8. Mexico

Mexico, the third largest North American country, is situated between the United States of America in the north and Guatemala and Belize in the south. The country has a population of 90208000 (1991), growing at a rate of 2.2% a year, an urbanization rate of 66.3% and a literacy rate of 90%. It has 1247 universities, second only to the United States in number. Its coasts are washed by the Pacific Ocean, the Gulf of Mexico, and the Caribbean Sea. A federal republic made up of 31 states, the country has a total area of 1958201km². The landscapes consist mainly of highlands 1000m above MSL, the low lying areas restricted to the coastal belts on either side of the mainland and the Yucatan peninsula. Nearly 5.5% of the national territory (0.107 million km²) is designated as national parks, biosphere reserves, protected areas for fauna and flora, national monuments and marine national parks. The main agricultural crops are coffee, corn, and cotton, and Mexico is one of the leading producers of salt, silver, crude petroleum products and lead. The GNP is $US156152 with an estimated annual growth rate of 1.4%.

Exploitation of fishery resources from the seas and the inland water bodies has always been an important economic activity in the country. In recent years, because of the ongoing economic reforms and the world-wide stress on aquaculture, the country's aquatic resources and their utilization have been receiving special attention. Between 1992 and 1993, the fisheries sector grew by 5.3% against the growth of 0.4% for the economy as a whole. In 1993, the contribution of the fisheries sector to the total Gross Domestic Product was 0.3%.

Mexico's coastline of 11500 km, including that of the offshore islands, is considered to be one of the longest of any country in the world. The rich and varied marine fisheries resources of Mexico include tuna, sardines, anchovies, red snappers, mullets, snappers, sharks, dogfish, king mackerel, grunts, shrimps, lobsters, abalone, oysters, clams, sea snails, octopuses, sea cucumbers and sea urchins. The surface area of inland waters is estimated at 2.9 million ha, which includes nearly 1 million ha of lakes and reservoirs and 29000 ha of ponds (Table 8.1). The marine waters contain a number of economically important species including 154 fish, 29 crustaceans, 59 molluscs, 4echinoderms and 4 species of seaweed. Forty-seven species of native and exotic fish, which contribute significantly to the fish production, can be found in the lagoons, reservoirs and ponds of the inland areas.

8.3 Geographical regions

The country's location and its varying altitudes create a climatic diversity which provides conditions for a variety of aquatic species native to inland and marine waters in both tropical and temperate areas. Mexico has six major regions (Figure 20). The northern plateau and the central plateau regions provide ideal conditions for production of species such as catfish, red tilapia, ornamental fish and black bass. While the gulf coastal slope and the Caribbean area are suited for the production of oysters, shrimps, tilapia, catfish, red drum and marine fish, the Pacific coastal slope is suited for abalone, oysters, bay clams, mother of pearl, sea urchins, sea cucumber, shrimp, red tilapia and marine fish. Mountainous areas provide excellent opportunities for the culture of rainbow trout.

Classification of the wide range of natural and man-made water bodies in Mexico is quite vague. Since water bodies are known by a number of names and located in regions with different kinds of land-use patterns, it is very difficult to bring all of them under common classification. The National Metropolitan University has classified the natural water bodies into lagos (lakes), lagunas (lagoons) and escurrimientos temporales, and the artificial ones into jaguey, bordo, and presa (Table 8.2). While the lakes and lagoons are used for drinking water, extensive aqua-culture, agriculture and recreation, the escurrimientos temporales are used mainly for aquaculture purposes. Jaguey are small, often household impoundments, usually less than 1 ha in size, made for watering animals and small agricultural farms. Bordos are small dams created primarily for irrigation purposes where aquaculture is usually practised. Sometimes small bordos are called microbordos and tagged along with jagueys. Presas are the large dams built for irrigation, hydroelectric power generation or city water supply. Embalse refers to all types of inland water bodies.

Since inventory and production data on inland fisheries maintained by the authorities do not have the above classification, it is difficult to make a separate study on the small water bodies such as jagueys and bordos. Therefore, this study is based on the available information on lakes and reservoirs. Some details on the distribution and fish production trends of presas are given in respect of a few states where direct observations were possible.

The landscape of the Mexican upland is dotted with a large number of man-made and natural lakes covering a total surface area of 2.9 million ha. However, many of these lakes, especially those lying in the protected areas, are either not available or not suitable for fisheries purposes. The national register of inland water bodies has at least 2029 entries, of which more than 500 are reservoirs. Apart from these, there are numerous small water bodies which are less than 10 ha in size. Hernandes et al. (1993, Aquila II) classified the 13 935 water bodies in the country into five size categories, 84% of them smaller than 10 ha in size (Table 8.3).

More than one-half (54%) of the water surface area is accounted for by only 23large lakes. Tomasini (1992, Aquila II), however, lists 24 large lakes covering an area of 671000 ha (Table 8.4). A total of 13200 water bodies fall under the 10-100 ha category. An overwhelming majority of Mexican reservoirs are very old, some dating from the 16th to 18th centuries. The Yuriria Lake of Guanajuato State and the Santa Cruz Lake of Zacatecas State were created in 1550 and 1602 respectively. While nine of them were constructed in the 18th century, more than one hundred reservoirs can be traced back to the 19th century. Guanajuato, Zacatecas, and Jalisco have the highest concentration of ancient reservoirs. Eighty-five percent of the reservoirs of the country were impounded well before the first half of the 1900s. Many of the old reservoirs are shallow and heavily infested with weeds, rendering them unsuitable for fishery development. Furthermore, many have been declared protected areas for conservation of flora and fauna.

The Mexican authorities have identified 613 reservoirs and 95 lakes in 30 states, with a total water surface area of 988008 ha, as suitable for extensive aquaculture. Jalisco, Michoacan, Nuevo Leon and Zacatecan have the highest number of reservoirs, while lakes are concentrated in the States of Chihuahua, and Tabasco. More than one-half of the inland water area falls within the States of Jalisco, Tamaulipas, Chiapas and Michoacan (Table 8.5). Intensive aquaculture, practised under controlled conditions, is mostly for oysters and marine shrimp. The total water area used for intensive aquaculture is estimated to be 29182 ha. Thus, for all practical purposes, inland fisheries in Mexico consist solely of the extensive aquaculture of reservoirs and lakes.

8.5 Organization of inland fisheries activities

A number of Mexican agencies, including the state, federal and local governments, cooperatives and the corporate sector, as well as individual entrepreneurs, are involved in fishery activities. Therefore, information on fishery resources, management norms, fish production trends and other related aspects is widely scattered. The problem is further compounded because norms for land tenure, ownership of water bodies, exploitation policy, licensing and crop sharing systems, and other vital parameters vary widely in different parts of the country. Many states have their own fisheries departments and laws, and are engaged in seed production and distribution and the collection of revenues. At the national level, the Secretariat of Fisheries (Secretaria de Pesca) was responsible for fisheries development until the recent formation of SEMARNAP. When both state and federal laws are in effect, the federal agency assumes an advisory role.

A new federal Secretariat for Environment, Natural Resources and Fisheries, Secretaria de Medio Ambiente, Recursos Naturales Y Pesca (SEMARNAP), was formed in 1995 as part of a holistic approach to natural resources and to their sustainable development. A number of federal agencies dealing with environment, forests, wildlife, water resources, fisheries, etc., were merged into a new organization in order to minimize conflicts between environmental and development agencies. SEMARNAP has three directors general dealing with various aspects of fisheries and aquaculture, i.e. the directors general of aquaculture, fisheries management, and international fisheries cooperation, all situated in Mexico City. Fisheries officials posted in the federal delegations of SEMARNAP at the state headquarters work in close liaison with the director general of aquaculture. The national database on fisheries located at SEMARNAP headquarters in Mexico is linked up with all the state delegations through a computer network. In the reorganization, the National Commission for Water, Comision Nacional del Agua (CNA), which is responsible for water resources development projects, was placed under SEMARNAP. Other national institutes involved in the process of fisheries development are:

• the National Institute of Fisheries, Instituto Nacional de la Pesca (INP);
• the National Institute of Ecology, Instituto Nacional de la Ecologia (INE);
• Attorney for Environment, National Resources and Fisheries; and
• universities.

In a limited number of reservoirs in each state, fishing groups are organized by SEMARNAP, while the other water bodies are managed by local communities. There are also many lakes and reservoirs that remain totally unmanaged. In Mexico, the systematic development of lakes and reservoirs through extensive aquaculture was initiated by SEMARNAP in order to increase the number of water bodies managed and to augment the productivity of those already managed. A proposal for organizing fishing groups in a reservoir is introduced by local community leaders, a group of local fishers, the state government or SEMARNAP. Sometimes, the suggestion originates from the National Water Commission as a part of its commitment to the rehabilitation of people displaced during dam construction.

Each proposal for organizing a fishing group is first sent to the National Institute of Fisheries (INP) for assessment of the existing fish stock of the lake in question. The INP decides the mesh size and quantity of nets to be used in the reservoir. It is also mandatory for the proposal to be evaluated by the National Institute of Ecology (INE) for an environmental impact assessment. Finally, the proposal goes to the Fisheries Management Group of SEMARNAP which issues the necessary permission and licence. More often it is the state delegation that organizes a cooperative society for the fishers of a reservoir and provides assistance such as stocking support, financial aid to buy nets and boats, and the creation of infrastructure facilities.

Inland production systems can be broadly classified as three types – restocking aquaculture, rural aquaculture and high yield aquaculture. Restocking aquaculture is a national development activity fostered by SEMARNAP in a number of reservoirs all over the country, while rural aquaculture is a poverty alleviation and rural employment programme aimed at improving the nutritional and economic standards of the rural poor. The major emphasis in high yield aquaculture is on the production of fish, crustaceans and molluscs through intensive culture under controlled conditions. As intensive culture entails heavy investment in the form of capital and infrastructure development, the private and corporate sectors are encouraged to take part in this venture. Mexico offers tax advantages to make investments in aquaculture more competitive. This includes a 50% concession on income tax for individuals, cooperatives and firms involved in aquaculture and reimbursement of value-added tax when the producer pays duty on inputs. An accelerated depreciation or a write-off of up to 62% on initial investment and 89% on machinery and equipment is allowed.

Since stocking is an essential step in reservoir fisheries management, SEMARNAP has begun the process of creating a network of fish seed production centres all over the country to meet the fish seed requirements of the reservoirs it controls. At present, SEMARNAP owns 39 seed production centres situated in 23 states (Table 8.6).

The total number of fish seed produced in these centres in 1994 was 144902, of which 58% was tilapia, 25% was carp and 3% was trout. While most of the centres produce tilapia, carp is bred mainly in the States of Hidalgo, Durango, Coahuila, San Luis Potosi and Aguascalientes. Out of the total 36 million carp fry produced in the country, 32 million come from the 11 land-locked states. Most of the trout seed are produced in the States of Mexico and Michoacan. A few centres produce grass carp, common carp and indigenous fish (Table 8.7).

Many of the hatcheries produce surplus seed which are sent to stock the reservoirs of the states in short supply. Durango and Aguascalientes are the main exporters of carp, while Morelos and Colima have excess tilapia seed for interstate transfer. The two fish seed production centres of Morelos, i.e. Fernando Obregan and Zacatepec, produce 6million fish fry a year which are more than the requirements of the state. These two farms have a total land area of 4 ha with 0.13 ha of water area including ten broodstock ponds and seven nursery ponds.

The State of Queretaro depends totally on other states for the fish seed requirements of its 32 reservoirs. In 1994, 2951460 fish fry were brought in from various states. Durango, Aguascalientes and Hidalgo supplied 634000, 468000 and 216000 carp respectively. While Aguascalientes was the main source of Lobina (black bass), the 200000 prawn juveniles stocked in Rio Conca and Estanques reservoirs originated from Guerrero.

8.5.4 Use of fish seed

Most of the fish seed produced in the country are used for stocking reservoirs. In 1994, 100% of the black bass seed, 90% of the carp seed and 75% of the tilapia seed produced were used for stocking reservoirs. Trout seed (95%) and freshwater prawn seed (100%) were used mainly in intensive aquaculture. While the seed produced in SEMARNAP centres are mainly used for free stocking in the reservoirs, the hatcheries run by state governments are mainly involved in producing fish, prawn and oyster seed for intensive aquaculture. With the increased competitiveness of intensive aquaculture, the seed production units for this segment have become commercial ventures. The fish seed produced in the state government farms is often sold to the aquaculture companies or entrepreneurs. Some hatcheries, such as the one in Baja California State, have been sold to private sector agencies. Stocking rates differ in the various states and reservoirs. SEMARNAP tries to follow a more or less uniform stocking rate as shown in Table 8.8.

8.6 Fish production trends

The lion's share of fish produced in Mexico, comes from marine capture fisheries. In 1994 marine capture fisheries contributed 86% of the total national fish catch of 1260019t. The remaining 171389t of fish came from brackishwater, marine and freshwater aquaculture systems. Fish production from inland sources is classified as intensive and extensive aquaculture, the latter including the culture-based fisheries of reservoirs and lakes. In national fisheries statistics there is no separate provision for the capture fisheries of large inland water bodies, which are accounted for in extensive aquaculture.

In 1994 extensive aquaculture produced 97658t of fish, mainly carp, tilapia and mojarra (Cichlasoma spp. and Lepomis spp.), catfish and charal (Chirostoma spp.), which accounted for less than 8% of the total fish production. Intensive culture, still in its infancy, is largely dominated by brackishwater culture (marine prawns) and mariculture (oysters). It contributed only 19905t (approximately 1.5%) of total fish production in 1994. The distribution of aquaculture production among different culture systems is shown in Table 8.9. Extensive aquaculture of the large man-made lakes (presas), lakes and lagoons produced 111870t of fish in 1994, which is equivalent to 65% of total aquaculture production. These large water bodies along with the small reservoirs (bordos) account for more than 70% of inland fish production (Table 8.10). The relative importance of carp in total fish production is increasing although the share of tilapia remains more or less constant. This is discernible from the catch data for the two groups for a ten-year period from 1983 to 1992 (Table8.11).

Culture fisheries has registered a comparatively faster growth during the last ten years than total fish production. While the production from culture increased from 133300t in 1985 to 171400t in 1994, total fish production increased from 1246000t to 1260000t during the same period. Aquaculture increased at an annual growth rate of 2.8%, compared with 0.1% growth of national fish production (Table8.12). Fish from reservoirs and lakes being the main components of aquaculture production, much of the growth in the fisheries sector is attributable to these inland water bodies.

8.7 Legal framework for inland fisheries

The inland fisheries activities of Mexico are governed by the new Fisheries Law and its Regulations of June 1992, which replaced the Federal Fisheries Law of 1986 and its Regulations. Under Articles 2 and 3 of the Law, the Secretariat of Fisheries had the authority to enforce the regulations in all waters under federal jurisdiction. Later this authority was given to SEMARNAP. According to the present law, licences, permits or authorizations are necessary to undertake any fishing activity other than that for domestic consumption. SEMARNAP has the authority to issue such authorizations, besides setting methods and measures for the conservation of fisheries resources and the restocking of fishing areas, regulating the creation of refuge areas to protect aquatic species requiring protection and establishing closed seasons and areas. It is also authorized to regulate the introduction of species of aquatic flora and fauna in bodies of water under federal jurisdiction and define technical sanitary standards to guarantee the healthy development of aquatic organisms.

Regulations on aquaculture are defined in Article 44 of the Law, which sanctions the role of SEMARNAP as promoter of aquaculture activities by establishing coordination between state governments and various national institutions. SEMARNAP is also required to provide technical and financial support to the aquaculture ventures of entrepreneurs. Only a permit is required to initiate an aquaculture venture while an authorization is needed for the introduction of exotic species. Article 51 stipulates that those parties authorized to collect organisms from the natural environment and aquaculturists who obtain their supplies from them are bound to restock the natural environment according to the terms and conditions as laid down by SEMARNAP.

Although the current federal law and its regulations provide a necessary framework for fisheries development in inland water bodies, their enforcement is not very consistent for many reasons. Apart from the inadequacy of SEMARNAP, in terms of human resources and infrastructure, to monitor fisheries in widespread water bodies, the socio-economic realities at the grassroots make it difficult to enforce many regulations effectively.

As regards the land distribution pattern in the country, only 20% of the total area is federal land where federal regulations can be easily implemented on the water bodies. Only 10% of the land is owned by private individuals and the remaining 70% is community-owned. There are two types of community land, the ejido land and the community farms. Ejidos, a legacy of the revolution, are large tracts of land allotted to the community for joint cultivation. The members of the community use the land as common property, without partitioning individual shares for the members. On community farms, on the other hand, members are allotted their respective portions of land. Ejido land is managed by elected representatives of the community, and often there are disputes with the federal agencies over the right to issue permits, the implementation of regulations and sharing of profits. Ejido leaders often question the right of individual fishers to their earnings, as the land, and by implication the water, belongs to the community as whole.

Recently, new amendments have been made in the provisions of the Fisheries Law to foster the growth of the aquaculture sector. The new law provides legal security, makes long-term investments possible, and promotes the inflow of investment resources. Currently, licences are issued for a period of up to 50 years, renewable for an additional 50-year period. The duration of a licence depends on the amount, period of maturity and recovery of the investment in the particular project. The new promotional activities launched by the Secretariat of Fisheries are focused on relaxing regulations imposed by other government agencies. One of these measures allows the possibility of foreign investors to own up to 100% of aquaculture enterprises. Under the new law, no licences are required by aquaculture producers interested in the development of sea farms or floating cages in inland water bodies.

One of the obstacles to the reform of land distribution has been the regulation that prohibited the fragmentation of ejido land, which prevented farmers from obtaining and transferring titles for the land. This law was amended in 1993 to allow the selective distribution of land among farmers, but the process, riddled with procedural delays, achieves only slow progress. In Sinola State where 90% of the land is ejido, the coastlands are unsuitable for agriculture, but potential exists for large-scale shrimp culture. Development in this direction is very slow owing to the problems involved in procuring land.

Of the total 48 species of freshwater fish, 12 are exotic species which were introduced to augment production. There are also six species of prawns and three species of crayfish, caught or cultured in the inland waters, of which four are purely freshwater forms. The five regions of Mexico in relation to distribution of fish are as follows.

Region I Baja California, Baja California South, Sonora, Sinaloa

Region II Colima, Guerrero, Jalisco, Michoacan, Nayarit, Oaxaca, Chiapas

Region III Tamaulipas, Veracruz

Region IV Tabasco, Campeche, Quintana Roo, Yucatan

Region V Aguascalientes, Chihuahua, Coahuila,Durango, Guanajuato, Hidalgo, Mexico, Morelos, Nuevo Leon, Puebla, Queretaro, San Luis Potosi, Tlaxcala, Zacatecas (Figure 21).

Cambarellus montezumae: distribution in Region V; maximum size 7 cm; average size 3cm; fished the entire year; no restrictions; total annual catch 33 t; catch shows a decreasing trend.

Ictalurus punctatus: distribution in Regions I, II, III & V; maximum size 132 cm (30 kg); average size 30 cm; marketed fresh filleted, fresh and frozen; catching season from 1September to 30 April; annual catch 2000 t; catch increasing.

Ictalurus dugesi: catch restrictions in Michoacan State; fishing in Chapala Lake with cueveo method not allowed.

Three varieties of Cyprinus carpio, i.e. var. specularis, var. communis and var. rubrofuscus; gold fish (Carassius auratus); grass carp (Ctenopharyngodon idella); silver carp (Hypophthalmichthys molitrix); bighead carp (Aristichthys nobilis); and, black carp (Mylopharyngodon piceus).

Cyprinus carpio specularis: distribution in Regions II, III & V; maximum size 80 cm (32kg); average size 60 cm (3 kg); fished the entire year; no restrictions; annual catch increasing.

Lepisosteus osseus: distribution in Regions III & IV; anadromous; maximum size 183 cm; average weight 25 kg; caught during the whole year; no restrictions; catch stable.

Chirostoma chapalae: distribution in Regions II & V; maximum size 14 cm; average size 5 cm; maximum weight 12 g; fishing season from May to February; closed season March to April (these restrictions are only for C. chapalae in the Chapala lake); decreasing trend.

Macrobrachium rosenbergii: distribution in all regions; maximum size 32 cm males, 26.5cm females; average size 15 cm; maximum weight 40 g; average weight 15 g; fishing season November to July; closed season August to October; no restrictions for the introduced species, M.rosenbergii; catch increasing.

Micropterus salmoides: distribution Regions I, II, III & V; maximum size 97 cm; average size 40 cm; maximum weight 10 kg; average weight 2 kg; fishing season June to March; closed season April to May; restrictions in sport fishery (maximum catch 10 kg/day, and minimum catch length 20 cm); fishery stable.

Chirostoma estor estor: distribution Regions II & V; endemic to Jalisco and Michoacan States; maximum size 42 cm; average size 30 cm; maximum weight 540 g; average weight 250 g; fishing season April to January; closed season February and March (these restrictions apply for C.sphyraena only in Chapala lake in Jalisco); decreasing trend.

Tilapia rendalli: introduced fish, found in all regions; maximum size 45 cm; average size 25cm; maximum weight 2.5 kg; average weight 300 g; no restrictions; increasing trend in catch.

Oncorhyncus mykiss: found mostly in Region V; anadromous; maximum size 114 cm; average size 60 cm; maximum weight 12 kg; average weight 0.8 kg; no restrictions in fishing; increasing trend in catch.