TANZANIA MARINE RESEARCH PROGRAMME TZM Phase 133 Science Report

Transcription

1 TANZANIA MARINE RESEARCH PROGRAMME TZM Phase 133 Science Report Utende Beach, Mafia Island, Tanzania 1 st July 30 st September 2013 Sarah Russwurm (Assistant Research Officer) Matthew Everatt (Research and Development intern)

2 Staff Members on TZM in 133 Name Position Jean Pearson (JP) Project Co-ordinator Alexandra Deamer-John (ADJ) Principal Investigator, incoming Alex Baker (AB) Principal Investigator, outgoing Sarah Russwurm (SR) Assistant Marine Research Officer Liv Ainsworth (LA) Assistant Marine Research Officer Greta HM (GHM) Assistant Marine Research Officer Sophie Thompson (ST) Conservation Apprentice Stephen Shaw (SS) Dive Officer, outgoing James Edmonds (JE) Dive Officer, incoming Chris Smith (CS) Assistant Dive Officer

3 Frontier-Tanzania Marine Science Report Phase 133 Content 1. Introduction Training Briefing sessions Science lectures Field Training Limitations Research Program Overview Survey Areas Milimani North & South Utumbei Deep Chole Wall Frogfish Limitations Benthic Composition Surveys Introduction Benthic Composition Methodology Results and Discussion Recommendations Invertebrate Survey Introduction Methods Results... Error! Bookmark not defined Discussion and Recommendations Commercial Fish Surveys Introduction Methodology Results /9/ of 36

4 Discussion and Recommendations Whale Shark Project Kitomondo Secondary School Project Cleaning of turtle nesting beaches, Juani Mangrove Project Proposed work programme for TZM References Appendix: Commercial fish list used for surveys /9/ of 36

5 1. Introduction Tropical marine ecosystems including coral reefs, mangrove forests and seagrass meadows, are valuable environmental resources that provide significant economic goods and ecosystem services (Kimirei, 2012; Nagelkerken et al., 2000 and Hughes et al., 2003). They contribute to the livelihoods and food security of millions of people living in coastal countries, and also play a crucial part in stabilizing global ecosystems and in preventing coastal erosion (Hoegh-Guldberg, 1999). The health and stability of these resources is therefore critical to human well-being world-wide (Wilkinson et al., 1999). Tanzania is currently ranked as one of the poorest countries in the world with a large proportion of its population directly or indirectly depending on coastal ecosystems for the provision of cheap protein through subsistence fishing, trade in marine resources and dive tourism (Francis et al., 1997). Amongst Tanzania s administrative regions, the Mafia Archipelago is one of the least developed with a disproportionally large percentage of the population depending on farming and subsistence fishing (Holberg, 2008). Mafia Island is located approximately 120 km south of Dar Es Salaam, 20 km offshore of the Rufiji Delta and 850 km south of the equator. It is the central island of the Mafia Archipelago consisting of about 15 sandstone and coral rag islands, several of which are inhabited. Mafia is the largest island, measuring approximately 50 km in length by 15 km across at its widest point. There is an estimated population of 40,000 people living on the main island with the majority being based in the south of the island. The archipelago is significantly less developed than its neighbours Pemba and Zanzibar (Holberg, 2008 and Boeser, 2005), and has far fewer tourists per year (Holberg, 2008). However, as foreign investment increases, it has been suggested that this will change over the coming years. Whilst increased tourism and infrastructure development is expected to benefit the local population, it also puts pressure on a way of life that has been established over countless generations. Subsistence fishing and unregulated small scale trade are often the only means of obtaining protein on Mafia Island (Holberg, 2008). Given the fragility of coastal ecosystems, an increase in these practices may lead to biodiversity loss. The creation of 16/9/ of 36

6 a sustainable system that guarantees the livelihood of people whilst also protecting the reefs, is thus of primary concern (White et al., 1994). Frontiers engagement in Tanzania began in 1989 with the first TZM project located in Utende, on Mafia Island ( ). The project s initial objectives were to supply a detailed and comprehensive set of baseline data on the marine environment within Chole Bay, on the east coast of Mafia. With the aid of this information, a management plan was formed and Tanzania s first multi-user marine park was gazetted in The Mafia Island Marine Park (MIMP) is responsible for the management of the park, and reports to the Marine Parks & Reserves Unit of Tanzania, based in Dar es Salaam. After the success of this initial programme, Frontier concentrated its efforts and research on a number of different locations along the Tanzanian coast. All base camps conducted a number of baseline surveying programmes, socio-economic data collection and joint ventures towards the establishment of other marine parks. Frontier returned to Utende, Mafia Island, in The base camp lies inside Mafia Island Marine Park in the village of Utende (S07 o E39 o ). Just 300 m from the camp is Chole Bay, a highly tidal and bathymetrically complex inlet, separated from the ocean by Kinasi Pass and Chole Pass, with an average depth of 20 m. The tidal range in the bay is approximately 3 m on springs and 1 m on neaps, with a small intertidal area at mean low water. Figure 1: Location of Mafia Island. The red marker shows the location of Kilindoni, the district capital. 16/9/ of 36

7 Figure 2: Location of Frontier base camp. The camp is located in Utende village in Chole Bay. Its approximate location is marked by the red marker. The aim of the current project is to implement and complete aspects of a five year survey and monitoring programme agreed between Frontier and MIMP. Objectives within the programme include but are not limited to: Collection of baseline biodiversity data on coral reefs within the MIMP Collection of baseline mangrove survey data and mapping of habitats Collection of baseline seagrass bed data and mapping of habitats Comparison of biodiversity in different use zones of the MIMP Collection of socio economic survey data on fisheries areas and fishing methods Collection of socio economic survey data on mangrove harvesting, forest logging and coral mining Collection of socio economic levels, including poverty, access to health care, education and impact of tourism Collection of socio economic data on community relations with the MIMP Feasibility studies of potential aquaculture projects Development of a management plan and risk assessment report for the MIMP, based on evaluation of datasets. 2. Training 2.1. Briefing sessions 16/9/ of 36

8 All RA are given a number of briefing sessions upon deployment. These briefings include health & safety, medical issues, TZM project history & objectives as well as general information about life in Utende and on camp as listed in Table Science lectures Marine science lectures concentrating on fish identification, coral morphologies and benthic composition were conducted throughout phase 133 in order to train RAs up to a suitable level to take part in the research programme. Additional lectures were well received and helped RAs develop a broader understanding of marine ecology and conservation. Lectures covered all fish families and species surveyed. The current Commercial Fish Species List is designed to suit the needs of the MIMP long term monitoring program and focuses on commercial fish and families which are targeted by local fishing communities and which are indicators of reef health. Fish tests were conducted as PowerPoint presentations, and new staff and RAs were required to reach a 95 % pass mark before surveying could commence. Where RAs initially failed to reach the pass mark, individual study periods were held and Ras were re-tested until they reached the required pass mark. Table 1. Briefing sessions conducted during phase 133. Briefings Health & Safety Medical brief Introduction to TZM project Camp life and duties Given By JP/AB JP/AB JP/AB/ADJ JP Table 2. Science lectures conducted during phase /9/ of 36

9 Science Lectures Coral Reef Ecology and identification Commercial Fish Fish morphology and ecology Surveying and Monitoring Benthic Invertebrates Angelfish Identification Surgeonfish Identification Butterflyfish Identification Hazards of the Reef Mangroves Marine Protected Areas Fisheries of Mafia Island Given By AB/ADJ/SR/MM AB/SR/MM/ADJ AB/SR/MM/ADJ AB/SR/MM AB/SR/MM/CS AB/SR/MM/CS MM MM MM AB/SR AB AB/SR AB 2.3. Field Training Field work training was provided through a series of practical sessions. After passing written fish and coral tests, underwater sessions were held with staff to further prepare RAs to take part in Underwater visual censuses (UVC). These sessions included in-situ fish ID, invertebrate spots and fish size estimation training. The size estimation training was carried out by snorkelling on shore and estimating the size of plastic fish on a line, held near the ocean floor by weights, at a distance of 1-2 m. RAs practiced and were tested multiple times until they were able to accurately estimate the size of model fish to within 5 cm. Fish ID training sessions were carried out until Ras could positively identify all species pointed out to them by experienced members of staff. The in-water training was supported by regular review sessions until an in-water fish ID test was passed. Benthic composition field training consisted of underwater training to ensure consistency between recorders. In order to ensure that volunteers were adequately 16/9/ of 36

10 trained to collect consistent data, a survey of 19 invertebrate species and families was constructed and added to the commercial fish and benthic baseline survey methodology. 2.4 Limitations It is not uncommon for ecological studies to incorporate data gathered by volunteers. Employing volunteers allows a larger amount of data to be collected over a shorter period of time, increases public awareness of ecological issues and greatly reduces the costs through free labour (Thompson & Mapstone, 1997; Darwall & Dulvy, 1996 and Gillet et al., 2012). Recently, studies have begun to question the reliability of data acquired by non-specialist surveyors, suggesting that there may be a substantial difference in recorded data between a specialist and a non-specialist surveyor (Gillet et al., 2012). However, a number of studies have shown that volunteer surveyors are able to reach a high level of accuracy given a certain number of training dives (Thompson & Mapstone, 1997; Darwall & Dulvy, 1996). By setting the pass marks for both on-land and in-water ID tests deliberately high, Frontier ensures quality and consistency in its data collection. 3. Research Program 3.1. Overview Establishing the abundance and distribution of species is the prime objective of the majority of ecological research on marine reef habitats (Brock, 1954 and Dickens et al., 2011). Observing spatial and temporal variations of marine organisms are vital for reef fish abundance studies, with a wide variety of underwater census methods available for their observation. The most commonly used method is the UVC established by Brock (1954). Dickens et al. (2011) established that 54% of reviewed reef fish abundance surveys used visual identification and tallying of species along a belt transect. Although several shortcomings of this method are known (Dickens et al., 2011; Brock, 1982 and Watson & Quinn, 1997), it is still widely implemented due to its non-destructive nature, relative ease and lack of specialized equipment required to conduct a study (Dickens et al., 2011 and Watson & Quinn, 1997). With most abundance surveys being carried out on a repeated, if not regular basis, it is vital to keep the survey method as low impact as possible (Willis, 2011). Frontier has continued to use UVC methods for these reasons. 16/9/ of 36

11 Other conservation work and ecological surveys completed during phase 133 included: Creation of a scientific lecture series to give volunteers a broader knowledge of the marine environment. Continuation of work with Kitomondo Secondary School Environmental Ambassadors'. Beach clean ups of turtle nesting beaches on Juani Island Survey Areas Sites surveyed during phase 133 were located in the Specified Use Zone within Chole Bay, the Core Zone at the mouth of the bay, and the General Use Zone close to Utende Shore. Figure 3: Zonation of the MIMP. See figure legend for the different zonation areas of the MIMP Milimani North & South 16/9/ of 36

12 The Milimani dive site is located several hundred metres west of Kinasi Pass and is surrounded by shallow expanses of sand and sea grass. Milimani contains a shelf of coral that gradually reaches a depth of around 20 m depth. The dominant coral morphologies are mainly foliose, massive and branching coral, this supporting a wide variety of invertebrates living in the relative shelter of these morphologies. Fish abundance is also very diverse, with fish species ranging from napoleon wrasse to juvenile groupers, with large schools of soldier fish frequently seen sheltering in the submassive coral. Since phase 131, Milimani reef has been divided into two separate survey sites, Milimani North and Milimani South. Milimani North is an area of fringing reef facing inwards from the mouth of the bay and relatively sheltered from strong currents. Milimani South is a fringing reef that runs perpendicular to Chole Wall, to the west of Kinasi Pass, and borders the channel running from the mouth of the bay inwards Utumbei Deep Utumbei dive site is a continuation of Kinasi Pass, leading into Milimani South (an area also known as Coral Gardens) and is the closest survey site to the mouth of Chole Bay. The bathymetry consists of a number of steep-sloped channels, with a maximum depth of 24 m. Utumbei is home to a high number of larger fish species, including rays and groupers. Although Utumbei straddles the border between the Core and Specified Use Zones, TZM is currently using it as a Core Zone survey site due to the inaccessibility of the Dindini and Jina Wall sites Chole Wall Chole Wall separates Utumbe from Kinasi Pass and lies 6 km from Utende. Chole Wall shows some of the highest benthic biodiversity of all the sites within the bay, with high abundances of Acropora formosia, Acropora validia and Montipora equitubercullatia scleractinian corals, dominating the benthos. A number of Alcyonacea species including Anthelia Glauca, Cespitularia erecta and Xeniidea sp, are all present in high abundance. The bathymetry of the site comprises a steep shelving wall from 5-14 m with a rich and biodiverse reef flat, falling away to sandy rubble filled deep water channel. Exposed to fast currents on the tidal ebb and flow, Chole Wall shows a high abundance of both 16/9/ of 36

13 commercial and reef fish species Frogfish Frogfish is an area of patch reef located South-East of Utende shore, within the General Use Zone. The site has a significant soft coral coverage and consists of several peaks, with depths ranging from 14 m to 5 m. Frogfish was the first General Use survey site to be selected for monitoring work, and it is accessed from the shore, providing a useful dive site should TZM's boat be unavailable. To reach the most established part of the reef a 15 minute swim is needed, rendering this dive site better suited to point counts as these require less time than BSP transects. TZM 134 is expected to look into the possibility of establishing a BSP transect time series using surveyors with good air consumption Limitations Due to mid-phase changes in methodology, severe weather conditions and lack in funding for fuel, only four of the necessary survey sites were monitored in full. This limited analysis between zones within the marine park. For the next phase priority will be given to one site in each zone. TZM were unable to conduct surveys within the Core Zone outside the bay this phase because weather and sea conditions between the end of March and the beginning of September make this area unreachable. Normally, TZM is reliant on MIMP boats and fuel in order to survey sites located outside of the bay as TZM's own craft is not powerful enough to safely operate in the rougher conditions found at these sites. In the past an agreement has been reached between MIMP and TZM regarding fuel and boat budgets which allows TZM to conduct research at external Core Zone sites on behalf of MIMP. Unfortunately, MIMP has so far been unable to secure funding for further research work. Whilst AB has approached MIMP with the aim of making more fuel available to TZM (in order to meet the needs of MIMP's own monitoring program), no further resources are currently available to TZM, though hopefully this situation will be resolved in time for survey work outside of the bay to recommence once conditions become suitable for survey work towards the end of September. 16/9/ of 36

14 Whilst data collection at Core Zone sites outside the bay has been impossible for Phase 133, the Utumbei Deep dive site, on the boundary between Core and Specified Use Zones has been identified as an effective proxy for Core Zone areas outside of the bay. This has allowed Core Zone data collection to take place in Phase 133, in addition to the full series of surveys that were conducted in the Specified Use Zone. The main focus of the work programme for Phase 133 was to continue the monitoring of key commercial species that had started in Phase 113, with the ultimate aim of presenting this data to MIMP management Benthic Composition Surveys Introduction Coral reefs are sensitive to climate and anthropogenic changes (Nyström et al., 2000) and as a result, it is imperative that we record the general health of coral reef systems in order to monitor the extent and severity of decline and determine the greatest causes of risk to reef health. Coral reefs are sensitive in part due to their complexity. There are many ecological, structural and functional factors at work, including coral cover, macroalgal abundance, colony size, species composition, predator/grazer interaction, mortality and recruitment (Done, 1997, Kramer et al., 2003, Mrowicki and Fanning, 2008). Frontier TZM aims to monitor any changes to the reefs over time, to be able to understand the processes at work on the reef and provide management information for MIMP. The composition of the substratum is commonly assessed through benthic surveys. To classify benthos, visual census is one of the most common quantitative and qualitative sampling methods. Benthic composition surveys have been carried out since phases 113 and were coupled with commercial fish surveys of abundance and size to allow for comparison between the benthic habitat and fish populations at each site. The primary purpose was to identify the substratum of a total of four reefs (two inside the Specified Use Zone and two inside the Core/No Take Zone of the Marine Park) and evaluate the results, with reference to any significant trends that can be observed. The methodology for the collection of benthic habitat data has been developed by Frontier and used to collect data at a number of locations, both across Tanzania and globally (English et al., 16/9/ of 36

15 1987) Benthic Composition Methodology Benthic composition data was collected in conjunction with commercial fish surveys. Surveyors recorded the benthic substrate type every 1 m starting at 0 along a 50 m transect set at a constant depth following the reef contour. This resulted in the collection of data at 50 points for each UVC. This allows conclusions about the most common types of substratum for each survey site. Knowledge of this allows researchers to draw correlations between species abundance of fish and invertebrates when compared to the most abundant benthos types. Table 3. Benthic composition categories displaying the codes during data collection. Category Code Category Code Category Code BIOTIC ABIOTIC CORAL MORPHOLOGY Hard Coral HC Sand SA Branching BR Soft coral SC Rubble RB Digitate DG Sponge SP Rock RK Laminar LA Sea grass SG Silt ST Tabulate TA Algae AL Dead coral DC Foliose FO Bleached Coral BC Other OT Solitary SO Massive Submassive Columnar MA SM CO In order to reduce inaccuracies in data recorded by volunteer RAs, identification of coral species is no longer required. Both the identification and recording process have been 16/9/ of 36

16 simplified to reduce error. Transects require division of coral into categories based on morphological characteristics, with coral morphological diversity acting as a proxy for species diversity. Whilst morphology is not a perfect substitute for diversity it is more accurate than attempting to identify coral to species level (which is often impossible without a microscope). TZM now simply record benthic data in the following categories (listed in Table 3): abiotic forms include rock, rubble, and sand; biotic forms include sea grass, soft coral and hard coral described by structure Results and Discussion Figure 4. Comparison of the substrate by hard coral and soft coral across survey sites. 16/9/ of 36

17 Figure 5. Diversity of hard coral morphologies across survey sites. The composition of hard and soft coral was found to be similar across all four survey sites, with Milimani South exhibiting the highest level of hard coral cover, specifically a high coverage of laminar and tabular corals. Both Milimani North and Utumbei Deep showed the highest average soft coral cover, reflecting the greater depth and exposure to currents and wave action experienced by these sites. All survey sites showed a good diversity of coral morphologies (Figure 8) indicating a high diversity of hard coral species at all sites and therefore suggesting that the reef is in good health. It should be noted that the status of coral reef systems is regularly measured using a limited number of factors (size and abundance of important taxonomic groups etc). Coral cover, however, is not a reliable measure of resilience as, for example, a recovering healthy reef may have substantially less coral than one that is struggling and dominated by macroalgae. Coral cover is not an indicator of reef resilience and it can only become a definitive indicator of phase shifts (when a reef is unable to remain in or return to a coral-dominated state) if the same site is monitored for many years (Alvarado et al., 2004; Hughes et al., 2010) Recommendations The current methodology for measuring the benthic profiles present across Chole Bay 16/9/ of 36

18 has proven effective, with volunteers easily able to learn how to carry out surveys and accurately categorize the type of benthos present. Benthic surveying will continue throughout Phase 134 so as to continue to add to the existing dataset and monitor any sudden changes in benthic makeup. However, it is also intended to update the coral species to a full species list, therefore giving a true representation of coral biodiversity and biomass across the marine park and between sites. Through both in situ and on land identification using surveyor knowledge and underwater photography, a full representation of scleractinian diversity is possible for every site. It has been proposed by Frontier and MIMP that a smaller number of transects be carried out at a larger selection of sites to give a more complete representation of the marine park, with occasional visits to sites further from the marine park should fuel requirements be met Invertebrate Survey Introduction Phase 133 saw work from Phases 130, 131 and 132 continued, with the aim of monitoring invertebrates populations through the addition of an invertebrate survey to every UVC conducted. Invertebrate species are important indicator species of overall reef health. As a result of this, invertebrate surveys form a crucial part of TZM's baseline survey monitoring program. It is important to utilise a survey method that will allow volunteer RAs to collect data quickly and accurately with only a small amount of training. For our purposes, a low resolution survey methodology such as the one utilized by ReefCheck (an international coral reef monitoring organization) or an adaptation of the UVC methodology outlined in English et al. (1997) would both fulfil these requirements. The goal for this phase was to gather more data through surveys in order to assess the species composition and abundance of indicator species present at our survey sites, as well as the feasibility of adding further invertebrates to Frontier s baseline survey protocol. 16/9/ of 36

19 Methods The methodology for collecting invertebrate data is based on visual ID of pre-selected organism groups. As part of the UVC, a team of survey divers swim along the transect tape, recording the number of 19 invertebrate groups encountered within a 5 m wide corridor (2.5 m either side of the transect tape), ensuring that the entire area is thoroughly searched. These 19 indicator species were originally taken from the ReefCheck Indo-Pacific survey protocol, however the list was adapted slightly after analysis of Phase 124's data in order to better reflect the local invertebrate community (Table 4). Table 4. Invertebrate category list surveyed in phase 133. Invertebrate Sponge Brittlestar Featherstar Crown of Thorns Other Sea Star Nudibranch Flatworm Segmented Worm Urchin (Diadema) Urchin (Non-diadema) Crab Mantis Shrimp Banded Coral Shrimp Other Shrimp Giant Clam Other Bivalve Sea Cucumber Mollusc Anemone 16/9/ of 36

20 Results Individuals of all indicator species were found at all survey sites across Chole Bay, with the exception of Crown of Thorns sea stars Discussion and Recommendations The invertebrate data collection begun in phase 133 builds on previous work carried out through 2011 and However there is currently no working previous dataset available for past comparison, making temporal analysis impossible. By continuing with the newly established invertebrate species list and making invertebrate surveys a key part of the Baseline Survey Protocol conducted by TZM within Chole Bay, TZM aims to monitor large scale outbreaks or population decreases experienced by invertebrate species, as well as the impact of extractive practices on crab, shrimp, sea cucumber, bivalve and mollusc species. The MIMP Crown of Thorns cull has apparently been successful in reducing populations of this voracious coral predator within Chole Bay. Further monitoring of the populations is required in order to assess how rapidly Crown of Thorns populations can recover and to allow MIMP to respond early on to any sudden population increase. As was found in Phase 132, sponges, brittlestars and segmented worms were also present in large numbers across the majority of survey sites, the presence of which would be expected in any healthy reef system. Whilst low numbers of crab, shrimp and sea cucumbers were recorded, this may reflect the fact that survey work is carried out during daylight hours, when these species are less active, and also the fact that these species are generally more prevalent in shallower waters (Richmond, 2002) Commercial Fish Surveys Introduction Marine protected areas (MPAs) are an important movement in conservation and habitat management (Pullin, 2009). MPAs can range from strict no take zones to communally managed multi-use parks. Multi-user marine parks aim to conserve resources and 16/9/ of 36

21 biodiversity and also improve local fisheries and livelihoods (Holberg, 2008). Successful MPAs have an increased abundance and biomass of targeted species (Lester et al., 2009), increased fish recruitment (Evans et al., 2008), and migration of adults into neighbouring areas (Jupiter and Egli, 2010). At the 2003 World Parks Conference in Durban, Tanzania pledged to have 10% of its marine area under conservation by 2012, and 20% by 2025 (Ruitenbeek et al., 2005). Tanzania currently has 12.5% of its coastal waters under some form of protection (World Bank, 2008). 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 new park boundaries, it was clear from the outset that the community would need to be involved and benefit from the park for conservation of marine resources to be successful (Mafia Island Marine Park General Management Plan, 2000). Within the park, a zoning policy was developed with three zones; Core/No-Take, Specified Use and General Use zones. 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 fishing regulations apply and non-residents require a permit to undertake activities within the park. An important practical indicator of the MIMP success is maintaining the health of its fisheries. Maintaining the fisheries can provide an indicator of overall community health and is also important to the local people, whose livelihoods depend on marine resources (Kimirei, 2012; Nagelkerken et al., 2000 and Hughes et al., 2003). MIMP and Frontier have developed a proposal to monitor fisheries in the different zones of the marine park. The aim of conducting commercial fish surveys is to assess the abundance, species richness and size of commercial fish within Chole Bay. This phase has seen monitoring sites largely within the Specified Use zones of the park Methodology TZM currently employs two separate methodologies for commercial fish survey work. The primary method for commercial fish data collection is through the use of UVCs, 16/9/ of 36

22 employing belt transects as well as point count methods based on Watson and Quinn (1997). Fourty eight surveys were intended to be conducted in total at the four study sites, with transects divided into two depth contours: shallower depths at the top of the reefs, and the outer reef slope at deeper depths. All surveys this phase were completed in the Specified Use zone (a total of 12 transects at each site, with six conducted at shallow depth and another six deeper down). SCUBA buddy teams descended at each site and began the survey on either the outer reef slope or top reef. Fish were either surveyed along a 50 meter transect using Underwater Visual Census (UVC) 2.5 meters on all sides of the transect line, or using point counts where the observer would remain at a fixed point and record all fish within a 10 m sphere around them. Fish were identified to family or species level (Appendix 1) and placed into 10 cm size categories. For the UVC method, one surveyor rolled out the transect line, maintaining constant speed and depth, whilst following the reef contour while the other recorded fish abundance and size categories on a pre drawn dive slate. Point count methods based on Watson and Quinn (1997) were also used at both sites to estimate fish abundance of the same commercial fish species. This involved the observer descending to mid water column and spending 10 minutes at a fixed point on either the shallow back reef, or deeper outer reef, whilst recording fish abundance and size categories within a 10 m sphere around the diver. Point counts were used to more efficiently record larger, more pelagic schooling fish that might not necessarily be recorded by the UVC transect method. Point Counts are advantageous as they can be carried out in smaller or larger teams than transects and are quicker to complete, making them more useful for survey sites that are difficult to access. However, they lack the benthic and invertebrate components of the BSP methodology, and so it has been decided that TZM will continue to operate both survey methods, choosing the most appropriate for the situation Results 16/9/ of 36

23 The fish families surveyed by Frontier on behalf of MIMP include Emperors, Groupers, Parrotfish, Rabbitfish, Snappers, Sweetlips, Trevallys and Unicornfish, which have been identified as those most frequently caught by artisanal fishing techniques based on research conducted in 2011, and discussion with the MIMP research team. All fish featured in our commercial fish list (see Appendix) were recorded during the surveys or observed during fish point and reconnaissance dives. Individuals of almost all species were found to be present at sites with all levels of protection. Surgeons, parrotfish and butterflyfish made up the largest part of the population within the Core Zone, whilst butterflyfish, fusiliers, surgeons and parrot fish were all present in high numbers within the Specified Use Zone. Wrasse, parrotfish and butterflyfish were found at highest abundance in the General Use Zone, suggesting that Surgeon fish are not a high priority target for those fishing (Figure 10). Angelfish Butterflyfish Emperor Fusilier Goatfish Grouper Moorish_Idol Parrotfish Rabbitfish Snapper Spinecheeck Surgeonfish Sweetlips Trevally Triggerfish Unicornfish Wrasse Figure 6. Core zone commercial fish compositi 16/9/ of 36

24 Angelfish Butterflyfish Emperor Fusilier Goatfish Grouper Moorish_Idol Parrotfish Rabbitfish Snapper Spinecheeck Surgeonfish Sweetlips Figure 7. General Use zone commercial fish community composition Angelfish Butterflyfish Emperor Fusilier Goatfish Grouper Moorish_Idol Parrotfish Rabbitfish Snapper Spinecheeck Surgeonfish Sweetlips Trevally Triggerfish Figure 8. Specified Use zone commercial fish community composition. 16/9/ of 36

25 The relatively large populations and size distributions of commercial fish in both the Core and Specified Use zones suggest that MIMP's restrictions on fishing gear are proving effective as a method for reducing the impact of extraction pressure on these fish Discussion and Recommendations The aim of the project is to compare characteristics of fish in different management zones of the park. This allows a review of the efficacy of the Marine Park policies; to be able to monitor fish community composition as well as monitor benthic coverage and invertebrate numbers. Without continuous data at the same sites in the General, Core and Specified Use zones over more than one phase it is difficult to create datasets to analyse the differences between protection zones. Logistical issues and a lack of resources mean that access to the Core Zone is often limited. Areas outside the bay will remain inaccessible until September due to changing weather conditions, and it is therefore vital for Core Zone survey sites inside Chole Bay to be surveyed if any comparisons between Core and Specified Use Zones are to be made. Data from this phase can be used to build upon in future surveys with the aim of creating a longstanding data set to produce more reliable scientific results. Fish assemblages are known to be affected significantly by various invasive fishing techniques, such as dynamite fishing, purse-seine netting and other trawling methods (Currie et al., 2012) which are banned within the Mafia Island MPA. These restrictions likely account for the health of the reef and fish populations found across it. Artisanal fishing methods such as pole-and-line fishing are used in the Specified Use zone, and healthy fish populations and diversity within the Specified Use Zone suggests that these techniques are having only a limited impact. These methods are also well reported in other studies to have minimal impacts of the growth limit and number of fish in coral reef areas (Jennings & Kaiser, 1998). Important commercial fish such as Groupers, Trevally, Snappers, Emperors and Parrotfish all show a similar distribution in size of individuals recorded. All recorded 16/9/ of 36

26 species show a good number of individuals reaching reproductive sizes, suggesting that marine park management strategies are functioning and restrictions on fishing gear are effective. Data collected throughout 2012 suggests that the existence of all levels of protection is biologically important, firstly for the protection and conservation of commercial fishing in the Mafia Archipelago (on which the majority of local communities are dependent) and also for the general promotion and preservation of biodiversity and biomass in the waters surrounding Mafia Island. The selected sites of Milimani and Chole Wall within the Specified Use zone are sites which can be easily accessed for monitoring, and also both represent the typical characteristics of sites within this zone. In the Core zone, Jina Wall is fully representative of the characteristics of sites within this zone, however the prohibitive cost of reaching the site and the inaccessibility throughout a large part of the year as a result of poor weather conditions meant that it was essential for TZM to identify a new survey site within the Core Zone (Utumbe Deep). Survey work for the Core Zone will be continued at this location from now on. Continued monitoring of these sites using the same methodology should guarantee the opportunity to compare benthic compositions, fish communities and invertebrate numbers between the two zones. With Frogfish, a General Use survey site has also been identified close to Utende shore. Further exploration of the General Use Zone for possible survey sites is still required. Obtaining this information on a quarterly basis will also allow for analysis of temporal changes in the sites of monthly and yearly cycles. This information could be used to monitor the impact of fishing practices on the reefs within the marine park, and also to suggest changes in management strategy to the Marine Park personnel Whale Shark Project TZM's whale shark project is currently on hold until the whale shark season recommences in September/October. Whale sharks are a highly migratory species with their seasonal migration leading them through the western waters around Mafia Island 16/9/ of 36

27 (Rowat, 2007). Peak numbers are recorded between September and January, during which the WWF concentrates their research efforts in the area. In Phase 113, Frontier TZM started work in collaboration with the tourist group Whale Shark Safaris, in order to devise a monitoring program to collect data on whale sharks on Mafia Island. Whale Shark Safaris take tourists staying on the island to go and see whale sharks when they are present on the island. Our aims were to train their staff in order to collect data whilst on their excursions with tourists. Workshops and training sessions were held with the group in order to help the group collect data on the size, sex and characteristics of the whale sharks, and a data sheet was composed to be able to collect data effectively. During Phase 124 TZM was unable to collect data for this project without the assistance of a tourist operator. However, we have held meetings with WWF researchers and all the whale shark excursion operators on Mafia Island in order to put a more concrete project in place recording whale shark behaviour with tourist interactions in the future. Phase 131 saw several TZM staff assist with research conducted by WWF into the impact of whale shark safaris on animal behaviour. Although TZM itself lacks the resources to conduct this research effectively, it is hoped that cooperation between WWF and TZM will be able to continue once the whale shark season recommences in November Kitomondo Secondary School Project TZM has continued the Kitomondo secondary school work started by Owen Jones. A group of around six Form 1 students visit the Frontier camp on a fortnightly basis, and spend 2 hourly sessions on various environmental topics. Sessions involve lectures, discussions, practical lessons and potentially snorkelling and other excursions to help the students observe the impacts that their communities were having on the natural environment. Past phases have seen TZM conducting beach cleans with the Kitomondo school students, and it is hoped that this practical approach will continue in the future, so as to 16/9/ of 36

28 increase their conservation knowledge with the potential for setting up environmental days for the students to share their knowledge with the community. A long term goal for the project is to develop closer relations with the students communities, and also to plan and carry out awareness raising and other events within those villages. The project has been successful so far, although attendance has dropped during the summer. For Phase 134, ADJ will investigate how keen students are to continue working with TZM and whether the Environmental Ambassadors project remains viable Cleaning of turtle nesting beaches, Juani During phase 133 TZM conducted a number of beach cleans at several turtle nesting beaches on Juani Island. The beach cleans were arranged by AB through collaboration with Sea Sense, a Tanzanian NGO. Frontier were met on Juani Island by a Sea Sense representative and guided to the beach most in need of attention. The nesting beaches on Juani are managed by Sea Sense, an NGO specialising in the conservation of Indian Ocean marine species (Sea Sense, 2011). Sea Sense monitor the beaches daily for turtle tracks to locate turtle eggs that are laid below the high tide mark, nests are then moved to a more suitable location to ensure that the survival rate for eggs is as high as possible (Sea Sense, 2011; Sea Sense, 2012). Unfortunately, Sea Sense lack the resources or man power to maintain the beaches (Pers comps. Sea Sense, 2013). The currents surrounding the Island of Juani cause a lot of litter, both local and from further afield, to be deposited on the beaches. The litter is mainly composed of flip flops and shoes, plastic bottles and discarded or lost fishing gear (Sea Sense, 2013). The nature of the rubbish means that it is non biodegradable and therefore accumulates in large quantities. The quality of the beach environment is vital to the survival rate of hatchlings and in turn the continued use of the area as a nesting site (Garcia et al., 2003). If female turtles approaching the beach to lay their eggs encounter large volumes of litter they may lay their eggs in a sub-optimum position, i.e. below the high tide mark. If the eggs are laid below the high tide mark, they may not remain at the correct temperature and may perish and rot if they become damp (SeaSense, 2011). It is thus essential that nests remain at the correct temperature in order not to bias the sex ratio (Morreale et al., 1982; Garcia et al., 2003). 16/9/ of 36

29 The cleaning of beaches on Juani Island, will hopefully mean that turtles will be able to access the appropriate laying areas, and that hatchlings will have the best chance of survival. The beach cleaning events have been very successful, with RAs completely clearing several beaches of rubbish. Rubbish collected was then burnt on site in controlled fires in areas above the high tide mark. Having cleared the beach site, RAs were able to watch green turtle (Chelonia mydas) young hatch and observe as hatchlings successfully made their first steps into the waters around Mafia unhindered by the litter on the beach. The volume of litter collected during the beach clean this phase suggests that regular beach cleans are necessary to ensure that the beaches remain as clear of debris as possible Mangrove Project Phase 133 saw work continue on TZM's project to assess mangrove stand composition and health along the coast of Utende, based on work started by Nikki Hume in Phase 124. It is hoped that this monitoring scheme will benefit both the marine and beach conservation volunteers, as well as providing a good back up project in case there are any problems with the boat or dive equipment. AB led a number of nature walks through the mangroves, identifying tree and invertebrate species. Snorkelling transects have also been piloted in order to begin identification of marine animals such as commercial fish and crustaceans. A number of terrestrial mangrove surveys were also completed, although further work is needed in order to fully asses that stands around TZM's camp. Socio-economic surveys have been planned in order to determine the usage of the mangroves by the local community. The long term aim of this project is to establish a baseline data collection regime of tree density, forest composition, and species biodiversity in the mangroves. 4. Proposed work programme for TZM 134 The proposed work programme for TZM during Phase 134 includes: Continued collection of long term commercial fish data on reefs within MIMP, in Core, Specified Use and General Use Zones. 16/9/ of 36

30 Identification of further Core Zone survey sites within Chole Bay, in order to facilitate data collection in the Core Zone even in poor weather and reducing TZM's reliance on MIMP resources. Continued work with Kitomondo students to hold awareness raising days on the island, as well as lessons every two weeks. Continued environmental education and awareness raising with local children in partnership with Frontier's Teaching project. Continued regular beach cleans and turtle hatchings to maintain our relationship with Sea Sense. Continued liaisons with WWF in regards to whale shark monitoring. Initiation of coral gardening project to gather necessary data for planned future studies. Revision of all species lists for biodiversity studies. Initiation of short 4 6 dive/snorkel projects for coming volunteers, should we finish collecting the above data or circumstances prevail in which we cannot take the boat out. 16/9/ of 36

31 5. References Alvarado, J. J. et al. (2004) Population densities of Diadema antillarum Philippi at Cahuita National Park ( ), Costa Rica. Caribb. J. Sci. 40: Boeser, S. (2005) Global Positioning Systems. Encyclopedia of Earth Science Series, Brock, R. E. (1982) A Critique of the visual census method for assessing coral reef fish populations. Bulletin of Marine Science, 32: Brock, V. E. (1954) A preliminary report on a method of estimating reef fish populations. Jour. Wildlife Mangt. 18: Currie J.C., Sink, K.J., Le Noury, P., & Branch, G.M. (2012) Comparing fish communities in sanctuaries, partly protected areas and open-access reefs in South-East Africa. African Journal of Marine Science 34:2, Darwall, W. R. T. & Dulvy, N. K. (1996) An evaluation of the suitability of non-specialist volunteer researchers for coral reef fish surveys. Mafia Island, Tanzania - A case study. Biological Conservation, 78: Dickens, L. C., Goatley, C. H. R., Tanner, J. K. & Bellwood, D. R. (2011) Quantifying Relative Diver Effects in Underwater Visual Censuses. Plos One, 6. Done, T.J. (1997) Four performance indicators for integrated reef resources management. Workshop on Integrated Reef Resources Management in the Maldives 1997, Evans, R.D, Russ, G.R. & Kritzer, J.P. (2008) Batch fecundity of Lutjanus carponotatus (Lutjanidae) and implications of no take marine reserves on the Great Barrier Reef, Australia. Coral Reefs. 27: /9/ of 36

32 Garcia, A.; Ceballos, G. & Adaya, A. (2003) Intensive beach management as an improved sea turtle conservation strategy in Mexico. Biological Conservation. 111 (2): Hoegh-Guldberg, O. (1999) Climate change, coral bleaching and the future of the world's coral reefs. Marine and Freshwater Research, 50(8): Hughes, T. P et al. (2003) Climate Change, Human Impacts, and the Resilience of Coral Reefs. Science. 301: Hughes, T.P., Graham, N.A.J., Jackson, J.B.C., Mumby, P.J. & Steneck, R.S. (2010) Rising to the challenge of sustaining coral reef resilience. Trends in Ecology and Evolution. 25: Jennings, S. & Kaiser M. J. (1998) The Effects of Fishing on Marine Ecosystems, Advances in Marine Biology. 34; , 212a, , 266a, Jupiter, S. & Egli, D. (2011) Ecosystem Based Management in Fiji: Success and Challenges after Five Years of Implementation. Journal of Marine Biology. Kramer, P. A., Kramer, P. R. and Ginsburg, R. N. (2003) Assessment of the Andros Island Reef System, Bahamas (Part 1: stony corals and algae). Atoll Res. Bull. 496; Lester, S. E., Halpern, B. S. & Grorud-Colvert, K. et al. (2009) Biological effects within notake marine reserves: a global synthesis. Marine Ecology Progress Series. 384: Morreale, S. J., Ruiz, G. J., Spotila, J. R. & Standora, E. (1982) Temperature-dependent sex determination: current practices threaten conservation of sea turtles. Science. 216: Mrowicki, R. J. & Fanning, E. (2008) Benthic Community Structure and Sea Urchin Distribution in The Bay of Diego-Suarez. London: Society for Environmental Exploration. Nyström, M., Folke, C. & Moberg, F. (2000) Coral reef disturbance and resilience in a 16/9/ of 36

33 human-domintaed environment. TREE. 15; pp Richmond, M. D. (2002) A Field Guide to the Seashores of Eastern Africa and the Western Indian Ocean Islands. Sida/SARED, UDSM. 461pp. Rowat, D. (2007) Occurrence of whale shark (Rhincodon typus) in the Indian Ocean: A case for regional conservation. Fisheries Research. 84: Ruitenbeek, J., Hewawasam, I. & Ngoile, M. (2005) Blueprint 2050: Sustaining the Marine Environment in Mainland Tanzania and Zanzibar. IBRD/ World Bank, Washington, DC. pp 125. Thompson, A. A. & Mapstone, B. D. (1997). Observer effects and training in underwater visual surveys of reef fishes. Marine Ecology Progress Series. 154: Watson, R. A. & Quinn, T. J. (1997). Performance of transect and point count underwater visual census methods. Ecological Modelling. 104: /9/ of 36