Human activities are directly or indirectly one of the main causes of change in marine biodiversity, and have been referred to in the past as critical environmental topics. In 1995 the Commission of Geosciences, Environment, and Resources defined 5 relevant agents of change in marine biodiversity from the level of population genetic changes to the level of ecosystems, where fishing activities is one of these. Alone or combined, these human disturbances can lead to changes in the energetic flow as well as to many more alterations in the structure and function of the ecosystems.

In 2001, the Declaration of Reykjavik on Responsible Fishing in the Marine Ecosystem was approved and signed in presence of FAO representatives of 60 countries (including Mexico) and representatives of 21 intergovernmental organizations, 11 non-governmental organizations, and around 200 scientists. Such declaration expresses the international guidelines to follow in fishery assessment and regulation. Likewise, it emphasizes the fact that "one needs to continue improving the scientific basis to include considerations related to the ecosystem in fishing regulation, and that scientific knowledge on structure, function, components, and properties of the ecosystem, as well as on the ecological effects of fishing"

Therefore, Mexico confronts the challenge of regulating its own fishery resources under an ecosystematic focus and with a view based on scarce, fragmented, and dispersed knowledge of its marine ecosystems, and still scarcer knowledge on the effects of fishing on such ecosystems.

Fishery activities are especially impacting the marine environment because they directly affect almost any habitat, except deep sea bottoms, where there is no fishing. Even with the most current and restricted management practices, fisheries can have a great impact in the marine environment, from extractions that induce over exploitation of some species up to incidental capture problems or "by catch" up to habitat alteration, genetic changes in populations, and food chains. It is very difficult to isolate specific impacts caused by fishing because the marine environment is also impacted by other human activities, as well as by natural fluctuations of the environment. More yet, lack of knowledge on fishing impacts on the environment, which increase by the complexity of the food chain, makes the relationship cause-effect between fishing and impacted environments not clearly defined.

On the other hand, renewable marine resources such as fishing and aquaculture can indefinitely provide benefits for humanity if they are managed with sustainability and in harmony with the changing dynamics of these resources.

The work of the Group collaborating in this line of research covers two aspects:

Trawl fishing:

Trawl fishing particularly affects sea bottom habitats all over the world. However, its consequences are not uniform because they depend on spatial and seasonal fishing distribution, which vary according to the type of habitat and environment where they are produced. Different fishery methodologies affect sea bottoms differently. Trawl fishing gear and hydraulic recollection devices make upper layers of sedimentary habitat stay suspended, and carry nutrients, pollutants, and fine particles within the water column. The ecological meaning of these fishery effects has not yet been determined.

Since 2004, CIBNOR has performed analyzes focused on assessing fishing effects on the marine benthic ecosystem of the Gulf of California, starting from a multidisciplinary focus and covering aspects at the level of individual, population, community, and ecosystem.

Coastal fishing

In México traditional fisheries have grown more each time as a consequence of population increase and the need for job and food sources. The fishery sector includes different locations with many fishing arts and methods (gill net, hooks, aggregating devices, and traps, among others) used with different species and which vary from one location to the other.

Besides its low technological development, coastal fisheries constantly impact the components of a high biological diversity (Cisneros-Mata 2002). Only in Sonora (WWF 2005) a recent study determined that coastal fisheries affect 57 resources (65% pelagic and 35% benthic), mostly fish (60%), same which are captured with traps, hooks, gill and trawl nets, and diving for fish and/or crustaceans. We have suggested eliminating nets as fishing arts in order to reduce capture of species that are not the fishing target, decrease habitat destruction, and reduce ghost fishing. We have explained that with a general use of circular hooks among coastal fleet would avoid incidental capture of endangered species, such as sea turtles (Cisneros-Mata 2004, WWF 2005, Santana-Hernández and Valdez-Flores 2005, Galeana-Villaseñor et al. 2005).

Specifically in the Gulf of California, the paternoster line of 450-500 hooks is used for the capture of different big pelagic fish like shark, dorado (Mahi-Mahi), among others. Likewise, it is common to use trolls and lines with hooks of different sizes and types in the State of Sinaloa, additional to the previous ones, the combination of fish aggregating devices (FADs), and lines whose use is estimated to increase capture 3 to 4 times more than what could be obtained without this type of devices. In the area in front of Mazatlán, there are at least 500 fish gatherers in an area of 20 thousand hectares, with an approximate capture of 1,000 annual tons of dorado (which could represent up to 60% of traditional fleet capture), and the participation of around 600 fishermen. Because the practice has spread to other coastal areas, the estimated numbers could be much higher (Aguirre 2006).

On the other hand, fishing with the paternoster line, fishing lines could reach 120 km in length; each one with up to 3.000 hooks, even though the common denominator within the Gulf of California is 450. It is estimated that close to one billion hooks are used annually, and the paternoster line is the fastest growing practice in the Pacific. Even though the main objectives of this fishing type are tuna fish and sword fish, this practice causes accidental capture of many marine species. Some animals are seriously affected by this practice, including sea birds, sharks, seals, sea turtles. Due to their extended use, these fishing arts require an urgent and serious assessment on selectivity (both in species and in size). Besides, there is the need to characterize their multiple variants and their operational efficiency to provide the necessary information and elements in court that could allow the corresponding authorities to advice the coastal fishery sector on good fishing regulations.

During 2007 the group working on this line of research analyzed the effects of coastal fisheries. We began studies to integrate a systematic list of the fishing target species and by catch of coastal fisheries, especially on the incidence of hook fishing art (mainly the paternoster line). The results we are looking for are from analyzes on fauna, trophic aspects, population dynamics, and selectivity of fishing arts, among others, both in the western coast of the Gulf of California and in the Gulf of California.