In this report, we describe pressures facing biodiversity in general. However, pressures facing aquatic ecosystems are described in detail in the Coasts (coastal and estuarine ecosystems), Inland water (freshwater ecosystems) and Marine environment reports. A summary of the pressures outlined in those reports is given below.

Coastal ecosystems

The Coasts report describes how pressures on the coastal zone are strongly related to catchment land use and development. Pressures on coasts outside urban areas include those associated with resource extraction and agriculture. The pressures described in the Coasts report include the following (pressures with high impacts and worsening trends are noted in brackets):

• tourism and recreation
• oil, gas and mining
• climate and weather (high, worsening)
• sea level change
• erosion and inundation (high, worsening)
• sediment transport (high, worsening)
• desalination
• coastal river and estuary pollution (high, worsening)
• nutrient pollution (high, worsening)
• toxins, pesticides and herbicides (high, worsening)
• water turbidity, transparency and colour (high, worsening)
• marine debris (high, worsening)
• flow regimes
• water abstraction (high, worsening)
• seawater intrusion (high, worsening)
• dredging (high, worsening)
• fishing (high, worsening)
• artificial reefs (high, worsening)
• aquaculture
• vessel activity and infrastructure (high, worsening)
• invasive species (high, worsening)
• disease, infestation and fish kills (high, worsening)
• algal blooms
• jellyfish blooms
• low-oxygen dead zones.

Freshwater ecosystems

The Inland water report describes the pressures on freshwater ecosystems that arise from:

• climate variability and change
• water resource development
• land use and management
• pests and invasive species.

All 4 of the above pressures are assessed as high impact. Pressures resulting from climate variability and climate change, and pests and invasive species had a worsening trend; the trend for water resource development, and land use and management was stable.

Marine ecosystems

Pressures described in detail in the Marine environment report include:

• climate system variability and climate change
• commercial and recreational fishing
• traditional use of marine resources
• marine oil and gas exploration, and marine mining and industry
• marine renewable energy
• shipping
• noise
• marine debris
• toxins, pesticides and herbicides
• dumped waste.

Among these pressures, ocean acidification associated with climate change received the highest impact grade (very high). Several other climate-related pressures received a ‘high’ impact grade, as did recreational fishing and marine debris.