Ecosystem services, multifunctionality, and diversity play a particular role in the management of carp pond aquaculture. These three concepts have been increasingly considered unsustainable aquaculture science and policymaking. However, the understanding and acceptance of sustainable aquaculture by fish farmers is a prerequisite for the successful implementation of such a targeted policy. Production services were indicated as the most important, but the role of ponds in the preservation of biodiversity was another highly valued service.
Aquaculture, or farming fish and other aquatic organisms, is an important and rapidly growing food-production industry around the world. Modern aquaculture should be developed as a system to increase product quantity and quality while preserving the environment, considering economic robustness, development of high-quality jobs, and building of new relationships among producers, consumers, and the production systems and their associated products. Traditional carp production is based on the use of natural food with supplementary feeding with cereals. The contribution of supplementary feed to the carp growth gain amounts to around 25–50% of the total yield. This semi-extensive fish production averages around 450–500 kg of fish per ha. Owing to the open nature of the ponds, their integration with the local water body system, and the natural feed-based management, such ponds have become integral parts of the local environment. Ponds play important landscape-related functions, especially in areas with no natural surface waters.
Apart from fish production, they supply many services, such as protection against floods, increasing water retention, creating a microclimate, and increasing biodiversity. All these benefits enable the ponds to be defined as an aqua-ecosystem, i.e., a human-managed aquatic ecosystem oriented towards the provision of ecosystem services.
Agriculture, as well as aquaculture, is considered multifunctional when it can produce various non-commodity outputs or has other additional functions for food production. Multifunctional agriculture and ecosystem services emerged during the same period and both were recognized as two important concepts for sustainable agricultural development and agricultural policymaking. The two concepts are closely related through their use of the term “function”. However, multifunctional agriculture considers functions as agricultural activity outputs and prefers farm-oriented approaches, whereas ecosystem services consider ecosystem functions in the provision of services and prefer service-oriented approaches. In other words, in multifunctional fish farming, all the commodity and non-commodity functions of the fishpond are the result of deliberate management.
A better understanding of the principle of multifunctional aquaculture and the more systematic application of the various elements of multifunctionality by farmers may contribute to the better placement of pond fish farms in an agroecosystem and improve their viability in the long term. Multifunctionality is often equated with diversification, defined as the adoption of wider application of new species, breeding types, and cultural systems, as well as various non-fish farming activities, such as the operation of angling ponds, small shops, restaurants, or even hotels (depending on the business opportunities). However, multifunctionality is a broader concept than diversification. In addition to activities/functions that are important from the point of income creation, it also includes all external effects and non-commodity outputs of actions taken, including negative ones. In simplified terms, the multifunctionality of fishponds can be defined as ecosystem services viewed from the perspective of aquaculture farms.
Level of Zakah for Fisheries/Farm
Nisab for fishery/agriculture is 5 wasq or equal to 653 kg. If these crops include staple foods, such as rice, corn, wheat, and dates, their nisab is 653 kg of the agricultural product. But if the agricultural product is not stapling foods, such as fruits, vegetables, leaves, and flowers, their nisab is synchronized with the nisab price of the most common staple foods in the region (country), for example, for Indonesia is rice. if watered with rainwater, river, or spring water is 10 percent, but if the crops are watered or irrigated with irrigation (extra charge), Zakah is 5 percent.
From this provision, it can be understood that the plants which are watered (irrigation), Zakah is 5 percent. This means the other 5 percent is allocated to the cost of irrigation. Imam az-Zarkani argued, if the management of the farm/fishery is irrigated with rainwater (rivers) and watered (irrigation) with a ratio of 50:50, the Zakah is 7.5 percent (three-quarters of 10 percent). The reason fishery Zakah is equated to farming Zakah is that there are many similarities in the development effort. The reason fishery Zakah is equated to farming Zakah is that there are many similarities in the development effort, besides that, the fishery is also listed as a farm in the information of profession.
Fishery Zakah cannot be equated to livestock farms Zakah, animal product Zakah or marine source results in Zakah because there is a mandatory requirement of livestock Zakah that animals must be held for one year and must be grazed while fishery must not be in the one-year maintenance process. While animal product Zakah is a Zakah issued from the results of animal products such as honey, milk, and silk so that the fishery does not include in the Zakah of the production of animal.
In relation to the Zakah compulsory property, from the six conditions of treasure that must issue its Zakah, treasure including fisheries (aquaculture) are classified into the following five requirements only, i.e., full ownership, active, reaching Nisab, Nisab is already more than the basic needs of its owners and debt-free. These five requirements must be met for a treasure that must be issued its Zakah. There is one condition that is not included in the mandatory requirement for aquaculture proceeds; the requirement is to haul that the treasure which reaches Nisab has passed one year. Haul applies to livestock, money, and trading property, while for agriculture and plantation one-year requirement is not applied.
Zakah comprehension by muzaki comes from three sources of information which become indicators in the formulation of research problems that will distinguish the quality of muzakki toward Zakah comprehension. Humans who understand Zakah as a command of God that must be carried out with the intention of sincerity is the embodiment of the faithful and devoted human.
The study showed that fish farmers are aware that the use of traditional carp breeding methods contributes to the preservation and development of biodiversity and generates other ecosystem services.