Biota removal/disturbance

Green sea turtle entwined in crab trap in Moreton Bay (photo by Ian Greenwood). The removal, loss or disturbance of individual organisms of a specific species results in loss of biodiversity. Biodiversity is the variety of life forms: the different plants, animals and microorganisms, the genes they contain and the ecosystems they form. Maintaining biological diversity is about the sustainable use of biological resources and safeguarding the life-support systems on earth.

View a conceptual model of potential causes of a change to biota removal/disturbance and the condition responses observed as a result of this change.

Potential indicators

There are a number of causes and symptoms related to this stressor. The following indicators are recommended for the stressor ‘Biota (plant or animal) removal / disturbance’:

Pressure indicators

Indicators of biota removal/disturbance sources:

  • Dredging activity in river system
  • Recreational bait (beachworm, bloodworm, bait fish, yabby, etc.) collector usage of an estuary
  • Commercial bait (beachworm, bloodworm and yabby) collector usage of an estuary and adjoining coastal waters
  • Boat moorings
  • Boating activity within the estuary
  • Recreational usage index
  • ‘Estuary’ population size
  • Number of recreational fishers using an estuary
  • Total recreational fisher catch from an estuary
  • Commercial trawl usage of an estuary and adjoining coastal waters
  • Commercial line fishing usage of an estuary and adjoining coastal waters
  • Commercial net and crab fisher usage of an estuary and adjoining coastal waters
  • Total commercial fisher catch from an estuary and adjoining coastal waters
  • Commercial licensed collector (of aquarium fish, shell, coral, etc.) usage of an estuary and adjoining coastal waters

Indicators of direct pressure:

  • None

Vulnerability indicators

  • None

Condition indicators

Physical-chemical condition indicators:

  • None

Biological condition indicators:

  • Commercial finfish catch per unit effort (estimate of fish abundance)
  • Commercial crab catch per unit effort (estimate of crab abundance)
  • Commercial prawn catch per unit effort (estimate of prawn abundance)
  • Recreational finfish catch per unit effort (estimate of fish abundance)
  • Recreational crab catch per unit effort (estimate of crab abundance)
  • Recreational prawn catch per unit effort (estimate of prawn abundance)
Possible causes Possible symptoms
The actions/events/situations that might induce this stress The actions/events/situations that might arise from a change to the stressor:

Fact sheets on background science and economics

Other information on direct disturbance to biota

New South Wales

Water Bug Survey. This page has results of water bug surveys used to calculate a Stream Pollution Index for a waterway.

Queensland

EHMP – Coral Monitoring measures the change in biological structure of coral reefs in Moreton Bay over time. Results for 2001 and 2002 coral monitoring are available from this site.

Fish kills . This page has information on fish kill incidents reported to the EPA since March 2002.

Seagrass depth range and distribution. The EHMP website has information on seagrass depth range and distribution in Moreton Bay, southern Queensland.

StrandNet – Marine Wildlife Strandings. The EPA maintains a database of marine wildlife strandings and deaths, called StrandNet. This records information on where injured, dying and dead marine cetaceans (whales and dolphins), pinnipeds (seals and sea lions), dugong and turtles have been found in Queensland.