Topic
 

biota

102 record(s)
 
Type of resources
Topics
Keywords
Contact for the resource
Provided by
Years
From 1 - 10 / 102
  • Categories  

    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.

  • Categories  

    Data were collected from 28 artificial reefs varying in size and supporting different densities of transplanted kelp (Ecklonia radiata). We used rope fibre habitats (RFHs) attached to the benthos of the reefs and destructive sampling of understory algae to collect data on epifaunal invertebrates that naturally colonised the reefs (e.g. secondary productivity, species richness, Shannon diversity). The goal of the research was to understand how kelp structure influences the biodiversity and secondary productivity of epifauna.

  • Categories  

    Diel partitioning of animals within ecological communities is widely acknowledged, yet rarely quantified. Investigation of most ecological patterns and processes involves convenient daylight sampling, with little consideration of the contributions of nocturnal taxa, particularly in marine environments. Here we assess diel partitioning of reef faunal assemblages at a continental scale utilizing paired day and night visual census across 54 shallow tropical and temperate reefs around Australia. Day/night differences were most pronounced in the tropics, with fishes and invertebrates displaying distinct and opposing diel occupancy on coral reefs. Tropical reefs in daytime were occupied primarily by fishes not observed at night (64% of all species sighted across day and night, and 71% of all individuals). By night, substantial emergence of invertebrates not otherwise detected during sunlit hours occurred (56% of all species, and 45% of individuals). Nocturnal emergence of tropical invertebrates corresponded with significant declines in the richness and biomass of predatory and herbivorous diurnal fishes. In contrast, relatively small diel changes in fishes active on temperate reefs corresponded to limited nocturnal emergence of temperate invertebrates. This reduced partitioning may, at least in part, be a result of strong top-down pressures from fishes on invertebrate communities, either by predation or competitive interference. For shallow reefs, the diel cycle triggers distinct emergence and retreat of faunal assemblages and associated trophic patterns and processes, which otherwise go unnoticed during hours of regular scientific monitoring. Improved understanding of reef ecology, and management of reef ecosystems, requires greater consideration of nocturnal interactions. Without explicit sampling of nocturnal patterns and processes, we may be missing up to half of the story when assessing ecological interactions.

  • Categories  

    The spatial extent of C. rodgersii "barrens" was estimated by surveying rocky reef habitat with a towed underwater video system. Sampling took place at 13 regions along the east coast of Tasmania, each comprising 3 subsites, this dataset refers to the Eddystone Point region, and its 3 subsites: Georges Bay, Lighthouse Point and Purdon.

  • Categories  

    A survey was conducted for Macrocystis pyrifera (Linnaeus) C. Agardh 1820 from Eddystone Point to South East Cape The survey was conducted from light aeroplane. Areas of Macrocystis pyrifera beds were marked on 1:100,000 topographical land tenure maps using landmarks as references. A Trimble GPS unit was used to track position in the aeroplane. As boundaries of the beds were flown over, these were marked on the GPS. When plotted up, these information assisted in determining Macrocystis bed boundaries where these were not close to the coast.

  • Categories  

    The spatial extent of C. rodgersii "barrens" was estimated by surveying rocky reef habitat with a towed underwater video system. Sampling took place at 13 regions along the east coast of Tasmania, each comprising 3 subsites, this dataset refers to the Bicheno region, and its 3 subsites: Denison, Governor Island and Lodi.

  • Categories  

    Zooplankton samples were collected at two sites in south eastern Tasmania, between the years 2000 and 2001 using two types of plankton net. Samples were collected using horizontal hauls during the daytime only. All copepods, salps and chaetognaths were identified and enumerated.

  • This global meta-analysis documents data from underwater visual surveys used to determine the effect of kelp bed disturbance and canopy density on the abundance and structure of fish communities. Spatial, temporal and ontogenetic variability of many key fish species was examined at various levels of kelp disturbance at sites spanning a global temperate distribution. Rocky reef habitats and fisheries management regimes of sites were also examined as covariates. This data spans from 1984 to present. Note that Emma has completely fabricated this abstract, and requires direct input from KEEN.

  • Categories  

    The data is quantitative abundance of fish, megafaunal invertebrates and percent algal cover derived from underwater visual census methods involving transect counts at rocky reef sites around Tasmania. This dataset allows examination of changes in Tasmanian shallow reef faunal and floral communities over a decadal scale, with initial surveys conducted in 1992-1995, and again 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.

  • Categories  

    Reef Life Survey is designed to develop and resource a network of skilled recreational divers for rapid and cost-effective assessment of the state of the inshore marine environment at the global scale. The project uses standardised underwater visual census methods employed by trained SCUBA divers to survey fish and invertebrate species and to record habitat type using photo quadrats - this particular dataset refers to the photo quadrats only.