Recent rise in exploitation of Tanzanian octopuses: a policy and management challenge

The artisanal octopus fishery is important for the coastal communities in Tanzania. In this work the octopi landing data from the United Nations Food and Agriculture Organization (FAO), Ministry of Livestock and Fishery Development (MLFD) and trade statistics from Comtrade of the United Nations were analysed. The FAO dataset show that from 1980 to 2017 annual octopus landings stayed below 2000 tons until 2018 when the catch increased to 2864 tons, and doubled to 5,687 tons in 2019. FAO datasets show large catches in 1995, 2003 and 2019, with 2019 recording the largest catch. For both Comtrade and MLFD export statistics, approximately 5,818 and 2,254 tons of octopus were exported globally from 2018 to 2020 with an equivalent value of approximately 13 and 19 million US$ respectively. Portugal was the largest importer of Tanzanian octopi, followed by Turkey, Italy, Spain, Netherlands, Israel, France and Panama. The current management interventions relating to octopi are presented, including the challenges needed to be addressed for sustainability of the octopi fishery. Voluntary octopi closures indicated some signs of success, but an in-depth assessment of the associated effects is required. The study recommends a need for verification mechanisms to ensure consistency of FAO and MLFD statistics, stock assessments, in-situ research on recruitment patterns of octopi, as well as innovation and research in designing sustainable fishing gear to support development of policies for sustainability.


Introduction
Octopi forms an important fishery for coastal communities along the coast of Tanzania and the Western Indian Ocean (WIO). In mainland Tanzania approximately 150 tons (10 % of the total landing) is consumed by the local community annually, and a significant proportion (nearly 1500 tons, or 90 %) is exported to the international markets mostly in Europe and Asia (Guard and Mgaya, 2002;Rocliffe and Harris, 2016). To ensure the effective governance and sustainability of the fishery, it is important to understand the biology of the species involved, the socio-economic impacts of the fishery and conduct catch assessments from time to time to better inform fishery management.
Gleaning is a technique applied mostly by women and children where they walk along the exposed shores and reefs during low tide hunting for octopus using sharp sticks.
The Tanzanian artisanal octopus fishery grew over the last decades due to a rise in international market demand and price paid for octopus (FAO, 2017).
In turn, the artisanal fishermen responded by increasing fishing effort and changed their focus from local markets to also supply the international markets . TANPESCA, Bahari Foods and Alphakrust are the main companies on the mainland that buy octopus from artisanal fishers, process and export to foreign markets (Anderson, 2014 as cited in Rocliffe and Harris, 2016). Information on recent (2018 -2020) annual exploitation rates is lacking. Previous reports indicate that from 2008 to 2012 Tanzania exported approximately 1,500 tons of octopi annually, equivalent to about US$ 6.8 million (Rocliffe and Harris, 2016). The important international buyers during the same period were Portugal, Italy, France, Mauritius and Spain.
In Zanzibar however, the main market is tourists and a smaller proportion (about 10 %) of the catch gets exported elsewhere (Pandu, 2014 as cited in Rocliffe andHarris, 2016). Due to its dependency on the tourism market, the octopus fishery in Zanzibar was severely impacted by the Covid-19 pandemic.  Perry et al. (1999) proposed three types of management strategies to safeguard the cephalopod fisheries: (i) catch regulation; (ii) size/sex limits; and (iii) control of fishing. As opposed to the large-industrialized fisheries, the artisanal octopus fishery consists of hundreds of fishers, making it challenging to implement effective management. Hence, in developing countries a combination of the three strategies is applied.
In Tanzania the octopi catch usually includes the two main species: the big blue octopus Octopus cyanea Gray, 1849; and the common octopus Octopus vulgaris Cuvier, 1797 (Guard, 2009;Pandu, 2014). O. cyanea is the larger species with a reported mean and maximum weight of 6 kg and 11.7 kg respectively (Guard and Mgaya, 2002).
O. cyanea dominates the catch and can make up to 99 % of overall octopus landings (Guard and Mgaya, 2002).
Research on life history, growth dynamics and the reproduction cycle of O. cyanea indicates that a time window (s) exist where short-term closures can have a positive effect on the fishery; especially when the females are nesting and during the period which the growth is exponential (Van Heukelem, 1973;Caveriviere, 2006;Raberinary and Benbow, 2012). Thus, several experimental periodic octopus closure initiatives were established at sites in Tanzania and in other areas of the WIO. Reports show that the closures resulted in increased catch and income in the communities, although these benefits disappeared a few days after the opening .
This study analysed the octopi catch statistics from the Food and Agriculture Organization of the United Nations (FAO) between 1908 and 2019, annual octopus landing from the Ministry of Livestock and Fishery Development (MLFD) of the United Republic of Tanzania, and the octopus export statistics provided by Comtrade of the United Nations to report on the exploitation rates, trading, and recommendations to avoid misinformation and improve consistency of the data. Furthermore, the study explored the current management tools in place, and gaps that need to be closed to improve sustainability of the octopus fishery.

Study area
The study assessed octopus landings and export data from Tanzania (Fig. 1) (MLFD 2003;2008;2011;2013;2018;2020). The reports contained annual octopus landing and general yearly exported amounts that were used for validation and comparison.

Export market
The export data from the United Nations Comtrade platform covering the years 2021 to 2017 are presented in Table 1     The differences in the annual exported amount reported by Comtrade and MLFD is illustrated in Figure 4. The annual exports recorded by Comtrade were consistently larger than the MLFD. Both datasets  (1) and its amendments of 2020 established an octopus fishing and handling size limit of 500 g. The regulation 59 (3) provides that no person shall trade or export processed octopus below the limit of four hundred and forty grams.
The fishing techniques are non-selective.
Although exporting industries follow the rule, the undersized octopus are consumed locally.

Management Zones:
The Fisheries Regulation of 2009 in the Section 17 provided a mandate to the minister to initiate measures to ensure sustainable management of the fishery such as prohibition of fishing in certain areas.
The regulation allows the minister to initiate controlled areas such as critical and potential breeding areas.
The regulation is essential, providing room for immediate conservation actions when a potential critical area is identified for biodiversity protection.

Access to Fishing (licensing):
The Fisheries Act No 22 of 2003 in the Section 22 established a license requirement for anyone before undertaking fishery activities such as fishing, marketing, processing and or production of fishery related products. The license is provided by the Director or authorized officer. Requirements of license apply also to the fishing vessels and traders.
The regulation has succeeded to control fishing, but a more detailed examination is required to assess the effectiveness. For instance, children also collect octopuses at low spring tide, as a part of cultural practices.
Compliance and law enforcement: Fisheries Act No 22 of 2003 in the Section 17 gives mandate to the minister to take necessary measures to ensure sustainability of the fishery resources, the interventions related to enforcement, monitoring and surveillance. Section 32 (1) provides for the establishment of the surveillance and control unit. It also directs mechanisms that enhance participation of communities and other entities through agreements in national, regional and international arena.
Law enforcement has been challenged by limited resources (boats, fuel, and compensations), and capacity of the surveillance team in the villages to ensure reefs are well protected against unsustainable fishing practices.

Co-management arrangements (the Beach Management Units or BMUs):
Fisheries Regulations, 2009 (13) provides for the establishment of the co-management structure from within the members of the fishing community to assist in activities like surveillance, control and catch inspection. Their roles also extend to data collection on 10 days of every month.
A good participatory approach, but the infrastructure and capacity of BMUs needs to be enhanced to improve their contribution to sustainability.
Marine Protected Areas: Marine Parks and Reserves Act No. 29 of 1994 (Section 8 (2) and Section 10 in particular provides a guide to establish the Marine Protected Areas (MPAs) for conserving biodiversity or at areas displaying features of significance such as historical, scientific or critical habitat values.
The approach is amongst the successful approaches, but more research and activities to enhance resilience of the ecosystems are needed.
Octopus fishing closure: These are self-driven participatory approaches when the community agree to implement a closure in their respective reef (s) with the goal of obtaining an improved yield and enhancing ecological benefit. They can be a pathway toward more concrete actions like establishment of new Marine Protected Areas.
The system worked best in remote areas with less population pressure. A more detailed assessment of the social-ecological benefits is needed. Program leads should use the best available science on recruitment of octopus for best results.

Existing governance tools and arrangements for octopus fishery management in Tanzania
The octopus fishery in Tanzania (Sauer et al., 2021). One of the challenges is that the methods used by fishers remained non-selective, such as the use of spears (Table 2). In most cases, fishers can injure or even kill undersized octopuses when they are still in the den before knowing the size, and therefore they don't find it logical to discard the octopus smaller

Octopus exploitation and trading
In this study it was found that, based on both data sets, the catch was above 2000 tons in 2018 and 2019. The reported estimations are considered as underestimations, and more effort needs to be made to support catch recording at various fishing sites in Tanzania. Data challenges and underestimation has been a challenge in various fishing localities in the world, and reconstruction of the data could be an option to address this (Bultel et al., 2015). Belhabib et al. (2015) for instance, re-analysed catch records provided by the Republic of the Gambia to the FAO and found that the corrected catch data was double the original reported values.
In this study it was found that the major importers of octopus between 2018 and 2020 were Portugal, Italy,

France and Spain, in addition to The Netherlands and
Israel which were not reported by the previous study (Rocliffe and Harris, 2016). This indicates an expansion of the Tanzanian octopus market with implications for fishery management and sustainability.

Inconsistence in the MLFD and FAO datasets
In this study there were discrepancies in the catch statistics data as reported by the FAO and the MLFD.
But because MLFD supply these data to the FAO, the observed difference could be caused by lack of good coordination between these bodies in providing the best estimates for octopus production, and limited validation, verification and inspection. There is also a challenge with regards to octopus species identification, with reports suggesting that Octopus cyanea constitute over 90 % of landings (Guard and Mgaya, 2002) which also includes species There is therefore a need for better science to inform management on estimates of stocks abundance and the number of fishers (fishing effort) allowed, to avoid overexploitation. Although the fishers were advised to use wooden sticks for fishing to protect the health of consumers, a large proportion of fishers still use iron rods (Guard and Mgaya, 2002;Sauer et al., 2021;Robertson et al., 2018). The use of fishing pots has been recommended as a more sustainable and selective fishing method that can avoid smaller individuals (Sobrino et al., 2011) it would be difficult to ensure and maintain the sustainability of the fishery. There is a need to strengthen the enforcement and awareness of fishery regulations to ensure fishers comply with the existing laws and policies. Although fishers found it challenging to preselect specimens that were below the recommended size when the octopus was in a den, some fishers still harvest small octopus intentionally.

Conclusions
The study identified discrepancies in the catch statistics