Issue: Direct pressure of human activities on coasts and oceans - Direct pressure of shipping
This is an issue under the Coasts and oceans theme of the Data Reporting System.
Humans use the ocean for transporting goods between settlements (ie shipping), and this activity can have a range of impacts on marine life. Oil and other pollutants, garbage and other debris, sewage, ballast water and even hot water from shipping discharged (intentionally or accidentally) from vessels can cause direct harm to marine life and consequential indirect harm to other species. Marine species can also be harmed directly by impact with ships and ships’ propellers. Impacts of sonar and electrical discharges may also have some impacts on marine life. Marine species can also be inadvertently transported to new locations, on hulls and in ballast water, where they can be invasive to resident ecosystems. Coastal benthos ecosystems can be damaged by channel dredging for shipping.
- CO-27 Number, frequency, extent and volume of oil spills from all sources
Oil spills from collisions, shipwrecks, leaks and other shipping accidents have direct and lethal impacts on marine biodiversity, suffocating and poisoning fish and invertebrates and rendering seabirds flightless (causing them to drown, starve or be taken by predators). Number, frequency, extent and volume of spills provides an indication of the intensity of this pressure.
- CO-32 Number of injuries to marine animals from marine debris
Ships transport materials which, if left in the ocean, can impact on marine life. Number of injuries reported that are attributable to this cause are one indicator of the intensity of this pressure.
- CO-50 Number of collisions with marine animals
As well as placing pressure on marine life through pollution, debris and introduced species, ships, as large, hard masses moving under power through the habitats of marine animals can exert pressure by colliding with those animals. Given the ever-increasing number of ships traversing the oceans, the potential for collisions with marine animals is continually increasing. Number of recorded instances of collisions would give some idea of the extent of this pressure.
- CO-51 Quantity of sewerage and ballast water dumped by shipping
Because they are mobile and temporary human settlements, ships produce a similar range of wastes to that of any other human settlements, with an additional waste product in the form of ballast water. If these wastes are discharged into marine waters in sufficient quantities, or in particularly sensitive or vulnerable habitats, they can have impacts on marine species, poisoning some, entangling others (see also Indicator: Number of injuries to marine animals from marine debris), providing excess nutrients which can change the balance of species, causing blooms of some and declines of others, or introducing foreign organisms which have the potential to become invasive in a different ecosystem. Changes in estimated quantities of ballast water, sewage or other waste released into the ocean gives an idea of changes in the potential pressure from this source.
- CO-52 Evidence or examples of impacts of channel dredging for shipping on marine life
Dredging of channels to provide access to ports and harbours for larger vessels involves removing part of the benthos. It is reasonable to assume that this removal could be disruptive to benthic species and interdependent organisms.
No indicator has been developed for measuring or assessing the extent of this pressure or its actual impact on marine organisms.
- CO-53 Evidence or examples of noise or visual disturbance of marine species by human activities
Many marine organisms rely on sound and visual signals for their survival. It is reasonable to assume that noise and visual cues from shipping may be disruptive to these signals and potentially uncomfortable, even lethal to some marine organisms.
No indicator has been developed for measuring or assessing the extent of this pressure or its actual impact on marine organisms. Some examples of impacts of sound and visual pollution from shipping on marine animals may be available.
- CO-65 Correlation between various human activities and introduction of coastal and marine species
Species can be introduced to an ecosystem from various sources, including from fishing activities, on exploration rigs and from coastal activity. However, the principal means of introduction is believed to be from ballast water and on the hulls of ships.
While number of introduced species is not indicative of anything in its own right, some introduced species do have the capacity to impact on resident species and ecosystems, especially in combination with other anthropogenic factors. However, the correlation between intensity of shipping activity (or other marine uses) and intensity of species introduction may shed light on the relative importance of the various ways in which species are introduced to new waters.
- CO-67 Progress of the Australian shipping fleet towards meeting the targets of the International Convention on the control of harmful anti-fouling systems on ships
Antifoulants are used on ships’ hulls to control marine fouling and rely predominantly on combinations of copper and tributyltin (TBT). Deposition of antifoulants at ship grounding sites and at mooring sites and slipways represents a significant risk to marine life. Leaching from antifouling paints, TBT and copper are directly available in the water column. TBT affects cell metabolism in organisms by causing malformations of the cell membranes, which adversely affect biological functions.
No indicator of the impact of anti-fouling paints across Australian ecosystems have been identified. However, proportion of shipping using such paints may be broadly indicative of the extent of the pressure.
- LD-40 Current research into pressures and contributions of naturalised introduced species
Other indicators for pressures of shipping, including the relationship between shipping and species introduction, do not inform on whether naturalised populations are exerting pressure on native species or ecosystems. Current research into this issue, even in the absence of national data, may shed some light on these effects.