Rui Mutombene

In the Western Indian Ocean (WIO) elasmobranchs play important roles in ecosystems as apex and mesopredators and contribute high socio-economic value to coastal communities. Their diversity in the WIO is amongst the highest globally yet few studies have assessed the occur- rence of various species in catches. Demersal trawl catches from Kenya, Tanzania, Mozambique, Madagascar and South Africa (East Coast) were analysed using Generalised Linear Models to esti- mate the probabilities of non-zero catches of sharks and batoids. The data were further subjected to non-metric multidimensional scaling to establish clusters of various communities and to sim- ilarity percentage analyses to determine the dominant taxa. The probability of catching sharks and batoids in trawl nets was high. While communities were not highly separated within factors, it was depth that showed the greatest influence on community structures. The genus Squalus dom- inated the shark catches as depth increased while species dominance of batoids changed from stingrays (Dasyatidae) to guitarfishes (Rhinobatidae) and to skates (Rajidae) as depth increased. This study underlines the need for improved species identification of elasmobranch catches and for marine protected areas on soft sediment habitats to protect these important species.

In the Western Indian Ocean (WIO) elasmobranchs play important roles in ecosystems as apex and mesopredators and contribute high socio-economic value to coastal communities. Their diversity in the WIO is amongst the highest globally yet few studies have assessed the occur- rence of various species in catches. Demersal trawl catches from Kenya, Tanzania, Mozambique, Madagascar and South Africa (East Coast) were analysed using Generalised Linear Models to esti- mate the probabilities of non-zero catches of sharks and batoids. The data were further subjected to non-metric multidimensional scaling to establish clusters of various communities and to sim- ilarity percentage analyses to determine the dominant taxa. The probability of catching sharks and batoids in trawl nets was high. While communities were not highly separated within factors, it was depth that showed the greatest influence on community structures. The genus Squalus dom- inated the shark catches as depth increased while species dominance of batoids changed from stingrays (Dasyatidae) to guitarfishes (Rhinobatidae) and to skates (Rajidae) as depth increased. This study underlines the need for improved species identification of elasmobranch catches and for marine protected areas on soft sediment habitats to protect these important species.

Fisheries are recognized as important in Mozambique, yet they are increasingly threatened by over-exploitation and climate change. We collate and synthesize the available literature and data on marine fisheries in Mozambique; assess the status of the main fishery species/stocks; give an overview of current management of the fishery, and discuss planning for fisheries resilience in the face of climate change predictions. In Mozambique there is a heavy reliance on marine fisheries. From a food security and local economy perspective, the critical sector is the artisanal fisheries which comprises over 90% of the total landings and provides food and livelihood for millions of people, particularly in the coastal zone. Regarding economic value and earning foreign currency, the most valuable industrial / semi-industrial fisheries are the shallow-water shrimp, the deep-water crustacean and the rocky bottom demersal. Current stock assessment for these sectors indicates that the core stock species are fully- or over-exploited. Limited data are available for the artisanal fishery, but it is likely that the same status applies to this sector. Globally, well-managed fisheries have been among the most resilient to climate change—overall, fisheries best practices confer ecological resilience by providing a portfolio of options to fishers and a buffer against losing target stock. Ideally, best practices include scientifically-informed catch limits, accountability measures, regional flexibility in policy practices, protection of essential fish habitat (Marine Protected Areas), and effective monitoring, control and surveillance. Mozambique has a relatively well-managed industrial/semi-industrial fishery. However, the artisanal fishery, due to its spatial scattering, multi-gear and multi-species nature, presents a huge challenge. Facing the future with climate change will require increased attention to reduce stressors to the social–ecological systems in which fisheries exist and persist. Specific recommendations in this context are presented.

Mozambique is amongst the most vulnerable of Western Indian Ocean (WIO] countries to the impacts of climate change on its marine fisheries. We used rapid assessment methods to evaluate sensitivity, exposure and vulnerability of fisheries species to climate change, appropriate for data-deficient, developing countries in the region. Species were selected based on their importance in industrial and artisanal fisheries’ landings, further prioritized by local experts. Species’ attributes likely to be sensitive to climate change were identified and scored, utilizing life history or biological characteristics. Sea Surface Temperature (SST] was the most prominent climate exposure factor and for which we could confidently predict likely future change. Most species had low or medium overall sensitivity to climate change, with only eight considered highly sensitive. Climate exposure (SST] scores were high off northern Mozambique, while the central and southern regions were generally of medium exposure. Ten species received a High vulnerability score, 14 were Medium, and 16 had a Low vulnerability score. The highly vulnerable species were all fishes, apart from one crustacean; 4 of the 9 were strongly estuarine-associated; the most vulnerable species was the parrotfish Scarus ghobban. This is the first attempt to use a rapid, semi-quantitative, specialist- and trait-based vulnerability assessment of the anticipated effect of climate change on marine fisheries species in the WIO. Challenges experienced were data paucity, limited resources, the large study area, and the complex oceanography of the region. However, a simple methodology was developed, derived from efforts elsewhere, and which can be used to undertake similar assessments for other WIO countries. Raised awareness of climate change among small-scale fishing communities is a necessity, combined with adaptation by promoting fisheries co-management. Also required is support from government to ensure that people can be flexible to change.