118
However, the target groups would have to be educated on the importance of consistently using these mooring buoys.
The movements of speedboats, both large and small, should be regulated with respect to speed as well as direction and distance from coral reefs. Though this requires further research Section 8.4, it would seem advisable for the
large speed boats that operate between Zanzibar and Dar es Salaam to pass on the outside of the reefs. If weather conditions force them to pass between the reefs and the land, they should reduce their speed and keep a good
distance from the reefs. After appropriate research is done, regulations should be made and enforced regarding appropriate speeds and distances from reefs.
4.8.5 Control of Pollution
Johnstone and Suleiman 1998 warned that coral reefs should not be regarded as remote from land-based factors such as urban and town sewage management, but rather, they recommended that the development of sewage
disposal systems must assume an integrated management approach, which includes full consideration of the sensitive character of coral reef ecosystems.
4.8.6 Alternatives to Coral Mining
With respect to the problem of coral mining, it is not recommended that this activity be immediate halted since certain communities depend upon this for either their supplementary or sole income and often there is no cheap,
locally available alternative building material Darwall et al., 2000. Darwall et al. 1995 demonstrated the feasibility of using sun-dried mud bricks as an alternative where suitable soils exist, such as on Mafia Island.
4.8.7 Mitigation of Natural Threats
One of the few natural threats for which mitigation efforts can be recommended is the Crown-of-Thorns starfish. Regular and frequent monitoring is required in order to have early warning of a possible outbreak. Where a rapid
increase in its abundance is detected, the population should be controlled.
4.8.8 Recommendations on RestorationRecruitment
Management programmes should put greater emphasis on restoration work than most of them are at the moment and consider it as a priority. For severely degraded reefs, mere protection is insufficient. Deliberate human
intervention is required in order to accelerate and ensure the recovery of coral reef ecosystems. Some of the studies done have made recommendations concerning methods for restoring degraded areas of reefs.
The removal of sediments and rubble is one simple method of intervention. Another method is the transplantation of coral fragments, whereby, fragments are broken from healthy colonies and attached to a suitable substrate using
cement or glue. Moreover, artificial substrates or reef structures can serve as fish sheltering devices and can also enhance coral larval settlement. Such methods can potentially greatly improve the recovery of degraded coral reef
ecosystems.
Lindahl 1998 recommended that, in areas that are moderately exposed to water movement, the transplantation of staghorn coral fragments at low density by tying them with string can be an effective, low tech method of
rehabilitating damaged areas of reefs. Besides increasing cover of the transplanted species, this technique also enhances the habitat, making it suitable for the establishment of other hard corals, soft corals and other organisms.
Franklin et al. 1998 recommended pre-culturing corals before transplanting them on damaged reefs. This could be done either by using coral larvae settled on artificial substrate or collecting fragments from natural colonies.
119
Wagner 2000 outlined the principles for ecosystem restoration and how these can be applied to restoring coral reefs in Tanzania. Various possible techniques for restoration were given, out of which, two methods were
particularly recommended, i.e., the transplantation of coral fragments and the placement of ceramic tiles to aid coral larval settlement. Wagner et al. 2000a suggested that training fishermen to transplant coral fragments using
cement could be an effective way of restoring dynamited areas of coral reefs. It could, moreover, be combined with ecotourism Section 6.3.
4.9 Management Programmes
