LATEST NEWS - Tanzania

TANZANIA MARINE - COMMERCIAL FISH SURVEYS


Since starting work on Mafia Island, Frontier-Tanzania’s Marine Team have been monitoring the abundance and size of commercially important fish species over a range of reefs surrounding the island which are located in different use zones of the Mafia Island Marine Park (MIMP); an important marine protected area in the region.

Marine protected areas (MPA’s) are a relatively new movement in conservation. MPA’s can range from strict no take zones to communally managed multi use parks. Multi user marine parks aim to conserve resources and biodiversity and also improve local fisheries and livelihoods. Successful MPA’s have been shown to increase abundance and biomass of targeted species, increase fish recruitment as well as increasing the migration of adults into neighbouring areas.

The MIMP was established in 1995 as Tanzania’s first multi-user zone marine park. With 14 villages and over 18,000 people living within the park boundaries, it was important to ensure that the community would be able to be involved in the running of the park and also that they would benefit from the park; this way the conservation of marine resources is more likely to be successful. The park itself has three different use zones; the core zone, the restricted use zone and the general use zone. Within the core zones there is no resource extraction but diving and research are permitted, within specified use zones there is no pull net fishing allowed and no fishing by non-residents, and within general use zones national regulations apply and non-residents require a permit to undertake activities within the park. By protecting certain areas in this way, commercial and non-commercial species are able to recover, increase in both abundance and size and then move out into the fishing areas to benefit those fishing in the area while maintaining the industry in a sustainable way.

This phase, the team have been monitoring the abundance and size of commercial fish species in a specified use zone of the park within the Chole Bay area. Those species that have been surveyed were compiled from a list of those fish species that are targeted and caught by local fishermen; these fish include those from the following families: Emperors, Groupers, Parrotfish, Rabbitfish, Snappers, Sweetlips, Trevallys and Unicornfish.

The focus this phase was on the Milimani dive site which is located within the specified use zone of the marine park. The team have been able to analyse over a years’ worth of data at this site to see if there have been any changes in this time period. The team have observed a number of fluctuations in the abundance of the commercial fish species being monitored over the five phases. Overall, there has been observed to be a general decline over all the species over this timeframe. However, some groups did show some different changes such as Unicornfish recordings which changed from just over 10 individuals in phase 113, to 110 in phase 114. Variations in Parrot fish numbers are also different, abundance peaked in phase 114 and has been in decline ever since. Although, these findings have shown that there have been changes in the species abundances over this timeframe – mainly of decline – the statistical analyses of these results were not statistically significant. If this downward trend continues over time however and becomes statistically significant, this may be a sign that the specified use area is not sufficiently protecting the species present within its limits. This is something that the Marine Team will continue to monitor.

By Charlie Outhwaite

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THE IMPORTANCE OF MANGROVE STANDS FOR COMMERCIALLY IMORTANT FISH SPECIES


Mangrove stands provide a unique system unlike any other on this planet. They are found growing within the intertidal zones of coastline and so are able to survive the dramatic changes in salt concentration experienced within that area, as well as the near constant water-logged state of the soil. Not only do they provide a unique habitat for a number of different species, but they also carry out a number of other important ecosystem functions and services. They are important for flood protection as they act as natural barriers against the influx of water, protecting natural systems and human habitations further inland. Mangroves act as a filtration system absorbing pollutants and heavy metal substances as well as reducing high nutrient levels from sewage. By stabilizing water and soil content and reducing sediment that flows downstream these systems are able to protect other systems, most importantly perhaps coral reefs which have become dependent on mangroves and these services.

One service that has a great deal of relevance to humans is the fact that the submerged root system of mangroves acts as a nursery for many species of fish; an environment where young fish individuals spend time sheltering from danger and feeding until they become large enough to survive out in the open ocean or around the adjacent coral reef areas. Many of these fish species are of great commercial importance and make up a large part of the catch for fisheries as well as acting as a sustainable food source for local coastal communities. Any degradation of the mangrove system would affect those species that utilise the area and so could affect the number of fish available for food. This is just one of the many incentives that mangrove systems offer and so it is important that these systems are protected and maintained so that they can continue to supply these services well into the future.

The Frontier Tanzania Marine team have found that there are many commercially important fish species found out on the coral reefs of Mafia Island, so now a new project is being set up that will hopefully be able to determine whether or not any of these species use the local mangrove stands as a nursery site in the earlier stages of their life cycle before they head out onto the reef system. There are many local people that rely on the local catch for food as well as for work and so by showing them that the mangrove systems are involved in this service, local protection and maintenance of the mangrove systems can be ensured.

This project will involve the implementation of underwater surveys within the root system of the mangroves to identify the species that are present as well as their abundance. It will then be possible to identify the proportions of the species that are of commercial importance in the area and show that the mangrove systems play an important role in the support of local fisheries.

By Charlie Outhwaite

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THE IMPORTANCE OF A CLEAN BEACH


The Tanzania marine and forest teams have been over to Juani Island to take part in a beach clean at one of the local turtle nesting sites.

The currents surrounding the island lead to the deposition of large amounts of litter onto the beaches. The litter found has been mostly composed of flip flops, plastic bottles and fishing gear. These beaches are an important area for nesting turtles and so it is important that they are kept in a good condition to maintain the viability of the beach for the species. If large amounts of litter have accumulated on a nesting beach, approaching female turtles may be forced to lay their eggs in an area that is inadequate for their development. If eggs are laid below the high tide mark for example they may not be kept at the correct temperature and so may not survive or the eggs could rot if they become damp. The sex ratio of the eggs is determined by temperature, by ensuring the eggs are kept at the appropriate temperature then there will be less of a bias towards the sex of the turtles one way or the other, male or female, ensuring a more equal outcome.

As well as hindering the turtles that come onto the beach for nesting, any litter present will also add to the difficulty the hatchlings will have when leaving their nests and make their way down to the water. Ensuring the beaches are cleared of litter will help the hatchlings take their first step unhindered into the vast ocean waters. Therefore it is clear that by keeping these beaches in the best conditions possible the local turtle population will have the best chance of surviving and thriving!

These beach cleans are carried out on a regular basis by both the forest and marine Frontier camps in collaboration with the Tanzanian NGO Seasense. Seasense monitor the beaches on a daily basis to identify any new turtle tracks so that they can ensure the nests are at an area above the high tide mark. If any nests are found below the high tide mark and so are at risk, they are relocated to a more suitable area to ensure their survival. Seasense do not have the resources available to them to keep up these regular searches as well as carrying out the beach cleans so the efforts provided by Frontier contribute a great deal to the survival of the turtles of Juani Island.

By Charlie Outhwaite

Learn more on Frontier’s Tanzania Marine Project and other opportunities to volunteer abroad.

COMMERCIAL FISH SURVEYS - MAFIA ISLAND, TANZANIA


Mafia Island Marine Park was established in 1995 as Tanzania’s first multi-user zone marine park. Currently, 14 villages and over 18,000 people live within the new park boundaries acting and interacting with the marine resources. A zoning policy was developed with three zones within the park; Core Zone, restricted use zone, and general use zone. Within the Core Zones there is no resource extraction but diving and research are permitted, within Specified Use zones there is no pull net fishing allowed and no fishing by non-residents, and within general use zones national regulations apply and non-residents require a permit to undertake activities within the park.

Mafia Island Marine Park and Frontier have developed a proposal to monitor fisheries in the different zones of the marine park. The aim of the study is to assess the influence of protection on improving the abundance, species richness and size of commercial fish within Chole Bay. Maintaining the fisheries can improve the overall health of the marine habitat and provide sustainability for local communities in the park.

In this phase Frontier- Tanzania team has commenced to monitor sites within two different zones of the park. All surveys were completed in the Specified Use zone using count points and transects each at the Milimani and Chole Wall site. The team was also able to complete one full day of surveying for the sites located in the Core Zone of the park at the Dinidini and Mikadini sites.

This phase saw a continuation of Frontier-Tanzania efforts to compare fish size and abundance within the two protection levels of the park, with the main focus of analysis on the most important commercial fish amongst those surveyed. Average fish sizes recorded were fairly consistent for Groupers, Parrotfish, Snappers and Unicornfish families over the four previous phases. However there were large differences in the sizes of Sweetlips and Rabbitfish recorded, while the Rabbitfish family records were flucual. An interesting note was that across the seven selected commercial fish families, average fish sizes peaked for category ‘5’ of those families during phase 114 ( 4years ago). The team is looking to continue surveys during this phase and compare it to the dataset collected in previous phases.

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COMMERCIAL FISHING SURVEYS: ABSENCE OF THE SWEETLIPS (HAEMIDULAE)


The Tanzanian coast is home to approximately 25% of the country's entire population. Fishing is a predominant primary means of subsistence for the majority of the communities living on the Western Indian Ocean coastline, and therefore the management and monitoring of commercial fishing is not only essential for the protection of species, but also the livelihoods of the local population. This phase the Tanzania Marine team have been further monitoring commercial fish species, in the hope of conserving biodiversity and resources for local livelihoods.

The current pressure on resources is elevating, with higher demands for food. Overexploitation can have extremely damaging effects on very poor communities who depend on ocean supply for survival. Marine protected areas (MPA’s), provide security through the implementation of core zones, restricted use zones, and zones for general use. This phase the team focused their attention on the surveying of specified use zones within the Mafia Island Marine Park (MIMP), which permit residents to fish within the zonal area. Commercial fish surveys were implemented to monitor abundance, species richness and size of fish species.

The most prevalent commercial fish families captured through artisanal fishing techniques include the Emperors (Pomacanthidae), Groupers (Serranidae), Rabbitfish (Siganidae), Snappers (Lutjanidae), Sweetlips (Haemulidae), Parrotfish (Scaridae), Trevallies (Carangidae) and Unicornfish (Acanthuridae). One of the most notable findings this phase was the absence of sweetlips fish from the specified use zones. 96 surveys were conducted at four study sites at varied depth contours, by the TZM team and research assistants. Six species of sweetlips have previously been documented, and therefore the notable absence of members of the sweetlips family was clear. Previous phases have recorded counts between 50 and 30 individuals, and therefore close future monitoring of this species would appear vital.

The absenteeism of sweetlips species may at first suggest overexploitation by local fisheries, however there may be a range of factors that could potentially explain this finding. Temporal variations in reef fish have often been documented, and variations in community compositions have been noted over daily, monthly, and yearly cycles. Seasonal variability often influences fish assemblages as a result of changing weather conditions, and therefore it would be expected that species presence may vary with seasons, or on a yearly basis.

The success of a Marine Protected Area relies on increased fish recruitment, abundance and increases in the biomass of selected species, and therefore the fluctuations in sweetlips may need close monitoring. The migration of adults into adjacent zones is essential for the zone network to be maintained, however future monitoring may demonstrate the reasons for species absences in particular areas.

By Laura Burton

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HIPPOPOTAMUS PROJECT PROGRESSES ON MAFIA ISLAND


The island of Mafia has a small population of Hippopotamus (Hippopotamus amphibious) which inhabit a network of lagoons in an inland area. As little is known about the population, a project was initiated in autumn 2011 with the aim of investigating its size and movements, as well as its impact on the community, with the ultimate goal of ensuring protection of the hippos. Following several meetings with the district council and local village council of Gonge, the project makes progress this quarter, with the village council approving the creation of a tourism board and hippopotamus ecotourism project.

It is believed from local sources that the hippos migrated to Mafia Island after a flood in the nearby Rufiji Delta 100 years ago. The population size is not accurately recorded, and remains relatively elusive, being estimated at 20-40 individuals. Due to the difficulty of monitoring this nocturnal, semi-aquatic mammal, there is very limited information on the current population, including its size. Unfortunately, hippos are strongly associated with crop damage and human wildlife conflict, making them a pest. Although the hippopotamus has an extensive range it is highly vulnerable to local extinction due primarily to habitat loss and fragmentation, as well as hunting for meat, and persecution due to conflict with people. Based on the estimated global population and current threats, the hippopotamus was recognized as threatened (vulnerable) on the IUCN Red list from 2006.

During winter 2011, questionnaires, posters and an overnight survey of suspected Hippo sites were conducted in order to gain the more information about the population. Future involvement in the protection of this species could assist towards funding, and tourist visits to Hippo lagoons (aided by the local village tourism board) to increase the numbers of ecotourists to the area. This in turn is hoped to result in an increase in funds which could compensate local farmers for hippo associated crop damage, or help to establish some sort of deterrent (e.g. electric fences or ditches) to protect farming land.

The importance of educating the local community in order to raise ecological awareness and create community based conservation initiatives should not be overlooked, as Hippo reserves have been proven to benefit communities in West Africa in the past, relieving poverty and encouraging ecotourism. The project continues to conduct workshops with general information on the life history and ecological importance of the hippopotamus, as well as an introduction to ecotourism and the duties of roles within the tourism board. Future work proposals include building of infrastructure to accommodate tourists, advertisement of hippo tours and movement range.

Learn more on Frontier’s Tanzania Marine Project and other opportunities to volunteer abroad.

INCREASED PROTECTION FOR WHALE SHARKS ON MAFIA ISLAND, TANZANIA


Whale sharks on Mafia Island are popular with tourists, and several whale shark safari tours operate in the area. With the possibility that whale sharks around the island are under threat, studies commenced at the beginning of the year to obtain scientific data on the whale shark population through collaboration with whale shark tour operators and the District Council. Workshops have also begun in order to train all stakeholders in the surveying techniques required to acquire scientifically viable data, and meetings to establish a patrol boat which will serve to protect the whale sharks have taken place.

Whale sharks are currently listed by the IUCN as threatened (vulnerable), and so require monitoring and increased protection to prevent their already dwindling numbers from decreasing. Previous studies on the whale sharks off Mafia Island has shown evidence that they are either partial or full residents of Mafia Island, with at least two recurring individuals The Tanzanian NGO “Sea Sense” outline the protection of whale sharks as one of their objectives, however they were unable to meet this due to lack of funding in 2010. Towards the end of 2011, it was observed that there were infringements on the Code of Conduct outlined by WHASCOS (Whale Shark Conservation Society of Mafia), regarding such points as proximity of fishing boats and their netting to whale sharks, tourist snorkelers and diver interaction, and the possibility that the whale sharks were being hunted. Whilst whale sharks are not actively harvested on Mafia Island, there is certainly evidence to show that they are victims of incidental capture and collisions with boats, especially during surface feeding. There was also concern that the tax charged to tourists visiting the whale sharks was not being utilised appropriately by the District Council. With the aim of improving the protection afforded by the WHASCOS, Frontier staff distributed questioners to tourists to establish their awareness of the conservation status and protection afforded by the code of conduct. Using the information gained, meetings were arranged with the District Council, who agreed to help implement patrolling of the protected area, raising awareness in the community and regular meetings with the local fishing council to discuss improvements to the fishing code of conduct. Local fishermen also began collecting basic information on the whale sharks. In the future, controlled monitoring and sufficient enforcement of the fishing Code of Conduct should serve to stabilise the whale shark population, bring about a decrease in conflicts with stakeholders and increase the quality of the tourist experience. It is crucial that all stakeholders must combine efforts to outline, monitor and reduce the impacts before the status becomes critical. Collaboration with the District Council and Mafia Island Marine Park (MIMP) will continue in order to assist long-term plans for gathering data on the whale sharks. This will create a safer environment for the whale sharks off Mafia Island that is both sustainable and provides the requirements of the whale sharks, the local community and tourists in mind. With better managed conservation and ecotourism, the potential income generated from protecting this species may be substantial.

Learn more on Frontier’s Tanzania Marine Project and other opportunities to volunteer in Tanzania.

Frontier runs a number of wildlife conservation and marine conservation volunteer projects in Africa and around the globe.