In Zanzibar, policy documents for marine management stress MPAs as well as coral and mangrove conservation (e.g. Ruitenbeek et al., 2005). In Chwaka Bay management

efforts and economic resources (coming from external donors) have historically been directed to mangrove conservation (RGZ, 2004, Saunders, 2011 and Lugomela, 2012) leaving the oceanic part unattended (de la Torre-Castro, 2012a and de la Torre-Castro, 2012b). Recent management plans for the bay have added coral protection; regrettably still missing MS-275 ic50 the seagrasses and lacking a holistic and integrative approach (DFMR/MIMCA, 2010 and Gustavsson et al., 2014). The results of this study suggest that these types of initiatives will most probably fail since there is a clear mismatch between the ecological features, the SSF dynamics and the proposed management. The asymmetry in management efforts not addressing the whole seascape has created a serious situation. High fishing pressure takes place on seagrass habitats (Table 1). The fishing pressure found for Chwaka Bay is similar to that reported for other regions in the WIO (e.g. Kenya, McClanahan et al., 2008); however, the fishing pressure on seagrass selleck chemicals areas

is about four times higher than for corals and mangroves with the dominating gear being drag-nets. These nets and the dragging technique damage the meadows through up-rooting and fragmentation. Since it is not known at what intensity levels fisheries may produce cascading trophic effects and finally affect seagrasses structure (Valentine et al., 2008), a precautionary approach is advisable. Gullström et al. (2006) found that the seagrasses in Chwaka Bay have been relatively stable during a 20 year period, but local gains and losses were found. They co-occurred with intensive human use Atezolizumab due to fishing and seaweed farming of red algae. In addition, there is evidence showing that heavy fishing pressure that removes sea urchin predators (e.g. trigger fish), can cascade resulting

in high densities of sea urchins that decimate seagrass beds through overgrazing (de la Torre-Castro and Jiddawi, 2005 and Eklöf et al., 2008). A severe decrease of herbivores like the “seagrass parrot fish” (Leptoscarus vaigiensis) may promote epiphyte increase, theoretically altering the rates of seagrass productivity ( de la Torre-Castro et al., 2008). The multiple pressures over ecosystems in the bay have created a situation in which the nursery grounds are heavily used and intense juvenile removal takes place, while fish adult biomass is constantly removed from corals diminishing potential spawning stocks ( de la Torre-Castro and Ronnback, 2004). This causes both growth and recruitment overfishing to be present.