Socio-economic Determinants of Mangrove and Seagrass Exploitation in Zanzibar

In all the study sites, the determinants of mangrove and seagrasses exploitation were demographic change and socio-economic characteristics. Increase in population growth has increased the demand for natural coastal resources from mangrove to seagrass. Good example is tremendous increase in demand for building poles, wood fuel, fish trap and charcoal marking, which specifically comes from mangroves. Quinn et al. (2017) reported similar situation in three countries Brazil, Vietnam and Zanzibar. The findings also reveals that increase in bivalve gleaners and seaweed farming along the coast of Charawe had significantly negative impacts on seagrass loss due to disturbance and light attenuation caused by seaweed farms. Mangroves and seagrass resource exploitation in the Zanzibar coastal communities is influenced by various factors and each factor reflected the reality in terms of social livelihood of the coastal communities in the study sites. The findings reveals that age of household head had significant influence on the extraction of both mangrove and seagrass resources in the study sites. Mangrove resources extracted were used for charcoal making, boat making, building poles and fuel wood whereas the resources extracted from seagrass included bivalves collection, seaweed through seaweed farming and fish by using fishnets and traps. The resources obtained from both mangrove forest and seagrass meadows were collected by economically active age {30-45 years old (88%)}. The resources were for substance use or sell within and outside the villages. These findings are consistent with the findings reported by Branch et al. (2002) who noted that productive age are involved in many development activities which may also be associated with degradation of natural resources.

Moreover, the results show that marital status of the household head had a significant influence in the exploitation of the mangroves resources as well as seagrass resources. It was observed from the focus group discussions and personal observation that married household heads extracted many resources from mangrove forest and seagrass meadows in order to meet the demands of their family members (wives and children). The involvement of the family members such as the elder sons in mangrove extraction and, wives, elder daughters and young children in seagrass resource extraction also increased the pressure on these resources. This was not the case in single household heads because this group has less demand when it came to seagrass and mangrove resources because they were living alone and had no family members of their own to take care of. These findings are in line with the earlier findings of Nussbaum (2000) and Shackleton et al. (2011) who noted that married male had huge responsibilities to provide for the family basic need all the time but women were limited to reach places and time to get mangrove resources.

The results showed that household size had significant influence on the extraction of both seagrass resources and mangrove forests. Increase in household size, increased the number of people who engaged in the extraction of seagrass and mangrove resources in the study sites. This therefore led to the decrease in the resources obtained from the mangrove forest and seagrass meadows as a result of increase in demand for these resources. This was observed from personal observation where there was increase in the number of bivalve collectors, net and trap fishers, seaweed farmers, charcoal making and building poles collectors. This increase has led to the decrease in the resources obtained from seagrass and mangrove forest respectively, through unsustainable harvesting. Related finding have been confirmed by Jiddawi and Öhman (2002) and Mtwana Nordlund (2012) who reported that household size with a lot of women are predominantly involved in the invertebrate harvesting, which is commonly conducted on rocky shores, in mangroves and seagrass meadows in unsustainable manner due to lack of formal management.

Educational level of the household head had significance influence on the extraction of mangrove resources and seagrass resources. The negative regression coefficient on the mangrove resource extraction implied that increase in education level of the household head lead to decrease in the extraction of the mangrove resources. Thirty five percent of the respondents have received at least primary education and this might have been attributed to development and engaging of community members to various livelihood activities such as owning small shops, food vending and casual labor therefore reducing pressure on the mangrove resource extraction. This study is in line with earlier findings of Nussbaum (2000) and Shackleton et al. (2011) who found out that the more education one attains helps one better in the management of natural resources. On the other hand, seagrass resource extraction has increased with increase in the level of education. This might be due to fact that since majority of the coastal communities in the study site have attained only primary level education it becomes very hard for this majority group to secure a white-collar job and hence ending up employing themselves in the small-scale fisheries (SSF) within the seagrass meadows and therefore promoting unsustainable extraction of seagrass resources. The results also revealed that household average annual income had significant influence on the extraction of mangrove resources. The increasing standards of living and low level of education to the majority of the coastal communities in the study sites have limited them to secure government employment opportunities therefore forcing them to relay on mangrove harvesting and selling so as to generate income and provide the basic needs for the family members. The increase rate of mangrove extraction has also lead to promotion of unsustainable harvesting of the mangroves for building poles, mangrove charcoal, fuel wood and poles for boat making. Similar findings were also reported by Dahdouh-Guebas et al. (2000) and Jin et al. (2003) in Kenya and China respectively. Despite the awareness on the importance of marine natural resources, particularly mangrove and seagrass its exploitation is still alarming due to economic dependency and lack of alternative source of energy for their daily use imposing significant pressure on the mangrove forestry.

Households headed by males had significant influence on seagrass resource extraction. These household heads had the ability of conducting fishing activities within and outside the villages on seagrass meadows found in shallow waters and deep waters using traps and fishing nets unlike their female-headed counterparts who engage themselves in bivalve collection and seaweed farming. This was noted from participant observation and focus group discussions conducted in the study sites. The different roles performed by different gender in exploitation of resources can in one way or another impact the conservation of a give resource. This finding is in connection with other studies conducted by Gadio and Rakowski (1999), Crus-Torres (2000), Mtwana Nordlund (2012) who noted that some roles of gender in the exploitation of natural resource may undermine ecosystem sustainability. The results further shows that period of residence of the household head in a given village had significant contribution on the extraction rate of the mangroves and seagrass resources. The less time /period people stay in a given area, the less their families grow in size, thus the less mangrove resources will be demanded from the mangrove forest and vice versa is true. Similar observation were reported by Nduwamungu (2001) and Kajembe (1994) which indicated that people who stay longer in a given area with resource availability are more likely to exploit more of those resources than those who stay for a short duration. Timeline analysis revealed continued decrease in mangrove due to active interaction between the coastal ocean and community surrounding the ocean. The most important drivers for coastal resources (mangroves and seagrass) exploitation is the demographic characteristics of the coastal community including population growth, limited arable land and development of tourism industry in Zanzibar. Despite the existence of law and bylaws governing the mangrove conservation and sustainable exploitation, there is a need for enforcement of these laws by the management committee members together with the local communities and introduction of laws and bylaws that will also promote sustainable exploitation and management of seagrass meadows which is been overlooked in policy and management. Introduction of alternative creditable livelihood and encouraging youth to attend and complete their tertiary education can contribute much on sustainable exploitation of mangrove and seagrass resources.