Plymouth Marine Laboratory, Plymouth Marine Laboratory, University of Dar es Salaam - Institute of Marine Science (IMS), Tanzania Fisheries Research Institute, University of Dar es Salaam, Lake Victoria Fisheries Organization, University of Dar es Salaam, University of Dar es Salaam, affiliation not provided to SSRN, affiliation not provided to SSRN, Plymouth Marine Laboratory, Government of the Republic of Finland - Finnish Environment Institute, Government of the Republic of Finland - Finnish Environment Institute, University of Liverpool, Rhodes University, Rhodes University, Plymouth Marine Laboratory, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN and affiliation not provided to SSRN