and contributed approximately 9% of all fishes caught. Most of the phyllosoma larvae were stages 7 and 8, and the greatest numbers were found in warm-core eddies. This study indicated that areas of higher prey concentrations were within the foraging range of the seabirds. However, warm-core eddies could be targeted by the seabirds as they appear to have more available surface prey than the surrounding ocean.

Australia made a significant contribution to the first International Indian Ocean Expedition. Five decades on, both the Intergovernmental Oceanographic Commission and the Scientific Committee for Oceanic Research have motivated for a modern phase Of co-ordinated international research in the Indian Ocean, namely, a second International Indian Ocean Expedition (IIOE-2: 2016-2020). The planned research is ambitions and concentrates on six themes- These are human impacts on the Indian Ocean; boundary current dynamics and upwelling; monsoon variability and ecosystem response; circulation, climate variability and change; extreme events and associated ecosystem responses and impacts; and discovery of unique physical, geological, biogeochemical and ecological features of the Indian Ocean. The planned research will provide a rich framework of data, process understanding and input to oceanographic, climate, bio-geochemical and ecosystem modelling through open ocean science. There will also be strong links to continental shelf and coastal systems and coupled climatic phenomena affecting society. The IOC Assembly of 147 Member States is formally considering the science and complementary plans for the expedition, as well as governance and timeframes for implementation, through an international 110F.-2 Planning Committee. Australia has formed a National Committee to lead participation in Indian Ocean research over the next five years. With the new Marine National Facility RV Investigator now commissioned and the Integrated Marine Observing System well—developed, various initiatives and planning are now underway for Australia to contribute to the second international Indian Ocean Expedition.

Monitoring and management of popular coastal destinations requires accurate benchmark data on access nodes, travel networks as well as detailed information on landscapes and seascapes. We investigated the 300 km long coastal strip along Ningaloo Reef using hyperspectral remote sensing techniques combined with extensive fieldwork. We mapped bathymetry and marine habitats at high resolution to a depth Of 20 In covering 762 km2 of the reef. We mapped land cover including vegetation along the coast for an area of 988 krn2. We also compiled a database of the track and road network up to 2 km inland from the coast and characterised the dominant sediment and vegetation cover along track buffers. Many of the areas with the highest density of tracks were adjacent to sanctuary areas in the marine pork with easy access to the reef from the beach. Land tenure is important in managing the coastal area and the highest track densities have been found in areas managed as pastoral stations while the lowest are in areas managed as national park. Track buffers contained a lot of vegetation and with track expansion this may be destroyed. With the proposed changes to the pastoral leases expected to result in changes in tenure, and it is vital that comprehensive and cost-effective monitoring is developed and implemented to protect the coastal area and adjacent reef. Remote sensing offers a range of quantitative, repetitive and operational methods suitable for creating benchmark data sets and follow up studies for monitoring. It is also effective for large areas where access and logistics for management are very challenging.

Human use of the coast, between Broome and Port Hedland in north-western Australia was examined by undertaking monthly aerial surveys (November 2012 to October 2013) using a Cessna 210 aircraft and two observers equipped with digital cameras and a GPS logger. Digital photographs were analysed using Aerial Survey Assistant software. Results with respect to the number of people on the shore and number of boats in adjacent coastal waters showed that there was much higher usage ill the dry season (May to October) than the wet season (November to April). Areas with highest densities of people were near 80 Mile Beach Caravan Park, Cape Keraudren and Barn Hill and, to a lesser extent, Port Smith and Bidyadanga. Of the people recorded, 46% were fishing from the shore and 33% were walking along the beach. Fishing was particularly popular near Eighty Mile Beach Caravan Park with anglers and their associated four- wheel drive vehicles spread along about 30 km of coastline. Camping along the coast during the dry season was largely within the confines of the large caravan parks at Eighty Mile Beach and Port Smith but there were also nodes of camping at, Barn Hill Station and Cape Keraudren. Boating activity occurred mainly in the northern part around Port Smith and to a lesser extent near Cape Keraudren. These boats were engaged in recreational fishing or motoring and pearling vessels were also recorded between Port Smith and Barn Hill. The distribution of human use was also examined relative to the proposed sanctuary zones of the new Eighty Mile Beach Marine Park. This study provides spatially explicit data on coastal recreational activities that can be used by managers as a benchmark of use prior to the implementation of the management plan for the new marine park.

The only known spawning ground of the Southern Bluefin Tuna (Thunnus maccoyii) occurs in the Eastern Indian Ocean between north-west Australia and Indonesia. This study examined environmental features of this spawning ground using remote sensing and in-situ archived oceanographic data relative to the habitat requirements of the Southern Bluefin Tuna. Environmental data (sea surface temperature, sea level height anomaly, surface chlorophyll a and XBT sections) were extracted from the IMOS portal and used to establish a spatial and temporal oceanographic synopsis Of the area. In addition, CSIRO Atlas of Regional Seas data (CARS; temperature, salinity, oxygen, silicate, nitrate and phosphate) and ARGO data (temperature and salinity) were extracted to supplement the remotely-sensed data. The SST data show significant upwelling (4 degrees Celsius less than the surrounding ocean) along the coastline of Java and Sumatra during the monsoon, about two months before the summer Southern Bluefin Tuna spawning season. This upwelling drives biogeochemical processes that support the pelagic ecosystem in the region. Southern Bluefin Tuna are fast growing; juveniles are voracious predators on macro-zooplankton and small nekton and migrate southwards in the Leeuwin Current to their cool temperate habitat in the Southern Ocean. These fish form the basis of the Port Lincoln tuna ranching industry in South Australia and the longline tuna fishery off New South Wales. It is anticipated that the understanding of the oceanographic features of the spawning ground will provide an important link into the year class strength for this extremely valuable, yet severely depleted, apex fish species.