Biology Reference
In-Depth Information
marine dumping and the move towards reuse and recycle, other treatment
options have to be explored (Reddignton, 2003). Fish farm waste affects not
only the area surrounding it and directly infl uenced by the effl uent, but can
alter a wider coastal zone at different ecosystem levels, reducing the biomass,
density and diversity of the benthos, plankton and nekton, and modifying
natural food webs (Gowen, 1991; Pillay, 1991). Most industrial facilities
discharge their wastewater to a local treatment facility. Due to federal
regulations regarding pretreatment and fees charged by local wastewater
treatment facilities, many industrial facilities provide pretreatment. Federal
regulations prohibit the discharge of wastes incompatible with: a) the
conveyance of the wastewater to the local facility (such as highly odorous
compounds), b) the processes at the local facility (such as chemicals that
would inhibit biological treatment) or c) the use or disposal of the treated
wastewater or resulting sludge (such as certain pesticides) (
http://www.
The environmental impact of marine aquaculture is managed in the
European Union (EU) through the implementation of legislative and
regulatory measures and Codes of Conduct and Codes of Practice. In
practice, compliance with these measures and codes requires the adoption
of Best Practice and Best Available Technology in relation to matters
such as: site selection; management practices that minimise food waste
and chemical usage and synchronised production, fallowing and disease
control (Cho et al
.
, 1994; Ervik et al., 1994). The objectives and principles
of the FAO's Code of Conduct for Responsible Fisheries are the basis for
an international commitment to responsible fi shing: it is now accepted
that the right to fi sh carries with it the obligation to do so in a responsible
manner. This has become widely recognised as the demand for fi sheries
products continues to grow whilst the resource remains limited. Like
other countries, the European Union is still in the process of following
up all the practical implications of the Code of Conduct but it is clear that
post-harvesting practices are an essential part in achieving its objectives
(OECD, 2000).
Microbial consortia involved in wastewater treatment have been a
major subject of microbial ecology, and many papers have been published
in which molecular tools were used for community analyses (Whiteley
and Bailey, 2000). The principal sources of aquaculture wastes are uneaten
feed and excreta. The bulk of this waste is in the particulate form and
in recirculating systems this is often removed in a concentrated form by
gravitational or mechanical methods (Chen et al
.
, 1994). Aquaculture
wastes, generated by fi sh and shellfi sh, can contain toxic levels of
ammonia in addition to large volumes of solid wastes. In many cases,
these wastes are fl ushed into nearby estuaries from coastal pond systems,
causing water quality problems (Ackefors and Enell, 1990). The world of
