Fishing countries pay a great deal of attention to the systematic study of such conditions and to their relationship with the different growing stages of resources so as to improve their fishery efforts and performance, as well as in setting up administrative measures to ensure the conservation of such resources.
It is absolutely evident then, that hydrographic knowledge of the oceanic environment is a primary tool, as much for those who accomplish the tasks of catching fishing resources as for those who have the responsibility of their suitable and efficient administration. Their aims are for sustainable exploitation and conservation.
Hydrography for fisheries is a whole field of oceanic research and it employs lots of technological tools which hydrographers know fairly well and are routinely used for hydrographic surveying activities. Thus, seabed surveying is proven to be truly necessary for fishermen, especially when they work in shallow waters or they fish demersal resources (those being associated with the seabed). Some species of commercial interest are found associated with certain features of the seabed such as mounts or trenches.
The increasing complex of oil pipelines and seabed structures presents, in some countries, a hazard to fishing gear. Surveyors can play an important role in working with the fishing and oil industries to devise methods which will both protect the interests and increase the safety at work of each industry.
In some countries, important efforts have been put into the making of distribution charts of marine resources and species, prepared with the same standards and technologies required for navigation nautical charts, under interesting and innovative associations between private consultants and hydrographic offices.
For the fishing industry, it is of utmost importance to be able to count on updated information about the marine environment, so as to be able to determine favourable conditions for fishing. This information can be in the form of sea surface temperature charts as well as thermal, salinity and other variables of the water column’s vertical structure. By means of this information their fishing efforts may be better focused and also predictions of probable fishing areas can be carried out. In order to get this valuable information, the remote perception, the hydroacoustic survey - by means of echo sounders designed for fishing - uses disposable batithermographs (XBT), conductivity-temperature-depth sensors CTD, and other methods frequently used in the hydrographic survey industry.
It is important to realise that today's fishing industry is highly equipped technologically. In addition to the remarkable improvements in navigation and fishing arts, the industry uses high resolution sonars, echo sounders, continuous temperature recorders, Inmarsat telephones, highly innovative radios, automatic pilots and electronic navigation systems, GPS, etc.
Many fisheries are over-exploited and need to be managed to ensure that the stocks are harvested at a sustainable level and not fished to extinction. The fisheries management, responsibility lying on each state's authorities, subject to national and international agreements and regulations, must strive for a suitable and harmonious environment between the fishing effort and the availability of resources. They have the dual responsibility of preserving fish stocks and enabling the fishing industry to operate profitably. This implies a very finely balanced equation between the need for economical development and the need for ensuring the future availability of these stocks.
This is an extremely complex task, caused partly by the natural variability of fish populations, among which the effects of phenomena such as El Niño - Southern Oscillation (ENSO) or the Global Change cannot be ignored. These phenomena are a matter of intense studies all over the world. Fish populations consequently show significant long-term abundance fluctuations, which have certain implications on the estimates of the regulating authority. A second problem lies in the lack of knowledge to adequately understand and correlate the behaviour of the resources with environmental variations.
The above mentioned leads to the need for long-term environmental studies so that they provide the most suitable information possible to those who make fisheries administration decisions, so as to promulgate proper conservation measures. Again, on this task, hydrography plays an important role, contributing with a series of long-term data allowing feed predictive models used by the authority.
In short, there is a wide field of potential users in the fishery industry for hydrographers to establish interesting co-operations and relationships with. These users however, will demand high value products of great usefulness for the various above-mentioned purposes. Hydrographers, commonly use the advanced and complex technology required; they should be able to satisfy such requirements.