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1. Need for harmonized long-term multi-lake monitoring of African Great Lakes

Author

Plisnier, Pierre-Denis, Kayanda, Robert, MacIntyre, Sally, Obiero, Kevin, Okello, William, Vodacek, Anthony, Cocquyt, Christine, Abegaz, Hussein, Achieng, Alfred, Akonkwa, Balagizi, Albrecht, Christian, Balagizi, Charles, Barasa, James, Bashonga, Rafiki Abel, Bishobibiri, Alexis Bashonga, Bootsma, Harvey, Borges, Alberto V, Chavula, Geoffrey, Dadi, Tallent, De Keyzer, Els LR, Doran, Patrick J, Gabagambi, Nestory, Gatare, Robert, Gemmell, Andrew, Getahun, Abebe, Haambiya, Lloyd H, Higgins, Scott N, Hyangya, Beni L, Irvine, Ken, Isumbisho, Mwapu, Jonasse, Carlos, Katongo, Cyprian, Katsev, Sergei, Keyombe, James, Kimirei, Ismael, Kisekelwa, Tchalondawa, Kishe, Mary, Koding, Simon Otoung A, Kolding, Jeppe, Kraemer, Benjamin M, Limbu, Peter, Lomodei, Evans, Mahongo, Shigalla B, Malala, John, Mbabazi, Stella, Masilya, Pascal M, McCandlessz, Matt, Medard, Modesta, Ajode, Zephaniah Migeni, Mrosso, Hillary D, Mudakikwa, Eric R, Mulimbwa, N'sibula, Mushagalusa, Deo, Muvundja, Fabrice A, Nankabirwa, Angela, Nahimana, David, Ngatunga, Benjamin P, Ngochera, Maxon, Nicholson, Sharon, Nshombo, Muderhwa, Ntakimazi, Gaspard, Nyamweya, Chrispine, Nyeko, Joyceikwaput, Olago, Daniel, Olbamo, Tekle, O'Reilly, Catherine M, Pasche, Natacha, Phiri, Harris, Raasakka, Nina, Salyani, Anham, Sibomana, Claver, Silsbe, Greg M, Smith, Stephanie, Sterner, Robert W, Thiery, Wim, Tuyisenge, Janviere, Van der Knaap, Martin, Van Steenberge, Maarten, van Zwieten, Paul AM, Verheyen, Erik, Wakjira, Mulugeta, Walakira, John, Wembo, Oscar Ndeo, and Lawrence, Theodore

Subjects
Fisheries, Limnology, Pollution, Biodiversity, Climate change, Erosion, Physical Geography and Environmental Geoscience, Environmental Science and Management, Environmental Engineering, Ecology, Environmental management
Published
2023

2. High-resolution bathymetries and shorelines for the Great Lakes of the White Nile basin

Author

Hamilton, Stuart E., McGehee, David D., Nyamweya, Chrispine, Ongore, Collins, Makori, Amina, Mangeni-Sande, Richard, Kagoya, Esther, Kashindye, Benedicto B., Elison, Mboni, Shaban, Sophia S., Mlaponi, Enock, Mwainge, Venny M., Ocaya, Henry, Krach, Noah, Ogari, Zachary, Mugeni, Bairon, Taabu-Munyaho, Anthony, Kayanda, Robert, Muhumuza, Elias, and Natugonza, Vianny

Published
2022
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4. Modelling and in situ observation of broadband acoustic scattering from the Silver cyprinid (Rastrineobola argentea) in Lake Victoria, East Africa.

Author

Yang, Yang, Gastauer, Sven, Proud, Roland, Mangeni-Sande, Richard, Everson, Inigo, Kayanda, Robert J, and Brierley, Andrew S

Subjects
BIOMASS estimation, SCHOOL size, SOUND wave scattering, LAKES, GEOGRAPHICAL distribution of fishes
Abstract

Lake Victoria is the second-largest freshwater lake in the world, and fish from the lake are a vital food resource for millions of people living around it. The silver cyprinid (Rastrineobola argentea) , a small schooling pelagic species known in Tanzania as "dagaa" contributes ca. 55% to the total annual catch (ca. 0.51 million tonnes (MT) in 2014). The acoustic target strength (TS, dB re 1 m2) of dagaa, a key factor for biomass estimation, is however not well described, and is a major source of uncertainty in biomass estimation. In this study, we developed a Kirchhoff-ray mode (KRM) model to predict the TS of dagaa at standard fisheries survey frequencies. The model was based on the morphology of the body and the dual-chambered swimbladder, as obtained from X-ray images of fish ranging in total length (TL) between 2.8 and 5.4 cm. The results suggested that the swimbladder (which comprises 2.6 to 8.2% of body volume) accounts for ca. 65 to 90% of the total backscattering at 120 kHz. The predicted TS was highly dependent on tilt angle, varying by 14.0 dB at 120 kHz across the tilt range 65–115˚ (where 0˚ is head up and 180˚ is tail up), and TS variability with tilt generally increased with increasing frequency. The tilt angle of acoustically tracked individual fish indicated a distribution of tilt angles with a mean and s.d. of 93.5 and 15.1°. Our model suggested a new tilt-averaged TS–TL relationship for dagaa [ |$T{S}_{120\ kHz} = 19.49\log ({TL}) - 70.3$| ], which leads to a TS 1.5 dB higher than the value in the relationship presently used to estimate stock biomass. The new relationship will lead to a substantial reduction (by ca. 30%) in estimated biomass. The discrepancies between the mean relative frequency response of the in situ measurements of backscatter from dagaa and the KRM model predictions were in the range of -2.9–3.1 dB at frequencies from 45 to 250 kHz. The KRM modelling and in situ broadband measurements of dagaa will be beneficial for acoustic identification and behavioural studies of dagaa, and will enable improved biomass assessment, thereby underpinning sustainable long-term management. [ABSTRACT FROM AUTHOR]

Published
2024
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6. The Impact of Land Use and Land Cover Change on Water Quality in Lake Victoria Catchment: A Case Study of Nkangabile River at Nyegezi Bay, Tanzania.

Author

Mashafi, Charles A., Mabula, Makemie, Semba, Masumbuko, Ezekiel, Charles N., Kashindye, Benedicto, Salehe, Mwanahamisi A., Mrosso, Hillary D. J., Kayanda, Robert, and Kimirei, Ismael A.

Subjects
LAND use, LAND cover, WATER quality, WATERSHEDS
Abstract

Understanding the trends and impacts of anthropogenic activities in the water basins and catchments is key to the effective management and conservation of aquatic environments. This study analyses the land use and land cover (LULC) changes in the Nkangabile catchment and their impacts on water quality in the Nyegezi Bay of Lake Victoria, Tanzanian side. GIS and Remote sensing techniques were used to analyze the multi-temporal changes in LULC that occurred in the past 30 years from 1983 to 2013, split into four epochs of 10-year intervals. The changes in LULC were analyzed using image differencing and crosstabulation for pairwise methods. The results indicated an increasing deterioration of water quality and a considerable transformation of LULC between the four epochs and more so in the long-term period from 1983 to 2013. The study provides evidence that LULC changes are accelerated by anthropogenic activities that severely affect the ecosystem through increased water pollution. Balancing human activities through proper land use planning as well as conservation awareness are strongly recommended to ensure adequate protection of the Lake Victoria ecosystem. [ABSTRACT FROM AUTHOR]

Published
2024
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7. Future success and ways forward for scientific approaches on the African Great Lakes

Author

Lawrence, Ted J., primary, Achieng, Alfred O., additional, Chavula, Geoffrey, additional, Haninga Haambiya, Lloyd, additional, Iteba, Jacob, additional, Kayanda, Robert, additional, Kaunda, Emmanuel, additional, Ajode, Migeni Z., additional, Muvundja, Fabrice A., additional, Nakiyende, Herbert, additional, Nyamweya, Chrisphine, additional, Obiero, Kevin, additional, Plisnier, Pierre Denis, additional, Phiri, Harris, additional, Sibomana, Claver, additional, and Smith, Stephanie, additional

Published
2023
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9. Lake Victoria: Overview of research needs and the way forward

Author

Nyamweya, Chrispine, primary, Lawrence, Ted J., additional, Ajode, Migeni Z., additional, Smith, Stephanie, additional, Achieng, Alfred O., additional, Barasa, James E., additional, Masese, Frank O., additional, Taabu-Munyaho, Anthony, additional, Mahongo, Shigalla, additional, Kayanda, Robert, additional, Rukunya, Edward, additional, Kisaka, Lilian, additional, Manyala, Julius, additional, Medard, Modesta, additional, Otoung, Simon, additional, Mrosso, Hillary, additional, Sekadende, Baraka, additional, Walakira, John, additional, Mbabazi, Stella, additional, Kishe, Mary, additional, Shoko, Amon, additional, Dadi, Tallent, additional, Gemmell, Andrew, additional, and Nkalubo, Winnie, additional

Published
2023
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10. Need for harmonized long-term multi-lake monitoring of African Great Lakes

Author

Plisnier, Pierre Denis, Kayanda, Robert, MacIntyre, Sally, Obiero, Kevin, Okello, William, Vodacek, Anthony, Cocquyt, Christine, Abegaz, Hussein, Achieng, Alfred, Akonkwa, Balagizi, Albrecht, Christian, Balagizi, Charles, Barasa, James, Abel Bashonga, Rafiki, Bashonga Bishobibiri, Alexis, Bootsma, Harvey, Borges, Alberto V., Chavula, Geoffrey, Dadi, Tallent, De Keyzer, Els L.R., Doran, Patrick J., Gabagambi, Nestory, Gatare, Robert, Gemmell, Andrew, Getahun, Abebe, Haambiya, Lloyd H., Higgins, Scott N., Hyangya, Béni L., Irvine, Ken, Isumbisho, Mwapu, Jonasse, Carlos, Katongo, Cyprian, Katsev, Sergei, Keyombe, James, Kimirei, Ismael, Kisekelwa, Tchalondawa, Kishe, Mary, Otoung A. Koding, Simon, Kolding, Jeppe, Kraemer, Benjamin M., Limbu, Peter, Lomodei, Evans, Mahongo, Shigalla B., Malala, John, Mbabazi, Stella, Masilya, Pascal M., McCandless, Matt, Medard, Modesta, Migeni Ajode, Zephaniah, Mrosso, Hillary D., Mudakikwa, Eric R., Mulimbwa, Nsibula, Mushagalusa, Déo, Muvundja, Fabrice A., Nankabirwa, Angela, Nahimana, David, Ngatunga, Benjamin P., Ngochera, Maxon, Nicholson, Sharon, Nshombo, Muderhwa, Ntakimazi, Gaspard, Nyamweya, Chrispine, Ikwaput Nyeko, Joyce, Olago, Daniel, Olbamo, Tekle, O'Reilly, Catherine M., Pasche, Natacha, Phiri, Harris, Raasakka, Nina, Salyani, Anham, Sibomana, Claver, Silsbe, Greg M., Smith, Stephanie, Sterner, Robert W., Thiery, Wim, Tuyisenge, Janviere, Van der Knaap, Martin, Van Steenberge, Maarten, van Zwieten, Paul A.M., Verheyen, Erik, Wakjira, Mulugeta, Walakira, John, Ndeo Wembo, Oscar, Lawrence, Theodore, Plisnier, Pierre Denis, Kayanda, Robert, MacIntyre, Sally, Obiero, Kevin, Okello, William, Vodacek, Anthony, Cocquyt, Christine, Abegaz, Hussein, Achieng, Alfred, Akonkwa, Balagizi, Albrecht, Christian, Balagizi, Charles, Barasa, James, Abel Bashonga, Rafiki, Bashonga Bishobibiri, Alexis, Bootsma, Harvey, Borges, Alberto V., Chavula, Geoffrey, Dadi, Tallent, De Keyzer, Els L.R., Doran, Patrick J., Gabagambi, Nestory, Gatare, Robert, Gemmell, Andrew, Getahun, Abebe, Haambiya, Lloyd H., Higgins, Scott N., Hyangya, Béni L., Irvine, Ken, Isumbisho, Mwapu, Jonasse, Carlos, Katongo, Cyprian, Katsev, Sergei, Keyombe, James, Kimirei, Ismael, Kisekelwa, Tchalondawa, Kishe, Mary, Otoung A. Koding, Simon, Kolding, Jeppe, Kraemer, Benjamin M., Limbu, Peter, Lomodei, Evans, Mahongo, Shigalla B., Malala, John, Mbabazi, Stella, Masilya, Pascal M., McCandless, Matt, Medard, Modesta, Migeni Ajode, Zephaniah, Mrosso, Hillary D., Mudakikwa, Eric R., Mulimbwa, Nsibula, Mushagalusa, Déo, Muvundja, Fabrice A., Nankabirwa, Angela, Nahimana, David, Ngatunga, Benjamin P., Ngochera, Maxon, Nicholson, Sharon, Nshombo, Muderhwa, Ntakimazi, Gaspard, Nyamweya, Chrispine, Ikwaput Nyeko, Joyce, Olago, Daniel, Olbamo, Tekle, O'Reilly, Catherine M., Pasche, Natacha, Phiri, Harris, Raasakka, Nina, Salyani, Anham, Sibomana, Claver, Silsbe, Greg M., Smith, Stephanie, Sterner, Robert W., Thiery, Wim, Tuyisenge, Janviere, Van der Knaap, Martin, Van Steenberge, Maarten, van Zwieten, Paul A.M., Verheyen, Erik, Wakjira, Mulugeta, Walakira, John, Ndeo Wembo, Oscar, and Lawrence, Theodore

Abstract

To ensure the long-term sustainable use of African Great Lakes (AGL), and to better understand the functioning of these ecosystems, authorities, managers and scientists need regularly collected scientific data and information of key environmental indicators over multi-years to make informed decisions. Monitoring is regularly conducted at some sites across AGL; while at others sites, it is rare or conducted irregularly in response to sporadic funding or short-term projects/studies. Managers and scientists working on the AGL thus often lack critical long-term data to evaluate and gauge ongoing changes. Hence, we propose a multi-lake approach to harmonize data collection modalities for better understanding of regional and global environmental impacts on AGL. Climate variability has had strong impacts on all AGL in the recent past. Although these lakes have specific characteristics, their limnological cycles show many similarities. Because different anthropogenic pressures take place at the different AGL, harmonized multi-lake monitoring will provide comparable data to address the main drivers of concern (climate versus regional anthropogenic impact). To realize harmonized long-term multi-lake monitoring, the approach will need: (1) support of a wide community of researchers and managers; (2) political goodwill towards a common goal for such monitoring; and (3) sufficient capacity (e.g., institutional, financial, human and logistic resources) for its implementation. This paper presents an assessment of the state of monitoring the AGL and possible approaches to realize a long-term, multi-lake harmonized monitoring strategy. Key parameters are proposed. The support of national and regional authorities is necessary as each AGL crosses international boundaries.

Published
2023

11. Response of fish stocks in Lake Victoria to enforcement of the ban on illegal fishing: Are there lessons for management?

Author

Nyamweya, Chrispine Sangara, primary, Natugonza, Vianny, additional, Kashindye, Benedicto Boniphace, additional, Mangeni-Sande, Richard, additional, Kagoya, Esther, additional, Mpomwenda, Veronica, additional, Mziri, Venny, additional, Elison, Mboni, additional, Mlaponi, Enock, additional, Ongore, Collins, additional, Makori, Amina, additional, Shaban, Sophia S., additional, Aura, Christopher Mulanda, additional, Kayanda, Robert, additional, Taabu-Munyaho, Anthony, additional, Njiru, James, additional, Ogari, Zachary, additional, Proud, Roland, additional, and Brierley, Andrew S., additional

Published
2023
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14. Mind the gaps for the best practices: Enhancing the management of Lake Victoria fisheries resources

Author

Aura, Christopher Mulanda, primary, Roegner, Amber, additional, Owiti, Horace, additional, Birungi, Dorothy, additional, Fiorella, Kathryn J., additional, Corman, Jessica, additional, Kayanda, Robert, additional, Mbullo, Patrick, additional, Nyamweya, Chrisphine S., additional, Mchau, Geofrey, additional, Daniels, Miles, additional, and Abila, Richard Oginga, additional

Published
2022
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15. Need for harmonized long-term multi-lake monitoring of African Great Lakes

Author

Plisnier, Pierre-Denis, primary, Kayanda, Robert, additional, MacIntyre, Sally, additional, Obiero, Kevin, additional, Okello, William, additional, Vodacek, Anthony, additional, Cocquyt, Christine, additional, Abegaz, Hussein, additional, Achieng, Alfred, additional, Akonkwa, Balagizi, additional, Albrecht, Christian, additional, Balagizi, Charles, additional, Barasa, James, additional, Abel Bashonga, Rafiki, additional, Bashonga Bishobibiri, Alexis, additional, Bootsma, Harvey, additional, Borges, Alberto V., additional, Chavula, Geoffrey, additional, Dadi, Tallent, additional, De Keyzer, Els L.R., additional, Doran, Patrick J., additional, Gabagambi, Nestory, additional, Gatare, Robert, additional, Gemmell, Andrew, additional, Getahun, Abebe, additional, Haambiya, Lloyd H., additional, Higgins, Scott N., additional, Hyangya, Béni L., additional, Irvine, Ken, additional, Isumbisho, Mwapu, additional, Jonasse, Carlos, additional, Katongo, Cyprian, additional, Katsev, Sergei, additional, Keyombe, James, additional, Kimirei, Ismael, additional, Kisekelwa, Tchalondawa, additional, Kishe, Mary, additional, Otoung A. Koding, Simon, additional, Kolding, Jeppe, additional, Kraemer, Benjamin M., additional, Limbu, Peter, additional, Lomodei, Evans, additional, Mahongo, Shigalla B., additional, Malala, John, additional, Mbabazi, Stella, additional, Masilya, Pascal M., additional, McCandless, Matt, additional, Medard, Modesta, additional, Migeni Ajode, Zephaniah, additional, Mrosso, Hillary D., additional, Mudakikwa, Eric R., additional, Mulimbwa, N'sibula, additional, Mushagalusa, Déo, additional, Muvundja, Fabrice A., additional, Nankabirwa, Angela, additional, Nahimana, David, additional, Ngatunga, Benjamin P., additional, Ngochera, Maxon, additional, Nicholson, Sharon, additional, Nshombo, Muderhwa, additional, Ntakimazi, Gaspard, additional, Nyamweya, Chrispine, additional, Ikwaput Nyeko, Joyce, additional, Olago, Daniel, additional, Olbamo, Tekle, additional, O'Reilly, Catherine M., additional, Pasche, Natacha, additional, Phiri, Harris, additional, Raasakka, Nina, additional, Salyani, Anham, additional, Sibomana, Claver, additional, Silsbe, Greg M., additional, Smith, Stephanie, additional, Sterner, Robert W., additional, Thiery, Wim, additional, Tuyisenge, Janviere, additional, Van der Knaap, Martin, additional, Van Steenberge, Maarten, additional, van Zwieten, Paul A.M., additional, Verheyen, Erik, additional, Wakjira, Mulugeta, additional, Walakira, John, additional, Ndeo Wembo, Oscar, additional, and Lawrence, Theodore, additional

Published
2022
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18. Automated classification of schools of the silver cyprinid Rastrineobola argentea in Lake Victoria acoustic survey data using random forests

Author

Proud, Roland, primary, Mangeni-Sande, Richard, additional, Kayanda, Robert J, additional, Cox, Martin J, additional, Nyamweya, Chrisphine, additional, Ongore, Collins, additional, Natugonza, Vianny, additional, Everson, Inigo, additional, Elison, Mboni, additional, Hobbs, Laura, additional, Kashindye, Benedicto Boniphace, additional, Mlaponi, Enock W, additional, Taabu-Munyaho, Anthony, additional, Mwainge, Venny M, additional, Kagoya, Esther, additional, Pegado, Antonio, additional, Nduwayesu, Evarist, additional, and Brierley, Andrew S, additional

Published
2020
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19. Changes in the Diet of Synodontis victoriae and Synodontis afrofischeri in Lake Victoria, Tanzanian waters

Author

Elison, Mboni V., Mlaponi, Enock, Musiba, Magreth J., Ngupula, Geoffery W., Kashindye, Benedicto B., and Kayanda, Robert J.

Subjects
Caridina nilotica, Diet expansion, Food and Feeding habits, Rastrineobola argentea, Seasonal variation
Abstract

The diet of Synodontis victoriae and S.afrofischeri was investigated from samples collected for stomach analysis in May 2013, October 2013, and April 2014 in the Tanzanian waters of Lake Victoria. The diet of S. victoriae was dominated by freshwater shrimps Caridina nilotica followed by unidentified fish remains, the cyprinids Rastrineobola argentea and Enteromius profundus as well as insects, molluscs, haplochromines and worms. The diet of S. afrofischeri was dominated by R. argentea followed by insects, fish remains, worms, molluscs, C. nilotica, algae and haplochromines. There was considerable variation in the diets of both species collected at different times and they displayed considerable plasticity in their diet. Both species exhibited a wider range of diet, utilizing food items that may not have been available before the changes in the lake that followed the Nile perch upsurge in the 1980s.Keywords: Caridina nilotica, Diet expansion, Food and Feeding habits, Rastrineobola argentea, Seasonal variation

Published
2018

20. Acoustic Monitoring of Blast Fishing: Pilot Study

Author

Cagua, Edgar Fernando, Basset, Christopher, Kayanda, Robert, and Rubens, Jason

Subjects
parasitic diseases
Abstract

Technical report: WWF Tanzania Country Office - Marine Programme Blast fishing is illegal fishing method according to Fisheries Act (2003) due to its negative impact especially on coral reefs. The method is widely used and it is a serious problem along the coast of Tanzania mainland. The most affected area is Dar es Salaam, where existing regulations are not effectively enforced to address the problem. Inadequate data on the frequency of occurrence and distribution of blast activity prevent effective control measures. Using Digital Spectrogram Long-Term Acoustic Recorders (DSG), we performed two deployments. One was a two-day long deployment to identify the acoustic characteristics of blasts, and the second was a two- month long deployment to monitor blast activity off Dar es Salaam coast. In the blast identification phase we deployed one DSG over two days on Milliards Bank recording sound at 80 kHz, we analysed the acoustic characteristics of 45 underwater explosions to identify and characterize blasts used during illegal fishing operations. We developed a neural- network that semi-automatically identifies explosion-like recordings. Ninety-five percent of the explosion-like events identified by the neural network are attributable to blast fishing, while the other five percent were other unidentified transient signals. During the monitoring phase two DSGs were deployed, however we were able to retrieve only one of them. Weather, currents, and possibly vandalism might be the causes for the loss. The retrieved DSG was deployed on Mbudya patches between 15 April and 30 May, 2014 recording at a sampling frequency of 40kHz during five minutes every ten minutes between 0600 and 1800 hrs. Using this additional data the neural network improved its classification accuracy to 98%. We estimate an average of 19 blasts per day during daytime off Mbudya, with most of the blasts occurring in the morning before 1300 hrs. To avoid further loss of instruments, we recommend the use of acoustic releases in further deployments. However care must be taken to avoid potential problems caused by biofouling as well as preventing interference from noise near the DSGs caused by floats and moving elements part of the release. In order to better understand blast fishing patterns as well as factors influencing underwater noise production we also recommend recording environmental variables related to weather and currents. This work represents the first steps of a potential future monitoring program off the Tanzanian coast. We provide methods and recommendations for future monitoring of blast fishing

Published
2014
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21. Acoustic Monitoring of Blast Fishing: Pilot Study - Dar es Salaam

Author

Cagua, Edgar Fernando, Basset, Christopher, Kayanda, Robert, and Rubens, Jason

Subjects
parasitic diseases
Abstract

Technical report: WWF Tanzania Country Office - Marine Programme Blast fishing is illegal fishing method according to Fisheries Act (2003) due to its negative impact especially on coral reefs. The method is widely used and it is a serious problem along the coast of Tanzania mainland. The most affected area is Dar es Salaam, where existing regulations are not effectively enforced to address the problem. Inadequate data on the frequency of occurrence and distribution of blast activity prevent effective control measures. Using Digital Spectrogram Long-Term Acoustic Recorders (DSG), we performed two deployments. One was a two-day long deployment to identify the acoustic characteristics of blasts, and the second was a two- month long deployment to monitor blast activity off Dar es Salaam coast. In the blast identification phase we deployed one DSG over two days on Milliards Bank recording sound at 80 kHz, we analysed the acoustic characteristics of 45 underwater explosions to identify and characterize blasts used during illegal fishing operations. We developed a neural- network that semi-automatically identifies explosion-like recordings. Ninety-five percent of the explosion-like events identified by the neural network are attributable to blast fishing, while the other five percent were other unidentified transient signals. During the monitoring phase two DSGs were deployed, however we were able to retrieve only one of them. Weather, currents, and possibly vandalism might be the causes for the loss. The retrieved DSG was deployed on Mbudya patches between 15 April and 30 May, 2014 recording at a sampling frequency of 40kHz during five minutes every ten minutes between 0600 and 1800 hrs. Using this additional data the neural network improved its classification accuracy to 98%. We estimate an average of 19 blasts per day during daytime off Mbudya, with most of the blasts occurring in the morning before 1300 hrs. To avoid further loss of instruments, we recommend the use of acoustic releases in further deployments. However care must be taken to avoid potential problems caused by biofouling as well as preventing interference from noise near the DSGs caused by floats and moving elements part of the release. In order to better understand blast fishing patterns as well as factors influencing underwater noise production we also recommend recording environmental variables related to weather and currents. This work represents the first steps of a potential future monitoring program off the Tanzanian coast. We provide methods and recommendations for future monitoring of blast fishing

Published
2014
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