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biota

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    Dive surveys using strip transects are used to determine species composition, size structure and abundance of scallops, with surveys conducted pre- and/or post fishing season. In addition, post season telephone surveys of recreational scallop dive licence-holders are conducted to collect information about scallop diving activity (including days fished, location and success), and a range of management-related issues (eg. attitudes to management options, communication strategies).

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    Belt transect surveys (50m) were used to monitor the benthic community structure through time at experimental (lobster additions/ research reserve sites or abalone diver urchin culls) and control sites in eastern Tasmania. Measures of percentage cover of key algal guilds, percentage of reef grazed by sea urchins, number of sea urchins (Centrostephanus rodgersii, Heliocidaris erythrogramma), Abalone (Haliotis Rubra), Rock lobsters (Jasus edwardsii) and type of substratum were recorded.

  • Sediment organic carbon assessments within plots of transplanted Posidonia australis seagrass, and compared to adjacent bare sand and healthy meadows, in Shark Bay, WA.

  • In Tasmania, SCUBA surveys of seahorses populations were conducted. Intensive surveys were conducted in 2000 to 2004 in the Derwent River around Hobart (submonthly & then monthly) and twice yearly surveys from 2004/5 on east coast and Derwent River, until 2007. Mark-recapture studies were done to estimate population size, and life history parameters.

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    This meta data describes the raw output of the SES DEB-IBM built in NetLogo (version 6.0.1, March 2017; available from http://modelingcommons.org/browse/one_model/5348). The raw output consists of .csv files from several model runs. The detailed explanation of the model workings and background are published in Goedegebuure et al. (2018, PLoS ONE; Modelling southern elephant seals Mirounga leonina using an individual-based model coupled with a dynamic energy budget; DOI: 10.1371/journal.pone.0194950). In short: we developed an individual-based model which is coupled with a dynamic energy budget (a DEB-IBM) for southern elephant seals to demonstrate a method for detailed representation of marine mammals. We aimed to develop a model which could i) simulate energy use and life histories, as well as breeding traits of southern elephant seals in an emergent manner, ii) project a stable population over time, and iii) have realistic population dynamics and structure based on emergent life history features (such as age at first breeding, lifespan, fecundity and (yearling) survival). We evaluated the model's ability to represent a stable population over long time periods (> 10 generations), including the sensitivity of the emergent properties to variations in key parameters. The model was developed using life history data of female southern elephant seals from Macquarie Island and follows individuals from birth to death. The information collected in the raw output are the same for the baseline model (stable, and with standard parameters), and the modified models to test for 1) low, and 2) high food availability, 3) low, and 4) high weaning thresholds (energetic level at which pups transition to juveniles), 5) low, and 6) high puberty thresholds (energetic level at which juveniles transition to physically mature adults). As well as recording the parameter values as set in the model, each .csv file records: 1) run number (usually 1-10) 2) step (time step, days) 3) min age at first breeding (years) 4) min age of adult 5) mean age of adult 6) mean age of juvenile 7) max age of individuals 8) max number of pups per female 9) fecundity 10) max size of individuals 11) mean size of adults 12) mean size of juveniles 13) total count of modelled population 14) total count of embryos 15) total count of pups 16) total count of yearlings 17) total count of juveniles (includes yearlings) 18) total count of adults 19) mean food availability of independent individuals (those not reliant on their mother) that are not fasting/moulting 20) carrying capacity (or expected equilibrium) 21) seed NB. NetLogo calls individuals within the model turtles - thus output will mention turtles. Stages are as follows 0 = foetus, 1 = pup, 2 = juvenile, 3 = adult. Status are as follows, 0 = dependent on mother, 1 = fasting, 2 = foraging.

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    The data is the percent algal cover derived from underwater visual census methods involving transect counts at rocky reef sites around Tasmania. This data forms part of a larger dataset that also surveyed fish and megafaunal invertebrate abundance for the area. The aggregated dataset allows examination of changes in Tasmanian shallow reef floral and faunal communities over a decadal scale - initial surveys were conducted in 1992-1995, and again at the same sites in 2006-2007. There are plans for ongoing surveys. An additional component was added in the latter study - a boat ramp study looking at the proximity of boat ramps and their effects of fishing. We analysed underwater visual census data on fishes and macroinvertebrates (abalone and rock lobsters) at 133 shallow rocky reef sites around Tasmania that ranged from 0.6 - 131 km from the nearest boat ramp. These sites were not all the same as those used for the comparison of 1994 and 2006 reef communities. The subset of 133 sites examined in this component consisted of only those sites that were characterized by the two major algal (kelp) types (laminarian or fucoid dominated). Sites with atypical algal assemblages were omitted from the 196 sites surveyed in 2006. This study aimed to examine reef community data for changes at the community level, changes in species richness and introduced species populations, and changes that may have resulted from ocean warming and fishing. The methods are described in detail in Edgar and Barrett (1997). Primarily the data are derived from transects at 5 m depth and/or 10 m depth at each site surveyed. The underwater visual census (UVC) methodology used to survey rocky reef communities was designed to maximise detection of (i) changes in population numbers and size-structure (ii) cascading ecosystem effects associated with disturbances such as fishing, (iii) long term change and variability in reef assemblages.

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    Sediment derived from the decomposition of Halimeda algae is a major contributor to the tropical back-reef carbonate depositions. Halimeda bioherms occur extensively on the northern Great Barrier Reef (GBR), Australia. This dataset represents the most complete, high-resolution spatial mapping of the extent of northern GBR Halimeda bioherms, based on airborne lidar and multibeam echosounder bathymetry data. Three distinct morphological sub-types are described: reticulate, annulate, and undulate. The northern GBR bioherms cover an area of 6095 km2, three times larger than previous estimates.

  • Meta data of all tagged hammerhead sharks detailing tag dates, locations, and shark biological details.

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    This dataset describes visual sightings of marine megafauna (whales, dolphins and sharks) obtained during a series of dedicated aerial surveys conducted as part of a NESP Marine Biodiversity Hub project within and around the Bremer Marine Park, southern Western Australia. The data reflect 25 hours of observer effort (on transect), and 62 sightings of four identifiable species, including killer whales (Orcinus orca), sperm whales (Physeter macrocephalus), long-finned pilot whales (Globicephala melas), and bottlenose dolphins (Tursiops sp.). Numerous unidentified cetaceans and sharks were also seen. For more information, see: https://www.nespmarine.edu.au/project/ep2-surveying-marine-life-canyons-bremer-bay

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    To test if the carapace length of lobsters changes during cooking, 21 legal-sized southern rock lobsters were collected in pots from Alum Cliffs, south-eastern Tasmania, Australia in October 1999 (42.95±S 147.35±E). The sample consisted of 7 female and 14 male lobsters ranging in carapace length from 106 mm to 153 mm (mean 120 mm). Each animal was abdominally tagged using individually marked t-bar tags (Hallprint T-bar anchor tag, TBA1; Hallprint Pty Ltd, 27 Jacobsen Crescent, Holden Hill, SA 5088, Australia). The carapace length of all lobsters were measured five times to the nearest 0.1 mm in a random manner, before and after processing. This repeated measurement of all specimens in random order was intended to evaluate measurement error. Processing was typical of that used commercially and involved killing the lobsters in fresh water before cooking in pre-boiling salted water for 12 minutes.